National Engineering Laboratory for Forest Tree Breeding, Key Laboratory for Genetics and Breeding of Forest Trees and Ornamental Plants of Ministry of Education, Beijing Forestry University Beijing, 100083, China.
State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences Beijing, 100093, China.
Ecol Evol. 2014 May;4(10):1890-902. doi: 10.1002/ece3.1062. Epub 2014 Apr 19.
Genetic analyses indicate that Pinus densata is a natural homoploid hybrid originating from Pinus tabuliformis and Pinus yunnanensis. Needle morphological and anatomical features show relative species stability and can be used to identify coniferous species. Comparative analyses of these needle characteristics and phenotypic differences between the artificial hybrids, P. densata, and parental species can be used to determine the genetic and phenotypic evolutionary consequences of natural hybridization. Twelve artificial hybrid families, the two parental species, and P. densata were seeded in a high-altitude habitat in Linzhi, Tibet. The needles of artificial hybrids and the three pine species were collected, and 24 needle morphological and anatomical traits were analyzed. Based on these results, variations in 10 needle traits among artificial hybrid families and 22 traits among species and artificial hybrids were predicted and found to be under moderate genetic control. Nineteen needle traits in artificial hybrids were similar to those in P. densata and between the two parental species, P. tabuliformis and P. yunnanensis. The ratio of plants with three needle clusters in artificial hybrids was 22.92%, which was very similar to P. densata. The eight needle traits (needle length, the mean number of stomata in sections 2 mm in length of the convex and flat sides of the needle, mean stomatal density, mesophyll/vascular bundle area ratio, mesophyll/resin canal area ratio, mesophyll/(resin canals and vascular bundles) area ratio, vascular bundle/resin canal area ratio) relative to physiological adaptability were similar to the artificial hybrids and P. densata. The similar needle features between the artificial hybrids and P. densata could be used to verify the homoploid hybrid origin of P. densata and helps to better understand of the hybridization roles in adaptation and speciation in plants.
遗传分析表明，云南松与华山松的同源多倍体杂种起源于云南松。针叶形态和解剖特征显示出相对的物种稳定性，可用于鉴定针叶树种。人工杂交种、云南松和双亲种之间的这些针叶特征和表型差异的比较分析可用于确定自然杂交的遗传和表型进化后果。在西藏林芝的一个高海拔生境中播种了 12 个人工杂交家系、两个亲本地种和云南松。收集了人工杂交种和三个松树种的针叶，并分析了 24 个针叶形态和解剖特征。基于这些结果，预测并发现人工杂交家系中 10 个针叶特征的变异和种间及人工杂交种间的 22 个特征受中度遗传控制。在人工杂交种中有 19 个针叶特征与云南松和两个亲本地种华山松和云南松相似。人工杂交种中有三个针叶簇的植株比例为 22.92%，与云南松非常相似。人工杂交种的 8 个针叶特征（针叶长度、2mm 长的凸面和平面针叶段中气孔的平均数量、平均气孔密度、叶肉/维管束面积比、叶肉/树脂管面积比、叶肉/（树脂管和维管束）面积比、维管束/树脂管面积比）与生理适应性有关，与人工杂交种和云南松相似。人工杂交种与云南松相似的针叶特征可用于验证云南松同源多倍体杂种的起源，并有助于更好地理解植物杂交在适应和物种形成中的作用。
