Correlation between per se and Testcross Performance in Rye (Secale cereale L.) Introgression Lines Estimated with a Bivariate Mixed Linear Model

Abstract

ABSTRACTIn hybrid breeding a high correlation between per se performance of parental lines and hybrid performance can help to reduce the efforts for testcross trials. Our objectives were (i) to investigate the correlation between per se and testcross performance of rye (Secale cereale L.) candidate introgression lines (pre‐ILs) for thousand‐kernel weight, test weight, falling number, starch, pentosan, and protein content; and (ii) to investigate the consistency of quantitative trait loci (QTL) determined in pre‐ILs and their testcross progenies. Eighty pre‐ILs carrying donor chromosome segments (DCS) from the Iranian primitive rye Altevogt 14160 in the genetic background of elite line L2053‐N, were evaluated at four locations over 2 yr. Genetic correlations between per se and testcross performance were estimated with a bivariate mixed linear model. Putative QTL regions were detected by comparing the performance of pre‐ILs carrying certain DCS with the performance of the recurrent parent. Genotypic variances and heritabilities were higher for per se than for testcross performance. Genetic correlations between per se and testcross performance were mostly intermediate. Common QTL regions were observed for test weight, starch, pentosan, and protein content. Our results revealed that a superior per se performance of rye pre‐ILs is not indicative for a superior hybrid performance. Consequently, using rye pre‐ILs in hybrid breeding programs requires testcross trials.