selection strategy to accomodate genotype-by-environment interaction for grain yield of wheat: managed-environment for selection among genotypes

• Published in: Theoretical and applied genetics Vol. 90; no. 3/4
• Main Authors: Cooper, M, Woodruff, D.R, Eisemann, R.L, Brennan, P.S, DeLacy, I.H
• Format: Journal Article
• Language: English
• Published: 1995
• Subjects: crop yield; environmental factors; genotype; genotype-environment interaction; grains; indirect selection; nitrogen; nutrient availability; plant breeding; selection criteria; selection methods; Triticum aestivum; water availability; Queensland
• ISSN: 0040-5752; 1432-2242

Selection for grain yield among wheat lines is complicated by large line-by-environment (L X E) interactions in Queensland, Australia. Early generation selection is based on an evaluation of many lines in a few environments. The small sample of environments, together with the large L X E interaction, reduces the realised response to selection. Definition of a series of managed-environments which provides discrimination among lines, which is relevant to the target production-environments, and can be repeated over years, would facilitate early generation selection. Two series of managed-environments were conducted. Eighteen managed-environments were generated in Series-1 by manipulating nitrogen and water availability, together with the sowing date, at three locations. Nine managed-environments based on those from Series-1 were generated in Series-2. Line discrimination for grain yield in the managed-environments was compared to that in a series of 16 random production-environments. The genetic correlation between line discrimination in the managed-environments and that in the production-environments was influenced by the number and combination of managed-environments. Two managed-environment selection regimes, which gave a high genetic correlation in both Series-1 and 2, were identified. The first used three managed-environments, a high input (low water and nitrogen stress) environment with early sowing at three locations. The second used six managed-environments, a combination of a high input (low water an nitrogen stress) and medium input (water and nitrogen stress) with early sowing at three locations. The opportunities for using managed-environments to provide more reliable selection among lines in the Queensland wheat breeding programme and its potential limitations are discussed.