三明格氏栲保护区种子植物区系特点及其地理意义

为弄清广西境内马褂木( Liriodendron chinense)天然群体的遗传多样性及分布情况,该研究运用ISSR分子标记,对广西境内现存的6个野生马褂木种群进行遗传多样性分析及评价。结果表明：广西马褂木群体具有较丰富的遗传多样性,6个参试群体的平均(及总体)有效等位基因数( Ne)、Nei’ s 基因多样度( H)和Shannon信息指数(I)分别为1.4541(1.6337)、0.2576(0.3633)和0.3786(0.5293)；群体间存在基因流动但水平有限( Nm＝1.2184),使群体间存在较高遗传分化( Gst ＝0.2910)；聚类分析( UPGMA)将6个天然群体分为东部(全州QZ、资源ZY及融水老堡RS￣L)、西部(融水安太RS￣A、环江HJ及乐业LY)两组,其中东部组具有较低遗传多样性及较高的遗传分化,可能受到较强的人为干扰；Mantel检验表明群体间符合距离隔离模式( R＝0.545, P＝0.043),表明人为破坏导致的生境碎片化是造成广西马褂木天然群体遗传分化的重要原因。针对广西马褂木天然群体较丰富的遗传多样性及较高的遗传分化,除了考虑对遗传多样性较高群体(如RS￣A及HJ)进行原地保护外,宜对各群体采集种子或穗条,统一营建基因资源收集区,以供后续育种及生产利用。

Spermatophyte flora and its geography implication of Sanming Castanopsis kawakamii Nature Reserve

Spermatophyte flora characteristics, from Sanming Castanopsis kawakamii Nature Reserve in Fujian Province, were analyzed and the differences among four adjacent regions were compared based on the spermatophyte list which was formulated according to specimens collection and relevant literatures. The results showed that flora origin was relatively old and maintained the original species composition that had kept a complete evolutionary series of seed plants since the Miocene. Due to its complex terrain conditions and alternate climate influence of wind belt from east and west, the species composition is abundant and consists of 1 303 species belonging to 149 families and 602 genera; the constructive species belongs to the families of Lauraceae and Fagaceae, has more complex family and genus geographic components of tropical distribution type than that of temperate distribution, and pantropical distribution has the largest proportion; by comparing with adjacent areas, the similarity with Daiyun Mountain is the highest and decreased with the movement toward north or south. Flora characteristic analysis illustrates that the spermatophyte flora, in Sanming Castanopsis kawakamii Nature Reserve, belongs to the Lingnan area but not the East China. Plants flora, in this area, belong to the Eastern Asiatic region, Sino-Japan forest subregion, Lingnan region, and North Guangdong subregion. The distribution of family, genus, species and specific degrees are discussed among. South Zhejiang subregion controlled by C. scleiophylla, North Fujian subregion, North Guangdong region and East Nanling subregion controlled by C. hystrix, North Fujian subregion neither controlled by the two species.