津巴布韦火炬松遗传资源林的评价与选择

研究了由津巴布韦引入的以家系为代表的火炬松遗传资源50个号的苗期与幼林生长表现。结果表明，5年生的单株材积差异显著，有14个系（含3个对照）与最劣系有显著差异，可列为优系。在30％的家系入选率下，配合选择的材积遗传增益为3．1％，入选优株148株；1、3年生树高与材积的早期相关为较显著或极显著，故早期试验林可测定树高为主，以减少工作量；还比较了3种统计分析方法应用效果和选留前1／3和淘汰后1／3，5年生时优系的保持率和丢失率，并主张早期选择以淘汰劣系，以指导育种与生产工作为好。

Assessment and Selection on the Genetic Resource Test Plantation of Loblolly Pine Introduced from Zimbabwe

Genetic resource of loblolly pine (Pinus taeda) represented by 50 families were evaluated for to study the growth performance in seedling and young stage. The result showed that there was significant difference for single tree volume at the age of 5. Fourteen families (include 3 check families) were significantly different from the most inferior one and were considered as superior families. Under the selection rate of 30% for family, the genetic gain for volume was estimated to be 3.1%, with combined selection and 148 selected trees. Height growth at the age of 1 and 3 was relative or extreme significantly correlated with the volume growth at the age of 5. Therefore, the test plantation could be measured only by height, in order to reduce work load, three statistical methods were compared for their using results. Maintenance rate and loss rate of superior families at the age of 5 were compared when selecting the top one third or superseding the bottom one third of all the families. It was suggested that early selection should be implemented by superseding the inferior families.