Structure And Evolution Of The Haplotypes In Soybean Cytoplasmic Genome

Wild and cultivated soybean with geographical representative were chosen forthe study of the soybean cytoplasmic genome genetic patterns and the rule of itschange during domestication process on DNA sequence level to leam the molecularprocess of soybean domestication and the molecular mechanism of soybean originand evolution. The main results are as follows:1 Twenty five cpDNA and 6 mtDNA fragments, have been successfullysequenced in all of the 80 soybean accessions. 39 SNPs have been found in soybeancpDNA in total of 14550 bp, including 34 single-base changes, 3 single-base indelsand 2 multi-base indels. 37 and 14 SNPs were found respectively in G soja and Gmax and the SNPs frequency (θ) was 0.00057 and 0.00021 respectively. Only 1 SNPwas found in mtDNA in total of 3 532 bp in G. soja, the SNPs frequency (θ) was0.00007, which indicated that there were abundant genetic diversity in G. soja. Thedistribution of SNPs was compared between the two populations, which implyedthat large amount of rare SNPs existed in G soja. The 34 single-base changes iscomposed of 32 transversion and 2 transition, and Ts/Tv is 1:16 showing a strong"transversion bias" in soybean cpDNA.2 Twenty three and 8 haplotypes were detected respectively in G. soja and G.max. The haplotype diversity (H) was 0.195 in G soja and 0.119 in G. max showingthat haplotype diversity was abundant in G soja, and r~2 was 0.1754 and 0.4219respectively in G. soja and G max indicating a stronger LD in G. max. 3 independentevolvement approach were deduced through the comparison of different cpDNAhaplotypes in haplotype network constructed by the 28 cpDNA haplotypes in G. sojaand G. max. The origin of cultivated soybean was supposed to be multi-centre, including Huang-huai River, Yangtse Rive and Midle-south three primarydomesticated centers and North and Huanan two sub domesticated centers with theintegration of the result of haplotype network and geographical distribution ofdifferent haplotypes.