形态与分子标记用于羊草种质鉴定与遗传评估的研究

Germplasm identification and genetic evaluation on Leymus chinensis with morphology and molecular marker

利用分子标记与形态标记对随机抽取的 17份禾草种质进行了种质评估的比较研究。结果表明 ,2种方法均在17份供试材料中鉴别出 9份羊草种质 ,占供试样品的 5 3% ,说明分子标记方法用于羊草种质资源鉴定是可行的 ,并具有快速、准确、不受环境条件限制等优点。在 4 0个 10 Mer的随机引物当中新筛选出 2 1个有效引物 ,以其对 9份羊草材料进行 RAPD分析 ,共扩增出 115条带 ,DNA片段大小在 0 .2 kb- 5 .5 kb之间 ,其中 95条带表现出多态性 ,多态比率 82 .6 1% ,平均每个引物扩增的多态性带为 4 .5条。研究表明 ,S12 13- 90 0 ,S12 13- 170 0 ,S12 15 -5 5 0 0 ,S1396 - 1370 ,S1384 - 90 0 ,S12 0 2 - 5 180 ,S12 2 0 - 2 2 0 0 ,S1381- 15 80 ,S12 11- 2 80 0 ,S12 11- 80 0为羊草种质所具有的 10个特异性标记 ,据此可将羊草种质与披肩草、赖草加以区分 ,同时在羊草种内亦发现 13条可区分供试羊草种质的特有标记。形态标记与分子标记相关性分析结果显示 :羊草种质的小穗数 ,种子千粒重 ,叶色 ,有性繁殖量和结实率 5个形态学指标与遗传多样性指标——特有带百分率及遗传距离之间 ,存在一定相关性 ,可以用于羊草种质的遗传评估。笔者对羊草种质资源在收集和评价过程中存在的问题进行了探讨。

In this paper, seventeen accessions were selected arbitrarily from collected germplasm resources. The identification on species of Leymus chinensis (Trin.) Tzvel. was carried out based on both RAPD and morphological data. The results revealed that nine of them were object species occupying 53% among all experiment materials. Compared with morphological data, RAPD marker is a efficient mean with advantages of rapidity, reliability and no influence by environment events. Twenty-one primers were screened from 40 ten mer arbitrary primers, and a total of 115 DNA fragments were amplified ranging from 0.2~5.5 kb in 9 L.chinesis, among which 95 (82.61%) were polymorphism. The average number of RAPD fragments produced by each primer was 4.5. Ten specific bands -S1213-900,S1213-1700,S1215-5500, S1396-1370,S1384-900,S1202-5180,S1220-2200,S1381-1580,S1211-2800,S1211-800 were found in nine genotypes of L.chinesis. Furthermore, the samples of L.chinesis could be distinguished with the 10 special marker. Based on morphological and RAPD data, there were some correlations between the morphological descriptors (number of spikes, weight of one thousand seeds, leaf color, the level of sexual propagation, setting percentage) and index of genetic diversity. Additionally, the problems in the process of collecting, arranging and evaluating for accession of L.chinesis are discussed.