The Pedigree and Genetic Diversity on Soybean Cultivars Released during 1923-2005 in Northeast China
|Keywords||Soybean Cultivar Genetic diversity Pedigree analysis Coefficient of parents SSR molecular marker|
Soybean [Glycine max (L) Merr] is one of importent economic crops and has its origin in China. It provides a major source of protein and oil for human consumption and widly-planted by mostly countries all over the world. Total 1300 soybean cultivars were released during 1923-2005 in China. The Northeast is major soybean growing area. The Northeast has the most numbers of soybean cultivars. There are 646 varieties beening bred from 1923 to 2005, accounting for 49.69 percent in China. The use of derivatives of elite germplasms be high frepuency .Through natural selection and artificial selection for a long time, Soybean Germplasm Resources has been accumulated large amounts of genetic variation. It is the material basis of breeding new elite cultivars and promoting the soybean product. The collection, preservation and evalution on the Northeast soybean germplasm resources will benefit soybean breeding and product.By analyzing the Northeast germplasm resources (especial the end ancestor parents), the dendrogram of agronomic traits and, SSR markers and pedigree analysis , the analysis of coefficient of parentage, the genetic diversityof the Northeast cultivars was illustrated and the status of soybean breeding was revealed in the paper.The main results were summarized as follows:1 Analysing 57 the end ancestor parents of the Northeast soybean, their karyon contributions is 459.47, and the cytoplasm contribution is 529. Amount to 35.34% and 40.69% in China respectively. Baimei, Heilongjiang’s varity, had 357 offsprings. Else, Jilin’s Silihuang and Liaoning’s Jinyuan had 497 and 577 offsprings respectively. They are the greastest pedigrees in China.2 13 agronomic traits of 646 cultivars was analysed. The data about quality traits shows: There are two kinds of flower colors mostly. And the varities of white flower is as much as the varities of purple. The color of cotyledon mostly is yellow, more than 89%. Gray pubescence and yellow seedcoat is the important traits, more than 80% in the Northeast. In 5 quantitative traits, the average growth period of the 646 cultivars is 122.12 days. The average weight of 100 seeds is 20 grams. There are 40.69 grams protein and 20.54 grams oils per 100 grams seeds in the 646 cultivars. Their average height is 84.30 cm.3 30 accessions was sampled from 646 cultivars. 12 Heilongjiang cultivars was included , Jilin and Liaoning has 9 varities respectively.SSR markers analysis: The ploymophism loci detected by 81 SSR primers was rich. A total of 875 allelic loci was detected with average 10.8 allelic per locus, Ranging from 4 to 18. The mean Simpson index and Shannon index were 0.8537 and 3.0711. The genetic diversity of cultivars in northeast is rich.Clusting analysis: Converting the molecular data and agronomic traits to "0"and "1". Construct matrix and form dendrogram. 30 accessions were divided into 4 groups in the dendrogram. The 4 groups was based upon the section of province. It suggests that the genetic background of cultivars is still based on its province.Pedigree analysis: most of the 30 accessions have common ancestors. Simplify the pedigree and line out their relationship. Many accessions can find in the same pedigree. The elite germplasm was widely usded in breeding, overcoming the geographical limitations.Coefficient of parents analysis: Calculation the COP of the 30 accessions. The COP of the cultivars in the same province is larger than the one of different provinces.