湿地松种子分级育苗的研究

Effect of Seed Sorting on Germination and Seedling Quality of Slash Pine

将湿地松混系种子筛分为大、中、小三个粒度级进行发芽和播种育苗。据此进行的两地点两年度的试验结果表明，分级改变了种子的大小和重量分布，影响种子的发芽速度，进而影响到苗木的早期生长。在芽苗时期和苗木生长早期，各粒度级种子所育苗木有差异，但在生长后期已基本消失，混系种子分级未能达到改进苗木质量和一致性的目的。在育苗时首先要考虑种批的遗传构成，其次才是按种子大小或重量分级。

Germination tests were conducted in two nurseries for two successive vearsby using slash pine seeds of 3 different size classes. The results show that seed sorting haschanged the seed size and weight distribution of seed lots,which influenced the speed of seedgermination,and then the early growth of the seedlings. In the germination stage and earlygrowing period,there were significant differences between the seedlings from different seedsize classes,but there was no difference in the late growing period.Using different size ofseed lot could not achieve the objective of increasing the seedling quality and uniformity.Innursery practices,the genetic makeup of seed lot would be of the first factor considered,thenthe seed size or weight.