Responses of Upland Cotton (Gossypium hirsutum L.) Lines to Irrigated and Rainfed Conditions of Texas High Plains

Abstract

Understanding drought stress responses and the identification of phenotypic traits associated with drought are key factors in breeding for sustainable cotton production in limited irrigation water of semi-arid environments. The objective of this study was to evaluate the responses of upland cotton lines to rainfed and irrigated conditions. We compared selected agronomic traits over time, final yield and fiber quality of cotton lines grown in irrigated and rainfed trials. Under rainfed conditions, the average number of squares per plant sharply declined during weeks 10 to 14 while the average number of bolls per plant significantly reduced during weeks 13 to 15 after planting. Therefore, weeks 10 to 14 and weeks 13 to 15 are critical plant growth stages to differentiate among upland cotton lines for square and boll set, respectively, under drought stress. Variation in square and boll set during this stage may translate into variable lint percent, lint yield and fiber properties under water-limited conditions. Lint yield and fiber quality were markedly affected under rainfed conditions in all cotton lines tested. Despite significantly reduced lint yield in rainfed trials, some cotton lines including 11-21-703S, 06-46-153P, CS 50, L23, FM 989 and DP 491 performed relatively well under stress compared to other cotton lines. The results also reveal that cotton lines show variable responses for fiber properties under irrigated and rainfed trials. Breeding line 12-8-103S produced long, uniform and strong fibers under both irrigated and rainfed conditions. The significant variation observed among cotton genotypes for agronomic characteristics, yield and fiber quality under rainfed conditions indicate potential to breed cotton for improved drought tolerance.

Response of Cotton Genotypes to Water-deficit Stress using Drought Tolerance Indices and Principal Component Analysis

“…According to the heatmap, the genotypes G4, G9, and G10 in both irrigation conditions, G2 and G3 in normal irrigation and water-deficit stress conditions, respectively, had the highest cotton yield across most years studied, while the genotypes G8 and G6 had the lowest cotton yield under normal irrigation and water-deficit stress conditions, respectively. Ayele et al [30], Yehia [34], and Eid et al [16] observed the same trend when compared to water-deficit stress conditions; cotton genotypes in normal irrigation conditions showed higher seed cotton yield, which ranged from 11.12% by G3 to 28.03% by G7, suggesting genetic variability in eleven studied genotypes for drought tolerance. Also, Grzesiak et al [13] and Sun et al [15] found a considerable decrease in yield in drought-sensitive genotypes, whereas yield decline was significantly lower in droughttolerant genotypes.…”

“…These findings show that genotypes have a lot of variation and are distinct, allowing us to choose genotypes under water-deficit stress conditions. In both irrigated and rainfed trials, Ayele et al [30] and Abo Sen et al [31] found high variability in yield among cotton genotypes. Our findings also revealed the variability and inconsistency in seed cotton yield responses among investigated genotypes in both irrigation conditions over a five-year period.…”

Response of cotton genotypes to water-deficit stress using drought tolerance indices and principal component analysis

“…Ayele et al (2020),Yehia (2020), andEid et al (2022) observed the same trend when compared to water-de cit stress conditions; cotton genotypes in normal irrigation conditions showed higher seed cotton yield, which ranged from 11.12% by G3 to 28.03% by G7, suggesting genetic variability in eleven studied genotypes for drought tolerance. Also,Grzesiak et al (2019) andSun et al (…”

“…Ayele et al (2020) and AboSen et al (2022) found high variability in yield among cotton genotypes. Our ndings also revealed the variability and inconsistency in seed cotton yield responses among investigated genotypes in both irrigation conditions over a ve-year period.…”

Mechanism of cotton resistance to abiotic stress, and recent research advances in the osmoregulation related genes

“… Chaves and Pereira (2003) and Onaga and Wydra (2016) investigated the influence of water stress on cotton seed germination, suggesting that cotton seeds under different drought stress were associated with decreases in water potential, germination rate, index, seedling height, root length, root-to stem ratio, dry weight and in associated with the fresh weight of young seedlings all decreased to varying degrees ( Pettigrew, 2001 ; Fahad et al, 2017 ). Studying the growth and development of cotton in Jiangsu Province under drought conditions ( Zhao et al, 2020 ), it was found that cotton growth was initially inhibited under drought conditions, and the plant height and leaf emergence rates were significantly slowed ( Gao et al, 2020 ) found that when cotton was subjected to drought stress at different growth stages, its growth, development and yield were affected to some extent, and the influence from largest to smallest was the flower-boll, bud, maturity and seedling stage ( Ullah et al, 2017 ; Ayele et al, 2020 ). The results show that drought resistant germplasm materials can effectively reduce water loss by increasing atmospheric pore resistance and reducing evapotranspiration intensity, thereby ensuring photochemical efficiency.…”