乐昌含笑家系试验初报

对乐昌含笑17个家系1～2年生树高、地径、主干通直度、树冠浓密度和叶片大小等生长指标和形质指标进行测定与分析，结果表明：2个生长指标和3个形质指标在家系间的差异均达到不同程度的显著水平；生长指标具有显著的家系×地点互作效应，而形质指标的差异不显著；所有指标在地点间差异都达到极显著水平（P〈0．01）。早期树高和地径遗传力在0．60～0．86之间，受到较强的遗传控制。九曲水林场试验点所有参试家系的树高年平均生长量达0．90m，地径年平均生长量达2．23cm，是林分树高、地径年生长量最高的试验点，其中表现较好的家系有乐九4和乐九5；大坑山林场试验点稍次之，其中表现较好的家系有乐九4、乐九3、乐两15和乐两12；增城市林业科学研究所试验点年生长量较高的家系为乐两6。

Study on Early Trials of Michelia chapensis Dandy Families

17 families of Michelia chapensis Dandy were tested in three different sites of Guangdong prov-ince. The growth and form indexes of one to two-year-old trials such as height, crown thickness and leaf size were measured and analyzed. The differences of two base diameter, bole straightness, growth indexes and three form indexes among families reached a certain significant level respectively. The mutual effects of family and environment were significant in the two growth indexes, whereas not in the three form indexes. There were highly significant differences in all indexes among sites（ P 〈0.01 ）. The heritability of height and base diameter were 0.60 -0.86, which indicated that the early height and base diameter were strongly controlled by gene. The average height and base diameter of all tested families reached as high as 0.90 m and 2.23 cm in Jiuqushui State Forest Farm trial, family LeJiu 4 and LeJiu 5 were considered as superior ones; which were lower in Dakengshan State Forest Farm trial, family LeJiu 4, LeJiu 3, LeLiang 15 and LeLiang 12 were considered as superior ones; family LeLiang 6 was superior in Zengcheng Forestry Research Institute trial.