Analysis On Genetic Diversity Of Maize(Zea Mays L.) Landraces In China

Maize(Zea mays L.) is the lagest grain crop cultivated in China which could not be taken place in nationl found security. The maize of Landraces possessed unique enironmental adaptation and abundant hereditary basis, so Landraces resource of maize has been to be the development research direction in development and utilization. We make the stydy of genetic diversity, classification, genetic relation were significant in native germplasm resource, germplasm enhancement, breeding population parent selection, germplasm resource conservation. The study utilized SSR molecular marker detection to Landraces material based on ABI automatic DNA analyzer. The ABI automatic DNA analyzer could accurate analysis the fragment length of amplified products and quantitative expansion final product abundance to analysis the genetic diversity of the existing material. The main results are as follows.1.The allele number present obvious difference in different population by per SSR primer. The range of allele number was in 2-4, 59% of SSR allele locus variation were center on 100-200 bp. The SSR allele locus were in 64-327 bp of offered native maize, but have not deteced the allele locus lower 50 bp or higher 330 bp. The allele loucus polymorphism and number reduced gradually when the allele locus greater than 200 bp.2. The detection of allele number discrepancy was large in different tranches Land races by 36 pairs of SSR primer tested in 259 samples allele number, but the number discrepancy was smaller in average detection of every Landraces. The allele number discrepancy was larger by detected in single Landraces.3. The detection allele number variation was larger by 36 pairs SSR primer in different geography Landraces, but it can reflect the abundant of allele number of native maize. Another reason was primer number and location in chromosome in this study.4. The Landraces were in same designation and cultivate district, but it possessed different germplasm.5. 259 offered samples were classified into 6 sbugroup by genetic structure, then analyzed the genetic constitute and represent variety of every Landraces. Pob43 and Yuzong5 were represented in R subgroup. CIMMYT group of Suwan1, Mohuang9, Mobai1 were represented in G subgroup. Pob69, BS26, Zhongzong5, Dongnong population were represented in Pop3-B subgroup. Three subgroups were represented in native variety of China. Yichangbairihan, Erhuangzao, Xiaohuangli, Qiyezao, Bairizao were represented in Pop6-O.6. 11 skeleton in bred lines and most groups of south west mountainous genetic structure were singleness which almost have no contain BSSS and CIMMYT consanguinty. It can reflect the group of local variety genetic composition were in indigenization. The Landraces have no come into being independent genetic structure in spring sowing of north, summer sowing of Huanghuaihai and southwest mountain of small region. The resons were related to the distribution of native variety and complex environment.