Identification and interaction analysis of QTL for phosphorus use efficiency in wheat seedlings

Abstract

An F7 recombinant inbred line (RIL) population consisting of 114 lines, derived from two varieties, W7984 and Opata85, were used in a hydroponic experiment with phosphorus (P) sufficient (0.25mmol/L) and deficient (0.025mmol/LP) treatments. After culture for 4 weeks, P concentrations were measured in shoot and in root respectively. P use efficiency (PUE) for shoot (SPUE), or whole plant (WPUE) was defined as shoot or whole plant biomass production per mg of absorbed P by the whole plant. Nine hundred eighteen RFLP markers mapped on all genome were used for analysis of QTL for these parameters. Under high P conditions, 2 and 3 QTL were identified for SPUE and WPUE respectively. Under low P conditions, 3 and 2 QTL were found influencing SPUE and WPUE, respectively. Epistatic interaction analysis indicated that there was 1 digenic interaction influencing SPUE and WPUE under high P environment, 1 digenic interaction was also found affecting WPUE at P deficient level. Among of the QTL detected, the locus on chromosome 7A influenced WPUE at both P levels, and this interval is also involved in the epistasis influencing WPUE under P sufficient environment; the genomic region containing this locus should be important for PUE in wheat. Additionally, the results indicated that Chromosome 5A was important for PUE under high P environment, while Chromosome 2D was important at low P level.