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Indirect selection alternatives to improve yielding ability across environments in sorghum (Sorghum bicolor L. Moench)
Abstract
Sorghum growing areas worldwide are normally under highly unpredictable rainfall patterns requiring the breeder to select genotypes which are both water responsive and drought resistance. The efficiency of selection of such traits depends primarily on the environment(s) involved and proper choice of selection criteria. Therefore, the main objective was to evaluate potential selection criteria in eight environments for selection of superior genotypes across a wide range of environments. Two hundred S$\sb1$ families from two sorghum populations (TP24D and KP9B) were evaluated in four dryland locations (Mead, NE; Hesston, Garden City, and Parsons, KS) during two years (1987 and 1988). Predicted response to selection and predicted correlated response to selection were estimated and the relative efficiency was calculated for each selection criterion. The relative efficiency of indirect selection criteria for each single environment was low but was improved when yields from the best (B), intermediate (I), and the worst (W) environments were combined to estimate mean productivity (MBIW) and rank summation (RBIW). The relative efficiencies of the stability parameters (regression coefficient, b and principal component, PC), as indirect selection criteria were low. However, their relative efficiencies increased substantially when mean yield over all was included along with a stability parameter in selection indices SIBYLD (includes b values and mean yield) and SIAMYLD (includes PC values and mean yield). Their relative efficiency were equal or higher than MBIW and RBIW which required fewer environments. Seed number (SDNB) and seed size (SDSZ) yield component analysis indicated that SDNB was the most limiting factor under stress environments, and that their relative efficiencies as indirect selection criteria were low. In general, the use of selection criteria involving environments that better represent the target area, such as MBIW and RBIW, and/or selection indices which include both a stability parameter and mean yield were the best alternatives for increasing predicted response to selection across high unpredictable environments.
Subject Area
Agronomy
Recommended Citation
Zavala-Garcia, Francisco, "Indirect selection alternatives to improve yielding ability across environments in sorghum (Sorghum bicolor L. Moench)" (1991). ETD collection for University of Nebraska-Lincoln. AAI9129575.
https://digitalcommons.unl.edu/dissertations/AAI9129575