灰楸不同杂交组合杂种后代叶片特征与光合能力的关系

以灰楸为母本，楸树、滇楸、灰楸为父本的杂交组合2年生苗为材料，分别测定了其叶片特征、叶绿素含量和光合特性，比较灰楸不同杂交组合杂种后代叶片性状及光合特性差异。结果表明：灰楸不同杂交组合杂种后代的叶片性状和光合性能指标均存在显著或极显著差异。叶面积的变异系数和重复力处于较高水平，比叶质量最低；叶面积遗传变异丰富高于其他指标。父本不同的杂交组合，叶片性状的变异趋势为滇楸>楸树>灰楸。灰楸种间杂交的光合能力、叶面积、叶绿素含量都大于种内杂交；灰滇杂最大净光合速率、叶面积分别高于灰楸杂、灰灰杂12.96%、22.39%，51.29%、46.19%。相关性分析显示，灰楸不同杂交组合杂种后代的光合能力与叶绿素含量，叶面积及比叶质量呈极显著正相关。29个杂交组合中，董水黄庄、石家庄选择的母本杂交组合的光合参数、叶面积、比叶质量高于廖家庄及高家庄选择的母本，董水黄庄3号×改毛4号的叶面积和最大净光合速率最高。初选5个具有杂种优势的杂交后代，其叶面积、比叶质量、光合能力的增益分别14.91%、5.71%、23.8%。

Relationship Between Leaf Characteristics and Photosynthetic Capacity of Hybrid Progenies of Different Hybrid Combinations of Catalpa fargesi

The trial with 2 years old seedlings of a hybrid combination of Catalpa fargesi as the female parent, Catalpa bungei, Catalpa fargesii and Catalpa fargesi as the male were used as materials. The differences of leaf traits and photosynthetic characteristics of different hybrid combinations of C. fargesi were compared and analyzed. The leaf characteristics, chlorophyll content and photosynthetic characteristics were determined respectively. The results showed that there were significant or extremely significant differences in leaf traits and photosynthetic performance indexes among different hybrid combinations of C. fargesi. The coefficient of variation and repeatability of leaf area were higher, and the specific leaf weight was the lowest. The genetic variation of leaf area was higher than other indexes. The variation trend of leaf characters of different male parent combinations was C. fargesii > C. bungei > C. fargesi. The photosynthetic capacity, leaf area and chlorophyll content of interspecific crossing species between C. fargesi were higher than those of intraspecific hybridization. The maximum net photosynthetic rate and leaf area of the hybrid of C. fargesi and C. fargesii were higher than those of C. fargesii and C. bungei and those of C. fargesii and C. fargesii, which were 12.96%, 22.39%, 51.29% and 46.19%. The correlation analysis shows that photosynthetic capacity, chlorophyll content, leaf area and specific leaf weight of hybrid progenies of different hybrid combinations of C. fargesiiwere significant positive correlation. Among 29 cross combinations, the photosynthetic parameters, leaf area and specific leaf weight of female parent selected by Dongshuihuangzhuang and Shijiazhuang were higher than those of Liaojiazhuang and Gaojiazhuang. The leaf area and the maximum net photosynthetic rate of hybrid progenies of Dongshuihuangzhuang 3# × Gaimao 4# were the highest. Preliminary selection of 5 hybrid progeny with heterosis, the gains of leaf area, leaf weight and photosynthetic capacity of 5 hybrid progenies with hybrid advantages were 14.91%, 5.71% and 23.8% respectively.