【摘要】 [目的]为评价和选育优良楸树(Catalpa bungei C. A. Mey)无性系。[方法]本研究利用32个楸树无性系7年的生长测定数据,以分析其生长规律及早期生长过程。对各无性系的单株材积生长进行Logistic拟合回归分析。在此基础上,分析不同指标间的相关性并对32个无性系进行聚类分析。[结果]楸树无性系在不同年份(1 a除外)胸径、树高、单株材积差异极显著,说明楸树无性系间变异丰富。楸树单株材积变异系数最大(7.84%～35.56%),胸径次之(11.89%～17.29%),树高最低(6.91%～10.87%),无性系单株材积改良潜力较大。同时生长后期单株材积(0.75)和胸径(0.82)保持较高的重复力,意味楸树单株材积受遗传控制较强。利用无性系单株材积生长平均值,拟合了楸树无性系单株材积生长曲线的Logistic模型,估算的生长参数在无性系间具有较大差异。楸树无性系7年生单株材积平均年生长量呈"S"型曲线生长趋势,而连年生长量先上升后下降,在第5年达到高峰,截止到本次调查时还未达到数量成熟。相关性分析显示:楸树无性系单株材积生长量与最大生长速率(MGR)、线性生长速率(LGR)、线性生长量(LGI)极显著正相关。聚类分析结果表明:供试的32个楸树无性系分为4大类,其中第I类的楸树单株材积生长总量较大,且具有较强的后期生长潜力。[结论]不同楸树无性系的遗传变异丰富, 1-1、22-07、19-01、16-05、16-01、16-07等6个无性系生长潜力较高,可作为楸树的优良无性系进行推广。更多还原

【Abstract】 [Objective] To evaluate and select Catalpa bungei superior clones. [Method] The field test data of seven years’ growth were collected to analyze the early growth processes and tendencies of different C. bungei clones. Logistic fitting regression analysis method was used on individual volume growth of each clone. In addition, the correlation among different indexes were analyzed and a cluster analysis of 32 clones was carried out.[Result] The differences in DBH, tree height and individual volume among C. bungei clones in different ages(except 1 year old) were extremely significant, indicating that there was a high variation among the clones. The coefficient of variation of individual volume showed the highest(7.84-35.56), followed by DBH(11.89-17.29) and tree height(6.91-10.87), suggesting a greater potential for improvement in the individual volume of clones. At the same time, in the later growth period, the individual volume(0.75) and DBH(0.82) maintained high repeatability, implying that individual volume was strongly controlled by heritability. Using the mean annual increment of individual volume growth in clones, a logistic model of the individual volume growth curve of the C. bungei clones was fitted. The estimated growth parameters were quite different among clones. The mean annual individual volume growth of 7-year-old C. bungei presented a S-shaped growth curve; the annual individual volume growth increased at first and then decreased, and reaching a peak at the 5 th year, however, the clones observed did not reach quantitative maturity according to the curves. The correlation analysis showed that the individual volume increment was significantly positively correlated with the maximum growth rate, linear growth rate, and linear growth increment of C. bungei clones. The results of cluster analysis showed that the 32 C. bungei clones could be divided into 4 categories, the total individual volume of category I was larger and with stronger potential for growth in the later period than the others. [Conclusion] The genetic variation of C. bungei clones is rich. The growth potential of 6 clones among the 32 clones is higher, so they can be used as superior clones for expanding.更多还原