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eSci Journal of Plant Pathology
   [5 followers]  Follow    
  This is an Open Access Journal Open Access journal
     ISSN (Print) 2306-1650 - ISSN (Online) 2305-106X
     Published by eSci Journals Publishing Homepage  [6 journals]
  • EVALUATION OF BIOAGENTS AND BIOFERTILIZERS FOR THE MANAGAMENT OF SEED AND
           SEEDLING DISEASES OF SESAMUM INDICUM (SESAME)

    • Authors: Venturla Bharathi, Ravuru Sudhakar, K. Parimala, Vishnuvardhan A. Reddy
      Abstract: The study was carried out to evaluate the response of biopeticides and biofertilizers on seed mycoflora and seed quality parameters of Sesame (Sesamum  indicum  L.). Untreated Sesame seeds were collected from farmers of Nizamabad and Karimanagar districts of Andhra Pradesh in India and discolored seeds were separated and treated with biofertilizers and biopesticides alone and in combination form. The seed mycoflora of Sesame seeds were screened by using Potato dextrose agar (PDA) medium and czaepek dox agar media. The results indicate that maximum numbers of fungi were recorded on PDA. The untreated seeds were found to be associated with maximum percent incidence of mycoflora and minimum population was recorded in the treatment of Trichoderma + Pseudomonas formulation followed by Azat obacter + Trichoderma, Pseudomonas and Azatobacter in the decreasing order of efficacy. This study also showed relation of biofertilizers and biopesticides and seed mycoflora on seed germination. Germination percentage was maximum in the treatment Trichoderma + Pseudomonas formulation, Azatobacter + Trichoderma, Pseudomonas and Azatobacter recording 96%, 94%, 90% and 88%, respectively. In the control, germination percentage was minimum compared with other treatments. Seeds treated with the mixed formulation were found beneficial in reducing the pathogenic fungi and decreasing seedling mortality.
      PubDate: 2013-12-30
      Issue No: Vol. 2, No. 3 (2013)
       
  • IN VITRO BIOLOGICAL CONTROL OF BRANCH CANKER (MACROPHOMA THEIOCOLA)
           DISEASE OF TEA

    • Authors: Iftekhar Ahmad, Md. Obaidullah, Mohammad A. Hossain, Mohammad Ali, Md. S. Islam
      Abstract: Antagonist microorganisms, such as Trichoderma spp. have long been recognized as biological agents, for the control of plant disease and for their ability to increase root growth and development, crop productivity, resistance to abiotic stresses, and uptake and use of nutrients. An attempt was made to evaluate the in vitro biocontrol of branch canker (Macrophoma theicola) of tea plants by Trichoderma spp. Isolation of Trichoderma spp. and M. theiocola was done carefully. Pure culture of Trichoderma spp. and M. theiocola and their morphological characteristics were studied at different intervals. Five M. theiocola and five Trichoderma isolates were collected from mature tea plants and tea soils respectively of Bangladesh Tea Research Institute (BTRI) main farm area. The cultural morphology and antagonistic potentiality of Trichoderma spp. against branch canker pathogen (M. theiocola) were taken into consideration. Trichoderma spp. controls the growth of M. theiocola at different intervals. After 24 hour growth rate of Trichoderma was 9.3% and M. theiocola was 0.88%. The antagonistic potentialities of isolated Trichoderma against pathogens (M. theiocola) were observed at different intervals (24-120 hrs) and the percentage of inhibition was 82% which were observed after five days (120 hours) of inoculation. The Trichoderma spp. antagonizes the pathogens by several mechanisms such as antibiosis, competition, mycoparasitism or other form of direct exploitation. From this study it was revealed that, the Trichoderma spp. was highly effective to control the isolates of M. theiocola that is responsible for branch canker in tea cultivation.
      PubDate: 2013-12-30
      Issue No: Vol. 2, No. 3 (2013)
       
  • HISTOPATHOLOGY OF MACROPHOMINA STEM CANKER DISEASE IN PIGEONPEA (CAJANUS
           CAJAN L.)

    • Authors: Sandeep K. Maurya, Surinder Kaur, Vijay B. Chauhan
      Abstract: Macrophomina phaseolina, causal agent of stem canker disease has recently emerged as an agriculturally important plant pathogen. Macrophomina stem canker disease (MSD), caused by Macrophomina phaseolina is a potentially serious disease in pigeonpea that occurs when reaches physiological maturity i.e., during flowering. The fungus incites necrotic lesions on stem and girdles the plant at the base leading to premature flower drop leading to complete witling and finally death of the entire plant. The mechanisms of infection remain to be fully elucidated. The present study investigated histopathology of MSD caused by M. phaseolina in pigeonpea seed and seedlings using light microscopy. Pigeonpea variety ‘Bahar’ was used in this study. Histopathological sections of seed, stem, root, and leaves were prepared and stained with safranin and trypan blue. Histopathology of the infected plant parts showed the presence of intercellular mycelia and microsclerotia in the cortex and vascular tissues. The germ tube colonized the plant with growth of seedlings following seed coat, cotyledon, stem, root and leaves. According to the results, the pathogen can penetrate and invade the seeds within 24 h post inoculation.
      PubDate: 2013-12-30
      Issue No: Vol. 2, No. 3 (2013)
       
  • BIOCONTROL POTENTIALS OF PLANT GROWTH PROMOTING RHIZOBACTERIA AGAINST
           FUSARIUM WILT DISEASE OF CUCURBIT

    • Authors: Avinash T. Shanthi, Ravishankar R. Vittal
      Abstract: Fusarium spp., are the major soil-borne as well as seed borne pathogens causing wilt and rot diseases in more than 80 plant species including cucurbits. Fusarium spp., causes up to 100 % yield loss in the worldwide. Eleven isolates including three standard isolates were tested both in-vitro and in-vivo. In-vitro assay was done by dual culture method. Maximum inhibition was in case of Fusarium solani by Bacillus cereus MIC5. Sarratia spp. MIC1 antagonized the F. verticillodes and F. solani2. P. aeruginosa MIC2 inhibits all tested isolates F. oxysporum1. P. aeruginosa MTCC2581 suppressed the radial growth rate of F. oxysporum2. The two systemic fungicides used were chlorothalonil + mefenoxam (1000 ppm) and carbendazim (75 ppm to 500 ppm) which checked the growth of F. oxysporum. Carbendazim was more effective compared to mefenoxam + chlorothalonil at all tested concentrations. The crude extract of P. aeruginosa MIC2 developed in chloroform: methanol (9:1) showed a metabolite at Rf - 0.77 which it may be 2,4- diacetylphloroglucinol (DAPG), a broad-spectrum antimicrobial agent. Increased cucurbit seeds germination and seedling vigour was observed in B. amyloliquefaciens MIC6 (68% & 1576) and P. aeruginosa MTCC2581 (70% & 1929) in primed seeds. Further P. aeruginosa MTCC2581 can be tested in the field against the Fusarium wilt.
      PubDate: 2013-12-30
      Issue No: Vol. 2, No. 3 (2013)
       
  • EFFECT OF STEM RUST INFECTION ON GRAIN YIELD AND YIELD COMPONENTS OF SOME
           WHEAT CULTIVARS IN EGYPT

    • Authors: Mamdouh A. Asmmawy, Walid M. El-Orabey, Mohamed Nazim, Atef A. Shahin
      Abstract: Stem rust, caused by Puccinia graminis f. sp. tritici is an important disease of wheat worldwide. To estimate grain yield losses due to stem rust, replicated experiments including twelve wheat cultivars i.e.  Gemmeiza 7, Gemmeiza 9, Gemmeiza 10, Gemmeiza 11, Sakha 61, Sakha 93, Sakha 94, Sids 12, Sids 13, Giza 168, Misr 1 and Misr 2 were evaluated for adult plant resistance at Sakha Research Station, Kafr El-Sheikh, Egypt during 2011/12 and 2012/13 growing seasons. The field experiment was surrounded by spreader area of highly susceptible varieties i.e. Morroco and Max inoculated with a mixture of stem rust races as a source of inoculum. Disease severity was recorded each 10 days and area under disease progress curve (AUDPC) was estimated and ranged from 100 to 475 in 2011/12 and 100 to 750 in 2012/13. It was found that, yield losses ranged between 2.47 % in the wheat cultivar Misr 2 to 6.29 % in the wheat cultivar Sids 12 during 2011/12, while during 2012/13 ranged from 1.96 % in the wheat cultivar Gemmeiza 7 to      8.21 % in the wheat cultivar Misr 1. High correlation was found between yield losses with disease severity and AUDPC.
      PubDate: 2013-12-30
      Issue No: Vol. 2, No. 3 (2013)
       
  • COMPLETE GENOME SEQUENCE OF TOMATO SPOTTED WILT VIRUS FROM PAPRIKA IN
           KOREA

    • Authors: Jae-Hyun Kim, Young-Soo Kim, Soo-Won Jang, Yong-Ho Jeon
      Abstract: We isolated tomato spotted wilt virus (TSWV-KP) from a diseased Capsicum annuum var. grossum with malformed leaves and necrotic spotted fruits. TSWV-KP produced necrosis or necrotic ring spots on inoculated leaves along with mosaic, vein necrosis, or death on the upper leaves on Datura stramonium, Nicotiana clevarandii, N. rustica, and N. tabacum cvs. Ultrastructurally, typical tospovirus particles were observed in the cytoplasm. The virion contained three molecules of genomic RNAs of approximately 9.0, 4.9, and 3.0 kb. The nucleocapsid (N) protein of the purified virion migrated as a single band with ~29 kDa molecular weight in SDS-PAGE. Complete nucleotide sequences of the large (L) genome segments of TSWV-KP were determined. Defective forms of L-RNA containing core polymerase regions were observed. L-RNA (8,917 nucleotides) contained a single open reading frame (ORF) in the viral complementary (vc) strand and encoded a 330-kDa protein. The L-protein had high identity in the “core-polymerase domain” with the corresponding regions of other tospoviruses. The complete nucleotide sequence of TSWV-KP medium-sized (M) RNA comprised 4,768 nucleotides and indicated a typical tospovirus with two genes in ambisense arrangement. The vRNA OFR coded for a potential cell-to-cell movement (NSm) 34.8-kDa protein; and the vcRNA ORF, for the viral glycoprotein (G1/G2) 128.0-kDa precursor. Multiple sequence alignment of the M-RNA showed highest homologies to TSWV-BR01. Amino acid sequences of TSWV-KP NSm and G1/G2 exhibited 48.7–85.3% and 34.9–96.2% identity, respectively. TSWV-KP small (S) RNA comprised 2,991 nucleotides with ambisense coding strategy. The sequence contained two ORFs—one in the viral sense, encoding a protein with predicted 52.4-kDa Mr; and another in the viral complementary sense, encoding the viral nucleocapsid protein of 28.8-kDa Mr. Amino acid sequences of TSWV-KP of S-RNA NSs and N exhibited 35.9–87.9% and 19.9–98.4% identity, respectively.
      PubDate: 2013-12-30
      Issue No: Vol. 2, No. 3 (2013)
       
  • TOXIGENICITY OF FUSARIUM SPECIES IN GIBBERELLA FUJIKUROI SPECIES COMPLEX
           (GFSC) ASSOCIATED WITH STALK AND EAR ROT DISEASE OF CORN

    • Authors: Titi Darnetty, Baharuddin Salleh
      Abstract: Fusarium stalk and ear rot disease did not only cause significant losses of yield but also produced mycotoxins that are harmful to animals and human. This study was conducted to elucidate three major mycotoxins i.e. fumonisin B1 (FUMB1), moniliformin (MON), and beauvericin (BEA) produced by the Fusarium spp. isolated from corn showing typical stalk and ear rot symptoms in Indonesia, Malaysia and Thailand. Twenty selected strains of Fusarium species in Gibberella fujikuroi species complex i.e. F.verticillioides, F. proliferatum, F. subglutinans, and F. konzum were analyzed for production of the three mycotoxins by using an Ultra Performance Liquid Chromatography (UPLC).  All strains of F. verticillioides and F. proliferatum produced FUMB1 at high levelsand MON at low levels. Many strains of F. verticillioides (67%) and F. proliferatum (50%) did not produce BEA while the others produced BEA at low levels. Two strains of F. subglutinans did not produce FUMB1 but produced MON at low levels. One strain of F. subglutinans produced BEA and the other one did not produce the toxin.  Two strains of F. konzum produced both MON and BEA at low levels but only one strain produced FUMB1 at a low level. These mycotoxins have not been reported from Fusarium spp. in Gibberella fujikuroi species complex isolated form stalk and ear rot diseases of corn in these areas. Therefore, concerted efforts must be made to educate all stake holders about the presence and health hazards of these mycotoxins.
      PubDate: 2013-12-30
      Issue No: Vol. 2, No. 3 (2013)
       
  • PLANT CLINIC TOWARDS PLANT HEALTH AND FOOD SECURITY

    • Authors: Mahendra P. Srivastava
      Abstract: Ever-growing population, climatic changes and unprecedented losses due to pests and diseases pose serious threat to food security. Precisely food security implies availability of adequate food to everyone in all times to come. Food and Agriculture Organization of united Nations (FAO) defines “food security” as a state of affairs where all people at all times have access to safe and nutritious food to maintain healthy and active life.  Food is one of the three basic needs of man, without which his survival is at stake. Plants constitute the basic source of food and as such, plant health management is crucial to food security, which is jeopardized due to unprecedented threat by large number of insect-pests, diseases, weeds and several edaphic and environmental stresses. Srivastava23 has very well highlighted the importance of plant heath security through phytomedicines/pesticides and plant health clinic in order to prevent 40 per cent losses occurring from field to fork globally. Due to unabated rise in population, reduction in arable land will be an ongoing process, hence we may have to strive hard to grow more food from limited land employing innovative strategies and more importantly adopting multipronged initiative and timely diagnostic and management strategies from plant health clinic to combat attack from pests and environmental stress, manage plant health mitigate losses.
      PubDate: 2013-12-30
      Issue No: Vol. 2, No. 3 (2013)
       
  • DEVELOPMENT OF EXPRESSED SEQUENCE TAG-DRIVED SIMPLE SEQUENCE REPEAT
           MARKERS AND DIVERSITY ANALYSIS OF PHYTOPHTHORA CAPSICI IN CHINA

    • Authors: Liu Pei-Qing, Wu Min-Liang, Li Ben-Jin, Lan Cheng-Zhong, Weng Qi-Yong, Chen Qing-He
      Abstract: Phytophthora capsici is a highly dynamic and destructive pathogen of vegetable and great interests on the genetic structure of P. capsici have grown in the world. However, there is little genetic information about P. capsici based on the EST-SSR markers. In this study, 193 SSR markers were developed and 33 selected markers were successfully detected and they were polymorphic with the number of alleles per locus ranging from 2 to 7. 4 SSR markers were further selected for genetic diversity analysis and Nei’s genetic diversity values of 15 populations ranged from 0.38 to 0.66, with an average of 0.53. The higher polymorphism and greater transport ability of these markers among P. capsici species were proved by the expected heterozygosity (He =0.64) and Shannon’s index of diversity (I =1.14), indicating that they maintained a substantial level of genetic diversity. Additionally, the genetic differentiation among the 4 markers (Fst =0.15) was moderate and the gene flow among groups was consequent (Nm =1.69). Clustering analyses revealed that 15 populations are made of two differentiated genetic clusters and are similar regarding genetic diversity composition. Our results suggest that there are considerable evolutionary potential of P. capsici in China and useful management strategies should be adapt to it.
      PubDate: 2013-12-30
      Issue No: Vol. 2, No. 3 (2013)
       
  • SEED BORNE MYCOFLORA OF SOME COMMERCIAL WHEAT (TRITICUM AESTIVUM L.)
           CULTIVARS IN PUNJAB, PAKISTAN

    • Authors: Muzammil Hussain, Muhammad U. Ghazanfar, Muhammad I. Hamid, Mubashar Raza
      Abstract: Seed borne mycoflora associated with ten commercial varieties of wheat viz. Blue silver, Faisalabad 85, Manthar-3, Pak 81, Parwaz 94, Pirsabaq 2005, Punjnad-1, Sariab-92, Sh-2002 and Wafaq-2001 was investigated through standard blotter paper and agar plate method by using Mann-Whitney U test. At least eleven fungal genera were recovered from seeds. The most frequently isolated fungi were Bipolaris sorokiniana (11.125%), Aspergillus flavus (9.825%), Alternaria alternata (7.15%) and Aspergillus niger (6.225%). It is apparent from the present investigation that all commercial wheat verities tested were contaminated by fungi. The rolled paper method was used to find out the effect of seed borne fungi on seed germination. Seeds of Pak 81, Wafaq-2001 and Blue silver were germinated in high proportion with variable number of normal and abnormal seedlings than the seeds of other varieties tested. The fungi associated with seeds of wheat cause dire diseases in wheat reducing the germination capacity.
      PubDate: 2013-08-25
      Issue No: Vol. 2, No. 3 (2013)
       
  • WHITEFLY- A STRONG TRANSMITTER OF PLANT VIRUSES

    • Authors: Suresh P. Tiwari, Sushma Nema, Mahendra N. Khare
      Abstract: Bemisia tabaci transmit 111 viruses. The silver leaf/sweet potato whitefly prefers 25°C to 30°C for development and rapid generation time while the greenhouse whitefly prefers temperatures of 20°C to 25°C. Eggs hatch in eight to 10 days. Resistance in B- and Q-biotype of B. tabaci appears to be linked to enhanced oxidative detoxification of neonicotinoids. Transmission efficiency from infected weeds to tomato varied from 66.7 to 100 percent, whereas, from tomato to these weeds varied from 58.3 to 83.3 percent. Increased mortality of biotype Q females and immature instars with lower rate of fecundity and progeny size compared to biotype B was recorded in such population when reared in single or mixed cultures. Two genetic types of B. tabaci were distinguished using RAPD-PCR and cytochrome oxidase I (COI) gene sequence comparisons. One type was assigned to biotype B and the other was genetically dissimilar to the populations described elsewhere and was named Ms. This new genetic type forms a distinct group that is sister to two other groups, one to which the B biotype is a member and Q bioype have  similar values of intra population diversity, which were higher than the values shown by populations of biotype B. Epidemics of begomoviruses have been observed in many crops including tomato for which Tomato yellow leaf curl China virus (TYLCCNV) and Tomato yellow leaf curl virus (TYLCV) have been identified as two major disease-causing agents. The replication of geminiviruses induces micro-structural changes in the nucleus of the host cells. The begomovirus vector B.  tabaci is  an  insect species  complex  that  has  geographically  distinct phenotypic and genotypic variants. Criniviruses are limited to phloem and are transmitted in nature in a semipersistent manner by whiteflies. The genus Ipomovirus includes viruses that are transmitted by the whitefly B. tabaci in a semipersistent manner. Virus particles occur in the cytoplasm singly or more often in large aggregates which are sometimes banded. The stem necrosis of soybean is caused by a virus of the Carlavirus and transmitted by the whitefly Bemisia tabaci, also infected beans and identified as Cowpea mild mottle virus. The early symptoms of Tomato torrado virus are necrotic or dead spots, surrounded by a light green or yellow area at the base of the leaflets. The affected areas may fall out, leaving holes (shot holes) in the leaflets. Necrosis and mottling extend to the remainder of the leaves. The article will bring role of whitefly in development of virus diseases in agricultural crops and management strategies could only be achieved when importance of this pest will be eradicated with non-chemical approach.
      PubDate: 2013-08-25
      Issue No: Vol. 2, No. 3 (2013)
       
  • THE POTENTIAL OF FIVE ECO-BIORATIONAL PRODUCTS ON THE REPRODUCTION OF
           ROOT-KNOT NEMATODE AND PLANT GROWTH

    • Authors: Mohamed S. Khalil
      Abstract: This work aimed to select potentially useful eco-biorational product that could be used to reduce the reproduction of root-knot nematode. The experiment was carried out in pots under net house. The results revealed that the bio-product Dipel® (Bacillus thuringiensis ) proved to be the most effective treatment that reduced the root galls and egg masses by 71.60 and 77.78%, respectively. Also, Dipel® (B. thuringiensis) & Bio-nematon® (Paecilomyces lilacinus) showed their superiority between all treatments on the shoot, root length and root weight.
      PubDate: 2013-08-25
      Issue No: Vol. 2, No. 3 (2013)
       
  • VIGOR OF PLANTLET FROM MICROPLANTLET TREATED BY FILTRATE AND CELL
           SUSPENSION OF SOME ISOLATES OF BACILLUS AND RESISTANCE TO BANANA WILT
           PATHOGEN AFTER ACCLIMATIZATION

    • Authors: Hadi wiyono, Salim Widono
      Abstract: Blood Disease Bacterium (BDB) and Fusarium oxysporum f.sp. cubense (FOC) is a couple wilt pathogen  of  banana.  These pathogens are the most important constraint in cultivation of banana in Indonesia.  In the integrated control strategy of the disease, the use of healthy seedlings produced from tissue culture technique is recommended.  The seedling produced by tissue culture technique however leads to lower vigor and susceptibility to the disease due to the aseptic work in vitro causing the beneficial bacterial endophytic to be eliminated. Therefore, the utility of the beneficial endophytic bacteria should be studied for recovering the vigor and resistance of the seedling.     Three isolates of endophytic Bacillus (B04, B05, B10) have been effective as growth promoter of microplantlet and antagonist of BDB and FOC in vitro.   Here then, this article reports the study results of the vigor of the plantlet (treated microplantlet by filtrate or cell suspension of the Bacillus) after 3 months in acclimatization. The results were similar to the previous results on microplantlet in vitro, that Bacillus isolates B04, B05, and B10 were capable of promoting the growth and inducing the resistance to wilt pathogens on banana plantlets.  The treatments with bacterial cell inoculums were more effective than those bacterial filtrate. Isolate B10 was most potential followed by B05 and B04 respectively.
      PubDate: 2013-08-25
      Issue No: Vol. 2, No. 3 (2013)
       
  • DEVELOPING CONTROL STRATEGIES OF POTATO WART DISEASE (SYNCHYTRIUM
           ENDOBIOTICUM) IN TURKEY

    • Authors: Hale Gunacti, Ali Erkılıç
      Abstract: The ultimate purpose of this study was to control Potato Wart Disease. Thus, during 2010 – 2011, in order to control the Potato Wart Disease caused by Synchytrium endobioticum the efficacy of seed fungicides and soil fumigants, the influence of 15 different plants used as alternative cropping to potato and the extracts derived from carrot, onion, garlic and radish were examined on the sporangium viability. The results revealed that the roots of turnip tuber were the most effective treatment among four different plant extracts used. Sunflower and Rye were found to be promising alternative crops to potato for the region with 74% and 73% of sporangium mortality, respectively. The most effective fumigant application on the viability of Synchytrium endobioticum sporangia in the soil was Formaldehyde with a 93.8 – 97.5 % efficacy rate. The fungicide efficacy on the diseases occurrence changed from 25.2 % to 62.5 % comparing to control plots. Although significant differences were obtained numerically between efficacy ratios, no statistically significant differences were found in all applications. The most effective application on Potato Wart Disease occurrence was the dosages of 60 and 80 g /m2 of Metham Sodium among the four different concentrations of Formaldehyde, Metham Sodium, Dazomet and Urea as plant fertilizer.
      PubDate: 2013-08-25
      Issue No: Vol. 2, No. 3 (2013)
       
  • SEROLOGICAL IDENTITY OF POTATO VIRUS X (PVX) AND PCR CHARACTERIZATION OF
           ITS COAT PROTEIN (CP) GENE

    • Authors: Qudsia Nosheen, Shahid Hameed, Sardar M. Mughal, Muhammad F. Abbas
      Abstract: Potato virus X (PVX) is among top ten most economically damaging plant viruses in the world and its increasing incidence is getting an alarming situation in potato crop of Pakistan. During two consecutive years (2010-11 and 2011-12), the incidence of PVX was recorded in potato fields at Rawalpindi, Islamabad, Faisalabad and Sahiwal. The samples were collected and subjected to Double Antibody Sandwiched (DAS) Enzyme Linked Immunosorbant Assay (ELISA) and average incidence of PVX was determined about 16.86% (OD405nm 1.38) during 2010-11 and 27.10% (OD405nm 0.479) in 2011-12. The infectivity of the virus was assayed through mechanical inoculation on Nicotiana tabacum cv. Samsun, N. rustica, Datura stramonium, Chenopodium sp. Gomphrena and Capsicum annuum producing local lesion, mosaic and mottling symptoms. Coat protein (CP) gene specific sense and antisense primer successfully amplified a 750bp fragments through Polymerase Chain Reaction (PCR) assay.
      PubDate: 2013-08-25
      Issue No: Vol. 2, No. 3 (2013)
       
  • PHYSIOLOGICAL RACES AND VIRULENCE DIVERSITY OF PUCCINIA GRAMINIS PERS. F.
           SP. TRITICI ERIKS. & E. HENN. ON WHEAT IN TIGRAY REGION OF ETHIOPIA

    • Authors: Teklay Abebe, Woubit Dawit, Getaneh Woldeab
      Abstract: Wheat stem rust caused by Puccinia graminis f. sp. tritici is a disease that causes complete annihilation of wheat crops over wide areas during epidemic years. The highland of Ethiopia is considered as a hot spot area for the development of stem rust complex. Hence, this study was carried out to detect the virulence diversity of P. graminis f. sp. tritici in Southern Tigray. The findings of this paper were based on race analysis through inoculation of stem rust populations, isolation and multiplication of single-pustule of the pathogen and race determination by inoculating on stem rust differential hosts. The phenotypic characterization of P. graminis f. sp. tritici resulted in identification of 20 races from 32 isolates, which included the most prevalent races TTSNK, RRJJC and HRJJC with a frequency of 9.4% each and the most virulent races TTKSK and TTSSK each making 85% of Sr genes ineffective. Three important races (TTSSK, TTSNK and RRTTF) are new to the study area and the country (Ethiopia) as a whole putting a significant wheat proportion at risk. Among 20 wheat stem rust differential hosts, four were found effective for 75% and more of the races identified. Differential host carrying Sr24 was effective to all, while gene SrTmp was effective to 90% of the races followed by Sr17 and Sr31 each effective for 75%. In contrast, differential hosts carrying SrMcN, Sr9b, Sr9g and Sr10 were ineffective to 96.9, 93.8, 87.5 and 81.2% of the isolates tested, respectively. Thus, use of effective Sr genes such as Sr24 and SrTmp in single cultivar through gene pyramiding has paramount importance as the additive effects of several genes gives the cultivar a wider base  stem rust resistance along with periodic race survey. 
      PubDate: 2013-04-30
      Issue No: Vol. 2, No. 3 (2013)
       
  • INCIDENCE OF POTATO VIRUSES IN DIFFERENT DISTRICTS OF KHYBER PAKHTUNKHAWA,
           PAKISTAN

    • Authors: Zishan Gul, Aftab A. Khan, Asif U. R. Khan, Zaheer U. Khan
      Abstract: Three consecutive potato crops are grown annually in Pakistan and Khyber Pakhtunkhawa (KPK) province is the main source for seed tubers. During the year 2010, 240 symptomatic and viral susceptible potato leave samples were collected from Swat, Dir, Abbottabad and Mansehra and serologically confirmed through Double Antibody Sandwich (DAS) Enzyme Linked Immunosorbant Assay (ELISA) against Potato virus X (PVX), Potato virus Y (PVY), Potato leaf roll virus (PLRV), Potato virus M (PVM), Potato virus S (PVS) and Potato virus A (PVA). The presence or absence of viruses was confirmed by observing the yellow and white color in ELISA plates respectively. According to ELISA results, overall percentage incidence of viral diseases was found highest in Swat (65%) followed by Mansehra (61%), Dir (53%) and Abbottabad (43.33%) while PVY and PVS were dominant in Swat (26.66%), Dir (20%), Mansehra (15%) and Abbottabad (21.66%) respectively. PVX was not detected in Abbottabad while Swat samples seemed to be free from PVM and PVA.
      PubDate: 2013-04-15
      Issue No: Vol. 2, No. 3 (2013)
       
  • DEVELOPMENT AND SUPPRESSION OF GRAPEVINE BLACK FOOT CAUSED BY ILYONECTRIA
           RADICICOLA

    • Authors: Wazer A. Hassan, Raed A. Haleem, Khadeeja A. Saido
      Abstract: Present study investigated the development and suppression of grapevine black foot using a highly virulent strain of Ilyonectria radicicola during 2010-2012 after its widespread outbreak in Duhok - Iraq since 2008. Inoculated roots showed distinctive symptoms of sunken necrotic lesions with internal black streaking of rootstocks. Production of mycelial mass (in vitro) was higher at pH 5.0 resulting in 57% severity of foot rot compared to 46.16% at pH 7.0. In general, Kamali cv. was the most susceptible cultivar with 59.29% of stubby root growth affected compared to 53.32% and 40.83% on Rashmew and Taefi cvs. respectively. Wounding roots of a susceptible cultivar developed the conspicuous symptoms of black foot rot with a severity of 90%. Increasing the conidial inoculum was essential for severe infection development to more than 62%, whereas interaction between inoculation and wounding of roots increased lesion severity to 80.09%. However, acidic pH significantly enhanced disease progression on inoculated vine cuttings to 84.41% compared to 40% at neutral pH. Unfortunately, inoculum of Ilyonectria radicicola was not suppressed significantly even with fungicide application and continued its damage on Rashmew cv. Resulting in disease severity of 23.70% . More than 25% of the inoculated vines grown in amendments of Trichoderma harzianum and farmyard manures were infected compared to 14.80% and 20.73% of the non-inoculated. Exclusion of fungal inoculum improved the plant vigours as measured by dry weight and shoot growth, whereas significant stimulation of root growth were evidenced in the amended treatments particularly those with farmyard manures and fungicides. 
      PubDate: 2013-04-15
      Issue No: Vol. 2, No. 3 (2013)
       
  • MASS PRODUCTION OF THE BENEFICIAL NEMATODE STEINERNEMA CARPOCAPSAE
           UTILIZING A FED-BATCH CULTURING PROCESS

    • Authors: Devang Upadhyay, Rinu Kooliyottil, Sivanadane Mandjiny, Floyd L. Inman III, Leonard D. Holmes
      Abstract: The present study deals with the batch and fed-batch mass production of Steinernema carpocapsae. S. carpocapsae is an entomoparasitic nematode that is used as a biological control agent of soil-borne crop insect pests. The ability and efficiency of fed-batch culture process was successful through the utilization of the nematode’s bacterial symbiont Xenorhabdus nematophila. Results from the fed-batch process were compared to those obtain from the standard batch process. The fed-batch process successively improved the mass production process of S. carpocapsae employing liquid medium technology. Within the first week of the fed-batch process (day six), the nematode density obtained was 202,000 nematodes mL−1; whereas on day six, batch culture mode resulted in a nematode density of 23,000 nematodes mL−1. The fed-batch process was superior to that of batch production with a yield approximately 8.8-fold higher. In fed-batch process, the nematode yield was improved 88.6 % higher within a short amount of time compared to the batch process. Fed-batch seems to make the process more efficient and possibly economically viable.
      PubDate: 2013-04-15
      Issue No: Vol. 2, No. 3 (2013)
       
  • IMPROVMENT BIOCONTROL OF DAMPING-OFF AND ROOT ROT/WILT OF FABA BEAN BY
           SALICYLIC ACID AND HYDROGEN PEROXIDE

    • Authors: Montaser F. Abdel-Monaim
      Abstract: Rhizoctonia solani, Fusarium solani, F. oxysporum and Macrophomina phaseolina were found to be associated with root rot and wilt symptoms of faba bean plants collected from different fields in New Valley governorate, Egypt. All the obtained isolates were able to attack faba bean plants (cv. Giza 40) causing damping-off and root rot/wilt diseases. R. solani isolates 2 and 5, F. solani isolate 8, F. oxysporum isolate 12 and M. phaseolina isolate 14 were the more virulent ones in the pathogenicity tests. Biocontrol agents (Trichoderma viride, Bacillus megaterium) and chemical inducers (salicylic acid and hydrogen peroxide) individually or in combination were examined for biological control of damping-off and root rot/wilt and growth promotion of faba bean plants in vitro and in vivo. Both antagonistic biocontrol agents and chemical inducers either individually or in combination inhibited growth of the tested pathogenic fungi.Biocontrol agents combined with chemical inducers recorded the highest inhibited growth especially in case SA + T. viride and SA+ B. megaterium. Under green house and field conditions, all treatments significantly reduced damping-off and root rot/ wilt severity and increased survival of plants. Also, these treatments increased fresh and dry weights of the survived plants in pots compared with control.  The combination of biocontrol agents and chemical inducers were more effective than using them individually and SA+ T. viride was the best treatment in this respect. Under field conditions, all these treatments significantly increased growth parameters (plant height and No. of branches plant-1) and yield components (No. of pods and seedsplant-1, weight of 100 seeds and total yield feddan-1 and protein content in both seasons (2010-2011 and 2011-2012). Faba bean seeds soaked in SA+ T. viride and SA+ B. megaterium were recorded the highest growth parameters and yield components. Generally, the combination of biocontrol agents and chemical inducers recoded the best results for controlling damping-off and root rot/wilt diseases in greenhouse and field with addition improved plant growth and increased yield components in the field. 
      PubDate: 2013-04-15
      Issue No: Vol. 2, No. 3 (2013)
       
  • ROLE OF EPIDEMIOLOGICAL AND BIOCHEMICAL FACTORS AGAINST EARLY BLIGHT OF
           POTATO

    • Authors: Saira Mehboob, Muhammad Aslam Khan, Abdul Rehman, Muhammad Idrees
      Abstract: Epidemiological and biochemical factors play a significant role in early blight disease development in potatoes. For this 29 test cultivars/ lines, were screened, 15 lines including Cardinal and Desiree were found to be very highly susceptible. Eight lines including Diament FSD-White, and TPS-9813 showed highly susceptible response. Two lines i.e. 9802 and 396266-33 were susceptible. Only one variety /advanced line FD-1-8 was found to be resistant. None of the 29 advanced lines was found to be highly resistant while two lines such as FD-3-9 and FD-48-41 were shown moderately resistant response. At varietal level, among 29 test varieties/ advanced lines, all the varieties showed highly significant correlation with minimum temperature and negative correlation with maximum temperature. 18 varieties/advanced lines have significant correlation with pan evaporation. Whereas all the 29 varieties/ advanced lines did not show any correlation with relative humidity and wind speed. Five varieties/ advanced lines namely Cardinal, 396240-181, 9803, FD-1-9 and 9801 were selected to study the relationship of environmental conditions with disease severity. Maximum disease severity was recorded at 17-200C maximum temperature, 6-9oC of minimum air temperature and 1.9-2.4 mm pan evaporation. Relative humidity and wind speed almost had no significant effect on disease severity. On varietal level early blight disease severity had significant correlation with phenolic production both in leaves and tubers. Among 29 varieties, 20 varieties had significant correlation with phenolic production while 9 had no correlation in case of leaves while in case of tubers 19 varieties/ lines showed significant correlation & 10 lines did not show any correlation with phenolics production. 
      PubDate: 2013-04-15
      Issue No: Vol. 2, No. 3 (2013)
       
  • PRODUCTION EFFICIENCY OF DIFFERENT STRAINS OF PLEUROTUS OSTREATUS USING
           VARIOUS CELLULOSIC AGRO-WASTES

    • Authors: Nazia Khaliq, Nasir A. Khan, Nazir Javed, Amjad S. Gondal
      Abstract: Different local strains of Oyster mushroom were evaluated using different cellulosic agro-wastes including cotton waste, paddy straw and wheat straw for mycelial growth, spawn running and  production efficiency of different strains of Pleurotus ostreatsus. Maximum production efficiency of P. Sajur caju was observed (195.9%) on wheat straw while minimum production efficiency was recorded (132.1%) on paddy straw followed by cotton waste where the production efficiency was 107.9%. P. ostreatus (white strain) showed maximum production efficiency (113.7%) on wheat straw and minimum (88.8%) on cotton waste. While the production efficiency of P. ostreatus (gray strain) was almost same on cotton waste and wheat straw but greater than paddy straw (128.3%). The Overall performance of P. Ostreatus (gray strain) remained best during its cultivation.
       
      PubDate: 2013-04-15
      Issue No: Vol. 2, No. 3 (2013)
       
  • STUDIES ON VASCULAR INFECTION OF FUSARIUM OXYSPORUM F. SP. CUBENSE RACE 4
           IN BANANA BY FIELD SURVEY AND GREEN FLUORESCENT PROTEIN REPORTER

    • Authors: Rong F. Xiao, Yu-Jing Zhu, Yan-Dan Li, Bo Liu
      Abstract: Fusarium wilt of banana (Musa spp.) caused by Fusarium oxysporum f. sp. cubense (Foc) is one of the most serious banana fungal diseases in the world. Understanding the infection process of Foc is important for development of effective ways in disease control. In order to follow infection and colonization of this pathogen from root to rhizome and pseudostem tissues of banana, a highly pathogenic strain FJAT-3076 of Foc race 4 (Foc4) was transformed with gene encoding green fluorescent protein (GFP) and the fungus carrying gfp (FJAT-3076-GFP) was used to inoculate banana plants (Cavendish cv. B.F.). After inoculation for 3 to 10 d, it was observed that the conidia and their germ-tubes had penetrated into epidermis of young roots. The hyphae were found inside the root xylem 10 d after inoculation in the rhizome and pseudostem xylem after inoculation for 17 d. All plants infected by Foc died in 24 d after inoculation. It was also observed that Foc had spread all over the xylem and part of hyphae reached the pseudostem surface. Hyphal population was found the highest in the pseudostem, lower in root and least in rhizome. Field survey confirmed that Foc4 were mostly present in the base of pseudostem and less in the rhizome. Thus, effective prevention of the Foc hyphae movement from the rhizome up to the pseudostem might delay or control banana wilt disease.
      PubDate: 2013-04-15
      Issue No: Vol. 2, No. 3 (2013)
       
  • INDUCTION OF SYSTEMIC RESISTANCE BY BIOCONTROL AGENTS AGAINST BACTERIAL
           BLIGHT OF COTTON CAUSED BY XANTHOMONAS CAMPESTRIS PV. MALVACEARUM

    • Authors: Vinay B. Raghavendra, Lokesh Siddalingaiah, Nagesh K. Sugunachar, Chandra Nayak, Niranjana S. Ramachandrappa
      Abstract: Bioagents such as Trichoderma harzianum, Pseudomonas fluorescens and Bacillus subtilis were isolated from cotton rhizosphere soil and tested individually for their effectiveness in controlling bacterial blight of cotton caused by Xanthomonas campestris pv. malvacearum (Xcm). Talc based formulations were prepared and used for seed treatment at different concentrations for assessing their ability to stimulate plant growth and to control bacterial blight disease. Among bioagents, P. fluorescens and T. harzianum proved to be effective in controlling disease under field conditions.  Other than direct action, these bioagents triggered the defense related enzymes involved in synthesis of phenols. Higher activity of peroxidase, phenylalanine ammonia-lyase, polyphenol oxidase and b-1,3-glucanase was observed in P. fluorescens and T. harzianum treated cotton plants after challenge inoculation with Xcm. Seed treatment with these bioagents enhanced the seed germination and growth parameters against blight disease and they also induced systemic resistance in plant for defense mechanisms. 
      PubDate: 2013-04-15
      Issue No: Vol. 2, No. 3 (2013)
       
  • EFFECT OF DIFFERENT INOCULATION METHODS AND INOCULUM LEVELS OF
           MACROPHOMINA PHASEOLINA ON OKRA

    • Authors: Anam M. Khanzada, Abdul M. Lodhi, Nargis Shah, Sultan A. Maitlo
      Abstract: Among two methods of Macrophomina phaseolina inoculation used for pathogenicity test, soil infestation method comparatively checked more plant growth of okra plants than seed infestation method. Minimum plant length and weight, as well as seed germination were observed by soil infestation method. Significantly maximum plant mortality and root infection was also occurred in soil infestation method. Seed germination, plant growth, plant mortality and root infection of okra plants were adversely affected with the increasing inoculum levels of M. phaseolina. Seed germination and plant growth were negatively correlated with inoculated pathogen population; whereas, plant mortality and root infection were positively correlated with the inoculum level of M. phaseolina.

      PubDate: 2012-12-15
      Issue No: Vol. 2, No. 3 (2012)
       
  • EFFECT OF TREATMENT WITH MOLD INHIBITORS ON PLANT GROWTH OF CORN AND SOME
           NUTRITIONAL COMPONENTS OF STORED GRAINS, INFECTED WITH A.
           FLAVUS
    AND F. VERTICILLOIDES

    • Authors: Ibrahim A. Elsamra, Saad M. Shama, Akila S. Hamza, Nessrine H. Youssef, Mervat S. Youssef, Sawsan M Alabd
      Abstract: Planting sterilized corn grains in soil, treated with the mold inhibitors Fix-a-tox (FAT) or Antitox Plus (AP) resulted, in cases, in dwarfed and malformed corn plants and in the development of deformed, bone-shaped and grain-free corn cobs. Moreover, treating corn grains with the mold inhibitors before storage for one month caused significant changes in some nutritional components of corn grains, i.e. proteins, aminoacids, crude fibers, moisture, fats, ash and carbohydrates. Insignificant differences in protein percetage were detected between control inoculated with Aspergillus flavus and those treated with butyl hydroxyanisole (BHA) antioxidant or FAT treatments, whereas ground clove significantly reduced protein content. In corn grains inoculated with Fusariumverticillioides, previous treatment with FAT resulted in significant reduction in the content of proline, aspartic acid, cysteine, valine, isoleucine and leucine, whereas treatment with BHA significantly reduced the content of threonine, serine, glutamic, glycine, alanine, phenylalanine and tyrosine. In Aspergillus flavus treatments, FAT significantly increased the content of methionine and threonine, whereas, aspartic acid showed 26 percentage decreases, compared to the control. Pronounced reductions in threonine, isoleucine and leucine were also detected in corn grains treated with BHA. Significant increases in fiber content were detected in inoculated corn grains treated with BHA, attaining 1.34 to 2.05-fold over that of control, respectively. Treatment with FAT and BHA led to pronounced reductions in moisture content in corn inoculated with both F. verticilloides and A. flavus trials. However, treatment with ground clove significantly increased the moisture content in A. flavus treatment. FAT treatment led to significant increase in ash and fat contents in both A. flavus and F. verticilloides treatments, whereas the other tested treatments of F. verticilloides significantly reduced ash content. Treatment with ground clove significantly reduced fat content in A. flavus treatment. All the tested materials significantly reduced carbohydrate content.


      PubDate: 2012-12-15
      Issue No: Vol. 2, No. 3 (2012)
       
  • EVALUATION OF SOME POTENTIAL BOTANICALS TO CONTROL POTATO TUBER MOTH,
           (PHTHORIMAEA OPERCULELLA) UNDER STORAGE CONDITION AT
           BAKO, WESTERN ETHIOPIA

    • Authors: Aschalew Sisay, Ahmed Ibrahim
      Abstract: Lantana camara, Eucalyptus globulus, Tagetus minuta, Pyrethrum flowers and Azaddiractha indica, were evaluated against potato tuber moth damage with two checks (Diazinon 60% EC and untreated check) at Bako Agricultural Research Center in 2007/2008 and 2008/2009 cropping seasons. A total of 21 huts (cottages) were constructed from locally available materials.   Inside each cottage (hut), 1m 2 bed was constructed 65 cm above the ground. Six hundred fifty (650) potato tubers were stored on the bed of each hut in two layers one over the other. The treatments were arranged in a Randomized Complete Block Design (RCBD) with three replications. Plants powder and Diazinon 60% EC were applied respectively, at the rate of 50 gm / bed and 3.5ml / bed at two months’ interval. The treatments that showed promising effects were further advanced on a large bed (2m x3m). Three thousand nine hundred (3900) potato tubers were stored on large beds and 150gm powders were used for each bed. Evaluations were made at the interval of 15 days for 7 consecutive months. Analysis of variance showed that number of potatoes infested and damaged by potato tuber moth was significantly (P<0.05) lower in the Lantana camara, Eucalyptus globulus and Pyrethrum flowers than the other treatments, which are similar to standard check. From the study it can be concluded that Lantana camara, E. globulus andPyrethrum flowers can be used to protect seed potatoes from potato tuber moth damage in storage.



      PubDate: 2012-12-15
      Issue No: Vol. 2, No. 3 (2012)
       
  • INFLUENCE OF CULTURAL PRACTICES ON THE DEVELOPMENT OF GRAY LEAF SPOT (GLS)
           ON MAIZE AT BAKO, WESTERN ETHIOPIA

    • Authors: Aschalew Sisay, Fekede Abebe, Kedir Wako
      Abstract: The experiment was conducted at Bako Agricultural Research Center from 2008 to 2009 cropping seasons in order to evaluate the effect of sowing dates and ploughing frequency on the development of Grey Leaf Spot (GLS) on maize. The susceptible variety Phb 3253, with three sowing dates (early, optimum and late at 10 days interval) and three ploughing treatments: Minimum tillage (once), farmer’s practice (three times ploughing) and four times ploughing were used. All plots were uniformly treated with GLS infected crop residue before first ploughing. Trial was laid out in factorial arrangement in Randomized Complete Block Design (RCBD) with three replications. Among the planting dates, the highest disease severity of 7.60, 7.44  & 7.00, (1-9 scale) and Area Under Disease Progress Curve (AUDPC) 305.83, 280.1 and 280.33 were recorded in early sown minimum (conservation) tillage practices, while the lowest was with AUDPC 161.50, 196.50 and 222.67 in four times ploughed plots in 2007, 2008 and 2009 years respectively. The highest thousand seed weight and grain yield was observed in four times ploughed and in early sown plots, while the lowest thousand seed weights and grain yield were recorded in the conservation tillage practice. Four times ploughed and early sown fields had a mean yield advantage of 474.73kg (6.66%) and a total yield advantage 2020.77kg (36.23.6%) over three times ploughed and minimum tillage practices for the three seasons 2008-2009. In general higher disease severity, low thousand seed weight and grain yield were recorded for the conservation tillage compared to other practices. The overall results showed that four times ploughing result in superior maize grain yield performance compared to others as it has resulted in reducing the disease development.


      PubDate: 2012-12-15
      Issue No: Vol. 2, No. 3 (2012)
       
  • GENOTYPIC DIVERSITY OF POTATO GERMPLASM AGAINST ROOT KNOT NEMATODE
           (MELOIDOGYNE INCOGNITA) INFECTION IN PAKISTAN       />

    • Authors: Amjad S. Gondal, Nazir Javed, Sajid A. Khan, Sajjad Hyder
      Abstract: Potato (Solanum tuberosum), an important vegetable crop of Pakistan endures significant yield losses due to root knot nematode (Meloidogyne incognita).. Research wok was designed to identify resistant potato germplasm against RKN (Meloidogyne incognita) infection. A field trial was conducted in the research area of Department of Plant Pathology, University of Agriculture Faisalabad. Thirty six (36) potato verities/ cultivars relocated five times were sown in four years sick plot containing root knot nematode (Meloidogyne incognita) in RCBD layout. Root knot nematode reproduction and host damage was accessed by recording nematode root galls and egg mass indices, root weight, shoot weight, , number of leaves, fruit weight, rate of reproduction and final population of nematodes. Experiment revealed a considerable variation in response against Meloidogyne incognita infection among the genotype tested but none of the single cultivar was immune. FD-8-1 was used as negative control. The cultivar FD-19-2 was highly susceptible followed by SH-692 and SH-5. All other cultivars had less galling index with low fecundity rate indicating their ability to suppress the adult female reproduction. The cultivar FD-1-3 scored least number of galls and egg mass indices followed by FD-49-62, SH-339 and SH-332.

      Amjad Shahzad Gondal
      PubDate: 2012-12-15
      Issue No: Vol. 2, No. 3 (2012)
       
  • EFFICACY OF RHIZOBACTERIA AND HUMIC ACID FOR CONTROLLING FUSARIUM
           
    WILT DISEASE AND IMPROVEMENT OF PLANT GROWTH, QUANTITATIVE AND
           QUALITATIVE PARAMETERS IN TOMATO

    • Authors: Montaser F. Abdel-Monaim, Mohsen A. Abdel-Gaid, Magd El-Morsy A. El-Morsy
      Abstract: The effect of tomato seedling treated with plant growth promoting rhizobacteria (PGPR) strains viz. Azotobacter sp. (AZM1),Bacillus cereus (BCM8), B. megaterium (BMM5) individually or combined with humic acid were evaluated for controlling wilt disease caused by Fusarium oxysporum f. sp. lycopersici, plant growth, fruit quantitative and qualitative (cv. Super Strain-B) during 2010-2011 and 2011-2012 growing seasons. Under greenhouse conditions, all treatments significantly reduced area under disease progress curve (AUDPC) and increased plant height, fresh and dry weights of survival plants growing in pots infested with the causal pathogen compared with control. Combination treatments of humic acid with PGPR reduced significantly wilt incidence and increased plant height, fresh and dry weights of tomato plants comparing with the application of each of them alone. Under laboratory conditions, all PGPR strains and humic acid able to inhibited leaner growth of the causal pathogen with different degrees and PGPR strains were more active than humic acid in this respect.  Under field conditions, all PGPR stains individually or combined with humic acid significantly reduced AUDPC and improved plant growth (plant height, number of branches plant -1) quantitative (number of fruits plant  -1, fruit weight plant -1, fruit weight, fruit yield fed.  -1, Number of fruit Kg  -1) and qualitative (degree of   fruit’s color, fruit diameters, firmness, fruit height, total soluble solids) parameters of tomato fruits compared with untreated plants (control) in both growing seasons. Combination treatments of humic acid with PGPR strains increase the effectiveness of them in this respect  more than   used alone.


      PubDate: 2012-12-15
      Issue No: Vol. 2, No. 3 (2012)
       
  • FUNGICIDAL INTERFERENCE DURING INFECTION RELATED DEVELOPMENTAL STAGES
           INMAGNAPORTHE GRISEA

    • Authors: Humira Sonah, Rupesh K. Deshmukh, Anil S. Kotasthane
      Abstract: Rice blast, a serious epidemic disease that limits grain yield worldwide is caused by fungal pathogen Magnaporthe grisea. The present investigation was carried out to identify the probable avenues of interference by different fungicides during the critical stages of infection related morphogenesis of M. grisea. Effect of six fungicides at different stages of infection related morphogenesis showed variable results like interference in conidial germination, distortion of surface structure of the spores,  interference in the germ tube elongation, interference in the transfer of the cell contents from spore to appresorrium, deformity in appressorial dome, interference in the melanin deposition. We speculate the critical stages at which these fungicides may interfere. The activity of immunosuppressive drug cyclosporin A (CsA) which is a potential antifungal agent was equated with all the fungicides used. We hypothesize that the exposure of the M. grisea spore to the fungicide may lead to the formation of a cyclophilin CYP1-fungicide complex, which inactivates calcineurin and prevents calcium/ calmodulin-dependent protein phosphatase signaling and is therefore one of the target of fungicidal interference. An understanding of how fungal pathogens break the protective barrier that comprise the surface of the host plant as well as precise identification of avenues of fungicidal interference during infection related development in M. grisea will lead to novel approach for controlling plant diseases.


      PubDate: 2012-12-15
      Issue No: Vol. 2, No. 3 (2012)
       
  • IMPACT OF CARBOHYDRATES AND MINERAL CONTENTS OF DIFFERENT INDIGENOUS
           STRAINS OF OYSTER MUSHROOM (Jacq.Fr.) CULTIVATED ON DIFFERENT AGRICULTURAL
           WASTES

    • Authors: Nasir A. Khan, Nazia Khaliq, Imran U. Haq, Nazir Javed, Amjad S. Gondal
      Abstract: Different strains of Pleurotus ostreatus were cultivated on different agro-cellulosic wastes viz. cotton waste, wheat straw and paddy straw to determine the effect of these agro wastes on biological efficiency, carbohydrate and mineral contents including Na, K, Ca, Cu, Zn and Fe. Maximum biological efficiency was recorded on P. ostreatus (grey strain, 134.4%) and (white strain, 113.7%) on wheat straw. P. sajor-caju showed maximum biological efficiency (195.9%) on wheat straw. Maximum amount of Na was found (0.18g/100g) on P. ostreatus (grey strain) and K was found on P. sajor-caju (4.58g/100g) cultivated on paddy straw followed by wheat straw and cotton waste. P. ostreatus (white strain) cultivated on paddy straw showed maximum amount of Cu (0.0009g/100g) while maximum amount of Zn was found (0.017g/100g) on P. ostreatus (white strain). Maximum amount of Fe was found (0.008g/100g) on P. sajor-caju cultivated on cotton waste. P. sajor-caju cultivated on cotton waste showed significantly highest carbohydrate (0.079g/100g).

      Amjad Shahzad Gondal
      PubDate: 2012-12-15
      Issue No: Vol. 2, No. 3 (2012)
       
  • HISTOPATHOLOGICAL CHANGES AND ENZYMATIC ACTIVITIES INDUCED BY
           MELOIDOGYNE INCOGNITA ON RESISTANT AND SUSCEPTIBLE
           POTATO

    • Authors: Mahfouz M. M. Abd-Elgawad, Marie-Claire Kerlan, Sergio Molinari, Farid Abd-El-Kareem, Sanaa S. A. Kabeil, Moawad M. Mohamad, Wafaa A. El-Nagdi
      Abstract: All potato cultivars are susceptible to root-knot nematodes (Meloidogyne spp.) which infest the roots and induce galls on the surface and necrotic spots in the flesh tuber of potato, Solanum tuberosum. Infested tubers are unacceptable for processing and fresh market. Tubers are also putative source of dissemination of the nematode. A French nematode- resistant tetraploid potato genotype gained from ex-S. sparsipilum material hybridized with S. tuberosum in F1 and in their back cross progenies and designated as 02T.155.6 was tested and compared in the present study in Egypt as a suitable different environment. Histopathological changes and chitinase activity induced by M. incognita population, of common occurrence in Egypt, in four French tetraploid materials and two common cultivars known as nematode- resistant and susceptible potato genotypes were investigated. Hypertrophied cells were initiated in both cortical and steler regions of the roots which were then developed to abnormal xylem elements expanding into the cortex in French susceptible genotypes designated as 02T.149.6, 02T.150.54, and 02T.157.16. Nematode within the vascular tissue (stele) could induce giant cell development close to nematode heads. The largest number of such induced cells was shown by the cultivars Spunta and Diamant. The clone 02T.155.6 with putative nematode resistance demonstrated none or very little nematode development. Recently dead second stage juveniles could also indicate incompatible plant reaction to the invading nematodes in 02T.155.6. M. incognita, Giza population, resistance was generally more coherent to 02T.155.6 as demonstrated by our histological investigations but less coherent as shown by another Egyptian M. incognita population. Chitinase activity was enhanced in M. incognita (Giza)-inoculated with respect to uninoculated roots in all plants. After inoculation, such an activity generally increased more in roots of a potato genotype previously known to have resistance or relatively low numbers of both nematode galls and eggmasses than in the other tested cultivars. Peroxidase and catalase activities of nematode- inoculated with respect to uninoculated potato roots were presented and discussed.


      PubDate: 2012-12-15
      Issue No: Vol. 2, No. 3 (2012)
       
  • GEOGRAPHICAL DISTRIBUTION OF PHYSIOLOGIC RACES OF PUCCINIA
           TRITICINA
    AND POSTULATION OF RESISTANCE GENES IN NEW WHEAT
           CULTIVARS IN EGYPT

    • Authors: Nour E. K. Soliman, Ashraf M. M. Abdelbacki, Mohammad A.A. Najeeb, Reda I. Omara
      Abstract: Knowledge of the geographical distribution for physiologic races of Puccinia triticina and identification of leaf rust resistance genes (Lr ,s) in the recent Egyptian wheat cultivars are essential for maximizing resistance in future-bred cultivars. The  aim   of   this   study   was   to   know   the   status  of resistance in Egyptian wheat cultivars against wheat leaf rust and the most frequent race distributed. Infected samples were collected from five Governorates, i.e.,  Dakahlia,  Kafr el-Sheikh,  Beheira,  Sharqia  and  Sohag comprised the wheat growing area in Egypt. These samples were isolated, purified and identified on the differential stes. Gene postulation was done using fifteen identified races on Egyptian wheat cultivars correlated with Lr genes. Thirty three races identified during three seasons 2009/2010, 2010/2011 and 2011/2012. The most frequent race was TK (10%) followed by race BB (7.58%), PK (6.55%), TT (4.82%), PT (3.79%) and MT (3.44%). Moreover, races; BB, TT and PT were present during three seasons while these races appeared in some Governorates and disappeared in other Governorates. On the other hand, the most frequently occurring gene in ten Egyptian wheat cultivars was Lr35 (70%), followed by Lr22 (60%), Lr27 (40%), Lr34 (30%), Lr19 (30%),Lr18 (10%), Lr36 (10%) and Lr46 (10%), eight out of sixteen Lr genes were not present in the tested cultivars. It is concluded that there was a good variation in Lr genes carried by wheat cultivars commercially grown in Egypt. Therefore, strategies for deploying resistance genes to prolong effective disease resistance are suggested to control wheat leaf rust disease.


      PubDate: 2012-12-15
      Issue No: Vol. 2, No. 3 (2012)
       
  • AN APPROACH TO THE PARASITISM GENES OF THE ROOT KNOT NEMATODE

    • Authors: Ajit K. Ngangbam, Nongmaithem B. Devi
      Abstract: Plant parasitic nematodes which are highly successful parasites evolved a very specialized feeding relationship with the host plant to cause the destructive root-knot disease. They initiate their parasitic relationship with the host by releasing their secretions into root cells which in turn stimulate the root cells of the host to become specialized feeding cells which are considered as the single source of nutrients essential for the nematode's survival. The parasitism genes expressed in nematode's esophageal gland cells encode secretory proteins that are released through its stylet to direct the interactions of the nematode with its host plants.


      PubDate: 2012-12-15
      Issue No: Vol. 2, No. 3 (2012)
       
  • ADVANCES OF BASIC MOLECULAR BIOLOGY TECHNIQUES: POTENTIAL TO APPLY IN
           PLANT VIROID DETECTION IN SRI LANKA

    • Authors: Yapa M.A.M. Wijerathna
      Abstract: Viroids are the smallest pathogens of plants. They are the cause of serious diseases on economic plants worldwide. Prevention and detection of the pathogens are the best method to reduce the economic loss from viroid infection. During last decade, genetics and molecular biology techniques have gained an increasing presence in plant pathology research. The purpose of this review is to highlight the most upgrade molecular biology techniques that have been used and studied recently. Most relevant published reports and hand skilled techniques have presented here with emphasis on suitable Viroid detection technique should be used for Sri Lanka.


      PubDate: 2012-12-15
      Issue No: Vol. 2, No. 3 (2012)
       
 
 
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