Stability Analyses of Early Segregating Egyptian Cotton Populations and Their Parents Across different Irrigation Intervals and Sowing Dates.

Abstract

This research was conducted to explore the potentiality of variable F2/F3 cross combinations and their six parents for developing climatic resilient genotypes under a wide range of environmental conditions. During 2019 and 2020 seasons, eight RCBD trials were carried out at the Faculty of Agriculture, Minia University, using two planting dates as early, (onset of April) and late planting, (onset of May). In each sowing date, two trials were conducted by irrigation each 14 and each 28 days as normal and stressed, respectively. Combined analysis showed that cotton genotypes, environments, and their interactions (GEI) were highly significantly for all traits with considerable magnitudes of GEI than other sources of variance. G.90CB58 exhibited the sole desirable parent for significantly highest seed cotton yield (SCY) and stability estimates with expected response to favorable environments. G.90CB58 shared Australian for better performance and stability the lint yield (LY). The cross combinations of G.90 with G.94, G.95 and Karashanky recorded significantly higher SCY and LY with somewhat stability in performance despite none of common parents exhibited similar superiority. The crosses of G.94 with G.90CB58 & Australian produced significantly higher SCY and LY with promising stability. The combinations of G.95 with G.90CB58 in addition to those of G.95 with Austalian recorded significantly the highest SCY and LY with simultaneously resilient performance to different environmental conditions. It could be concluded that these eight out of studied fifteen cross combinations may be considered as encouraging resources for selecting promising higher SCY and LY accompanied to desirable stability

Selection Response for Improving the Performance of Egyptian Cotton under Late Planting and Soil Moisture Stress

“…Twenty-seven selected Egyptian cotton progenies traced back to a diallel cross were carried out among six cotton elite genotypes during 2015 [9]. The resulting fifteen F 2 /F 3 segregating populations along with their parents were evaluated under eight trials during the 2019 and 2020 seasons [7,10]. In each season, four field trials were conducted using two sowing dates denoted as early (E) and late (L) during April and May, respectively.…”

“…Stressful environmental conditions along with insufficient water irrigation influence the phenology and yielding performance of Egyptian cotton [3,4]. However, unpredictable climatic fluctuations greatly affect the productivity and resilience of Egyptian cotton varieties and, consequently, they should be considered for releasing new varieties [5][6][7]. Genetic improvement in a crop requires in-depth knowledge of the variability along with information about the interrelationships among various traits so that an efficient selection strategy can be formulated.…”