Abstract:

Glutenin macropolymer (GMP) content is a key factor influencing wheat processing quality, which is determined by quantitative trait locus (QTL). To date many QTLs related to quality characteristics, including the GMP content, have been mapped on wheat chromosomes. However, these researches were all focused on gene expression at a certain developmental stage, and could gave little information to understand the dynamic effects of corresponding QTLs at different developmental stages as well as the directions of gene action. In the present paper, QTL mapping for developmental behavior of wheat GMP content was studied, using recombinant inbred lines (RIL) population derived from Jing 771×Pm97034. The results showed that eight conditional QTLs and ten unconditional QTLs were detected in different seed filling periods totally, but no one was detected in all periods. Each of these genes expressed in a special period. The additive effects of a conditional QTL located on chromosome 1A could be detected 12 days after anthesis, which could account for 6.21% of phenotypic variation in GMP content. A new conditional QTL was detected 17 days after anthesis, accounting for 14.14% of phenotypic variation. At the period of 17–22 days after anthesis the gene expression was active, and three unconditional QTLs and the two conditional QTLs were detected to be located on chromosome 1B, 5B, 6B and 7B with smaller additive effects, and the general contribution rate of the two conditional QTLs was 12.67%. Four QTLs located on chromosome 2D and 3B were detected 27 days after anthesis with larger additive effects, in which the two conditional QTLs accounted for 16.37% of phenotypic variation, while the other two unconditional QTLs accounted for 23.94%. Up to 32 days after anthesis, there still two new expressed genes were detected, but the net genetic variation declined, and conditional QTL just explained 11.43% of phenotypic variation.

Key words: Wheat, RIL population, GMP content, Developmental behavior, QTL mapping