Genetic Variability and Phenotypic Correlation Between Growth and Yield Characters in some Grain Sorghum (Sorghum bicolor L. Monech) Genotypes under Stress Conditions

Abstract

The experiments was conducted during two successive summer seasons (2012 and 2013), in Demonstration Farm of the Collage of Agricultural Studies at Shambat , Sudan University of Science and Technology, to evaluate twenty two genotypes of grain sorghum (Sorghum bicolour L Moench), for growth and yield characters, under two different water regimes, well watering (7days) and drought stress (21days) using split plot trail in three replications. The objectives of this study were to assess the genetic variability among grain sorghum genotypes under drought stress condition, to estimates the phenotypic correlation between different characters and to identify the most drought tolerance genotypes under drought stress conditions. Characters studied were plant height, stem diameter, number of leaves per plant, leaf area, days to 50% flowering, days to maturity, panicle length, yield/plant, thousand seed weight, yield (Ton/ha). The results showed that there were significant differences among most of the characters studied in both seasons. Highly heritability were showed in this study among growth characters, plant height (0.69-0.90), plant dry weight (0.89-0.92), 50% flowering (0.72-0.91) and days to maturity (0.79-0.80) for the two seasons. Genotypic coefficient of variation (GCV) was maximum in leaf area (2149.74, 1599.89) for the two seasons and plant height (1529.29, 1231.71) and it was not different with phenotypic coefficient of variation (PCV). It was also showed maximum value in leaf area (975.71, 486.19) for the two seasons and plant height (1051.97, 1114.53). This result was indicating that these traits were affected by environmental fluctuations. The high value of (GCV) and (PCV) suggested that there is possibility to utilize environmental effects through direct selection for these traits.