Drought is a major environmental stress factor that affects the growth and development of plants. Most of the physiological traits associated with drought tolerance are quantitative in nature. An important research strategy that has been widely used to deal with such complexity is to use molecular markers to identify quantitative trait loci (QTLs) in appropriate mapping populations. In response to drought brought about by soil water deficit, plants can exhibit either drought escape or drought resistance mechanisms, with resistance further classified into drought avoidance and drought tolerance. Drought escape is the ability of plants to complete the life cycle before severe stress arrives. Drought avoidance is the maintenance of high tissue water potential in spite of soil water deficit. Drought avoidance is consequence of improved water uptake under stress and the capacity of plant cells to hold acquired water that reduces water loss. Drought tolerance is the ability to withstand water deficit with low tissue water potential. Plant water status that includes leaf water potential, osmotic potential and relative water content (RWC) represents an easy measure of water deficit and provides best sensor for stress. Genomics-assisted breeding (GAB) approaches, such as markerassisted selection (MAS), can greatly improve precision and efficiency of selection in crop breeding. Molecular markers can facilitate indirect selection for traits that are difficult or inconvenient to score directly, pyramiding genes from different sources and combining resistance to multiple stresses. Conventional breeding for developing drought-tolerant crop varieties is time-consuming and labor intensive due to the quantitative nature of drought tolerance and difficulties in selection for drought tolerance. The identification of genomic regions associated with drought tolerance would enable breeders to develop improved cultivars with increased drought tolerance using marker-assisted selection (MAS). This requires integration of knowledge from plant physiology and biotechnology into plant breeding. The availability of a large number of molecular markers, dense genetic maps and markers associated with traits and transcriptomics resources have made it possible to integrate genomics technologies into chickpea improvement.

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The arbuscular mycorrhiza fungus (AMF) (Glomus mosseae) is a beneficial microorganism used in agriculture as an efficient tool to improve plant growth and nutrition by inducing symbiotic association with crops. The present investigation was conducted to study the contribution of arbuscular mycorrhizal fungus to drought tolerance in wheat (Triticum aestivum L.) grown under normal irrigated conditions and in water stress created by withholding irrigation at jointing and heading stage under net house environment. Wheat seeds of two wheat varieties WH 1025 and WH 1105 were grown in pots after treatment with or without the AMF. Under water stress conditions, the wheat variety WH 1025 performed better in terms of growth and yield attributes as compared to WH 1105. The results obtained showed a significant improvement by AMF on plant height, number of productive tillers, spike length, number of spikelet, grain/spike, grain weight/spike and test weight under both irrigated and drought stress condition. Biomass and grain yields were higher in plants treated with mycorrhiza than non-mycorrhizal plants of both the varieties irrespective of soil moisture. Therefore, the results suggest that mycorrhizal inoculation play a vital role in improving growth and yield in wheat by reducing the effects of drought stress and sustain the wheat crop under the semi-arid environments.

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Soil moisture stress is one of the most serious aspects of climate change. Selenium (Se) is regarded as an essential element for animal health and has been demonstrated to protect plants from a number of abiotic challenges; however, our knowledge of Se-regulated mechanisms for enhancing crop yield is limited. We investigated the effects of exogenous Se supplementation on physiological processes that may impact wheat productivity during soil moisture stress. The plants were grown in plastic containers under screen-house conditions. The experiment was laid out in CRD consisting of three soil moisture regimes, i.e., control (soil moisture content of 12.5 ± 0.05%), moderate (soil moisture content of 8.5 ± 0.05%), and severe moisture stress (soil moisture content of 4.5 ± 0.05%). Selenium was supplied using sodium selenite (Na2SeO3) through soil application before sowing (10 ppm) and foliar application (20 ppm and 40 ppm) at two different growth stages. The foliar spray of Se was applied at the vegetative stage (70 days after planting) and was repeated 3 weeks later, whereas the control consisted of a water spray. The water status, photosynthetic efficiency, and yield were significantly decreased due to the soil’s moisture stress. The exogenous Se application of 40 ppm resulted in decreased negative leaf water potential and improved relative water contents, photosynthetic rate, transpiration rate, and stomatal conductance in comparison to the control (without selenium) under water shortage conditions except the plants treated with soil application of selenium under severe moisture stress at 70 DAS. Subsequently, Se-regulated mechanisms improved 100 seed weight, biological yield, and seed yield per plant. We suggest that Se foliar spray (40 ppm) is a practical and affordable strategy to increase wheat output in arid and semi-arid regions of the world that are experiencing severe water shortages.