木荷种源遗传多样性和种源区初步划分

Genetic Diversity Analysis and Provenance Zone Allocation of Schima superba in China Using RAPD Markers

利用RAPD分子标记研究我国高效生物防火和优良用材树种木荷主要分布区15个地理种源的遗传多样性和遗传结构。结果显示,木荷具有丰富的遗传多样性,木荷种内平均基因多样度为0.3636。研究发现木荷种源Shannon表型多样性与产地纬度呈显著的负相关,南部种源的遗传多样性显著高于北部种源,从而推测25°N左右的自然分布区可能是木荷的分布中心。木荷有27.14%的遗传变异存在于种源间,而72.86%的遗传变异来自于地理种源内。基于分子水平上的种源聚类,可将木荷分布区划分为3个种源区:北缘种源区(安徽南部和浙江北部)、中部种源区(南岭以北、浙江南部以南)和南部种源区(南岭以南),而南部种源区和中部种源区又都可再分为东部和西部2个种源亚区。

Genetic diversity and genetic structure of 15 provenances from main natural range of Schima superba, an effective biological fire-resistance and high-quality timber species in South China, were analyzed using RAPD markers. It was indicated that there existed a high degree of genetic diversity for S. superba. Nei＇s gene diversity was 0. 363 6. Shannon＇s information index of provenances was significantly and negatively related to the latitudes of the seed sources. The southern provenances had higher genetic diversity than the northern ones. The natural distribution area at latitude of approximately 25°N may be the central distribution zones of S. superba. Genetic differentiation among provenances was found to be high, and 27.14% of genetic variation existed among provenances. Based on the Nei＇s unbiased genetic distance, the whole natural range of S. superba might be obviously divided into North provenance zone （ the south of Anhui Province and the north of Zhejiang Province）, Middle provenance zone （the north of Nanling mountain and the south of South Zhejiang） and South provenance zone （the south of Narding mountain）. The South and Middle provenance zone could all be further subdivided into East and West sub-zones.