Abstract: ABSTRACT Salinity is a growing problem worldwide and techniques are needed to mitigate this problem. The experiment was conducted to examine if biochar could improve growth, physiological response, and DM yield of forage sorghum (Sorghum bicolor (L.) Moench) under saline conditions. Sorghum seedlings were transplanted in sandy loam soil (0-20 cm layer of a Typic Fluvaquents Entisols) treated with sodium chloride at rates of 0.26, 5.8, and 12.6 dS m-1. The saline soil was treated with four biochar rates, 0%, 2.5%, 5%, and 10% (w/w). Plant height, fresh weight, photosynthetic rate (A), stomatal conductance (gs), transpiration rate (E), catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) were affected by the interaction between salinity and biochar. At the 12.6 dS m-1 salinity rate, 5% biochar increased plant height, leaf area, fresh weight, DM yields, A, gs, and E by 20.1%, 16.5%, 26.2%, 27.4%, 14.5%, 31.1%, and 26.7%, respectively. At the 12.6 dS m-1 salinity rate, 5% biochar decreased CAT, POD, and SOD by 56.8%, 44.8%, and 18.9%, respectively. Furthermore, among all biochar rates used in this investigation, the 5% rate had a better result for forage sorghum production. These findings demonstrated that the lowest biochar soil amendment application could alleviate the harmful impact of salinity; a high biochar application rate can have a negative influence.
Abstract: ABSTRACT Plant tissue culture techniques are useful for producing a large number of disease-free plant material. The aim of the present study was to determine the optimal nodal explant type (terminal, intermediate and basal) and cytokinins (6-benzyladenine and thidiazuron [TDZ] at concentrations of 0 to 3 mg L-1) for bud break and axillary shoot proliferation of Glycyrrhiza glabra L. The intermediate nodal explants were effective for the establishment of G. glabra aseptic culture when compared with terminal or basal nodal explants. The highest bud break (89%) and axillary shoot proliferation (eight shoots) were observed when the intermediate nodal explants were cultured on MS medium supplemented with 2 mg L-1 TDZ for 30 d. The best rooting medium was MS medium supplemented with naphthalene acetic acid (NAA) compared with indole acetic acid; NAA at 6 mg L-1 yielded 78% rooting and an average of 6.3 roots per plantlet. The regenerated plantlets were acclimatized, with a survival rate of 77.7%, when transferred to ex vitro conditions and showed no morphological abnormalities. Thus, the high percentage of bud break and rate of shoot proliferation and successful acclimatization established a simple and efficient micropropagation of G. glabra.
Abstract: ABSTRACT The effects of two manure crops on the yield of organically grown maize (Zea mays L.) hybrids were evaluated during the growing seasons 2017-2018 and 2018-2019. The experimental treatments included the use of red clover (Trifolium pratense L.) and white clover (T. repens L.) as green manure crops and an untreated control treatment. ‘Factor’, ‘Dracma’, and ‘Brasco’ were the maize hybrids studied. A split plot design was employed with three replicates. The results of ANOVA indicated that the number of kernels per row as well as number of kernels per plant and weight of 1000 kernels were affected by the different green manure treatments (P < 0.001, P < 0.001 and P < 0.01, respectively). Trifolium pratense residuals increased maize grain yield by up to 6% as compared to control treatment during the first year. Similar were the corresponding results recorded during the second experimental year. Trifolium repens green manure increased maize yield by approximately 5% during either the first or the second experimental year as compare to control treatment. Maize grain yield was influenced by the factor of hybrid either in the first or in the second year of the experiment (P < 0.01 and P < 0.001, respectively) and ‘Factor’ was by 5%-6% and 10%-11% more productive than ‘Dracma’ and ‘Brasco’. In conclusion, the results of the present study proved that both red and white clovers were beneficial for the productivity of maize crop under the climatic conditions of Greece, while the selection of the appropriate hybrid can further improve grain yield.
Abstract: ABSTRACT Passiflora is a group of species of economic importance in Colombia because of their productive potential and nutritional, pharmaceutical and industrial properties; therefore, it is necessary to study the genetic diversity of the species cultivated in principal productive departments, such as Boyacá. The use of molecular markers has become a fundamental tool for germplasm characterization, which effectively complements morphological and agronomic information. This research aimed to characterize the genetic diversity of Passiflora spp. grown in the Department of Boyacá using inter-simple sequence repeat (ISSR) markers. The eight ISSRs generated a total 138 bands with molecular weights between 250 and 1350 kb. With a similarity coefficient of 0.60, seven groups were formed, showing lax distribution of the individuals. The percentage of polymorphic loci was between 56% (TG) and 90% (AG). The average value of heterozygosity was with a genetic differentiation coefficient (FST) of 0.16, which indicated great genetic diversity but without a defined population structure. The AMOVA showed that 64% of the observed genetic variation was due to the component within the groups. The results suggested levels of hierarchy and subdivision finer than those considered in this study, in addition to a complementary morphoagronomic characterization that established the total genetic diversity, which can be used to implement a breeding program for more productive cultivars that are resistant to the principal phytosanitary problems.
Abstract: ABSTRACT Plant biodiversity provides a natural source of several compounds with biological activity, such as antioxidant and antifungal properties; such effects are related with the concentrations of phenols and flavonoids and different organs of the plants. In this research, aqueous (W) and 70% ethanol (Et70) extracts from flowers (F), leaves (L), stems (S) and roots (R) of Barkleyanthus salicifolius (Kunth) H. Rob. & Brettell were used to test antioxidant and antifungal activities and also the total concentration of phenols and flavonoids were analyzed; and types of phenolic acids and flavonoids were determined for each plant organ extract by HPLC. The Et70 enhance the extraction process of phenols and flavonoids, also showed higher antifungal and antioxidant activities. The obtained extract of the Et70 × F interaction showed the higher concentration of total phenols (57.90 mg GAE), flavonoids (91.03 mg QE) and antioxidant activity (285.07 Μm Trolox) per gram of dry extract. In addition, this extract shows an antifungal inhibition interval of 66.17% (Fusarium oxysporum) to 92.89% (Colletotrichum gloeosporioides). The phenol ferulic acid (35.57 mg g-1) and the flavonoid naringenina (206.60 mg g-1) were the compounds with the highest values founded in Et70-R, both of them compounds had been tested against fungal pathogens. Data indicate that antifungal and antioxidant activities are in function of phenolic acids and flavonoids concentration, as well as solvent used to extraction. Therefore, B. salicifolius species growing on wild form have the ability of accumulate several compounds with biological activity.
Abstract: ABSTRACT In semi-arid zones, feedlots are considered a tool to minimize the impacts of seasonal forage on the production of sheep meat in the tropics. However, the use of alternative tropical ingredients as substitutes for corn (Zea mays L.) and soybean (Glycine max [L.] Merr.) meal in formulations of confined sheep diets is recurrent. The aim of this study was to evaluate the effect of diets containing corn and soybean meal (CS), corn (CU), cassava (Manihot esculenta Crantz) root (CRU) or spineless cactus (Opuntia ficus-indica [L.] Mill., SCU) associated with urea on the performance, carcass characteristics and meat quality of confined lambs. Forty non-castrated Santa Inês sheep with average age of 150 d and average initial weight of 22.6 ± 2.3 kg were confined in individual pens for 76 d and slaughtered. The diets effects were contrasted by Tukey test. Empty body weight was different among the treatments (P < 0.05) and was 27.3, 25.3, 23.0 and 21.1 kg for the animals fed CS, CU, CRU and SCU, respectively. CS diet presented higher cold carcass weights while SCU diet presented lower cold carcass weights (P < 0.05) (11.37 kg) and higher cooling losses. Luminosity, yellow color intensity and meat moisture content were higher (P < 0.05) in SCU than CS. Liver, skin and internal fat weights were similar (P > 0.05) in CU and CRU, but higher (P < 0.05) than SCU. The replacement of corn and soybean meal for different carbohydrate sources associated with urea reduces the body weight components in confined sheep.
Abstract: ABSTRACT Drought resistance mechanisms of sugarcane (Saccharum officinarum L.) vary with different conditions and locations. Understanding physiological and morphological responses of sugarcane cultivars grown under uniform and controllable conditions needs to be established. Therefore, the objective of this study was to investigate the mechanisms of drought responses of sugarcane cultivars grown under low water potential conditions via polyethylene glycol (PEG) induction. The hydroponic experiment was conducted under open greenhouse conditions. A split-plot in a randomised complete block design with three replicates was used. The PEG rates (0% and 1%) were assigned as main factor. Six sugarcanes cultivars differing in drought-resistance levels were sub-plot factors. To understand drought mechanisms, physiological and morphological traits were measured during stress and recovery periods. Drought mechanisms clearly evidenced only low water potentials at early growth stages, but not terminal drought stress. The six cultivars used in this study could be classified into two groups based on responses of shoot mass after exposure to early drought, consisting of reduced shoot dry weight when exposed to early drought stress and insensitive to early drought stress. In recovery phase, shoot DM of reduced shoot dry weight cultivar (‘KKU99-03’) was 754.6 and 499.5 g pl-1 under control and PEG treatments, respectively, whereas shoot DM of insensitive group did not differ from control conditions. Drought resistance mechanisms, which can maintain aboveground DM of sugarcane cultivars under this condition, varied. Good adaptations for maintenance shoot mass under hydroponics were photosynthesis, stomatal conductance, partitioning of dry weight, root dry weight and green leaf number proportions. The ability to perform well with acclimation of these traits might be useful for improving drought resistance genotypes in the future.
Abstract: ABSTRACT The uniform seed material is a prerequisite of stable yields. Therefore, the aim of the study was to observe variability of physiological seed traits depending on the classification of seeds by size and shape, and to determine advantages of large over small seed fractions. Three maize (Zea mays L.) hybrids (ZP 505, ZP 677, ZP 684), produced in two locations (Orahovo, Plavna), were classified into six fractions; small flat seed (SFS), medium small flat seed (MSFS), large flat seed (LFS), small round seed (SRS), medium small round seed (MSRS) and large round seed (LRS). Two laboratory treatments were applied on seed: TR1 (cold test) and TR2 (20/30 ºC). In both temperature treatments, the first evaluation was done after 72-h germination, and then every 24 h until 7th day. The highest total germination (G) was recorded for ZP 677 (93.7%), location Orahovo (94.9%), temperature TR2 (95.2%) and MSFS fraction (89.7%). The total proportion of factors in the variance for G was R2 = 0.694. Locations and genotypes predominantly affected the germination rate (GR), η = 0.338. Flat fraction seeds had more rapid emergence (> 90%) of seedlings than the round fraction seeds (> 85%). Round seeds were more susceptible and seed size had a greater effect on vigour than LRS, 70%. The partial effect of the fraction on G was not estimated (η = 0.037), but its cumulative effect with other factors was evident (Hybrid × Fraction, η = 0.070).
Abstract: ABSTRACT Denitrification could lead to N loss from agricultural soil resulting in a low rate of N availability by crops. We investigated the response of nirK and nirS denitrifiers in a paddy soil to the incorporation of green manure and reduced chemical fertilizer. Soil samples were collected from plots of a short-term fertilization experiment initiated in 2009. The treatments were no chemical fertilizer, no Chinese milk vetch (Astragalus sinicus L., CK), chemical fertilizer (NPK), Chinese milk vetch (MV) plus 80% chemical fertilizer (MF80), MV plus 60% chemical fertilizer (MF60) and MV plus 40% chemical fertilizer (MF40). Abundance and community composition of nirK and nirS denitrifiers were analyzed using quantitative PCR and Miseq sequencing. Reduced chemical fertilizer did not reduce content of total N and available N in soils amended with green manure. Abundances of nirK and nirS genes in different treatments were 1.04 ×108 to 4.89×108 and 1.22 ×107 to 7.04 ×107 copies g-1 soil, respectively, which were significantly higher in NPK treatment than those in soils with green manure. NirK abundance was positively correlated with the potential denitrifying activity (PDA) (r2 = 0.827, p < 0.01). Green manure combination with reduced chemical fertilizer significantly changed the community structure of nirK denitrifiers but not nirS denitrifiers relative to soils amended with chemical fertilizer and unfertilized soil. Shifts of community structure of nirK denitrifiers were closely associated with soil organic matter (r2 = 0.623, p = 0.003), available N (r2 = 0.507, p = 0.01), pH (r2 = 0.661, p = 0.006), and PDA (r2 = 0.633, p = 0.005). In conclusion, nirK-type denitrifying community was more sensitive to the incorporation of green manure and reduced chemical fertilizer and they played a more important role in the denitrification process in this study.
Abstract: ABSTRACT Yellow rust is an important destructive fungal disease caused by Puccinia striiformis in small grain cereals, and the prevalent Chinese yellow race CYR34 has recently become widespread in China. To detect quantitative trait loci (QTLs) responsible for resistance to CYR34 in triticale (×Triticosecale Wittm.), 520 F2 plants derived from the cross between cv. Gannong No. 1 (susceptible parent) and cv. Gannong No. 2 (resistant parent) were used as mapping population. Fourteen inter-simple sequence repeat (ISSR) markers were used for constructing the linkage map. The obtained results indicated that 92 loci have been mapped on seven linkage groups (LG1-LG7). The total map length was 542.9 cM with an average of 6.95 cM per marker. Six QTLs (qdr1, qdr3, qdr4, qdr5-1, qdr5-2, and qdr6) related to the resistance to CYR34 have been detected. The contribution of these QTLs varied from 5.1% to 11.2%. Moreover, qdr5-1 was the main QTL responsible for CYR34 resistance.
Abstract: ABSTRACT Gaultheria pumila (L.f.) D.J. Middleton is a native shrub of Chile that produces edible berry fruits. This species is related to the cultivated Vaccinium species; for this reason it is currently called Chilean blueberry locally. Although G. pumila has important attributes, it has been largely ignored, and remains an unexplored genetic resource. This study investigates the genetic diversity to support the efforts to domesticate the species. Sampling was carried out in 11 sites collected from four Regions of Chile. In total, 160 individuals were collected and analyzed using a set of 10 simple sequence repeats (SSRs) markers. The average observed heterozygosity was Ho = 0.50, while the expected heterozygosity was He = 0.46. The fixation index (FIS) showed an average of -0.07, and the proportion of differentiation among populations (FST) was 0.11. The average level of polymorphic loci in all populations (PPL) was 96.97%. AMOVA showed that the genetic diversity among populations was very low (ΦPT = 6%). Significant correlations were found between genetic and geographic distance. Multivariate and Bayesian analyses identified two genetic groups. These results will be very useful to support the efforts to domesticate and increase the value of this species.
Abstract: ABSTRACT Effective microorganism biochar-based fertilizer (EMBF) can improve the physiological properties of tobacco (Nicotiana tabacum L.) In this study, the irrigation and EMBF rates were applied as factors that influence the photosynthetic characteristics and chlorophyll content of tobacco. The experiment involved 12 treatments: CK1-CK3, T1-T3, T4-T6, and T7-T9; these four groups represented 0, 100, 300, and 600 g EMBF pot-1, respectively. Each group was irrigated at rates of 40, 80, and 120 L pot-1. When comparing with the control treatment CK, results showed that net photosynthetic rate (Pn), stomatal conductance (gs), intercellular CO2 concentration (Ci), transpiration rate (Tr), and soil plant analysis development (SPAD) increased by 8.21%-107.03%, 18.78%-118.27%, 18.78%-118.27%, 7.24%-104.15%, and 3.47%-69.09%, respectively, after EMBF application. The Pn, gs, Ci, and Tr at the growth and maturity stages were highly significant (P < 0.01) and positively correlated with EMBF application. The Pn, gs, and Tr were significant (P < 0.05) and positively correlated with irrigation, and Ci was less affected by irrigation (P > 0.05). The SPAD value of flue-cured tobacco at three growing stages was highly significant (P < 0.01) and positively correlated with the irrigation and fertilization rates. The SPAD values at the growth and maturity stages were higher than those at the rooting stage by 46.73%-79.2% and 2.21%- 46.17%, respectively. Furthermore, the 80 L pot-1 irrigation rate combined with 300 g EMBF pot-1 is the best water and fertilizer combination. The results of this study might provide theoretical and practical guidance for growing flue-cured tobacco in production areas.
Abstract: ABSTRACT Wheat (Triticum aestivum L.) is often affected by abiotic stress such as high temperatures and water deficit. Due to this, grain yield can be reduced by a water deficit and an inadequate grain filling as well as affect synthesis of polyphenolic compounds. The aim of this study was to determine the influence of water deficit on yield in spring wheat cultivars during grain filling stage, and evaluate total polyphenol content in whole wheat flour. Experiments were conducted at two locations during 2016-2017 growing season, using a randomized complete block design with a split-plot arrangement, with 12 treatments consisting of three irrigations levels and four spring wheat cultivars. In Site 1, interaction (P < 0.05) was obtained between water deficit level and cultivar, ‘Pantera-INIA CL’ achieved highest grain yield (10.5 Mg ha-1), with a well-watered treatment, while ‘Lasana’ reached lowest grain yield (8.5 Mg ha-1), with a severe water deficit. However, water deficit did not affect significantly (P > 0.05) grain yield in Site 2, and differences were observed only between cultivars (P < 0.05) in a range of 6.1 to 7.1 Mg ha-1. Total polyphenol content was not affected by water deficit, differences were only observed between cultivars in both locations (P < 0.05). However, cultivars showed a higher total polyphenol content in Site 1. Water deficit level did not negatively influence yield of four wheat cultivars evaluated in Site 2. While in Site 1, only yield of ‘Lasana’ and ‘Pantera-INIA CL’ was reduced, with severe water deficit.
Abstract: ABSTRACT The application of stabilized organic matter to the soil is essential for the sustainability of a production system. Bokashi is a biofertilizer produced by the aerobic decomposition of organic matter that contributes to the conservation of soil fertility. The objective of this study was to evaluate the effect of bokashi improved with rock phosphate on a curled parsley crop (Petroselinum crispum [Mill.] Fuss var. crispum) under organic management. The process to prepare bokashi at 9% rock phosphate (BP) and without rock phosphate (BK) was evaluated in all treatments at the same temperature, pH, electrical conductivity, and moisture content. Afterward, the effect of applying bokashi on potted curled parsley was evaluated for 10 treatments and 5 replicates. Treatments consisted of three rates (10%, 15%, and 30%) of three P fertilization sources: bokashi with rock phosphate added to the process (BRE), bokashi without rock phosphate (BSR), bokashi without rock phosphate in the process plus rock phosphate added to the pot (BRM), and a control without bokashi (B0). The chlorophyll index, dry matter (DM), foliar P content, and soil available P were evaluated after harvest. The addition of rock phosphate to the compost increased soluble P content by 17.7% and nearly doubled soluble Ca. The BRM treatment at 30% obtained the highest chlorophyll index and BRE at 15% had the maximum DM value. Treatments with bokashi at 30% obtained the highest foliar P content and soil available P. All treatments, except BSR at 10%, improved the chlorophyll index and DM. The evaluated parameters did not vary according to the type of bokashi, but responded to different rates.
Abstract: ABSTRACT Eucalyptus spp. and Acacia spp. have been reported as major invaders in several regions and Mediterranean climates. It has been documented that E. globulus and E. camaldulensis can serve as resources of allelochemicals, which can be used as tools of control strategy of noxious weed species infesting the agricultural areas of the Mediterranean region. Additionally, the remarkable allelopathy potential of A. dealbata Link against various weed species has been highlighted in many recent studies. There is also evidence that other species belonging to Acacia spp. can suppress the native vegetation, including weeds, due to their allelopathic potential. However, allelochemical extracts from different plant tissues seem variable in terms of their effects on various species germination and growth parameters. Furthermore, the effectiveness of the allelochemicals in weed management is also a matter of choosing the most appropriate application rate at any case. In the present review, aspects of the potential role of Eucalyptus spp. and Acacia spp. allelochemicals in weed management were discussed. Further research is needed in order to optimize the use of such allelochemicals produced by invasive plants in the Mediterranean region in both organic and sustainable agriculture systems.
Abstract: ABSTRACT Melientha sauvis Pierre is an edible wild tree in Thailand. Local communities in Thailand harvest new shoot of the plant by burning the forest to stimulate it, a process that destroys the forest. This study was aimed at developing a methodology for callus culture production of M. suavis. Callus was induced from leaf, young stem, and shoot tip of M. suavis on Murashige and Skoog (MS) basal medium supplemented with various formulations of 2,4-dichlorophenoxyacetic acid (2,4-D) and 6-benzylaminopurine (6-BA). Callus produced from young stem explants appeared faster (14 d). Maximum callus growth (40%) and fresh weight (5.56 g) were observed in young stem explant cultured on MS medium containing 2 mg L-1 2,4-D. The findings of this work contribute to large scale micropropagation or bioactive compound production in M. suavis.
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