银杏主要栽培品种遗传多样性分析

The Fingerprinting and Genetic Diversity of Main Ginkgo Cultivars

以44个银杏主要栽培品种为材料,应用ISSR分子标记为手段,利用5个标记所产生的16个多态位点绘制这44个银杏栽培品种的ISSR指纹图谱,对这44个栽培品种进行了区分,并结合RAPD分子标记对该栽培群体的遗传多样性进行了研究。结果表明:ISSR所估算出的平均有效等位基因数目、基因多样度和Shannon指数分别为1.730 7,0.410 1和0.596 3,而RAPD所估算出的值分别为1.573 5,0.333 1和0.497 9,说明该群体有较高的遗传多样性。ISSR技术在估算银杏遗传多样性时较RAPD更为精确。

In order to distinguish the main Ginkgo cultivars and genetic diversity among them, 44 main Ginkgo cultivars planted in Pizhou Ginkgo Germplasm Garden, Jiangsu, China were sampled and analyzed by molecular marker RAPD and ISSR. These cultivars are planted widely in China. The ISSR results showed that 44 main Ginkgo cultivars could be identified by 16 polymorphic sites amplified by 5 ISSR primers. A computerized ISSR fingerprinting of the 44 Ginkgo cultivars was drawn to facilitate the management of cultivars. The genetic diversity of the cultivar population was studied by RAPD and ISSR. The results showed that the average effective number of alleles, gene diversity and Shannon＇s information index revealed were 1. 730 7,0. 410 1 and 0. 596 3 respectively by ISSR, and were 1. 573 5,0. 333 1 and 0.497 9 respectively by RAPD, which indicated high genetic diversity among the population. ISSR marker was more accurate in assessing the genetic diversity of Ginkgo than that of RAPD. So it indicated that ISSR is a good molecular marker to distinguish Gingko cultivars, and it can be put into practical use when more cultivars are added and more appropriate primers are sequenced. As there exist high genetic diversity in Ginkgo cultivars, it is important to collect as many representative trees planted in different places as possible, in order to protect and exploit them better.