马尾松无性系幼林生长性状变异分析

利用10个马尾松组培无性系苗木为母株营建采穗圃，繁育扦插苗营造无性系试验林，分别使用性状表现水平分析法和加权系数法对其1年生林分内无性系进行了综合评价。结果表明：马尾松无性系地径、树高和成活率平均值分别为25.64 mm、1.32 m和95.8%，分别超过对照平均值8.5%、21.1%和6.4%，无性系生长与实生苗差异达极显著水平（P < 0.01）；参试无性系地径和树高分别介于22.16～31.07 mm和1.12～1.57 m之间，生长差异达到显著水平（P < 0.05），无性系间表型变异丰富；无性系地径和树高重复力分别为0.84和0.92，生长主要受遗传控制。按20%入选率筛选出2个无性系MGC-1和MGC-7，其地径和树高平均值分别为29.80 mm和1.53 m，平均遗传增益分别为13.61%和14.64%，平均现实增益分别为16.21%和15.91%，与对照相比平均遗传增益分别为21.87%和37.01%。

Variation Analysis of Growth Characters in Young Clones Forest of Pinus massoniana

Pinus massoniana cutting orchard was constructed with 10 tissue culture seedlings as mother plant for the setting up of experimental clonal forest with cutting propagation. The comprehensive evaluation of 1-year-old clone was carried out by character expression level analysis and weighted coefficient method respectively. Results show that the average ground diameter and height and survival rate of clones in P. massoniana were 25.64 mm, 1.32 m and 95.8% respectively, which exceeded the control mean 8.5%, 21.1% and 6.4% respectively. The difference of growth characters between clones and seedlings was very significant (P < 0.01); The ground diameter and height of clones were between 22.16−31.07 mm and 1.12−1.57 m respectively, and the growth difference reached a significant level (P < 0.05), phenotypic variation was abundant between clones; The repeatability of ground diameter and height of clones was 0.84 and 0.92 respectively, and the growth was mainly controlled by heredity. According to the 20% selection rate, MGC-1 and MGC-7 were selected, which average ground diameter and height were 29.80 mm and 1.53 m respectively, the average genetic gain were 13.61% and 14.64% respectively, the average real gain were 16.21% and 15.91% respectively, compared with the control group, the average genetic gain were 21.87% and 37.01% respectively.