Data from: Genetic parameters in subtropical pine F1 hybrids: heritabilities, between-trait correlations and genotype-by-environment interactions

Growth and stem straightness traits of 29 Pinus caribaea var. hondurensis × Pinus tecunumanii (PCH × PTEC) and 26 P. caribaea var. hondurensis × Pinus oocarpa (PCH × POOC) hybrid pair-crosses plus a total of 16 intraspecific families were assessed at ages 5, 8 and 15 years from planting at two sites. The PCH × PTEC hybrid was the most productive, yielding 37 % more than a Pinus elliottii local control and was 21 % superior to either parental species in DBH growth. PCH × POOC hybrid was, on average, 16 % superior to either parental species for DBH. Narrow-sense heritability estimates were low to moderate for growth traits (average of 0.27) and stem straightness (0.16). The estimated additive genetic correlations between growth traits and ages within traits were high (>0.8) and positive, providing confidence in early selection based on diameter at breast height. The high proportion of estimated additive genetic variance compared to dominance variance in the F1 pine hybrids suggests that breeding strategies that maximize the use of additive genetic variance may be effective. The ranking of the 11 PCH parents based on general hybridizing ability predictions (estimated breeding values as hybrids) was somewhat inconsistent between PTEC and POOC hybrid crosses for all traits (r 9 d.f. = 0.38–0.45; p ∼0.15–0.25). There was no evidence of practically important G × E interaction for the hybrids except for PCH × PTEC height growth. This study suggests that a single, multi-hybrid breeding population seems appropriate in Zimbabwe if the trial sites are representative of the planting target zone.

本研究在2个试点开展造林试验，于造林后5、8、15年对供试材料的生长性状与树干通直度性状进行测定。供试材料包括29个洪都拉斯加勒比松（*Pinus caribaea* var. *hondurensis*）×特库马内松（*Pinus tecunumanii*，简称PCH×PTEC）杂交组合、26个洪都拉斯加勒比松×卵果松（*Pinus oocarpa*，简称PCH×POOC）杂交组合，以及共计16个种内家系。其中PCH×PTEC杂交组合表现最优，其材积产量较当地湿地松（*Pinus elliottii*）对照品种高出37%，在胸径（Diameter at Breast Height，DBH）生长方面较其两个亲本种均提升21%。PCH×POOC杂交组合的胸径生长平均较其两个亲本种高出16%。生长性状的狭义遗传力估计值处于低至中等水平（平均为0.27），树干通直度的狭义遗传力为0.16。生长性状间以及同一性状在不同林龄间的加性遗传相关系数均较高（>0.8）且为正值，这为基于胸径开展早期选择提供了可靠依据。与显性遗传方差相比，F1代松类杂交组合的加性遗传方差占比更高，这提示最大化利用加性遗传方差的育种策略或可取得良好效果。基于一般杂交配合力预测值（即作为杂交亲本的估计育种值）对11个PCH亲本进行排名，结果显示，在所有性状上，该类亲本在PTEC与POOC两类杂交组合中的排名存在一定不一致性（自由度为9时，相关系数*r*=0.38~0.45；*P*≈0.15~0.25）。除PCH×PTEC杂交组合的树高生长性状外，未发现供试杂交组合存在具有实际重要性的基因型×环境（G×E）互作。本研究表明，若试验试点能够代表目标造林区域，则在津巴布韦构建单一的多杂交组合育种群体似乎是适宜的。