| Drought is the main factor that limiting the production of soybeans, at present, soybean drought tolerance is one of the hot issues in the field of crop genetic breeding. In this study, This study is based on192accessions from different geographical locations in Shanxi Province, take the drought stress and normal water supply as the experimental conditions, and finally measured the stomata traits related to drought conditions and the SPAD of3stages for bearing, the study analysis the genetic diversity and population structure by choosing97pairs of primers to cover the SSR markers in soybean genome at the same times. The main results are as follows:1. The representative of core germplasm were evaluated by analysis the representative morphological, geographical and38primer pairs of data, and the average shape index of degree is87.03%, indicated that the core germplasm can represent the original quality.2.97markers were used in192soybean germplasm to analysis the genetic diversity, finally got702alleles, ranged from4to14; The average number of alleles is7.237. Through compare the genetic diversity of the soybean that were different varieties,different chromosomes and different geographical sources, showed that cultivated soybean was richer in genetic than wild soybean; the alleles of8th chromosome was the highest than other chromosomes, in addition, also found that the population of Jinzhong area has the highest allele count and Shannon diversity index(1.3394), and the population of Jincheng area is lowest (0.9703).Analysis the population genetic structure of Soybean Germplasm, can be divided into2mutually independent populations, wild soybean and cultivated soybean were divided into two classes, through the Cluster analysis of inter group; the soybean will be divided into two classes of cultivated soybean and wild soybean. Show that the natural evolution and artificial selection has made the cultivated soybean appeared obvious genetic differentiation.3. The chlorophyll content for three periods of soybean in Shanxi Province were analyzed, drought stress made the chlorophyll content decreased, but different wilting level were existent and the wild soybean are stronger than ordinary ones in drought resistance. In addition, the highest diversity index was at the level of second wilting, which said the soybean germplasm variations the rich in this level.4. Identification the stomatal traits of Shanxi soybean germplasm. The results show that: under drought stress the net photosynthetic rate, transpiration rate, intercellular CO2concentration and stomatal conductance decreased in soybean germplasm, water use efficiency and stomatal density increased in different degrees. what’s more, the correlation coefficient were high. In addition, the wild soybean drought has advantage in resistance than cultivated soybean whether in the low transpiration rate, intercellular CO2concentration, stomatal conductance, or in the water use efficiency.5. Using TASSEL software to analyze the content of chlorophyll in the3periods, the percentage of phenotypic variation explained in condition that r2>0.05, P<0.05.Correlation analysis showed that:(1) detected43sites were related with the3periods of chlorophyll content, which are distributed in15chromosomes of soybean genome, under drought stress, the content of chlorophyll at seedling stage have the most elevant sites (13), the elevant sites are least in blossom period (3), the average trait loci is7.167.(2) associated with6stomatal traits loci accumulated have85, which were distributed in19chromosomes of soybean genome, in all of them, the related sites to drought stress and water use efficiency were the most (13), and the loci to the stomatal density were the least (2), the average site associated to each properties were7.083.Generally speaking, the result got form the study for the site associated to drought resistance traits can provide indirect and rapid reliable to early generation selection though the drought resistant breeding of soybean markers. |
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