Detection of quantitative trait loci controlling UV-B resistance in soybean

Abstract

The depletion of stratospheric ozone has resulted in increased amounts of ultraviolet-B radiation (UV-B: 280–320 nm) reaching the Earth’s surface. Even a small increase in the incident UV-B radiation could cause significant biological effects in plants. In this study, we identified putative quantitative trait loci (QTL) associated with the resistance to enhanced UV-B radiation in soybean. A population of 115 recombinant inbred lines (RILs) derived from a cross between Keunolkong (a sensitive soybean variety) and Iksan 10 (a resistance soybean line) was analyzed. A total of 110 SSR markers were used to construct a linkage map. RILs and both parents were grown with supplemental UV-B radiation in a greenhouse. In order to screen for UV-B resistance, the degree of leaf chlorosis (DLC), degree of leaf shape change (DLS), degree of petiole color change (DPC) and degree of total plant damage (DTP) were evaluated. Using composite interval mapping analysis, one major QTL associated with all of the characteristics, DLC, DLS, DPC, and DTP, was detected on soybean chromosome 19 between Satt495 and Satt238, accounting for 10.76–32.8 % of the phenotypic variance. The ‘Iksan 10’ allele increased the resistance to UV-B radiation for the DLC, DLS, DPC, and DTP traits. This study is the first trial for identification of QTLs associated with UV-B resistance in soybean. In addition, these results provided basic information not only for the improvement of UV-B resistance through marker-assisted selection, but also for the future identification of putative candidate genes of UV-B resistance.