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QUANTITATIVE GENETICS OF AGRONOMIC TRAITS AND EVALUATION OF SEEDLINGS FOR DROUGHT RESISTANCE UNDER STRESS AND NON-STRESS ENVIRONMENTS, AND RESISTANCE TO PERICONIA CIRCINATA (MANGIN) SACC. IN TWO DIVERSE GRAIN SORGHUM (SORGHUM BICOLOR (L.) MOENCH) RANDOM-MATING POPULATIONS
Abstract
Quantitative genetic studies were conducted in three separate experiments using 140 S(,1) families from each of the two diverse random-mating grain sorghum populations NP5R and NP21R by evaluating them for their breeding potential, seedling resistance to drought and Periconia circinata. Variability was observed between and within families in the two populations in the breeding potential study. Yield and its primary components had significantly large year x family interactions and henceforth high phenotypic variances, indicating low stability in variable environments. However, variance component estimates indicated large family genetic variances especially in NP5R than NP21R because of its broader genetic base. Similarly heritability estimates were moderate to high (0.35-0.98) in favor of NP5R than NP21R, and the selection of desirable traits should be relatively simple. The number of seeds/panicle in NP21R and plant height and panicle length in NP5R were the most important traits. Genetic correlations were higher in NP5R than NP21R except for seeds/panicle. Phenotypic correlations were generally low in both populations. Predicted gains from selection were positive for most traits in both populations, but the number of seeds/panicle was more important than seed size in contributing to higher yields. NP5R may be preferred over NP21R for a long-term breeding program due to lower mean yield and higher variability for agronomic traits. Genetic variation occurred in both populations for all traits evaluated under the non-stress environment only. Larger estimates of variance components were observed in the non-stress environment in the two populations though NP5R was superior to NP21R. Selection for drought resistance was inconclusive under the non-stress environment. All the families in NP5R and NP21R were resistant to Periconia circinata indicating the durability of the recessive resistance gene pc in this host-parasite interaction.
Subject Area
Agronomy
Recommended Citation
MUSHI, ROBERT SHEKIAELI, "QUANTITATIVE GENETICS OF AGRONOMIC TRAITS AND EVALUATION OF SEEDLINGS FOR DROUGHT RESISTANCE UNDER STRESS AND NON-STRESS ENVIRONMENTS, AND RESISTANCE TO PERICONIA CIRCINATA (MANGIN) SACC. IN TWO DIVERSE GRAIN SORGHUM (SORGHUM BICOLOR (L.) MOENCH) RANDOM-MATING POPULATIONS" (1986). ETD collection for University of Nebraska-Lincoln. AAI8614466.
https://digitalcommons.unl.edu/dissertations/AAI8614466