恩施楸树半同胞家系幼林综合评价

Comprehensive Evaluation on Young Stand of Half-sib Families of Catalpa bungei from Enshi

为了比较恩施楸树半同胞家系幼林表现差异,以恩施地区收集的天然楸树种子所育实生苗为材料造林,通过测量不同半同胞家系的生长、叶绿素、光合特征等,利用模糊函数对不同半同胞家系进行综合评价。结果显示,不同家系间胸径差异没有达到显著水平(P>0.05),而树高差异则达到了显著水平(P<0.05),这主要与栽植密度过大有关,不同家系间叶片叶绿素含量差异达到了极显著水平(P<0.01)。不同家系表现出不同的光强适应性,‘7号’和‘54号’家系光饱和点均超过1700μmol/(m^(2)·s),对强光有着较好的适应性,‘8号’家系最大净光合速率达到23.24μmol/(m^(2·)s),具有较大的光合潜力,‘11号’和‘8号’家系有较好的弱光适应性,‘7号’和‘8号’家系暗呼吸速率相对较高,代谢活跃。树高、叶片叶绿素含量、光饱和点、最大净光合速率、光补偿点、暗呼吸速率等均与胸径呈正相关,几个家系的综合评价排序为‘8号’>‘54号’>‘9号’>‘7号’>‘12号’>‘11号’‘,8号’家系选育潜力巨大。

In order to compare the performance difference of young stand of half-sib families of Catalpa bungei in Enshi,the seedlings bred with natural Catalpa bungei seeds collected in Enshi were used as materials for afforestation.By measuring the growth,chlorophyll content,and photosynthetic characteristics of different half-sib families,the fuzzy function was used to comprehensively evaluate the difference among these half-sib families.The results showed that the difference in diameter at breast height(DBH)among different families did not reach a significant level(P>0.05),while the difference in tree height reached a significant level(P<0.05),which was mainly related to the excessive planting density.The difference in leaf chlorophyll content among different families reached a highly significant level(P<0.01).Different families showed different light intensity adaptability.The light saturation point of‘No.7’and‘No.54’families both exceeded 1700μmol/(m^(2)·s),and they had good adaptability to strong light;the maximum net photosynthetic rate of‘No.8’family reached 23.24μmol/(m^(2)·s),with great photosynthetic potential;‘No.11’and‘No.8’families had relatively good low light adaptability;and‘No.7’and‘No.8’families had relatively high dark respiration rate and active metabolism.Tree height,leaf chlorophyll content,light saturation point,the maximum net photosynthetic rate,light compensation point and dark respiration rate were all positively correlated with DBH.The comprehensive evaluation ranking of the families was‘No.8’>‘No.54’>‘No.9’>‘No.7’>‘No.12’>‘No.11’,and‘No.8’family had a great potential for breeding.