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Publisher: Indian Council of Agricultural Research   (Total: 6 journals)   [Sort by number of followers]

Showing 1 - 6 of 6 Journals sorted alphabetically
Fishery Technology     Open Access   (Followers: 2)
Indian Horticulture     Full-text available via subscription   (Followers: 10)
Indian J. of Agricultural Sciences     Open Access   (Followers: 13, SJR: 0.238, h-index: 18)
Indian J. of Animal Sciences     Open Access   (Followers: 7, SJR: 0.233, h-index: 16)
Indian J. of Fisheries     Open Access   (Followers: 2, SJR: 0.154, h-index: 5)
Indian Phytopathology     Open Access   (Followers: 2)
Journal Cover Indian Phytopathology
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  This is an Open Access Journal Open Access journal
   ISSN (Print) 0367-973X - ISSN (Online) 2248-9800
   Published by Indian Council of Agricultural Research Homepage  [6 journals]
  • Dialogue between Xop-T3SS effectors of Xanthomonas oryzae pv. oryzae and
           rice during bacterial blight pathogenesis

    • Authors: KALYAN K. MONDAL
      First page: 269
      Abstract: Bacterial blight caused by Xanthomonas oryzae pv. oryzae (Xoo) is a major biotic threat to rice production globally. Xoo initiates dialogue with rice plant through its effectors that are secreted via type 3 secretion system (referred to as T3SS effectors). The result of this dialogue leads to the phenotype of either susceptible or resistance reaction. Xoo secrets two type of T3SS effectors, Xop (Xanthomonas outer protein) and TAL (Transcription activator like) effectors. We screened the total composition of T3SS effectors in one of the most virulent Xoo race 4 from India. Xoo race4 contains 21 Xop and 18 TAL effectors. This paper discusses our recent insight into the dialogue between Xop T3SS and rice. We studied inducible, hrp-dependent expression pattern of the Xop T3SS effectors. We created null mutants for each Xop T3SS effectors to understand their function in blight induction. Our subsequent investigation revealed that major Xop T3SS effectors like XopF, XopR plays crucial role during blight pathogenesis. The major effectors regulate the in planta Xoo growth and suppress PAMP-triggered immune (PTI) response in rice. Though there was no aberration in phenotypic as well as in vitro growth characters between wild and mutants, but mutants showed significant reduction in planta colonization relative to the wild strain. The quantitative RT-PCR analysis indicated significant fold increase in expression of the PTI marker genes in rice upon challenge-inoculation with mutants suggesting the role of effectors in suppressing rice PTI. We evident that mutants induced more callose deposition in infected rice leaves. When transiently expressed in Nicotiana benthamiana, fusion effector gene products localized to the plasma membrane. Collectively, our insight into the Xop T3SS effectors leads to the understanding that the major T3SS effectors like XopF, XopR suppress rice immune responses, and thereby favours Xoo for its in planta growth and pathogenicity during bacterial blight development.
      PubDate: 2017-07-24
      Issue No: Vol. 70, No. 3 (2017)
  • Plant disease diagnosis: technological advancements and challenges

      First page: 275
      Abstract: Plant diseases cause substantial losses in yield of plants, leading to huge economic losses. Accurate identification and diagnosis of plant diseases are very important in the era of climate change and globalization for food security as well as prevention of the spread of invasive pests/pathogens. In addition, for an efficient and economical management of plant diseases accurate, sensitive and specific diagnosis is necessary. The science of plant disease diagnosis has evolved from visual inspection and identification of plant diseases to detect with high-throughput serological techniques like enzyme-linked immunosorbent assay (ELISA) and molecular methods such as polymerase chain reaction (PCR). With the applications of bioinformatics in plant pathology, identification of specific motifs, DNA sequences has become possible, which ultimately increase the accuracy of modern techniques in plant disease diagnosis. Though advances have been made in every aspect of diagnosis of plant diseases; increasing sensitivity and specificity have remained the key area for development. This review briefly describes the various techniques used for plant disease diagnosis and their evolution to meet the contemporary challenges.
      PubDate: 2017-07-24
      Issue No: Vol. 70, No. 3 (2017)
  • Molecular screening of hybrid rice parental lines for bacterial blight
           resistance genes

      First page: 282
      Abstract: A set of twenty-nine parental lines of hybrid rice of five CMS lines and twenty-four newly identified elite restorers showing field resistance towards bacterial blight (BB) under artificial inoculation conditions were selected for molecular characterization to detect the presence of anticipated known BB resistance genes. Gene specific primers were used to detect the presence of Xa4, xa13 and Xa21 genes. Nineteen restorer and four CMS lines confirmed the presence of Xa4 gene in homozygous condition exhibiting a resistant band of 150bp. For xa13 gene only twelve restorer lines could show the presence of the gene in homozygous condition exhibiting a resistant band size of 500bp while none of the CMS lines showed the presence of this gene. Thirteen restorer lines and two CMS lines showed the presence of Xa21 gene in homozygous condition with the presence of single band of 1000bp. A total of five restorer lines were identified which had all the BB resistance genes and only two CMS lines showed the presence of two BB resistance genes (Xa4 + Xa21). The comparison of disease reaction of different restorer and CMS lines against all the ten pathotypes of bacterial blight pathogen prevalent in Punjab state indicated that gene combinations Xa4 + xa13 + Xa21, Xa4 + xa13 or xa13 + Xa21 were effective in providing resistance against all Xoo pathotypes. The lines which carried these genes individually had variable reaction against different pathotypes. The information generated in this study will be helpful in the stacking of multiple BB resistance genes especially into CMS lines in order to provide durable resistance against the disease and for the long term sustainability of hybrids.
      PubDate: 2017-07-24
      Issue No: Vol. 70, No. 3 (2017)
  • Perpetuation of Stemphylium blight of garlic under mid hill conditions of
           Himachal Pradesh

      First page: 294
      Abstract: Blight of garlic caused by Stemphylium vesicarium is of common recurrence and is known to occur in almost all the garlic growing areas of India including Himachal Pradesh. In the present study, surveys during 2014 and 2015 were conducted to assess the pathogen associated and its mode of perpetuation. The morpho-cultural and pathological tests with fungal isolates taken from different areas indicated S. vesicarium to be the cause of garlic blight. The pathogen was invariably found to be soil borne in nature and seed borne to some extent. The sexual fruiting bodies (pseudothecia) of Pleospora alli were detected from garlic debris buried at different depths. Inoculation of healthy leaves with pseudothecia produced characteristic leaf spots that highlight the role of plant debris as a source of perpetuation.
      PubDate: 2017-07-24
      Issue No: Vol. 70, No. 3 (2017)
  • Postharvest application of fungicides, antagonists and plant products for
           controlling storage scab and rots of apple fruits

      First page: 315
      Abstract: Apple scab (Venturia inaequalis) is widely prevalent in all the season in and around Gangotri valley. Three important commercial cultivars of apple namely, ‘Red Delicious’, ‘Royal Delicious’, and ‘Golden Delicious’ were screened against post-harvest rot causing fungi. Fruits of the cv. Red Delicious developed more scab lesions than those of ‘Red Delicious’ and ‘Golden Delicious’. Scab lesions gradually increased in all the fruits of Delicious cultivars stored at ambient temperature. The rate of lesion expansion was inversely related to the number of lesions on the fruit. Scabbed fruits showed pronounced shriveling as compared to healthy fruits.  Other fungal pathogens associated with scab lesion were identified as Trichothecium roseum, Penicillium expansum, Glomerella cingulata, Botrytis cinerea and Monilinia spp. which were responsible for fruit decay in storage. ‘Red Delicious’ was highly susceptible to most of the post-harvest pathogens. Postharvest sprays of flusilazole (0.015%) bitertanol (0.075%) and carbandazim (0.05%) were effective in controlling storage scab and other rotting fungi. Biocontrol agents effective against P. expansum and B. cinerea were isolated from apple leaves, and a quantitative relation between antagonists and pathogen inoculum concentration was determined. Bitertanol (0.075%) and Penconazole (0.05%) were highly effective as pre-harvest sprays for inhibiting scab lesions after 30, 45 and 60 days of storage at room temperature. In protective spray programme, propineb (0.4%) was highly effective for storage rot even after 60 days. Thiophanate methyl (0.10%) was effective against development of storage scab and fruit rot. Aonla leaf extract, garlic extract, bitertanol and carbendazim completely inhibited the storage scab and fruit rot up to 60 days during post-harvest dip treatment. It could be suggested that antagonist, plant product and fungicides could make them an excellent treatment for controlling postharvest losses of apple fruits and increase the shelf-life of apple.
      PubDate: 2017-07-24
      Issue No: Vol. 70, No. 3 (2017)
  • Assessment of yield loss of mustard due to Alternaria leaf blight in
           Gangetic plains of West Bengal

      First page: 322
      Abstract: Alternaria leaf blight of mustard caused by Alternaria brassicae and Alternaria brassicicola occur severely in different districts of West Bengal. A mustard variety ‘Binoy’ was used to assess the effect of iprodion. Three sprays of Iprodion @0.2% at 10 days interval beginning from 45 days after sowing resulted in lowest alternaria blight under moderate disease pressure and four sprays for high disease pressure resulted in highest seed yield and cost benefit ratio of 5.19 and 4.61 respectively for commercial seed and 8.43 and 7.48 for certified seed. Highest avoidable losses of seed yield and 1000 seed weight due to the alternaria blight infection were 27.24% and 5.98% for three sprays and 30.71% and 0.74% for four sprays respectively. The results indicated that three sprays of Iprodion (0.2%) resulted in minimum disease severity and maximum profit whereas under high disease pressure four sprays were essential for minimum disease severity and maximum profit in Indo-Gangetic plains of West Bengal.
      PubDate: 2017-07-24
      Issue No: Vol. 70, No. 3 (2017)
  • Histopathological and molecular characterization of false smut pathogen
           (Ustilaginoidea virens) of rice

    • Authors: POOJA KUMARI*; R.K. SHARMA
      First page: 326
      Abstract: Histopathological studies of false smut balls on rice spikelet were conducted through SEM and microtomy. Detection and identification of the fungal culture of Ustilaginoidea virens from infected host tissue was done through polymerase chain reaction (PCR) using U. virens specific internal transcribed spacer (ITS) primer. The primer amplified 380bp product.
      PubDate: 2017-07-24
      Issue No: Vol. 70, No. 3 (2017)
  • Diversity and characterization of Citrus tristeza virus and Candidatus
           Liberibacter asiaticus associated with citrus decline in major citrus
           growing areas of India

      First page: 359
      Abstract: Tristeza and Citrus greening disease (Huanglongbing, HLB) are two most destructive diseases of citrus worldwide. Tristeza disease is caused by Citrus tristeza virus (CTV), a phloem limited, monopartite, and single-stranded RNA virus whereas citrus greening disease is induced by three different species of a Gram negative, non-cultured, alpha proteobacteria ‘Candidatus Liberibacter'. Among the three species, ‘Candidatus Liberibacter asiaticus’ is most devastating and widely distributed pathogen in Indian subcontinent. In the present study, thirty leaf and twig samples were collected during 2013-16 from citrus plants showing moderate to severe decline symptoms in field from three different states viz., Maharashtra, Assam and West Bengal that are considered as important citrus growing belts of India. Molecular diagnosis by PCR (Polymerase chain reaction) using pathogen specific primers shows that out of thirty samples tested, twenty one samples were found positive with CTV, seventeen samples were infected with ‘Ca. L. asiaticus’ and ten samples were mix infected with both the pathogens while two tested negative. Sequences of coat protein gene (CPG) of CTV isolates showed 97% to 100% sequence identity with CTV sequences available in the GenBank. In phylogenetic analysis, all sequenced CTV isolates were grouped into five clades indicating the presence of at least five different CTV strains that are associated with declined citrus trees of Maharashtra, Assam and West Bengal. Similarly, nucleotide sequence of 16S rRNA gene of ‘Ca. L. asiaticus’ shows 97% to 100% identity with sequences of other reported isolates. Phylogenetic analysis of the 16S rRNA gene indicated that HLB isolates associated with citrus decline in the present study belong to ‘Ca. L. asiaticus’ species. A robust and sensitive duplex PCR has also been developed for the detection of mixed pathogen infection in field samples.
      PubDate: 2017-07-24
      Issue No: Vol. 70, No. 3 (2017)
  • Identification and Characterization of 16SrIX and 16SrXI groups of
           phytoplasmas associated with leaf yellows and declining disease of garlic
           and onion in India

      First page: 368
      Abstract: Leaf yellows and declining symptoms were observed on garlic and onion plants at Pune and Nasik region of Maharashtra, and Gorakhpur region of Uttar Pradesh in March-April 2016. The disease incidence varied from 12% to 30% in different surveyed regions. After nucleic acid extraction and nested PCR analysis using phytoplasma specific primer pairs (P1/P7 followed by 3F/3R) of 16S ribosomal gene an expected DNA fragments of 1.3 kb were amplified in two onion symptomatic samples (from Gorakhpur and Narayangaon) and one garlic symptomatic sample (from Pune). Pair wise sequence comparison of 16S rDNA sequence analysis of the onion leaf yellows phytoplasma (GKP strain) showed 100 percent sequence identity with strain of sugarcane grassy shoot phytoplasma (KP746932) and 99 percent sequence identity with strains of Jasminum sambac little leaf phytoplasma (KF728950) and Ca. P. oryzae (AB052873) belonging to rice yellow dwarf (16SrXI) group. However, another strain of onion leaf yellows phytoplasma (Narayangaon strain) and garlic leaf yellows and declining phytoplasma (Pune strain) showed 99 percent sequence identity with phytoplasma strains of grapevine yellows (KX011516), eggplant big bud (JX464672) and sesame phyllody (JX464672) belonging to Ca. P. phoenecium (16SrIX) group. Phylogenetic analysis of 16Sr DNA sequences of phytoplasma strains from onion and garlic in the present study confirmed their close relationships with phytoplasma strains of 16SrXI and 16SrIX groups. This is the first report of association of 16SrXI and -IX groups of phytoplasma causing leaf yellows and declining disease of onion and garlic in India.
      PubDate: 2017-07-24
      Issue No: Vol. 70, No. 3 (2017)
  • Selection of host differentials for the identification of Albugo candida

    • Authors: PUJA PANDEY*; A.K. TEWARI
      First page: 378
      Abstract: Albugo candida (A. cruciferum) the cause of the white rust/white blister of the rapeseed and mustard occurs in all cruciferous growing countries. The present investigation was conducted to study disease reaction on different Brassica genotypes viz., EC-399301, NRCDR-513, EC-399296, Rohini, EC-399299, NRCDR-515, BIOYSR, EC-399313, JM-1 (B. juncea), EC-414293 (B. rapa), GSL-1 (B. napus), PBC -9221 (B. carinata) and B. nigra local during year 2010-11 and Rohini, EC-399299, EC-414293, B. nigra local, EC-399296, EC-399313, EC-399301, JM-1, PBC-9221, NRCDR-515, GSL-1 using different A. candida isolates (Pantnagar, Ludhiana, Hisar, Bharatpur and Delhi) for the selection of host differentials and identification of A. candida pathotypes. Based on phenotypic disease reactions at cotyledonary and true leaf stage, the Brassica genotypes were grouped into a set of five host differentials. Among various disease management practices, breeding for resistant genotype/varieties is one of the most ecofriendly, economic and effective method for the management of plant diseases.
      PubDate: 2017-07-24
      Issue No: Vol. 70, No. 3 (2017)
  • Biocontrol agent based management approach for root rot and damping off
           complex in French bean

      First page: 388
      Abstract: French bean (Phaseolus vulgaris) is one of the important food legume crops used as green vegetable and pulse in different parts of India. Among the diseases, root rot (Rhizoctonia solani) and damping off (Pythium ultimum) complex are considered an important factor for low productivity of the crop. The experiments were conducted during 2013 and 2014 at IARI, New Delhi to evaluate the performance of different seed dressing and soil application formulations of Trichoderma species and talc based formulation of Pseudomonas fluorescens (IBSD-P137) against root rot and damping off complex in French bean. The seeds treated with seed dressing formulations of Trichoderma and Pseudomonas alone and in combinations increased the seed germination, root and shoot length, plant dry weight and pod yield and decreased the disease incidence. The seeds treated with Pusa 5 SD (T. harzianum-IARI P4) in combination with P. fluorescens gave the highest seed germination, shoot and root length, dry plant weight and pod yield along with the lowest disease incidence followed by Pusa 5 SD (T. harzianum-IARI P4) alone and Pusa 5SD (T. viride; IBSD T-20) in combination with IBSD isolate of P. fluorescens. Seed germination, root length and disease incidence in these treatments did not differ significantly. Soil application of Pusa bio-pellets of T. harzianum (IARI P4) and T. viride (IBSD T-20) also enhanced the seed germination, shoot and root length, dry plant weight and pod yield and reduced disease incidence. Thus, the root rot and damping off in French bean could be managed by soil application and seed treatment with bio-formulations of T. harzianum alone and in combination with P. fluorescens. 
      PubDate: 2017-07-24
      Issue No: Vol. 70, No. 3 (2017)
  • Enhancement of growth, defense response in brinjal and inhibitory
           potential of salicylic acid against Fusarium oxysporum f. sp. melongenae
           under in vitro conditions

    • Authors: BANU NAZIYA*; M.S. SHARADA
      First page: 391
      Abstract: The present study was carried out to evaluate the effects of salicylic acid in enhancement of growth, defense response and inhibition of colony growth of the Fusarium oxysporum f. sp. melongenae under in vitro conditions. The collected seed samples were primed with different concentrations of salicylic acid for 3 h to assess its effect on brinjal seed germination and seedling vigor using paper towel method. Inhibitory effect of salicylic acid was also tested against Fusarium oxysporum f. sp. melongenae using poisoned food technique. Hypersensitive response in salicylic acid treated seedlings was also studied. Among salicylic acid treatments, 20 mM concentration for 3 h duration recorded maximum seed germination of 95% and seedling vigour of 874.6 over non-treated control. In addition, the treatment also stood best in inhibiting mycelial growth of the pathogen under in vitro conditions and showed enhanced hypersensitive response in treated seedlings. Thus, the study suggested that salicylic acid at 20 mM concentration proved to be good in enhancement of seedling growth with significant inhibition of pathogen growth and also enhanced hypersensitive response in brinjal seedlings inoculated with Fusarium wilt pathogen under in vitro conditions.
      PubDate: 2017-07-24
      Issue No: Vol. 70, No. 3 (2017)
  • Factors affecting Mycoparasitism of Sclerotinia Sclerotiorum by
           Trichoderma spp.

      First page: 397
      Abstract: Studies were conducted to investigate different factors favoring mycoparasitism of Sclerotinia sclerotiorum by Trichoderma spp. Results indicate that both temperature and pH have a significant effect on mycoparasitism. Trichoderma viride at 15°C and T. harzianum (Th3) at 25°C were most effective in inhibiting upto 86.90% and 78.96 % mycelial growth, respectively. The pathogen growth was not observed in most of the dual culture plates as well as in control at 35°C. At different pH, Trichoderma behaved differently as it was less effective at pH 9 as compared to pH 5 and 7. At pH 5 Th3 inhibited up to 92 per cent growth of some of the isolates of S. sclerotiorum while at pH 7 it inhibited up to 79 per cent of growth of pathogen. At combination of different temperature and pH, Th3 inhibited up to 81, 73 and 60 per cent growth at pH 5, 7 and 9 at 15°C respectively. At 25°C Th3 inhibited 86, 82 and 55 per cent growth of pathogen at pH 5, 7 and 9 respectively. Th3 had a very effective biocontrol potential at temperature 15°C, 25°C and pH 5 and 7. At pH 9 it was able to inhibit the mycelial growth of pathogen up to 55 per cent.
      PubDate: 2017-07-24
      Issue No: Vol. 70, No. 3 (2017)
  • First report of twig blight disease of green pea (Pisum sativum) caused by
           Choanephora infundibulifera in India

      First page: 400
      Abstract: The present report describes Choanephora infundibulifera as causal pathogen of twig blight disease of Pisum sativum recorded from the Gangetic alluvial region of West Bengal, India, in September 2015. Severe disease infestation with the initiation of shoot apical meristem, leaf, blossom blight was observed. The monsoon season (June-September) with optimum temperature (28-30°C) and high moisture (80-90%) level was found to enhance the disease progress. The pathogen was identified based on its cultural, morphological, and the internal transcribed spacer (ITS) - r DNA sequence analysis. To our understanding, this pathogen is being described for the first time as causal agent of twig blight disease of pea in India.
      PubDate: 2017-07-24
      Issue No: Vol. 70, No. 3 (2017)
  • First record of scab disease of almond caused by Cladosporium carpophillum
           in India

      First page: 403
      Abstract: In India Almond (Prunus amygdulus Batsch.) is commercially grown in Jammu and Kashmir state. During 2012 -2014, circular to oval lesions with brown centers and slightly raised purple margins were observed on twigs of almond, while on leaves lesions appeared as many small, indistinct, somewhat circular, greenish yellow blotches under surface. On fruit, spots were dark grey to black sooty appearance that coalesced into large dark blotches. Average disease intensity of 24.30 per cent and 26.50 per cent was recorded on leaves and twigs respectively. The culture obtained from the diseased sample was identified as Cladosporium carpophillum Thum. on the basis of the colony and morphological characters. To our knowledge, this is the first report of scab of Almond fruit caused by C. carpophillum in India. This disease can seriously affect Almond quality and yield, so effective measures should be implemented to control it.
      PubDate: 2017-07-24
      Issue No: Vol. 70, No. 3 (2017)
  • Woody veins: A disease of Peepal (Ficus religiosa)'

    • Authors: Y.S. AHLAWAT
      First page: 406
      Abstract: Ficus religiosa or Peepal is a sacred tree native to Nepal, India, Bangladesh, Myanmar, Pakistan, Sri Lanka, south-west China and Indochina. It is also known as the bodhi tree, pippala tree, peepal tree or ashwattha tree (in India and Nepal). Ficus religiosa is a large dry season-deciduous or semi-evergreen tree up to 30 meters (98 ft) tall and with a trunk diameter of up to 3 meters (9.8 ft). As an interesting fact, the leaves of this tree move continuously even when the air around is still and no wind is blowing. This phenomenon can be explained due to the long leaf stalk and the broad leaf structure. However, religious minded people in Hindu/Buddhist religion attribute this movement of the leaves to the fact that “devas” or “gods” reside on these leaves and make it move continuously. This fact is also mentioned in the Bhagavad Gita as a verse “O Ashvatha, I honour you whose leaves are always moving” Ficus religiosa is used in traditional medicine for about 50 types of disorders including asthma, diabetes, diarrhea, epilepsy, gastric problems and inflammatory disorders. Several peepal trees in Dwarka, New Delhi have been observed with woody vein of leaves (Fig. 1). Up to 60% of leaves of infected trees showed woody vein. Such leaves also showed mosaic mottling. Some leaves showed vein woodyness only one or two veins while other showed all the veins with woody symptoms. I am reporting this disorder as it appears concern to our religious tree with the hope that working scientists will investigate the etiology of this disease.
      PubDate: 2017-07-24
      Issue No: Vol. 70, No. 3 (2017)
  • Multi-location evaluation of gene pyramided lines of MTU 1010 and JGL 1798
           against bacterial blight of rice

      First page: 287
      Abstract: Cottondora Sannalu (MTU 1010) and Jagitial Sannalu (JGL 1798) are widely cultivated rice varieties in Telangana and Andhra Pradesh and very popular among the farmers because of their high yield, slender grain and good cooking quality. Despite their popularity, they are susceptible to many pests and diseases including bacterial blight (BB), caused by Xanthomonas oryzae pv. oryae (Xoo). Two BB resistance genes viz., xa13 and Xa21 were introgressed in these two varieties using marker assisted backcross breeding. Homozygous lines possessing BB resistance genes xa13 or Xa21 and their combination were evaluated for BB resistance with multiple Xoo isolates under controlled condition in glass house and also at different hot spot locations in the states of Telangana and Andhra Pradesh, India. Both the recurrent parents (MTU 1010 and JGL 1798), TN1 (susceptible check) and Improved Samba Mahsuri (resistant check) were also included for resistance evaluation. All the gene-pyramided lines showed high level of resistance against BB both under glass house and field condition. Individually, BB resistance gene xa13 showed higher level of resistance than Xa21. The level of resistance was higher in the lines possessing both the BB resistance genes compared to the lines possessing single BB resistance genes. The results showed that combination of BB resistance genes xa13 and Xa21 can provide broad level of resistance against BB in Telangana and Andhra Pradesh.
      Issue No: Vol. 70, No. 3
  • Trichoderma harzianum in the management of root rot and blight of okra

    • Authors: D.B. OLUFOLAJI*; M.E. UDOH M.A. AJAYI
      Pages: 297 - 301
      Abstract: Okra is an important vegetable rich in essential vitamins and iodine in human diet. However, okra production in Nigeria is severely affected by root rot and blight. The efficacy of T. harzianum as seed treatment in the management of root rot and blight of okra was tested. The antagonist inhibited the mycelial growth of M. phaseolina in all the treatments. Significantly (P< 0.05) highest inhibition of 92.11% was recorded in 72 hours and the least in curative having 14.97% at 72 hours. In in-vivo studies, seed germination of 76.90% recorded in T72M  was significantly the highest. Highest disease incidence of 70.25% was significantly higher in seeds treated with pathogen alone. There was no significant difference in the number of flowers produce by the treatments. Also, it was observed that okra seeds treated with T72M  had significantly highest number of pods. The result revealed that the use of T. harzianum would be more beneficial, environment friendly in okra cultivation and may be used as an alternative to synthetic fungicides to enhance plant growth and reduce disease incidence, resulting in high okra yield in Nigeria.
      Issue No: Vol. 70, No. 3
  • Generation mean analysis of maydis leaf blight resistance in maize

      First page: 302
      Abstract: Studies on inheritance of the disease resistance were conducted on ten crosses using six generations derived from 4 susceptible (HKI 209, HKI 1332 , HKI 488-1RG and HKI 325-17AN) and 4 resistant inbred lines (HKI 1128, HKI 163, HKI 164D-4-(O) and HKI 193-2-2). The genetic material for field evaluation comprised of six generations i.e. 5 parental inbred lines (P1 and P2), 6 F1’s, their F2 and back crosses (BC1 and BC2) of ten crosses were studied for reaction to maydis leaf blight at CCS, HAU Regional Research Station, Karnal, during Kharif 2014. Significant additive and dominance variances were observed in most of the crosses. The study suggested that both additive and dominance components were important in the inheritance of maydis leaf blight, the magnitude of additive component being relatively higher than non-additive component. Cross HKI 209 x HKI 193-2-2, HKI 488-1RG x HKI 164D-4-(O) and HKI 325-17AN x HKI 164D-4-(O) were found to have duplicate type of epistatis. Gene interactions and environment were also found to be important. The higher estimates of additive component of variance, heritability and genetic advance indicated that selection for maydis leaf blight resistance is likely to be more effective.
      Issue No: Vol. 70, No. 3
  • Detection of new Yr1-virulences in Puccinia striiformis f. sp. tritici
           population and its sources of resistance in advance wheat lines and
           released cultivars

      First page: 307
      Abstract: Five hundred and eight yellow rust (YR) samples were pathotyped from Northern states of India during 2014-15 and 2015-16 cropping seasons. The virulence of these samples was tested on 16 wheat differentials and 6 supplementary varieties. Eleven known pathotypes were identified from the analysis of 508 YR samples during this period. Additionally, the infection types of three samples on differentials, collected from US Nagar (Uttarakhand), Kangra and Kinnaur (Himachal Pradesh) districts, were dissimilar to the known pathotypes in India. Subsequently, three isolations were taken from each sample, established separately on susceptible check (A-9-30-1) and each isolation was used to inoculate differentials. All the isolations taken from single sample, showed similar reaction types on differentials. It proved the presence of new pathotype. The new pathotypes (virulences) were designated as 111S68, 79S4 and 79S68. Rust resistance genes Yr2 (Heines VII), Yr5, Yr9, Yr10, Yr15, Yr24, YrA were found effective to all these new pathotypes, identified in this study. Evaluation of 135 advance lines and released varieties of bread, durum, dicoccum wheat and triticale indicated that new pathotypes (111S68, 79S4, and 79S68) were less virulent than known pts. 47S103 (T) and 47S102 (K) virulent to Yr1. More than 70 per cent evaluated wheat and triticale material was found resistant to moderately resistant to all Yr1-virulences. New pathotypes, identified from indigenous wheat, would aid in understanding the evolution mechanism in Yr1-virulences of yellow rust pathogen in India for better management of yellow rust.
      Issue No: Vol. 70, No. 3
  • Harnessing biocontrol potential of Trichoderma harzianum for control of
           Meloidogyne incognita in tomato

      First page: 331
      Abstract: The aim of the study was to evaluate the biocontrol potential of Trichoderma harzianum against Meloidogyne incognita and decipher mechanisms of induced systemic resistance and disease suppression in tomato grown in net house conditions. The fungal biocontrol agent T. harzianum UBSTH-501 was evaluated against M. incognita on dual plate under in vitro conditions and in planta under nethouse conditions. The results of in vitro parasitism on dual plates showed that T. harzianum causing infection on the eggs and juveniles of root-knot nematode, whereas, in planta assay showed that plants treated with talc based bioformulation T. harzianum UBSTH-501 exhibited manifold increase in the accumulation of total chlorophyll and enzymes, viz. chitinase, phenylalanine ammonia lyase (PAL) and peroxidase which is known to confer systemic resistance in tomato against M. incognita resulting into decreased nematode population and disease severity. Results revealed that T. harzianum UBSTH-501modulated phenylpropanoid pathways led to enhanced accumulation of defence related mediator molecules and enzymes in tomato resulted in disease suppression to a significant extents.
      Issue No: Vol. 70, No. 3
  • In vitro evaluation of bio-control agents and fungicides against Ganoderma
           lucidum causing basal stem rot of arecanut

      First page: 336
      Abstract: Basal stem rot or Ganoderma wilt caused by Ganoderma lucidum (Curtis Ex.Fr.) Karst is one of the major constraints in arecanut cultivation in Assam, India. Pure culture of Ganoderma was isolated from fruiting bodies of diseased arecanut palms. Twenty-two Trichoderma spp. and twelve Pseudomonas fluorescens isolates were prepared from rhizosphere of healthy arecanut palms from different locations. Thestudy was carried out during 2012-13 and 2013-14. Dual culture study revealed that among the Trichoderma spp., T. viride Tv-16 isolate, produced maximum reduction in radial growth of G. lucidum (88.56%) followed by Ta-7 and Ta-10 with 88.26 and 84.07 per cent inhibition over control after 144 hrs of incubation respectively. Among the twelve isolates of P. fluorescens, Pf6 was most effective, followed by Pf10 with 77.55 and 77.33 per cent inhibition over control, respectively. Seven fungicides were assayed for their efficacy against the test pathogen at 0.1, 0.2 and 0.3 per cent concentration. Among the systemic fungicides, hexaconazole 5EC and tridemorph 80EC completely inhibited the growth of G. lucidum at all the concentrations. Among the contact fungicides, mancozeb 75%WP (86.11% inhibition over control) gave maximum control against the pathogen. Compatibility study of fungicides with T. viride Tv-16 revealed that the systemic fungicides, carbendazim 50%WP, hexaconazole 5%EC and tridemorph 80%EC were highly sensitive to T. viride with 100 per cent inhibition at all the tested concentration. Non-systemic fungicide mancozeb 75%WP was found to be compatible, whereas copper oxychloride 50%WP and captan 50%WP showed low to moderate degree of compatibility with T. viride T16.
      Issue No: Vol. 70, No. 3
  • Identification and biochemical characterization of resistance against
           downy mildew in snapmelon

      First page: 341
      Abstract: Snapmelon downy mildew, an important foliar disease caused by Pseudoperonospora cubensis is an obligate parasite, which can survive and reproduce on living host tissue, causing significant yield losses. Forty six accessions of snapmelon were screened against P. cubensis in the cropping season 2015 and 2016. Plants were inoculated at optimum level of sporangial suspension (4.0 ´ 104 sporangia per ml) to create downy mildew. Out of forty six accessions, three were resistant having incidence in the range of 20-30 per cent and rest were moderately resistant, moderately susceptible, susceptible and highly susceptible. Significant mean maximum disease severity was observed in snapmelon accession SM 2013-7 and minimum in accession MC 2013-4. For further confirmation, biochemical studies of various defense enzymes were carried out in resistant accessions and compared with susceptible. The data pertaining to the activity of peroxidase, catalase, phenylalanine ammonia lyase and total phenols revealed significant differences (p=0.05) among the different accessions of snapmelon showing different reactions against P. cubensis. Higher activity of all those antioxidant enzymes were observed in resistant, followed by moderately resistant whereas activity gradually declined among susceptible and highly susceptible accessions. Negative values of Pearson’s correlation coefficient were obtained between antioxidant enzyme activity and disease development suggesting possible involvement of these enzymes in imparting disease resistance against downy mildew in snapmelon. The narrow genetic base of modern snapmelon accessions and a few sources of resistance make downy mildew resistance an important objective in snapmelon breeding programs. Thus, improving the genetic resistance of snapmelon to downy mildew through introgressive breeding could be an effective way to control this disease.
      Issue No: Vol. 70, No. 3
  • Biodiversity substrate relationship and distribution of Lichens from
           Telangana and Andhra Pradesh, India

      Pages: 347 - 352
      Abstract: Lichens are one of the important most viable and successful alliances of photobiont and Mycobiont in nature. Lichens exist in three different growth forms and are distributed throughout the world including in Polar Regions. There is little or no information on lichen floristics, their distribution and substrate relationship from Telangana and Andhra Pradesh states. The survey (2010-13) of different forest localities resulted in the collection of 65 Lichens which have been identified upto species level. The data pertaining to their substrate relationships, growth forms and distribution has been presented.
      Issue No: Vol. 70, No. 3
  • Screening of blackgram genotypes for molecular variability in reaction to
           Mungbean yellow mosaic virus (MYMV)

      First page: 353
      Abstract: Sixteen blackgram genotypes were tested for yellow mosaic disease under field conditions and identified nine genotypes as resistant, one as moderately resistant, four as susceptible and two as highly susceptible. No genotypes were found to be immune or highly resistant against yellow mosaic disease. Polymerase Chain reaction (PCR) of DNAs from sixteen genotypes using Sequence Characterized Amplified Region (SCAR) markers namely, SCAR 20F/20R resulted in specific amplification in nine genotypes indicating resistant nature of these genotypes. There was no amplification in six genotypes while faint amplification could be observed in the genotype LBG-752 that recorded 14.47% incidence of the disease along with moderately phenotypic reaction.
      Issue No: Vol. 70, No. 3
  • Use of NCM based DNA extraction method for simultaneous detection of
           citrus mosaic badnavirus and Candidatus Liberibacter asiaticus by duplex

      First page: 373
      Abstract: Candidatus Liberibactor asiaticus (Ca. Las), a phloem limited, gram negative bacterium is the causal organism of citrus greening disease (Huanglongbing/HLB) whereas citrus yellow mosaic disease is caused by Citrus mosaic badnavirus (CMBV). Both the diseases, singly or as mixed infection in the grove are considered as serious threat to Indian citrus industry. Early diagnosis for these systemic pathogens are essential in order to prevent the spread of these diseases and finally to devise their integrated management strategies. In the present study, a method of simultaneous detection of CMBV and ‘Ca. Las’ was developed using a simple nitrocellulose membrane (NCM) based DNA isolation protocol in three commercially grown citrus cultivars in India, viz. mandarin (Citrus reticulata), sweet orange (Citrus sinensis), and acid lime (Citrus aurantifolia) infected with these pathogens. Citrus tissues were crushed in extraction buffer containing NaOH and EDTA. The crude extract was spotted on NCM and incubation elution was done in nuclease-free water after 30 minute of NCM spotting. Eluted products were taken for simultaneous detection of CMBV and ‘Ca. Las’ using duplex PCR with newly designed primers. The developed protocol was found to be equally sensitive as multistep DNA isolation method and commercially available kit. The protocol is simple, rapid and inexpensive thus can be used for large-scale pathogen indexing of citrus plant samples in orchards and nurseries.
      Issue No: Vol. 70, No. 3
  • Some mycomycetes from Telangana state, India

      Pages: 381 - 383
      Abstract: This communication deals with thirty myxomycetous taxa collected and identified from different forests of Telangana state, India. This report is an addition to the previously described taxa from India.
      Issue No: Vol. 70, No. 3
  • Effect of β-amino butyric acid in induction of disease resistance against
           Xanthomonas campestris pv. campestris causing black rot disease of cabbage

      First page: 384
      Abstract: A defense activator chemical, β-aminobutyric acid (BABA) is capable of inducing local as well as systemic resistance against numerous plant pathogens. An experiment was conducted to evaluate induction of defense related enzyme peroxidase (POX) by BABA for imparting systemic resistance against Xanthomonas campestris pv. campestris (Xcc) inciting black rot disease of cabbage. Effect of BABA (1000 µg/ml) on the induction of POX activity in the leaves of cabbage resistant cv. Pusa Mukta and susceptible cv. Golden Acre in response to BABA and X. campestris pv.campestris revealed that the POX was found increasing in BABA + Xcc treated plants and reached maximum level at 5 days after inoculation, in comparision with BABA or Xcc treated alone. The bacterial population of X. campestris pv. campestris was also reduced significantly in both the cultivars of cabbage treated with BABA (1000 µg/ml) as compared to control (water) treated plants. The level POX activity was observed to be low in both uninoculated and inoculated susceptible cv. Golden Acre as compared to resistant seedlings during time course. Thus explaining the importance of POX activity in reducing population level of X. campestris pv. campestris, whose activity was enhanced with the application of BABA.
      Issue No: Vol. 70, No. 3
  • Genetic variability of multifunctional HC-Pro gene of Lettuce mosaic virus
           in northern region of India

      First page: 394
      Abstract: Lettuce mosaic virus (LMV) is an economically important pathogen causing mosaic disease in lettuce like it causes in spinach (Spinacia oleracea). Isolates of LMV originating from different geographical regions in northern India were collected during the survey of 2013-2014. Lettuce mosaic virus (LMV) belongs to Potyviridae family (genus Potyvirus) and is mainly transmitted by aphids. This study covered the genetic variability of Helper component proteinase (HC-Pro) gene of LMV isolates. HC-Pro is multifunctional activity gene, which helps in transmission of virus. The amplified PCR products of ~1.3 kilo basepairs (kb) were obtained from five different isolates, sequenced and deposited in NCBI GenBank. Two isolates R4 and HR1 from Rajasthan (KJ558375, KM501033), isolate R5 from Haryana (KP635365), isolate R6 from Uttar Pradesh (KP635366) and isolate R4 from Delhi (KP635367)]. The phylogenetic analysis of LMV HC-Pro sequences is showed divergence with other isolates. These isolates showed two different clusters vis-a-vis diversity amongst each other.
      Issue No: Vol. 70, No. 3
  • First report of leaf spot of lentil caused by Alternaria tenuissima in

      First page: 405
      Abstract: Lentil (Lens culinaris) is an important pulse crop plant belonging to the family Fabaceae. Lentil leaves exhibiting pale to tan spots were observed in the breeding trial fields at Indian Agricultural Research Institute (IARI), New Delhi in Feb, 2015 (Fig. 1a.). Brownish spots on leaves later coalescing to form larger patches and consequently caused blighting of the entire leaves.
      Issue No: Vol. 70, No. 3
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
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Fax: +00 44 (0)131 4513327
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