| Drought is a major abiotic stress factors influencing soybean production. It is difficult to research drought resistant breeding, because drought resistance is a complicated quantitative trait. The most effective way of soybean drought resistance breeding is analyses drought resistant related traits at the level of molecular. Association analysis is to detect locus and elite allele of these loci related to genotypes using natural population. This study analyzed locus at 35 SSR markers distributed on 20 chromosomes, SNP and InDel marker exploited from the key enzyme of proline synthesis pathway P5CS gene and SCAR markers and variation of related drought resistant traits from wild soybean in different regions of Shanxi province.The major results were as follows:1 The analysis of natural population showed that most wild soybean had the biological character of brown pod, brown pubescent, present bloom, black seedcoat and hilum, ellipse seed. Comparison of wild soybean from different regions, wild soybean from TY had abundant variation type. The diversity index of pod color from JZ was highest, the diversity index of pubescent color from YC was highest, and the diversity index of bloom, seed color, hilum color and seed shape from TY were highest.Association analysis using TASSEL soft showed that 65 marker loci distributed in soybean 15 chromosome were detected, which were related to 6 biological characteristics. There were 16 marker loci associated with MPC,4 marker loci associated with PC. There also found a certain number of loci associated simultaneously with two or more relative traits. The loci satt197 distributed in Chr.15 significantly associated simultaneously with 6 traits.2 The analysis of leaf pubescence density under different water treatment showed that leaf pubescence density from different regions had different in adaptability to drought. Comparison of wild soybean and landrace, traits of pubescence from landrace were more than these traits from wild soybean, except pubescence density in upper surface (PDU).Association analysis showed that there are 14 marker loci distributed in soybean 8 chromosomes were detected in wild soybean in Shanxi, which were related to PDD and PDU. Only the loci satt268 were significantly associated with PDU-W. The maximum positive phenotypic allele effect was 2.010, the average positive allele effect (AAE) of a satt268 was 1.016.3 The analysis of physiological traits under different water treatment showed that proline content, malondialdehyde (MDA) content, soluble sugar content had increased in different degree under drought stress, while chlorophyll content had decreased. Physiological traits from different regions had different in adaptability to drought. Comparison of wild soybean and landrace, wild soybean from LL had larger drought resistance than landrace, and wild soybean from SZ under drought stress had larger drought resistance than landrace.Association analysis showed that 30 marker loci distributed in soybean 11 chromosomes were detected, which were related to physiological trait. There also found 9 locus simultaneously associated with two or more relative traits. Loci of satt571 and satt168 were simultaneously associated with 4 relative traits, which might be the genetic reason of pleiotropic phenomena. There are 16 loci were highly significantly associated with physiological traits, the study also found that there are differences on phenotypic effects among allelic variation from same locus. The locus Satt279 significantly associated with MDA-D have 10 allelic variation, and the maximum positive phenotypic allele effect was 14.0456, the average positive (negative) allele effect (AAE) of a satt268 were 2.7433 and (-1.8744).4 The analysis of yield related traits under different water treatment showed that all yield related traits were decreased under drought stress. All traits had different performance under drought stress,100-seed weight(SW) and seed number per plant(SP) from JZ and seed weight(SW) and plant weight(PW) from SZ had small descent. Comparison of wild soybean and landrace, SP, plant height(PH), branch number(BN) and pitch number of stem(PN) in wild soybean more than these in landrace, meanwhile SW and SW in wild soybean less than these in landrace.Association analysis showed that 96 marker loci were detected, which were related to yield-related traits. There also found 21 locus simultaneously associated with two or more relative traits. There were 64 marker loci were highly significantly associated with yield-related traits. The study on phenotypic effects of allelic variation from same locus found that the phenotypic effects of positive (negative) alleles were different from each other, and the average positive (negative) effect of a locus were also different from each other. The locus Satt279 significantly associated with SW-W had 10 allelic variations, and the maximum positive phenotypic allele effect was 7.168, and the maximum negative phenotypic allele effect was 7.026 in drought condition.5 P5CS genetic polymorphism was analysis of 10 different drought resistance soybean materials. To obtain 5407 bp gene fragments,6 polymorphic loci were detected, consist of 5 SNP and 1 InDel. Length polymorphism marker named SCAR 1 was developed from the 9bp deletions fragment between 2160 bp and 2168 bp in 7th intron of P5CS gene, which was amplified and the product of PCR was 136bp. Association analysis with drought related traits using this marker, the results showed that PDU-W, Chi-W and SW-W were significant association with SCAR1.66 SCAR markers from the drought resistant related gene were used for association analysis. The results showed that PDU-D, BN-D, SS-W, SW-W, SW-D, PN-W and PN-D were significant association with SCAR221, of which SW and PN on two treatments were highly significant association with SCAR221. Chi-W, SWP-W, SW-W, SW-D, PW-D, PH-D, BN-D and PN-D were highly significant association with SCAR261. PH-D, PS-D were significant association with SCAR211, of which PS-D were highly significant with SCAR211. Pro-W, SS-W, SW-W, PW-W, PH-W and PN-W were significant with SCAR216, of which Pro-W, PW-W, PH-W and PN-W were highly significant with SCAR216.On the whole, these loci associated with drought resistant trait were detected to provide simple early generation selection markers for soybean drought resistant breeding. |
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