Genotype × Environment Interaction and Stability of Sorghum bicolor Lines for Some Agronomic and Yield Traits in Egypt

Abstract

Developing high performing and stable sorghum genotypes across different environments is of utmost importance to plant breeders. This study was conducted to compare relative stability of 25 grain sorghum B-lines under Egyptian conditions for some agronomic and yield traits. Six experiments with 25 sorghum B-lines were conducted at two locations in Egypt (Giza and Shandaweel) in two years and two planting dates in one location (Giza). A randomized complete block design was used in each environment with three replications. The three evaluation parameters used were mean performance, regression coefficient and the deviation from regression. Stability analysis was performed for five traits, namely days to flowering (DTF), plant height (PH), 1000-grain weight (TGW), grains/plant (GPP) and grain yield/plant (GYPP). The top five high yielding lines (G1, G3, G10, G12 and G25) displayed regression coefficient much lower than unity, indicating their adaptability to poor environments. The genotypes G12 and G20 exhibited significant deviation from regression for GYPP, indicating that they are unstable. The most responsive genotype for GYPP was G9 followed by G2 and G20; they are adapted to high- yielding environments. The three lines G11 (ICS-8001), G21 (BTX-407) and G24 (BTX -631) displayed above average grain yield/plant (GYPP), regression coefficient (bi) value near unity (1.07 and 1.05) and small and non-significant deviation from regression (S2 d), indicating that these genotypes are stable and widely adapted to different environments. The most stable genotypes were G17, G19 and G6 for days to flowering, G1, G4, G22, G24 and G16 for plant height, G8, G17, G19 and G16 for grains/plant and G14 and G22 for 1000-grain weight. These B-lines can be utilized as parental lines for the development of grain sorghum hybrids in view of their stability for the respective traits