Dissection of Drought Tolerance in Upland Cotton Through Morpho-Physiological and Biochemical Traits at Seedling Stage

Abstract

Cotton is an important fiber and cash crop. Extreme water scarceness affects the growth, quality, and productivity of cotton. Water shortage has threatened the future scenario for cotton growers, so it is imperative to devise a solution to this problem. In this research, we have tried to machinate a solution for it. 23 genotypes have been screened out against drought tolerance at the seedling stage by evaluating the morphological, physiological, and biochemical traits in a triplicate completely randomized design plot experiment with two water regimes [50 and 100% field capacity]. Genotypic differences for all the morphological and physiological traits revealed highly significant differences except transpiration rate (TR). Moreover, the interaction between genotype and water regime (G × W) was highly significant for root length (RL, 5.163), shoot length (SL, 11.751), excised leaf water loss (ELWL, 0.041), and stomatal conductance (SC, 7.406). A positively strong correlation was found in TR with relative water content (RWC; 0.510) and SC (0.584) and RWC with photosynthesis (0.452) under drought conditions. A negative correlation was found in SC with SL (−0.428) and photosynthesis (−0.446). Traits like RL, SL, SC, photosynthesis, proline, catalase, and malondialdehyde were visible indicators, which can differentiate drought-tolerant genotypes from the susceptible ones. A wide range of diversity was found in all the morpho-physiological traits with the cumulative variance of four principal components (PCs) 83.09% and three PCs 73.41% under normal and water-stressed conditions, respectively, as per the principal component analysis. Hence, selection criteria can be established on the aforementioned traits for the development of drought-tolerant cultivars. Moreover, it was found that out of 23 experimental varieties, NIAB-135, NIAB-512, and CIM-554 could be used to devise breeding strategies for improving drought tolerance in cotton.

Melatonin Mediated Differential Regulation of Drought Tolerance in Sensitive and Tolerant Varieties of Upland Cotton (Gossypium hirsutum L.)

“…Water scarcity affects food crops and economically important species, including cotton ( Gossypium spp.). Gossypium hirsutum , also known as upland cotton, accounts for 90% of global cotton production ( Zahid et al, 2021 ). Decrease in rainfall, groundwater levels, and reduced soil moisture affect the growth, productivity, and fiber quality of cotton ( Parida et al, 2007 ), and it also surges the incidence of diseases, and pest attacks ( Zahid et al, 2021 ).…”

“…Gossypium hirsutum , also known as upland cotton, accounts for 90% of global cotton production ( Zahid et al, 2021 ). Decrease in rainfall, groundwater levels, and reduced soil moisture affect the growth, productivity, and fiber quality of cotton ( Parida et al, 2007 ), and it also surges the incidence of diseases, and pest attacks ( Zahid et al, 2021 ). Berry et al (2013) estimated that the yield loss due to drought in cotton ranges from 50 to 73% globally.…”

“…Xeromorphic traits and structures conferring tolerance to drought are well-studied in cotton ( Iqbal et al, 2013 ; Ullah et al, 2017 ). At the biochemical level, phytohormones, including abscisic acid and jasmonic acid, and production of reactive oxygen species (ROS) and ROS redox homeostasis were reported to play roles in conferring drought tolerance ( Chen et al, 2013 ; Ma et al, 2016 ; Zahid et al, 2021 ). In addition, genes and regulatory pathways underlying drought stress response were delineated in G. hirsutum .…”

Genome-Wide Identification and Expression Analysis Elucidates the Potential Role of PFK Gene Family in Drought Stress Tolerance and Sugar Metabolism in Cotton

“…Like other abiotic stresses, it is one of the most significant environmental elements influencing cotton production and growth, as well as fiber quality, due to inadequate cellulose cell formation in the bolls ( Azhar and Rehman, 2018 ). Drought has put cotton growers’ future prospects in jeopardy; thus, finding a solution to this challenge is critical ( Zahid et al, 2021 ).…”

Consequences of Drought Stress Encountered During Seedling Stage on Physiology and Yield of Cultivated Cotton

“…At the onset of wilting of the leaves (38 days of stress) shoot length (SL) of control and water stressed plants of each genotype in both treatments was measured in centimetres (cm) by using the ruler from the ground level of plant to the highest fully expand leaf. The difference in the mean SL of stressed and non-stressed plants was used to assess the susceptibility of genotypes as previously described ( Zahid et al, 2021 ). The measure of resistance based on phenotypic response under any stress in comparison with response under the optimal environment is termed the SSI.…”