湿地松与加勒比松杂交子代具有显著大于湿地松纯种的生长量优势，与湿地松种子园后代相比，湿地松×洪都拉斯加勒比松杂种的树高、材积平均增益分别为３５．８％，２４４．６％；湿地松×本种加勒比松杂种的树高、材积增益分别为４０．８％，２１０．９％。从中选择出的８个优良杂交组合，其树高、材积平均增益分别达５０．８％和３４９．５％。文中还从理论上探讨了控制杂种优势的遗传因素、湿地松一般配合力与一般杂交力的关系，分析了杂交制种的效果和存在问题 Compared with the progeny of the Pinus elliottii plantation, the tree height and the average volume gain of the hybrids of Pinus elliottii and Honduras were 35.8% 244.6%, respectively; and the tree height of Pinus elliottii × P. caribaea hybrids was 40.8% and 210.9% respectively. Eight excellent hybrid combinations were selected, and the average tree height and volume gain were 50.8% and 349.5% respectively. The article also discussed the genetic factors controlling heterosis, the relationship between the general combining ability of P. elliottii and the general hybrid vigor, and analyzed the effect and existing problems of hybrid seed production