Genetic Analysis And Environmental Response And QTL Mapping Of Plant Height In Soybean

Soybean（Glycine max（L）Merr.） originated from China, is not only the important source of vegetable oil and protein for people, but also the important materials for livestock and industry. At present, soybean yield in China is low, and the quality is less than the American soybeans, seriously restricting the development of the soybean industry and can not meet the domestic demand for soybeans to result in a sharp increase in imports of transgentic soybeans. Previous results showed that close planting technique with the core technology of applied dwarf soybean varieties could increase the soybean yield. Therefore, breeding dwarf soybean new varieties combining close planting technique is one of most important methods to improve high-yield soybean. Moreover, analysis of genetic rule and influencing factors of soy plant height in depth and fine mapping semi dwarf gene play an important role for molecular assisted breeding dwarf soybean new varieties and have important application value in improving soybean yield. In order to explore the genetic factors inside and outside that impact the soybean plant height, 141 soybean germplasm resources at different breeding stage in Heilongjiang Province and three recombinant inbred line（RIL） populations（hybrid from Hefeng 47 and Heinong 37, Hefeng 47 and Heinong44, Dongnong 46 and Kenjian 23, respectively） were used as materials in this study.Change rule of different breeding period, planting year and location, plant height and pitch number between varieties were analyzed. At the same time, the growth period of soybean varieties was divided by using the control of foreign birth, and change rule of soybean plant height and pitch number were analyzed among different maturity groups. In order to identify semi-dwarf plant height genes, 143 RILs cross from Charleston and Dong Nong 594 were used to analyze the genetic pattern of soybean plant height, and QTL mapping was carried out to identify QTL associated plant height in this study. The results of present study were as follows:⑴Plant height and node number showed that both of them declined firstly, then rised slightly and declined. Significant difference could be seen in plant height between different planting years while not in node number; significant difference also could be observed between soybean varieties released in different breeding stages in plant height and node number. Moreover, significant difference could be seen between two different planting locations in the three RIL populations.⑵In 2013 and 2014, all the varieties were divided into five groups. Most of them in group 00 were soybean varieties from Heihe institute; most of them in group 0 consisted of core germplasms and most of soybean varieties in Heilongjiang Province; group I was comprised of part of soybean varieties were named Heinong and Suinong; group II were landraces and few of soybean varieties were named Heinong; group III were most of soybean varieties collected from Jilin Province and Liaoning Province. With the delay of maturity, the plant heights and node numbers showed an increased trend.⑶Correlation analysis of soybean plant height and node number in the major cultivated varieties and the three RIL populations indicated that both of them reached an extremely significant level at different breeding period.⑷Plant height of the RILs cross from Charleston and Dong Nong 594 were analyzed through multiple years and locations, and the results showed that the genetic model of plant height was controlled by two pairs of additive major genes plus polygenes model or two pairs of additive-epistatic major genes plus polygene model.⑸We constructed a partial high density linkage map containing 36 SSR markers and 2 In Del markers in the RIL population cross from Charleston and Dong Nong 594, and QTL associated with semi-dwarf gene was identified beweent SSR marker SSR₃ and 1248. On known AUX-28 regulated auxin was identified as the potential candidate gene through scaning the genome of the marker interval.