Background Cotton is a strategically important fibre crop for global textile industry.It profoundly impacts several countries’industrial and agricultural sectors.Sustainable cotton production is continuously threaten...Background Cotton is a strategically important fibre crop for global textile industry.It profoundly impacts several countries’industrial and agricultural sectors.Sustainable cotton production is continuously threatened by the unpre-dictable changes in climate,specifically high temperatures.Breeding heat-tolerant,high-yielding cotton cultivars with wide adaptability to be grown in the regions with rising temperatures is one of the primary objectives of modern cotton breeding programmes.Therefore,the main objective of the current study is to figure out the effective breed-ing approach to imparting heat tolerance as well as the judicious utilization of commercially significant and stress-tolerant attributes in cotton breeding.Initially,the two most notable heat-susceptible(FH-115 and NIAB Kiran)and tolerant(IUB-13 and GH-Mubarak)cotton cultivars were spotted to develop filial and backcross populations to accom-plish the preceding study objectives.The heat tolerant cultivars were screened on the basis of various morphological(seed cotton yield per plant,ginning turnout percentage),physiological(pollen viability,cell membrane thermostabil-ity)and biochemical(peroxidase activity,proline content,hydrogen peroxide content)parameters.Results The results clearly exhibited that heat stress consequently had a detrimental impact on every studied plant trait,as revealed by the ability of crossing and their backcross populations to tolerate high temperatures.However,when considering overall yield,biochemical,and physiological traits,the IUB-13×FH-115 cross went over particularly well at both normal and high temperature conditions.Moreover,overall seed cotton yield per plant exhibited a posi-tive correlation with both pollen viability and antioxidant levels(POD activity and proline content).Conclusions Selection from segregation population and criteria involving pollen viability and antioxidant levels concluded to be an effective strategy for the screening of heat-tolerant cotton germplasms.Therefore,understanding acquired from this study can assist breeders identifying traits that should be prioritized in order to develop climate resilient cotton cultivars.展开更多
Background SRO(Similar to RCD1)genes family is largely recognized for their importance in the growth,develop-ment,and in responding to environmental stresses.However,genome-wide identification and functional character...Background SRO(Similar to RCD1)genes family is largely recognized for their importance in the growth,develop-ment,and in responding to environmental stresses.However,genome-wide identification and functional characteri-zation of SRO genes from cotton species have not been reported so far.Results A total of 36 SRO genes were identified from four cotton species.Phylogenetic analysis divided these genes into three groups with distinct structure.Syntenic and chromosomal distribution analysis indicated uneven distribu-tion of GaSRO,GrSRO,GhSRO,and GbSRO genes on A2,D5 genomes,Gh-At,Gh-Dt,Gb-At,and Gb-Dt subgenomes,respectively.Gene duplication analysis revealed the presence of six duplicated gene pairs among GhSRO genes.In promoter analysis,several elements responsive to the growth,development and hormones were found in GhSRO genes,implying gene induction during cotton growth and development.Several miRNAs responsive to plant growth and abiotic stress were predicted to target 12 GhSRO genes.Organ-specific expression profiling demonstrated the roles of GhSRO genes in one or more tissues.In addition,specific expression pattern of some GhSRO genes dur-ing ovule development depicted their involvement in these developmental processes.Conclusion The data presented in this report laid a foundation for understanding the classification and functions of SRO genes in cotton.展开更多
Background High temperature stress at peak flowering stage of cotton is a major hindrance for crop potential.This study aimed to increase genetic divergence regarding heat tolerance in newly developed cultivars and hy...Background High temperature stress at peak flowering stage of cotton is a major hindrance for crop potential.This study aimed to increase genetic divergence regarding heat tolerance in newly developed cultivars and hybrids.Fifty cotton genotypes and 40 F1(hybrids)were tested under field conditions following the treatments,viz.,high temperature stress and control at peak flowering stage in August and October under April and June sowing,respectively.Results The mean squares revealed significant differences among genotypes,treatments,genotype×treatment for relative cell injury,chlorophyll contents,canopy temperature,boll retention and seed cotton yield per plant.The genetic diversity among 50 genotypes was analyzed through cluster analysis and heat susceptibility index(HSI).The heat tolerant genotypes including FH-Noor,NIAB-545,FH-466,FH-Lalazar,FH-458,NIAB-878,IR-NIBGE-8,Weal-AGShahkar,and heat sensitive,i.e.,CIM-602,Silky-3,FH-326,SLH-12 and FH-442 were hybridized in line×tester fashion to produce F1 populations.The breeding materials’populations(40 F1)revealed higher specific combining ability variances along with dominance variances,decided the non-additive type gene action for all the traits.The best general combining ability effects for most of the traits were displayed by the lines,i.e.,FH-Lalazar,NIAB-878 along with testers FH-326 and Silky-3.Specific combining ability effects and better-parent heterosis were showed by the crosses,viz.,FH-Lalazar×Silky-3,FH-Lalazar×FH-326,NIAB-878×Silky-3,and NIAB-878×FH-326 for seed cotton yield and yield contributing traits under high temperature stress.Conclusion Heterosis breeding should be carried out in the presence of non-additive type gene action for all the studied traits.The best combiner parents with better-parent heterosis may be used in crossing program to develop high yielding cultivars,and hybrids for high temperature stress tolerance.展开更多
Nine genotypes were evaluated under greenhouse conditions for antixenosis and tolerance against brown planthopper(BPH, Nilaparvata lugens St?l). In antixenosis studies, proportion of insects settled on a test genotype...Nine genotypes were evaluated under greenhouse conditions for antixenosis and tolerance against brown planthopper(BPH, Nilaparvata lugens St?l). In antixenosis studies, proportion of insects settled on a test genotype in relation to the susceptible control TN1 was recorded, with significantly lower proportion of nymphs(55.22%–59.18%), adult males(60.33%–60.75%), and adult females(80.56%–79.26%) settled on RP2068-18-3-5 and Ptb33 in relation to those on TN1. Based on number of feeding sites, the test genotypes were ranked in order from the highest to the lowest as RP2068-18-3-5, Ptb33, MR1523, Rathu Heenati, Sinnasivappu, ARC10550, MO1, INRC3021 and TN1. The order was exactly reverse in terms of fecundity expressed as number of eggs laid per female. In tolerance studies, days to wilt, functional plant loss index and plant dry weight loss to BPH dry weight produced were recorded. RP2068-18-3-5, Rathu Heenati and Ptb33 performed better than the other test genotypes. These results helped in relative quantification of BPH resistance levels in the genotypes. RP2068-18-3-5, a new effective source of BPH resistance, can be used in resistance breeding after tagging of resistant genes/QTLs linked to different parameters of antixenosis and tolerance with selectable molecular markers.展开更多
Despite the longstanding importance of silage as a critical feed source for ruminants,its quality improvement has been largely overlooked.Although numerous quantitative trait loci(QTL)and genes affecting silage qualit...Despite the longstanding importance of silage as a critical feed source for ruminants,its quality improvement has been largely overlooked.Although numerous quantitative trait loci(QTL)and genes affecting silage quality in maize have been reported,only a few have been effectively incorporated into breeding programs.Addressing this gap,the present study undertook a comprehensive meta-QTL(MQTL)analysis involving 523 QTL associated with silage-quality traits collected from 14 published studies.Of the 523 QTL,405 were projected onto a consensus map comprising 62,424 genetic markers,resulting in the identification of 60 MQTL and eight singletons.The average confidence interval(CI)of the MQTL was 3.9-fold smaller than that of the source QTL.Nine of the 60 identified MQTL were classified as breeder’s MQTL owing to their small CIs,involvement of more QTL,and large contribution to phenotypic variation.One-third of the MQTL co-localized with DNA marker-trait associations identified in previous genomewide association mapping studies.A set of 78 high-confidence candidate genes influencing silage quality were identified in the MQTL regions.These genes and associated markers may advance marker-assisted breeding for maize silage quality.展开更多
Rice root-knot nematode(RRKN,Meloidogyne graminicola)and brown spot(BS,Drechslera oryzae)are serious constraints on the quality of rice grains,particularly under direct-seeded rice conditions in many parts of the worl...Rice root-knot nematode(RRKN,Meloidogyne graminicola)and brown spot(BS,Drechslera oryzae)are serious constraints on the quality of rice grains,particularly under direct-seeded rice conditions in many parts of the world.Developing rice varieties resistant to RRKN and BS will be the most effective and environmentally friendly management strategy.A total of 93 and 58 Oryza rufipogon accessions were screened against RRKN and BS,respectively,for two years under artificial inoculation conditions.Among the 93 O.rufipogon accessions。展开更多
Background Boron(B)deficiency is an important factor for poor seed cotton yield and fiber quality.However,it is often missing in the plant nutrition program,particularly in developing countries.The current study inves...Background Boron(B)deficiency is an important factor for poor seed cotton yield and fiber quality.However,it is often missing in the plant nutrition program,particularly in developing countries.The current study investigated B’s effect on growth,yield,and fiber quality of Bt(CIM-663)and non-Bt(Cyto-124)cotton cultivars.The experimental plan consisted of twelve treatments:Control(CK);B at 1 mg·kg^(−1) soil application(SB1);2 mg·kg^(−1) B(SB2);3 mg·kg^(−1) B(SB3);0.2%B foliar spray(FB1);0.4%B foliar spray(FB2);1 mg·kg^(−1) B+0.2%B foliar spray(SB1+FB1);1 mg·kg^(−1) B+0.4%B foliar spray(SB1+FB2);2 mg·kg^(−1) B+0.2%B foliar spray(SB2+FB1);2 mg·kg^(−1) B+0.4%B foliar spray(SB2+FB2);3 mg·kg^(−1) B+0.2%B foliar spray(SB3+FB1);3 mg·kg^(−1) B+0.4%B foliar spray(SB3+FB2).Each treat-ment has three replications,one pot having two plants per replication.Results B nutrition at all levels and methods of application significantly(P≤0.05)affected the growth,physiological,yield,and fiber quality characteristics of both cotton cultivars.However,SB2 either alone or in combination with foliar spray showed superiority over others,particularly in the non-Bt cultivar which responded better to B nutrition.Maxi-mum improvement in monopodial branches(345%),sympodial branches(143%),chlorophyll-a(177%),chlorophyll-b(194%),photosynthesis(169%),and ginning out turn(579%)in the non-Bt cultivar was found with SB2 compared with CK.In Bt cultivar,although no consistent trend was found but integrated use of SB3 with foliar spray performed relatively better for improving cotton growth compared with other treatments.Fiber quality characteristics in both cultivars were improved markedly but variably with different B treatments.Conclusion B nutrition with SB2 either alone or in combination with foliar spray was found optimum for improving cotton’s growth and yield characteristics.展开更多
The availability of favorable genetic diversity is a thriving vitality for the success of a breeding program.It provides a firm basis of selecting superior breeding lines for the development of high yielding crop geno...The availability of favorable genetic diversity is a thriving vitality for the success of a breeding program.It provides a firm basis of selecting superior breeding lines for the development of high yielding crop genotypes.In this context,present investigation aimed to generate information on genetic divergence and character association in a diversity panel of 123 local and exotic soybean genotypes.Analysis of variance revealed significant response of the evaluated genotypes based on studied attributes.It depicted the probability of selecting desirable soybean genotypes by focusing on character association studies and genetic diversity analysis.Correlation analysis revealed that seed yield per plant showed high positive correlation with 100-seed weight followed by pods per plant and plant height.Furthermore,path coefficient analysis exposed that pods per plant had maximum direct contribution in seed yield per plant followed by 100-seed weight,days to flowering and SPAD measurement.Genotype named“G-10”showed maximum yield per plant followed by 24607,G-52,24593,Arisoy,24566,17426,A-3127,24570 and 24567.Genetic diversity analysis grouped the evaluated germplasm into 17 clusters.All clusters showed zero intra-cluster variability;while inter-cluster divergence ranged from 9.00 to 91.11.Cluster V showed maximum inter-cluster distance with cluster XII followed by that of between V and VIII.Moreover,cluster IV with superior genotypes(G-10,24607,24593 and 24566),VI(17426 and 24567),XIII(24570)and X(Arisoy and G-52)showed above mean values for most of the studied characters.Overall,the results of hybridization between the superior genotypes of these cluster pairs might be useful for soybean breeding with improving agronomic traits and adaptability.展开更多
Six rice cultivars viz. PR120, PR116, Feng Ai Zan, PR115, PAU201 and Punjab Mehak 1 under the direct-seeded and transplanted conditions were used to investigate the involvement of antioxidative defence system in relat...Six rice cultivars viz. PR120, PR116, Feng Ai Zan, PR115, PAU201 and Punjab Mehak 1 under the direct-seeded and transplanted conditions were used to investigate the involvement of antioxidative defence system in relation to polyamine catabolism in temporal regulation of developing grains. Activities of ascorbate peroxidase(APx), guaiacol peroxidase(GPx), catalase(CAT), superoxide dismutase(SOD), polyamine oxidases(PAO) and contents of ascorbate, α-tocopherol, proline and polyamines increased gradually until mid-milky stage and then declined towards maturity stage under both planting conditions. The transplanted condition led to higher activities of antioxidative enzymes(APx, GPx and CAT) and contents of ascorbate, α-tocopherol and proline whereas the direct-seeded condition had elevated levels of PAO and SOD activities and contents of polyamines, lipid peroxide and hydrogen peroxide. Cultivars Feng Ai Zan and PR120 exhibited superior tolerance over other cultivars by accumulating higher contents of ascorbate, α-tocopherol and proline with increasing level of PAO and SOD activities under the direct-seeded condition. However, under the transplanted condition PR116 and PAU201 showed higher activities of antioxidative enzymes with decreasing content of lipid peroxide. Therefore, we concluded that under the direct-seeded condition, enhancements of polyamines content and PAO activity enabled rice cultivars more tolerant to oxidative stress, while under the transplanted condition, antioxidative defence with decreasing of lipid peroxide content was closely associated with the protection of grains by maintaining membrane integrity during rice grain filling. The results indicated that temporal dynamics of H2O2 metabolic machinery was strongly up-regulated especially at the mid-milky stage.展开更多
Acorn squash(Cucurbita pepo)is an iconic fall vegetable in the United States,known for its unique fruit shape and also prized for its culinary properties.Little is known about the metabolism that underlies the develop...Acorn squash(Cucurbita pepo)is an iconic fall vegetable in the United States,known for its unique fruit shape and also prized for its culinary properties.Little is known about the metabolism that underlies the development of fruit quality attributes such as color,sweetness,texture and nutritional qualities in acorn squash,or any other winter squash grown worldwide.To provide insight into winter squash fruit and seed development and add to the genomic resources in the Cucurbita genus,RNA sequencing was used to generate an acorn squash fruit and seed transcriptome from the cultivar Sweet REBA at critical points throughout fruit development.141838600 high-quality paired-end Illumina reads were assembled into 55949 unigenes.85%of unigenes with predicted open reading frames had homology with previously identified genes and over 62%could be functionally annotated.Comparison with the watermelon and cucumber genomes provided confirmation that the unigenes are full-length and comprehensive,covering an average of 90%of the coding sequence of their homologs and 72%of the cucumber and watermelon exomes.Key candidate genes associated with carotenoid and carbohydrate metabolism were identified toward a resource for winter squash fruit quality trait dissection.This transcriptome represents a major advance in C.pepo genomics,providing significant new sequence information and revealing the repertoire of genes expressed throughout winter squash fruit and seed development.Future studies on the genetic basis of fruit quality and future breeding efforts will be enhanced by tools and insights developed from this resource.展开更多
Malnutrition is one of the prevailing health problems worldwide, affecting a large proportion of the populations in rice-consuming countries. Breeding rice varieties with increased concentrations of elements in the gr...Malnutrition is one of the prevailing health problems worldwide, affecting a large proportion of the populations in rice-consuming countries. Breeding rice varieties with increased concentrations of elements in the grain is considered the most cost-effective approach to alleviate malnutrition. Development of molecular markers for high grain concentrations of essential elements, particularly Zn, for use in marker-assisted selection (MAS) can hasten breeding efforts to develop rice varieties with nutrient-dense grain. We performed QTL mapping for four agronomic traits: days to 50% flowering, plant height, number of tillers, grain yield, and 13 grain elements: As, B, Ca, Co, Cu, Fe, K, Mg, Mn, Mo, Na, P, and Zn, in two doubled-haploid populations derived from the crosses IR64 × IR69428 and BR29 × IR75862. These populations were phenotyped during 2015DS and 2015WS at IRRI, Los Ba os, The Philippines, and genotyped them with a 6 K SNP chip. Inclusive composite interval mapping revealed 15 QTL for agronomic traits and 50 QTL for grain element concentration. Of these, eight QTL showed phenotypic variance of >25% and 11 QTL were consistent across seasons. There were seven QTL co-localization regions containing QTL for more than two traits. Twenty five epistatic interactions were detected for two agronomic traits and seven mineral elements. Several DH lines with high Fe and Zn in polished rice were identified. These lines can be used as donors for breeding high-Zn rice varieties. Some of the major QTL can be further validated and used in MAS to improve the concentrations of nutritive elements in rice grain.展开更多
Deposition of protein and metal ions (Fe, Zn) in rice grains is a complex polygenic trait showing considerable environmental effect. To analyze the effect of nitrogen application levels and native soil properties on r...Deposition of protein and metal ions (Fe, Zn) in rice grains is a complex polygenic trait showing considerable environmental effect. To analyze the effect of nitrogen application levels and native soil properties on rice grain protein, iron (Fe) and zinc (Zn) contents, 32 rice genotypes were grown at three different locations each under 80 and 120 kg/hm2 nitrogen fertilizer applications. In treatments with nitrogen fertilizer application, the brown rice grain protein content (GPC) increased significantly (1.1% to 7.0%) under higher nitrogen fertilizer application (120 kg/hm2) whereas grain Fe/Zn contents showed non-significant effect of nitrogen application level, thus suggesting that the rate of uptake and translocation of macro-elements does not influence the uptake and translocation of micro-elements. The pH, organic matter content and inherent Fe/Zn levels of native soil showed significant effects on grain Fe and Zn contents of all the rice genotypes. Grain Zn content of almost all the tested rice genotypes was found to increase at Location III having loamy soil texture, neutral pH value (pH 6.83) and higher organic matter content than the other two locations (Locations I and II), indicating significant influence of native soil properties on brown rice grain Zn content while grain Fe content showed significant genotype × environment interaction effect. Genotypic difference was found to be the most significant factor to affect grain Fe/Zn contents in all the tested rice genotypes, indicating that although native soil properties influence phyto-availability of micronutrients and consequently influencing absorption, translocation and grain deposition of Fe/Zn ions, yet genetic makeup of a plant determines its response to varied soil conditions and other external factors. Two indica rice genotypes R-RF-31 (27.62 μg/g grain Zn content and 7.80% GPC) and R1033-968-2-1 (30.05 μg/g grain Zn content and 8.47% GPC) were identified as high grain Zn and moderate GPC rice genotypes. These results indicate that soil property and organic matter content increase the availability of Fe and Zn in rhizosphere, which in turn enhances the uptake, translocation and redistribution of Fe/Zn into rice grains.展开更多
Rice is an important crop and the food security of the world is strongly associated with it as it is the staple food of half of the world’s population. Among various agro-management practices seedling age and nitroge...Rice is an important crop and the food security of the world is strongly associated with it as it is the staple food of half of the world’s population. Among various agro-management practices seedling age and nitrogen rates significantly affected its growth, development and yield components. Rice cultivars performed differently when transplanted in field at varying seedling ages depending upon their genetic makeup and adoptability to certain environmental conditions. Seedling age plays an important role in yield contributing parameters like number of productive tillers, panicle length, filled grains panicle-1 and 1000-kernel weight leading to higher paddy yield in different rice cultivars and hybrids. Nitrogen is required in huge quantity in rice production as it is an important constituent of plant parts and processes. Paddy yield increases significantly with the increase in nitrogen rate but after a certain limit yield starts decreasing. Keeping in view the significance of seedling age and nitrogen rates in different rice cultivars and hybrids, an effort has been made to review some research work already conducted and will be helpful to the researchers and scientists to plan future strategies.展开更多
Intensively farmed crops used to experience numerous environmental stresses.Among these,shade and drought significantly influence the morpho-physiological and biochemical attributes of plants.However,the interactive e...Intensively farmed crops used to experience numerous environmental stresses.Among these,shade and drought significantly influence the morpho-physiological and biochemical attributes of plants.However,the interactive effect of shade and drought on the growth and development of soybean under dense cropping systems has not been reported yet.This study investigated the interactive effect of PEG-induced osmotic stress and shade on soybean seedlings.The soybean cultivar viz.,C-103 was subjected to PEG-induced osmotic stress from polyethylene glycol 6000(PEG-6000)under shading and non-shading conditions.PEG-induced osmotic stress significantly reduced the relative water contents,morphological parameters,carbohydrates and chlorophyll contents under both light environments.A significant increase was observed in osmoprotectants,reactive oxygen species and antioxidant enzymes in soybean seedlings.Henceforth,the findings revealed that,seedlings grown under non-shading conditions produced more malondialdehyde and hydrogen peroxide contents as compared to the shade-treated plants when subjected to PEG-induced osmotic stress.Likewise,the shaded plants accumulated more sugars and proline than non-shaded ones under drought stress.Moreover,it was found that nonshaded grown plants were more sensitive to PEG-induced osmotic stress than those exposed to shading conditions,which suggested that shade could boost the protective mechanisms against osmotic stress or at least would not exaggerate the adverse effects of PEG-induced osmotic stress in soybean seedlings.展开更多
Present study was conducted to characterise ten rice(Oryza sativa L.) cultivars viz. IET-23466, Dhan-201, IET-23448, MAS-946, IET-23445, IET-23463, IET-23455, PR-123, PR-115 and IET-23449 based on antioxidants(total p...Present study was conducted to characterise ten rice(Oryza sativa L.) cultivars viz. IET-23466, Dhan-201, IET-23448, MAS-946, IET-23445, IET-23463, IET-23455, PR-123, PR-115 and IET-23449 based on antioxidants(total phenolics, flavonols and tannins), bioactive compounds(phytic acid, gamma amino butyric acid, tocopherol and reduced ascorbate) and antioxidant activity(1,1-diphenyl-2-picrylhydrazyl radical scavenging activity, hydroxyl radical scavenging activity, free radical antioxidant power and total reducing power) with an aim to identify cultivars containing higher health promoting components after germination. Three cultivars IET-23466, IET-23463 and PR-123 performed better as revealed by higher level of antioxidants, bioactive compounds and antioxidant activity before and after germination. Three cultivars MAS-946, IET-23445 and IET-23449 had moderate level of antioxidants, bioactive compounds and antioxidant activity. Four cultivars Dhan-201, IET-23448, IET-23455 and PR-115 performed intermediately. Strong positive correlation was observed among total phenolics and the antioxidant activity. Phytic acid was found to be negatively correlated to the antioxidant activity. Our results highlighted that cultivars IET-23466, IET-23463 and PR-123 hold great potential after germination and would open up a useful opportunity for the functional food industry, and consumption of these cultivars after germination would afford health benefits to consumers since they contain higher level of antioxidants.展开更多
Genetic diversity is the base of any genetic improvement breeding program aimed at stress breeding.The variability among breeding materials is of primary importance in the achievements of a good crop production.Herein...Genetic diversity is the base of any genetic improvement breeding program aimed at stress breeding.The variability among breeding materials is of primary importance in the achievements of a good crop production.Herein,105 wheat genotypes were screened against drought stress using factorial completely randomized design at seedling stage to determine the genetic diversity and traits association conferring drought tolerance.Analysis of variances revealed that all the studied parameters differed significantly among all genotypes,indicating the significance genetic variability existed among all genotypes for studied indices.The 10 best performance genotypes G1,G6,G11,G16,G21,G26,G39,G44,G51,and G61 were screened as drought tolerant,while five lowest performance genotypes G3,G77,G91,G98,and G105 were screened as drought susceptible.Root length,chlorophyll a,chlorophyll b,and carotenoid contents were significantly correlated among themselves which exhibited the importance of these indices for rainfed areas in future wheat breeding scheme.Shoot length exhibited non-significant and negative association with other studied traits,and its selection seems not to be a promising criteria for this germplasm for drought stress.Best performance genotypes under drought stress conditions will be useful in future wheat breeding program and early selection will be effective for developing high yielding and drought tolerant wheat varieties.展开更多
A field study was undertaken to ascertain the effects of elicitors viz.benzothiadiazole(BTH)and salicylic acid(SA)on defense related enzymes viz.peroxidase,phenylalanine ammonia lyase,superoxide dismutase,chitinase an...A field study was undertaken to ascertain the effects of elicitors viz.benzothiadiazole(BTH)and salicylic acid(SA)on defense related enzymes viz.peroxidase,phenylalanine ammonia lyase,superoxide dismutase,chitinase andβ-1,3-glucanase,and phenols in rice(Pusa Basmati I)plants.First foliar spray of BTH(50 mg/kg)and SA(50 mg/kg)was done at the maximum tillering stage and inoculation with Rhizoctonia solani was carried 24 h after elicitor treatment.Elicitors were further sprayed at every growth stage.Time course analysis showed peak accumulation of defense related enzymes and phenols in the rice leaves treated with BTH and SA,and accumulation was the highest at the flowering stage.Higher enzymatic activity was observed in elicitor treated plants inoculated with R.solani.Compared to the untreated control plants,application of elicitors before R.solani inoculation significantly elicited the defense related enzymes and phenols.Moreover,application of elicitors had a positive effect on yield and disease reduction.It is suggested that pretreatment of rice leaves with BTH and SA could be used to enhance the level of protection against sheath blight and to improve rice yield in the fields.展开更多
Oxidative stress occurs when crop plants are exposed to extreme abiotic conditions that lead to the excessive production and accumulation of reactive oxygen species(ROS).Those extreme abiotic conditions or stresses in...Oxidative stress occurs when crop plants are exposed to extreme abiotic conditions that lead to the excessive production and accumulation of reactive oxygen species(ROS).Those extreme abiotic conditions or stresses include drought,high temperature,heavy metals,salinity,and ultraviolet radiation,and they cause yield and quality losses in crops.ROS are highly reactive species found in nature that can attack plant organelles,metabolites,and molecules by interrupting various metabolic pathways until cell death occurs.Plants have evolved defense mechanisms for the production of antioxidants to detoxify the ROS and to protect the plant against oxidative damage.Modern researches in crop plants revealed that low levels of ROS act as a signal which induces tolerance to environmental extremes by altering the expression of defensive genes.In this review,we summarized the processes involved in ROS production in response to several types of abiotic stress in cotton plants.Furthermore,we discussed the achievements in the understanding and improving oxidative stress tolerance in cotton in recent years.Researches related to plant oxidative stresses have shown excellent potential for the development of stress-tolerant crops.展开更多
Grapes are one of the most economically and culturally important crops worldwide,and they have been bred for both winemaking and fresh consumption.Here we evaluate patterns of diversity across 33 phenotypes collected ...Grapes are one of the most economically and culturally important crops worldwide,and they have been bred for both winemaking and fresh consumption.Here we evaluate patterns of diversity across 33 phenotypes collected over a 17-year period from 580 table and wine grape accessions that belong to one of the world’s largest grape gene banks,the grape germplasm collection of the United States Department of Agriculture.We find that phenological events throughout the growing season are correlated,and quantify the marked difference in size between table and wine grapes.By pairing publicly available historical phenotype data with genome-wide polymorphism data,we identify large effect loci controlling traits that have been targeted during domestication and breeding,including hermaphroditism,lighter skin pigmentation and muscat aroma.Breeding for larger berries in table grapes was traditionally concentrated in geographic regions where Islam predominates and alcohol was prohibited,whereas wine grapes retained the ancestral smaller size that is more desirable for winemaking in predominantly Christian regions.We uncover a novel locus with a suggestive association with berry size that harbors a signature of positive selection for larger berries.Our results suggest that religious rules concerning alcohol consumption have had a marked impact on patterns of phenomic and genomic diversity in grapes.展开更多
基金Centre for Advance Studies in Agricultural Food Security and Punjab Agricultural Research Board for providing funds under CAS-PARB project(No.964).
文摘Background Cotton is a strategically important fibre crop for global textile industry.It profoundly impacts several countries’industrial and agricultural sectors.Sustainable cotton production is continuously threatened by the unpre-dictable changes in climate,specifically high temperatures.Breeding heat-tolerant,high-yielding cotton cultivars with wide adaptability to be grown in the regions with rising temperatures is one of the primary objectives of modern cotton breeding programmes.Therefore,the main objective of the current study is to figure out the effective breed-ing approach to imparting heat tolerance as well as the judicious utilization of commercially significant and stress-tolerant attributes in cotton breeding.Initially,the two most notable heat-susceptible(FH-115 and NIAB Kiran)and tolerant(IUB-13 and GH-Mubarak)cotton cultivars were spotted to develop filial and backcross populations to accom-plish the preceding study objectives.The heat tolerant cultivars were screened on the basis of various morphological(seed cotton yield per plant,ginning turnout percentage),physiological(pollen viability,cell membrane thermostabil-ity)and biochemical(peroxidase activity,proline content,hydrogen peroxide content)parameters.Results The results clearly exhibited that heat stress consequently had a detrimental impact on every studied plant trait,as revealed by the ability of crossing and their backcross populations to tolerate high temperatures.However,when considering overall yield,biochemical,and physiological traits,the IUB-13×FH-115 cross went over particularly well at both normal and high temperature conditions.Moreover,overall seed cotton yield per plant exhibited a posi-tive correlation with both pollen viability and antioxidant levels(POD activity and proline content).Conclusions Selection from segregation population and criteria involving pollen viability and antioxidant levels concluded to be an effective strategy for the screening of heat-tolerant cotton germplasms.Therefore,understanding acquired from this study can assist breeders identifying traits that should be prioritized in order to develop climate resilient cotton cultivars.
文摘Background SRO(Similar to RCD1)genes family is largely recognized for their importance in the growth,develop-ment,and in responding to environmental stresses.However,genome-wide identification and functional characteri-zation of SRO genes from cotton species have not been reported so far.Results A total of 36 SRO genes were identified from four cotton species.Phylogenetic analysis divided these genes into three groups with distinct structure.Syntenic and chromosomal distribution analysis indicated uneven distribu-tion of GaSRO,GrSRO,GhSRO,and GbSRO genes on A2,D5 genomes,Gh-At,Gh-Dt,Gb-At,and Gb-Dt subgenomes,respectively.Gene duplication analysis revealed the presence of six duplicated gene pairs among GhSRO genes.In promoter analysis,several elements responsive to the growth,development and hormones were found in GhSRO genes,implying gene induction during cotton growth and development.Several miRNAs responsive to plant growth and abiotic stress were predicted to target 12 GhSRO genes.Organ-specific expression profiling demonstrated the roles of GhSRO genes in one or more tissues.In addition,specific expression pattern of some GhSRO genes dur-ing ovule development depicted their involvement in these developmental processes.Conclusion The data presented in this report laid a foundation for understanding the classification and functions of SRO genes in cotton.
基金Higher Education Commission of Pakistan for funding the experiments
文摘Background High temperature stress at peak flowering stage of cotton is a major hindrance for crop potential.This study aimed to increase genetic divergence regarding heat tolerance in newly developed cultivars and hybrids.Fifty cotton genotypes and 40 F1(hybrids)were tested under field conditions following the treatments,viz.,high temperature stress and control at peak flowering stage in August and October under April and June sowing,respectively.Results The mean squares revealed significant differences among genotypes,treatments,genotype×treatment for relative cell injury,chlorophyll contents,canopy temperature,boll retention and seed cotton yield per plant.The genetic diversity among 50 genotypes was analyzed through cluster analysis and heat susceptibility index(HSI).The heat tolerant genotypes including FH-Noor,NIAB-545,FH-466,FH-Lalazar,FH-458,NIAB-878,IR-NIBGE-8,Weal-AGShahkar,and heat sensitive,i.e.,CIM-602,Silky-3,FH-326,SLH-12 and FH-442 were hybridized in line×tester fashion to produce F1 populations.The breeding materials’populations(40 F1)revealed higher specific combining ability variances along with dominance variances,decided the non-additive type gene action for all the traits.The best general combining ability effects for most of the traits were displayed by the lines,i.e.,FH-Lalazar,NIAB-878 along with testers FH-326 and Silky-3.Specific combining ability effects and better-parent heterosis were showed by the crosses,viz.,FH-Lalazar×Silky-3,FH-Lalazar×FH-326,NIAB-878×Silky-3,and NIAB-878×FH-326 for seed cotton yield and yield contributing traits under high temperature stress.Conclusion Heterosis breeding should be carried out in the presence of non-additive type gene action for all the studied traits.The best combiner parents with better-parent heterosis may be used in crossing program to develop high yielding cultivars,and hybrids for high temperature stress tolerance.
文摘Nine genotypes were evaluated under greenhouse conditions for antixenosis and tolerance against brown planthopper(BPH, Nilaparvata lugens St?l). In antixenosis studies, proportion of insects settled on a test genotype in relation to the susceptible control TN1 was recorded, with significantly lower proportion of nymphs(55.22%–59.18%), adult males(60.33%–60.75%), and adult females(80.56%–79.26%) settled on RP2068-18-3-5 and Ptb33 in relation to those on TN1. Based on number of feeding sites, the test genotypes were ranked in order from the highest to the lowest as RP2068-18-3-5, Ptb33, MR1523, Rathu Heenati, Sinnasivappu, ARC10550, MO1, INRC3021 and TN1. The order was exactly reverse in terms of fecundity expressed as number of eggs laid per female. In tolerance studies, days to wilt, functional plant loss index and plant dry weight loss to BPH dry weight produced were recorded. RP2068-18-3-5, Rathu Heenati and Ptb33 performed better than the other test genotypes. These results helped in relative quantification of BPH resistance levels in the genotypes. RP2068-18-3-5, a new effective source of BPH resistance, can be used in resistance breeding after tagging of resistant genes/QTLs linked to different parameters of antixenosis and tolerance with selectable molecular markers.
文摘Despite the longstanding importance of silage as a critical feed source for ruminants,its quality improvement has been largely overlooked.Although numerous quantitative trait loci(QTL)and genes affecting silage quality in maize have been reported,only a few have been effectively incorporated into breeding programs.Addressing this gap,the present study undertook a comprehensive meta-QTL(MQTL)analysis involving 523 QTL associated with silage-quality traits collected from 14 published studies.Of the 523 QTL,405 were projected onto a consensus map comprising 62,424 genetic markers,resulting in the identification of 60 MQTL and eight singletons.The average confidence interval(CI)of the MQTL was 3.9-fold smaller than that of the source QTL.Nine of the 60 identified MQTL were classified as breeder’s MQTL owing to their small CIs,involvement of more QTL,and large contribution to phenotypic variation.One-third of the MQTL co-localized with DNA marker-trait associations identified in previous genomewide association mapping studies.A set of 78 high-confidence candidate genes influencing silage quality were identified in the MQTL regions.These genes and associated markers may advance marker-assisted breeding for maize silage quality.
文摘Rice root-knot nematode(RRKN,Meloidogyne graminicola)and brown spot(BS,Drechslera oryzae)are serious constraints on the quality of rice grains,particularly under direct-seeded rice conditions in many parts of the world.Developing rice varieties resistant to RRKN and BS will be the most effective and environmentally friendly management strategy.A total of 93 and 58 Oryza rufipogon accessions were screened against RRKN and BS,respectively,for two years under artificial inoculation conditions.Among the 93 O.rufipogon accessions。
文摘Background Boron(B)deficiency is an important factor for poor seed cotton yield and fiber quality.However,it is often missing in the plant nutrition program,particularly in developing countries.The current study investigated B’s effect on growth,yield,and fiber quality of Bt(CIM-663)and non-Bt(Cyto-124)cotton cultivars.The experimental plan consisted of twelve treatments:Control(CK);B at 1 mg·kg^(−1) soil application(SB1);2 mg·kg^(−1) B(SB2);3 mg·kg^(−1) B(SB3);0.2%B foliar spray(FB1);0.4%B foliar spray(FB2);1 mg·kg^(−1) B+0.2%B foliar spray(SB1+FB1);1 mg·kg^(−1) B+0.4%B foliar spray(SB1+FB2);2 mg·kg^(−1) B+0.2%B foliar spray(SB2+FB1);2 mg·kg^(−1) B+0.4%B foliar spray(SB2+FB2);3 mg·kg^(−1) B+0.2%B foliar spray(SB3+FB1);3 mg·kg^(−1) B+0.4%B foliar spray(SB3+FB2).Each treat-ment has three replications,one pot having two plants per replication.Results B nutrition at all levels and methods of application significantly(P≤0.05)affected the growth,physiological,yield,and fiber quality characteristics of both cotton cultivars.However,SB2 either alone or in combination with foliar spray showed superiority over others,particularly in the non-Bt cultivar which responded better to B nutrition.Maxi-mum improvement in monopodial branches(345%),sympodial branches(143%),chlorophyll-a(177%),chlorophyll-b(194%),photosynthesis(169%),and ginning out turn(579%)in the non-Bt cultivar was found with SB2 compared with CK.In Bt cultivar,although no consistent trend was found but integrated use of SB3 with foliar spray performed relatively better for improving cotton growth compared with other treatments.Fiber quality characteristics in both cultivars were improved markedly but variably with different B treatments.Conclusion B nutrition with SB2 either alone or in combination with foliar spray was found optimum for improving cotton’s growth and yield characteristics.
基金The authors extend their appreciation to Researchers Supporting Project No.(RSP2023R298),King Saud University,Riyadh,Saudi Arabia.
文摘The availability of favorable genetic diversity is a thriving vitality for the success of a breeding program.It provides a firm basis of selecting superior breeding lines for the development of high yielding crop genotypes.In this context,present investigation aimed to generate information on genetic divergence and character association in a diversity panel of 123 local and exotic soybean genotypes.Analysis of variance revealed significant response of the evaluated genotypes based on studied attributes.It depicted the probability of selecting desirable soybean genotypes by focusing on character association studies and genetic diversity analysis.Correlation analysis revealed that seed yield per plant showed high positive correlation with 100-seed weight followed by pods per plant and plant height.Furthermore,path coefficient analysis exposed that pods per plant had maximum direct contribution in seed yield per plant followed by 100-seed weight,days to flowering and SPAD measurement.Genotype named“G-10”showed maximum yield per plant followed by 24607,G-52,24593,Arisoy,24566,17426,A-3127,24570 and 24567.Genetic diversity analysis grouped the evaluated germplasm into 17 clusters.All clusters showed zero intra-cluster variability;while inter-cluster divergence ranged from 9.00 to 91.11.Cluster V showed maximum inter-cluster distance with cluster XII followed by that of between V and VIII.Moreover,cluster IV with superior genotypes(G-10,24607,24593 and 24566),VI(17426 and 24567),XIII(24570)and X(Arisoy and G-52)showed above mean values for most of the studied characters.Overall,the results of hybridization between the superior genotypes of these cluster pairs might be useful for soybean breeding with improving agronomic traits and adaptability.
文摘Six rice cultivars viz. PR120, PR116, Feng Ai Zan, PR115, PAU201 and Punjab Mehak 1 under the direct-seeded and transplanted conditions were used to investigate the involvement of antioxidative defence system in relation to polyamine catabolism in temporal regulation of developing grains. Activities of ascorbate peroxidase(APx), guaiacol peroxidase(GPx), catalase(CAT), superoxide dismutase(SOD), polyamine oxidases(PAO) and contents of ascorbate, α-tocopherol, proline and polyamines increased gradually until mid-milky stage and then declined towards maturity stage under both planting conditions. The transplanted condition led to higher activities of antioxidative enzymes(APx, GPx and CAT) and contents of ascorbate, α-tocopherol and proline whereas the direct-seeded condition had elevated levels of PAO and SOD activities and contents of polyamines, lipid peroxide and hydrogen peroxide. Cultivars Feng Ai Zan and PR120 exhibited superior tolerance over other cultivars by accumulating higher contents of ascorbate, α-tocopherol and proline with increasing level of PAO and SOD activities under the direct-seeded condition. However, under the transplanted condition PR116 and PAU201 showed higher activities of antioxidative enzymes with decreasing content of lipid peroxide. Therefore, we concluded that under the direct-seeded condition, enhancements of polyamines content and PAO activity enabled rice cultivars more tolerant to oxidative stress, while under the transplanted condition, antioxidative defence with decreasing of lipid peroxide content was closely associated with the protection of grains by maintaining membrane integrity during rice grain filling. The results indicated that temporal dynamics of H2O2 metabolic machinery was strongly up-regulated especially at the mid-milky stage.
基金This research was supported through funds from Cornell University and the Vegetable Breeding InstituteSupport for Lindsay Wyatt was provided by a Cornell University Presidential Life Sciences Fellowship,USDA National Needs Graduate Fellowship Competitive Grant No.2008-38420-04755 from the National Institute of Food and Agriculturethe Agriculture and Food Research Initiative Competitive Grant No.2013-67011-21122 from the USDA National Institute of Food and Agriculture.
文摘Acorn squash(Cucurbita pepo)is an iconic fall vegetable in the United States,known for its unique fruit shape and also prized for its culinary properties.Little is known about the metabolism that underlies the development of fruit quality attributes such as color,sweetness,texture and nutritional qualities in acorn squash,or any other winter squash grown worldwide.To provide insight into winter squash fruit and seed development and add to the genomic resources in the Cucurbita genus,RNA sequencing was used to generate an acorn squash fruit and seed transcriptome from the cultivar Sweet REBA at critical points throughout fruit development.141838600 high-quality paired-end Illumina reads were assembled into 55949 unigenes.85%of unigenes with predicted open reading frames had homology with previously identified genes and over 62%could be functionally annotated.Comparison with the watermelon and cucumber genomes provided confirmation that the unigenes are full-length and comprehensive,covering an average of 90%of the coding sequence of their homologs and 72%of the cucumber and watermelon exomes.Key candidate genes associated with carotenoid and carbohydrate metabolism were identified toward a resource for winter squash fruit quality trait dissection.This transcriptome represents a major advance in C.pepo genomics,providing significant new sequence information and revealing the repertoire of genes expressed throughout winter squash fruit and seed development.Future studies on the genetic basis of fruit quality and future breeding efforts will be enhanced by tools and insights developed from this resource.
基金HarvestPlus for funding development of high Zinc rice
文摘Malnutrition is one of the prevailing health problems worldwide, affecting a large proportion of the populations in rice-consuming countries. Breeding rice varieties with increased concentrations of elements in the grain is considered the most cost-effective approach to alleviate malnutrition. Development of molecular markers for high grain concentrations of essential elements, particularly Zn, for use in marker-assisted selection (MAS) can hasten breeding efforts to develop rice varieties with nutrient-dense grain. We performed QTL mapping for four agronomic traits: days to 50% flowering, plant height, number of tillers, grain yield, and 13 grain elements: As, B, Ca, Co, Cu, Fe, K, Mg, Mn, Mo, Na, P, and Zn, in two doubled-haploid populations derived from the crosses IR64 × IR69428 and BR29 × IR75862. These populations were phenotyped during 2015DS and 2015WS at IRRI, Los Ba os, The Philippines, and genotyped them with a 6 K SNP chip. Inclusive composite interval mapping revealed 15 QTL for agronomic traits and 50 QTL for grain element concentration. Of these, eight QTL showed phenotypic variance of >25% and 11 QTL were consistent across seasons. There were seven QTL co-localization regions containing QTL for more than two traits. Twenty five epistatic interactions were detected for two agronomic traits and seven mineral elements. Several DH lines with high Fe and Zn in polished rice were identified. These lines can be used as donors for breeding high-Zn rice varieties. Some of the major QTL can be further validated and used in MAS to improve the concentrations of nutritive elements in rice grain.
文摘Deposition of protein and metal ions (Fe, Zn) in rice grains is a complex polygenic trait showing considerable environmental effect. To analyze the effect of nitrogen application levels and native soil properties on rice grain protein, iron (Fe) and zinc (Zn) contents, 32 rice genotypes were grown at three different locations each under 80 and 120 kg/hm2 nitrogen fertilizer applications. In treatments with nitrogen fertilizer application, the brown rice grain protein content (GPC) increased significantly (1.1% to 7.0%) under higher nitrogen fertilizer application (120 kg/hm2) whereas grain Fe/Zn contents showed non-significant effect of nitrogen application level, thus suggesting that the rate of uptake and translocation of macro-elements does not influence the uptake and translocation of micro-elements. The pH, organic matter content and inherent Fe/Zn levels of native soil showed significant effects on grain Fe and Zn contents of all the rice genotypes. Grain Zn content of almost all the tested rice genotypes was found to increase at Location III having loamy soil texture, neutral pH value (pH 6.83) and higher organic matter content than the other two locations (Locations I and II), indicating significant influence of native soil properties on brown rice grain Zn content while grain Fe content showed significant genotype × environment interaction effect. Genotypic difference was found to be the most significant factor to affect grain Fe/Zn contents in all the tested rice genotypes, indicating that although native soil properties influence phyto-availability of micronutrients and consequently influencing absorption, translocation and grain deposition of Fe/Zn ions, yet genetic makeup of a plant determines its response to varied soil conditions and other external factors. Two indica rice genotypes R-RF-31 (27.62 μg/g grain Zn content and 7.80% GPC) and R1033-968-2-1 (30.05 μg/g grain Zn content and 8.47% GPC) were identified as high grain Zn and moderate GPC rice genotypes. These results indicate that soil property and organic matter content increase the availability of Fe and Zn in rhizosphere, which in turn enhances the uptake, translocation and redistribution of Fe/Zn into rice grains.
文摘Rice is an important crop and the food security of the world is strongly associated with it as it is the staple food of half of the world’s population. Among various agro-management practices seedling age and nitrogen rates significantly affected its growth, development and yield components. Rice cultivars performed differently when transplanted in field at varying seedling ages depending upon their genetic makeup and adoptability to certain environmental conditions. Seedling age plays an important role in yield contributing parameters like number of productive tillers, panicle length, filled grains panicle-1 and 1000-kernel weight leading to higher paddy yield in different rice cultivars and hybrids. Nitrogen is required in huge quantity in rice production as it is an important constituent of plant parts and processes. Paddy yield increases significantly with the increase in nitrogen rate but after a certain limit yield starts decreasing. Keeping in view the significance of seedling age and nitrogen rates in different rice cultivars and hybrids, an effort has been made to review some research work already conducted and will be helpful to the researchers and scientists to plan future strategies.
基金supported by the National Natural Science Foundation of China(31871552 and 31671445)the Sichuan Science and Technology Program,China(2018HH0108)the Sichuan Innovation Team Project of National Modern Agricultural Industry Technology System,China(sccxtd-2020-20)。
文摘Intensively farmed crops used to experience numerous environmental stresses.Among these,shade and drought significantly influence the morpho-physiological and biochemical attributes of plants.However,the interactive effect of shade and drought on the growth and development of soybean under dense cropping systems has not been reported yet.This study investigated the interactive effect of PEG-induced osmotic stress and shade on soybean seedlings.The soybean cultivar viz.,C-103 was subjected to PEG-induced osmotic stress from polyethylene glycol 6000(PEG-6000)under shading and non-shading conditions.PEG-induced osmotic stress significantly reduced the relative water contents,morphological parameters,carbohydrates and chlorophyll contents under both light environments.A significant increase was observed in osmoprotectants,reactive oxygen species and antioxidant enzymes in soybean seedlings.Henceforth,the findings revealed that,seedlings grown under non-shading conditions produced more malondialdehyde and hydrogen peroxide contents as compared to the shade-treated plants when subjected to PEG-induced osmotic stress.Likewise,the shaded plants accumulated more sugars and proline than non-shaded ones under drought stress.Moreover,it was found that nonshaded grown plants were more sensitive to PEG-induced osmotic stress than those exposed to shading conditions,which suggested that shade could boost the protective mechanisms against osmotic stress or at least would not exaggerate the adverse effects of PEG-induced osmotic stress in soybean seedlings.
文摘Present study was conducted to characterise ten rice(Oryza sativa L.) cultivars viz. IET-23466, Dhan-201, IET-23448, MAS-946, IET-23445, IET-23463, IET-23455, PR-123, PR-115 and IET-23449 based on antioxidants(total phenolics, flavonols and tannins), bioactive compounds(phytic acid, gamma amino butyric acid, tocopherol and reduced ascorbate) and antioxidant activity(1,1-diphenyl-2-picrylhydrazyl radical scavenging activity, hydroxyl radical scavenging activity, free radical antioxidant power and total reducing power) with an aim to identify cultivars containing higher health promoting components after germination. Three cultivars IET-23466, IET-23463 and PR-123 performed better as revealed by higher level of antioxidants, bioactive compounds and antioxidant activity before and after germination. Three cultivars MAS-946, IET-23445 and IET-23449 had moderate level of antioxidants, bioactive compounds and antioxidant activity. Four cultivars Dhan-201, IET-23448, IET-23455 and PR-115 performed intermediately. Strong positive correlation was observed among total phenolics and the antioxidant activity. Phytic acid was found to be negatively correlated to the antioxidant activity. Our results highlighted that cultivars IET-23466, IET-23463 and PR-123 hold great potential after germination and would open up a useful opportunity for the functional food industry, and consumption of these cultivars after germination would afford health benefits to consumers since they contain higher level of antioxidants.
基金the National Key R&D Program of China (2018YFD0200500) for the financial support
文摘Genetic diversity is the base of any genetic improvement breeding program aimed at stress breeding.The variability among breeding materials is of primary importance in the achievements of a good crop production.Herein,105 wheat genotypes were screened against drought stress using factorial completely randomized design at seedling stage to determine the genetic diversity and traits association conferring drought tolerance.Analysis of variances revealed that all the studied parameters differed significantly among all genotypes,indicating the significance genetic variability existed among all genotypes for studied indices.The 10 best performance genotypes G1,G6,G11,G16,G21,G26,G39,G44,G51,and G61 were screened as drought tolerant,while five lowest performance genotypes G3,G77,G91,G98,and G105 were screened as drought susceptible.Root length,chlorophyll a,chlorophyll b,and carotenoid contents were significantly correlated among themselves which exhibited the importance of these indices for rainfed areas in future wheat breeding scheme.Shoot length exhibited non-significant and negative association with other studied traits,and its selection seems not to be a promising criteria for this germplasm for drought stress.Best performance genotypes under drought stress conditions will be useful in future wheat breeding program and early selection will be effective for developing high yielding and drought tolerant wheat varieties.
基金supported by the University Grants Commission Rajiv Gandhi National Fellowship(RGNF) of India
文摘A field study was undertaken to ascertain the effects of elicitors viz.benzothiadiazole(BTH)and salicylic acid(SA)on defense related enzymes viz.peroxidase,phenylalanine ammonia lyase,superoxide dismutase,chitinase andβ-1,3-glucanase,and phenols in rice(Pusa Basmati I)plants.First foliar spray of BTH(50 mg/kg)and SA(50 mg/kg)was done at the maximum tillering stage and inoculation with Rhizoctonia solani was carried 24 h after elicitor treatment.Elicitors were further sprayed at every growth stage.Time course analysis showed peak accumulation of defense related enzymes and phenols in the rice leaves treated with BTH and SA,and accumulation was the highest at the flowering stage.Higher enzymatic activity was observed in elicitor treated plants inoculated with R.solani.Compared to the untreated control plants,application of elicitors before R.solani inoculation significantly elicited the defense related enzymes and phenols.Moreover,application of elicitors had a positive effect on yield and disease reduction.It is suggested that pretreatment of rice leaves with BTH and SA could be used to enhance the level of protection against sheath blight and to improve rice yield in the fields.
文摘Oxidative stress occurs when crop plants are exposed to extreme abiotic conditions that lead to the excessive production and accumulation of reactive oxygen species(ROS).Those extreme abiotic conditions or stresses include drought,high temperature,heavy metals,salinity,and ultraviolet radiation,and they cause yield and quality losses in crops.ROS are highly reactive species found in nature that can attack plant organelles,metabolites,and molecules by interrupting various metabolic pathways until cell death occurs.Plants have evolved defense mechanisms for the production of antioxidants to detoxify the ROS and to protect the plant against oxidative damage.Modern researches in crop plants revealed that low levels of ROS act as a signal which induces tolerance to environmental extremes by altering the expression of defensive genes.In this review,we summarized the processes involved in ROS production in response to several types of abiotic stress in cotton plants.Furthermore,we discussed the achievements in the understanding and improving oxidative stress tolerance in cotton in recent years.Researches related to plant oxidative stresses have shown excellent potential for the development of stress-tolerant crops.
基金We acknowledge the funding from the Canada Research Chairs program,the National Sciences and Engineering Research Council of Canada and Genome CanadaZM was supported in part by a Killam Predoctoral Scholarship from Dalhousie University.
文摘Grapes are one of the most economically and culturally important crops worldwide,and they have been bred for both winemaking and fresh consumption.Here we evaluate patterns of diversity across 33 phenotypes collected over a 17-year period from 580 table and wine grape accessions that belong to one of the world’s largest grape gene banks,the grape germplasm collection of the United States Department of Agriculture.We find that phenological events throughout the growing season are correlated,and quantify the marked difference in size between table and wine grapes.By pairing publicly available historical phenotype data with genome-wide polymorphism data,we identify large effect loci controlling traits that have been targeted during domestication and breeding,including hermaphroditism,lighter skin pigmentation and muscat aroma.Breeding for larger berries in table grapes was traditionally concentrated in geographic regions where Islam predominates and alcohol was prohibited,whereas wine grapes retained the ancestral smaller size that is more desirable for winemaking in predominantly Christian regions.We uncover a novel locus with a suggestive association with berry size that harbors a signature of positive selection for larger berries.Our results suggest that religious rules concerning alcohol consumption have had a marked impact on patterns of phenomic and genomic diversity in grapes.
