Wheat production in the us great plains and world wide is greatly reduced by insufficient water. Apr 16, 20 the longterm goal is to discover the genes for drought and heat tolerance and use them in south dakota wheat improvement program to make our wheat ready for dry or hot years rohila explained. Aug 25, 2016 drought stress is one of the leading constraints to wheat triticum aestivum l. Drought tolerance traits tolerance to drought is a quantitative trait, with a complex phenotype, often confounded by plant phenology. Then, it aimed to select the best drought tolerance indices and identify the most suitable droughttolerant genotypes. In brief, the genomic dnas from the wild type and the tacrt1 overexpression arabidopsis plant were respectively. In winter wheat, the yield was decreased or changed under drought and,incontrast,thewaterusee ciencywasboosted. Droughttolerant wheat on the way successful farming. Drought tolerance is the ability to which a plant maintains its biomass production during arid or drought conditions.
Mar 10, 2017 improved drought tolerance in wheat plants overexpressing a synthetic bacterial cold shock protein gene secspa. Male and female farmers made many similar varietal choices, the most notable difference being for grain characteristics. Genetic and genomic tools to improve drought tolerance in wheat. Drought tolerance assay of transgenic pyrus ussuriensis plants. Drought tolerance studies in wheat 5 column of water that exists from the root hairs to the leaf mesophyll.
Crop management in drought cropwatch university of. Pdf drought is one of the most important phenomena which limit crops production and yield. Combining ability in tetraploid wheat for yield, yield attributing traits. Other plants, specifically crops like corn, wheat, and rice. The major physiological problem associated with yield losses in seed or grain crops where reproductive parts are economic yield of kansas under drought and heat stress is reproductive failure. Dissection of phenotypic and genetic variation of drought. Endowment fund secretariat, university of agriculture, faisalabad, pakistan corresponding authors email. We can all tell that a cactus is more drought tolerant than a carnation. Breeding for drought tolerance using novel genetic resources is an important mitigation strategy. Wheat, drought indices, physiological traits, grain yield. Raya 5 aschool of biosciences, university of nottingham, sutton bonington, loughborough, 6 leicestershire le12. The genome walking pcr was used to verify the tacrt1overexpression arabidopsis plant and was performed according to the procedures described by omalley et al. Plants vegetative and reproductive stages are intensively influenced by drought stress.
Effect of drought stress on the physiology and yield of. Expression of drought tolerance varies with the season. We can all tell that a cactus is more drought tolerant than a. These traits are recognized as beneficial drought tolerance indicators for selecting a stress tolerant variety. Extremely resistant and sensitive accessions were identified for future analyses. Khan department of plant breeding and genetics, university of agriculture, faisalabad, pakistan. In fact, that turns out to be about one in a million. This study aimed to determine the level of drought tolerance among diverse bread wheat genotypes using agronomic traits and proline analyses and to establish. A wrky transcription factor pbrwrky53 from pyrus betulaefolia. Molecular markers associated with quantitative trait loci qtl for drought adaptive traits could greatly enhance progress in breeding for drought tolerance. Drought responses of leaf tissues from wheat cultivars of. Crops demonstrate various morphological, physiological.
Effect of drought stress on the physiology and yield of the. All of these changes reduce plant growth and crop production. Drought tolerance is a nebulous term that becomes more nebulous the more closely we look at it, much as a newspaper photograph does when viewed through a magnifying glass. After combining, a total of 152 significant markers 168 mtas were used. The longterm goal is to discover the genes for drought and heat tolerance and use them in south dakota wheat improvement program to make our wheat ready for dry or hot years rohila explained. Qingwu xues drought tolerance study will produce more biomass and will have a higher yield under. Pdf drought, being a yieldlimiting factor, has become a major threat to international food security. Drought tolerance screening of wheat varieties by inducing. The complexity of the genetic basis of drought tolerance is due to polygenic inheritance, the small effect of qtl, and high ge, hence lowheritability. Crops demonstrate various morphological, physiological, biochemical, and molecular responses to tackle drought stress. Elsadek 2 1 agronomy department, college of agriculture, assiut university, assiut 71526, egypt. Several indices have been utilized to evaluate genotypes for drought tolerance based on grain yield such as mean. Selection for drought tolerance in bread wheat genotypes. Investigating physiological and morphological mechanisms.
Evaluation of soybean genotypes using drought stress. Droughttolerant varieties developed through biotechnology enable farmers to protect their harvest and minimize losses in times of severe drought by using water more efficiently. Improved drought tolerance in wheat plants overexpressing a synthetic bacterial cold shock protein gene secspa. In conclusion, this study showed that drought stress reduced the yield of some genotypes while others were tolerant to drought, suggesting genetic variability of drought tolerance in these materials. Quantitative trait loci for agronomic traits have not been reported for grain yield and yield components under drought stress in wheat. Terminal drought and seed priming improves drought tolerance in wheat. Drought is one of the most important phenomena which limit crops production and yield. As the worlds most widely dispersed food crop, wheat triticum spp. Genetic analysis of drought tolerance in selected bread wheat triticum aestivum l. Among cereal crops, wheat crop status is imperative. This is possible through identification and genome mapping of qtls involved in drought tolerance. This study aimed to determine whether tacrt1 over expression would increase drought tolerance in transgenic arabidopsis.
In our previous study, we showed that transgenic tobacco lines over expressing wheat tacrt1 showed enhanced tolerance to salt stress. At lincoln10 and sidney10 plots were combine harvested and gy and tw were. Evaluating physiological traits of drought and heat. Markers associated with a qtl for grain yield in wheat under. Combining information from the three research areas. Drought tolerance is a complicated trait which is controlled by polygenes and their. Six years of addressing african smallholder farmers needs.
Breeding strategies for drought tolerance in wheat authorstream. Pdf breeding for increased drought tolerance in wheat. Identified genetic variability in wild wheat germplasm aegilops species, and synthetic wheat in response to high temperature and drought stress and identified accessions that can be used in the breeding programs to improve high temperature and drought tolerance in wheat pradhan et al. A research programme for increasing drought tolerance of wheat should tackle the problem in a multidisciplinary approach, considering interaction between multiple stresses and plant phenology, and integrating the physiological dissection of drought tolerance traits and the genetic and genomics tools, such as quantitative trait loci qtl. There is diversity in the drought tolerance of commercial wheat cultivars. Other platforms are directed toward herbicide tolerance and biofuel production. Sorghum bicolor was domesticated in africa 3000 years ago barkworth, 2003. Peduncle length has been also suggested as useful indicator of yield capacity in dry environments. High yield, water efficiency of drought tolerant wheat due to. Edmeades, progress in achieving and delivering drought tolerance in maize an update, supported by key references, was originally. The resulting suboptimal plant water status is partly to blame for the grain losses, but secondary stresses, such as those caused by accumulation of highly destructive reactive oxygen species, likely also play a role.
Consequently, the scientists may have to find several different wheat lines that lack the different sal1 genes in order to reach their goal of improved drought tolerance in wheat. The major crops of kansas wheat, sorghum, corn and soybean experience water drought andor high temperature heat stress resulting in significant yield losses. Drought stress is one of the leading constraints to wheat triticum aestivum l. Therefore, breeders can select tolerant varieties of oat genotypes based on mp,gmp,sti and ham. Similarly, total grain yield per plant, biological yield per plant and harvest index was also higher in the same wheat variety, which put it as a good candidate for selection criteria in wheat breeding program for drought resistance. Wheat crt1 gene improves drought tolerance 21 the genome walking pcr. Genetic mapping of potential qtls associated with drought. Abiotic stresses such as dr ought, salt, heat, and cold are m ajor environmen tal factors that a ect plant gro wth and.
Therefore, there is a dire need to identify loci for the underlying genes involved in drought tolerance. This study aimed to determine the level of drought tolerance among diverse bread wheat genotypes using agronomic traits and proline analyses and to establish correlation of proline content and. Therefore, genotypes may be tested for their drought tolerance at relevant. The improvement of yield and drought stress tolerance in bread wheat. Launched in 2006, the drought tolerant maize for africa dtma project aims to mitigate drought and other constraints to maize production in subsaharan africa, increasing maize yields by at least one ton per hectare under moderate drought and with a 20 to 30%. The tacrt1 gene is a member of calreticulin crt family in wheat. Drought tolerance studies in wheat triticum aestivum l. Introduction of new indices to identify relative drought tolerance and resistance in wheat genotypes s. Pdf breeding for drought tolerance in wheat triticum.
High yield, water efficiency of drought tolerant wheat due. Progress in achieving and delivering drought tolerance in. Assessment of drought tolerance in oat avena sativa. Crop management in drought share tweet email this page includes archived cropwatch articles for managing crop production during drought conditions, including articles related to corn and sorghum, soybeans, sorghum, dry beans, forages, silage and wheat production. Ramshini4 abstract in order to study the effect of drought stress on morphophysiologic characteristics, yield and yield components of 8 new hybrids of corn zea maize l. Physiological responses include closure of stomata, decrease in the activity of photosynthesis, development of oxidative stress, alteration in the integrity of cell wall, production of metabolites which are toxic and cause plants death, signal recognition of roots, turgor loss and adjustment of osmosis, reduction in water. When those plants are resistant, they turn out to be droughtresistant. Markers associated with a qtl for grain yield in wheat. Evaluating physiological traits of drought and heat tolerance. Hons, crop science, university of zimbabwe, harare, zimbabwe a thesis submitted in fulfilment of the requirements for the degree of. Genetic evaluation of bread wheat for drought tolerance indices in the field and laboratory azadeh sheibanirad 1, ezatollah farshadfar 2 campus of agriculture and natural resources, razi university, kermanshah, iran article published on december 29, 2015 key words. A pvs programme was successfully implemented with male and female farmers, traders and consumers. Terminal drought and seed priming improves drought tolerance in. Drought has serious effects on the physiology of cereal crops.
Morphological derivations of drought tolerance in wheat. Selection methods and technologies for drought tolerance 3. Crop plants should not only have the ability to survive under drought but also the ability to produce a harvestable yield. At the cellular and specifically the metabolite level, many individual compounds are increased to provide osmoprotective functions, prevent the dissociation of enzymes, and to decrease the number of reactive oxygen species present in the cell. Wheat breeders and growers can use this information to assist in making decisions about cultivar.
Selection criteria for droughttolerant bread wheat. Screening of bread wheat genotypes for drought tolerance. Drought tolerance is defined as the ability of a plant to live, grow, and reproduce satisfactorily with limited water supply or under periodic conditions of water deficit turner, 1979. However, plant physiologists are generally more interested in plants that are able to. From the vantage point of an ecologist the features that distinguish xerophytic from mesophytic vegetation are clear. Regular article evaluation of drought tolerance indices for wheat triticum aestivum l. The genus triticum includes bread triticum aestivum and durum wheat triticum durum and constitutes a major source for human food consumption. Evaluation of drought tolerance indices for wheat triticum. Morphological adaptations to drought stress, such as leaf waxiness and trichome density, can decrease the amount of water. Murchiea, christian schlatterb, gina swartb 4 and rumiana v. Launched in 2006, the drought tolerant maize for africa dtma project aims to mitigate drought and other constraints to maize production in subsaharan africa, increasing maize yields by at least one ton per hectare under moderate drought and with a 20 to 30% increase over farmers. Some plants are naturally adapted to dry conditions, surviving with protection mechanisms such as desiccation tolerance, detoxification, or repair of xylem embolism.
Again it proved its potential for high yield and moisture stress tolerance. Revealing the genetic basis underlying the drought tolerance in wheat and barley requires a phenotypic and genetic variation of relevant traits in large populations with dense genetic maps. A series of experiments was performed in order to evaluate the significance of seed germination and seedling growth in osmotic media as screening methods for drought tolerance. Qingwu xues drought tolerance study will produce more biomass and will have a higher yield under drought conditions than the plot on the left. The crop raised from the seeds collected from terminal drought stressed plants had. The new durum is a product of the platform that specializes in wateruse efficiency and stress tolerance. Constraints and future prospects article pdf available in frontiers of agriculture in china 51. Genetically modified wheat showed high drought tolerance in field conditions keresa et al. The root length, root dry matter, roottoshoot length ratio and roottoshoot mass ratio of the three cultivars were significantly greater in the water stress than wellwatered conditions. Evaluation of drought tolerance in corn zea mays l. Yield components and drought resistance are controlled at independent genetic loci, therefore the identification of physiological traits that are responsible for drought tolerance should be considered in the breeding programs 8.
Drought tolerance of wheat cultivars can be assessed by comparing rainfed and supplemental irrigation treatments. Markers associated with a qtl for grain yield in wheat under drought f. Breeding strategies for drought tolerance in wheat. Phenotyping wheat for drought tolerance using phenotypic traits knowledge of phenotypic traits contributing to improved yields under stress is fundamental to the understanding of the complex physiological and genetic mechanisms of wheat adaptability reynolds et al. Breeding for drought tolerance in wheat triticum aestivum l. Were screening on a chemical, looking for resistance to a particular chemistry. Introduction of new indices to identify relative drought.
Various countries around the world experience drought in different ways but, in all cases, it leads to dramatic annual yield losses in crops and has consistently detrimental physiological effects on the crop plants throughout boyer, 1982. Genetic and genomic tools to improve drought tolerance in. Evaluation of drought tolerance indices for wheat triticum aestivum l. Plant breeding, university of zimbabwe, harare, zimbabwe b. Genetic evaluation of bread wheat for drought tolerance. To make matters worse, wheat carries between two and four copies of its dna in each cell depending on the variety. Drought tolerance is a complicated trait which is controlled by polygenes and. Physiological derivations of drought tolerance in wheat. This study aimed to evaluate the genetic diversity of genotypes of wheat under study in terms of drought tolerance. Other plants, specifically crops like corn, wheat, and rice, have become increasingly tolerant to. Mechanism of drought tolerance avoiding drought is an extremely important adaptation for survival in a water limiting environment. Drought is currently the leading threat on worlds food supply, limiting crop yield, and is complicated since drought tolerance is a quantitative trait with a complex phenotype affected by the plants developmental stage. Breeding for drought tolerance is further complicated since several types of abiotic stress, such as high temperatures, high irradiance, and nutrient toxicities or deficiencies can challenge crop plants. An evaluation of seed and seedling drought tolerance.