厦门木麻黄种群交配系统及近交衰退

木麻黄耐沙生，盐碱，是沿海优良的防护林树种，从20世纪80年代开始，木麻黄林呈现出衰退现象。采用等位酶分析技术研究木麻黄种群的交配系统及近交衰退，木麻黄种群异交率为0．622，表明为混合酱类型，与其亲缘种比较来看，引种降低了木麻黄异交率，增加了近交，采用电是接估算的近交衰退程度很高。结果表明，引种过程中的建立者效应引起的近交及其后的近交衰退确定在木麻黄林衰退中起了重要作用，根据基因型有选择地引起木麻黄以减轻衰退。

Mating system and inbreeding retrogression of Casuarina equisetifolia plantation, an introduced species in Xiamen

Casuarina equisetifolia, an introduced species, is a good shelter species planted along coastlines due to its enduring sandy and saline habitats.Decline was,however,observed in C. equisetifolia plantations in many areas since 1980's. Mating system and inbreeding retrogression of a plantation of C.equisetifolia in Xiamen and their roles in the decline of C.equisetifolia forests were thus researched using allozyme technique.Multilocus outcrossing rate was 0^622, lower than that expected from related species,indicating a mixed mating system,and more inbreeding caused through this introduction.Calculations from electrophoresis data showed that very a high inbreeding retrogression occurred in the C.equisetifolia plantation,indicating that inbreeding an its subsequent retrogression played an important role in the decline of C. equisetifolia plantation.Alleviating the decline through genotype species introduction was also proposed.