Genetic regulation of growth and nutrient content under phosphorus deficiency in the wild barley introgression library S42IL

Abstract

Abstract Phosphorus (P) is an important macronutrient required for plant growth and yield formation. Since decades, breeders aim to optimize P efficiency in crops. We studied a set of 47 wild barley (Hordeum vulgare ssp . spontaneum, Hsp) introgression lines ( IL s) in hydroponic culture to identify quantitative trait loci ( QTL s) improving growth and nutrient content under P deficiency. Applying a mixed model analysis, a total of 91 independent QTL s were located among 39 IL s, of which 64 QTL s displayed trait‐improving Hsp effects. For example, an unknown Hsp allele on barley chromosome 4H increased shoot dry weight under P deficiency in three overlapping IL s by 25.9%. Likewise, an Hsp allele on barley chromosome 6H increased root dry weight under P deficiency in two overlapping IL s by 27.6%. In total, 31 QTL s confirmed Hsp effects already identified in previous field and glasshouse experiments with the same IL s. We conclude that wild barley contains numerous trait‐improving QTL alleles, which are active under P deficiency. In future, the underlying genes can be subjected to cloning and, simultaneously, used in elite barley breeding.