Analysis Of Genetic Diversity For Soybeans Core Collection Of Three Provinces In Southwest China

Soybean is one of the important economic crops and originated in China with long cultivated history. More than 23000 accessions have been conserved in National GeneBank. Constructing core collection is essential to manage, evaluate and use so many accessions. The three provinces of Yunan, Sichuan and Guizhou have complex landform and changeful climate, which formed abundant varieties. It has been presumed that this region is likely to be one of original centers of China soybean and have soybean with generally high seed protein content. Thus, conserving the germplasm in the region has important value for us to improve quality of soybean. In this study, 182 soybean accessions are selected from the three provinces, consisting of 22 accessions from Yunnan; 40 accessions from Guizhou; 120 accessions from Sichuan. Based on the sowing types, these accessions are grouped as 24 south spring sowing soybeans; 92 south summer sowing soybeans; 66 changjiang spring sowing soybeans. These accessions were evaluated with morphological traits and 60 SSR loci distributed evenly across 20 linkage map. 1.In this study, 182 core collection from the three provinces of Yunnan Guizhou and Sichuan attached on the core collection of China soybeans. Analysis of agronomic traits find out that the majority are heavy-colored seed color,high-protein and low-oil materials. Most of them are early mature or mid-mature and small seed. Analysis of primary component shown that plant height and grown habit are two biggest positive effect for quantitive and qualitive traits. Then these germplasm are also used to parents selection as to low plant breed. 2.Through analysis of agronomic and molecular genetic diversity, plant height and 100-seeds weight are separately lowest and highest in quantitive traits. Cotyledon color and seed color are separately lowest and highest in qualitive traits. As a whole, quantitive traits` genetic diversity is higher than qualitive traits`. Satt309,Satt387 and Sct₁88 are the first three of smallest genetic diversity loci in the 60 loci. Satt 281,Satt 373 and Satt462 are the first three of biggest. These 182 core collection from the province, the ecotype, the latitude ,the longitude and the elevation different populations angle analyzed diversity discovered that, between three provinces, Sichuan's genetic diversity is relative biggest, Guizhou Province is next, Yunnan Province is smallest; In three ecotype, south summer and Changjiang spring do not have the difference in 60 loci genetic diversity, south spring is relative smaller. 3.From the longtitude, the latitude and the elevation three-dimensional looked that, the east longitude 102° - 108°, the north latitude 25°- 31° and the elevation approximate 230 - 750 meters regions are the southwest three provinces genetic diversity center. In this region genetic diversity is richest and the differentiation coefficient among these population is smaller. 4.In three provinces core collection test, It does not have the difference to maximum value, minimum value, mean value, standard difference and coefficient of variation of 5 quantitive traits for core collection and the total material of Yunnan, Guizhou and Sichuan`s corresponding value. Indicating the representation is very good to the quantitive traits of core germplasm. In the 9 qualitive traits of core germplasm, 8 ones tally completely with collectivity. And the complete coincidence rate is 88.9%. Further examinating the coincidence on relative traits for core collection and collectivity of the three provinces by the chi-square test. In 9 qualitive traits, besides seed color and growth habit, it is accordant ratio for other 7 ones between core collection and three provinces` total materials. Accordingly the coincidence rate is 77.8%. The two ratio is bigger than 70% representation which Brown etal (1989) proposed. Show the representation being good. About molecular level examination, it add up to above 95% regardless of the total alleles or the average alleles` representation and the genetic diversity inde...