红椿不同种源的苗期生长节律研究

【目的】揭示红椿Toona ciliata 18个种源的苗期生长规律,为培育优质红椿苗木和选择优良种源提供科学依据。【方法】对红椿18个种源一年生苗木的苗高和地径进行定期观测,利用SPSS进行方差分析,获得遗传变异系数,并利用Logistic方程对苗高和地径进行曲线拟合,估算生长参数,分析苗高、地径与地理及生态因子的相关性。【结果】红椿苗期苗高和地径遗传变异系数分别为43.31%和36.25%;参试种源苗高和地径生长的地理变异以经度控制为主。苗高和地径的生长均呈现"慢-快-慢"的"S"型生长曲线模式;在观测期间,苗高与地径生长都出现2次高峰;不同种源红椿生长性状的Logistic方程拟合决定系数为0.971~0.998,均达到了显著水平;可将红椿苗高和地径的生长分为生长前期、速生期及生长后期3个阶段。参试红椿种源在各个时期的起始及持续时间存在差异。【结论】红椿苗高和地径遗传潜力大。不同种源生长性状的地理变异趋势明显,采种点由东到西苗高及地径生长变快。苗期生长节律存在显著差异。在速生期中,华中及华东地区种源苗高和地径快速生长持续时间较长,但生长量较小,并且年总生长量较低。

Growth rhythms of Toona ciliata seedlings from different provenances

Objective] To study the growth rhythms of Toona ciliata seedlings from 18 provenances, to provide a scientific basis for breeding and screening high-quality T. ciliata provenance. Method]Heights and ground diameters of one-year-old T. ciliata seedlings from 18 provenances were regularly observed. Analysis of variance was performed using SPSS, and the genetic coefficients of variation ( GCV) were obtained. The Logistic equations were used for fitting the growth curves of seedling heights and ground diameters, and for estimation of the growth parameters. The correlations between seeding height, ground diameter and geographical, ecological factors were investigated. Result]The GCV of seeding height and ground diameter of T. ciliata were 43. 31% and 36. 25% respectively. The geographic variations in two traits were mainly influence by longitude. The growths of the two traits were both in a “slow-fast-slow” pattern showing a similar “S” curve. Two growth peaks of each trait were observed. The determination coefficients of Logistic equations varied from 0. 971 to 0. 998 for T. ciliata from different provenances, and the fitting degrees reached significant levels. The growth of T. ciliata seedlings could be divided into three stages, including the early, fast and late growth stages. T. ciliata from different provenances had different starting and ending time for the three stages.Conclusion]There are great heredity potentials in seeding height and ground diameter of T. ciliata. Geographic variation trends of the two traits are obvious among different provenances. The seeding height and ground diameter grew faster for T. ciliata from western provenances compared to eastern provenances. There were significant differences in seedling growth rhythms. During the fast growth stage, the growths in seedling height and ground diameter for T. ciliata from eastern provenances lasted longer compared to western provenances, while the extent of growth of this stage and yearly growth were both smaller for the provenances from central China and east China.