厚荚相思家系抗寒性变异与选择

Genetic Variation of Cold Resistance of Acacia crassicarpa Between Different Families and Family Selection

为探索厚荚相思(Acacia crassicarpa)不同家系在抗寒能力上的差异和筛选耐寒家系,对遭受2008年特大寒流袭击的不同试点1年生厚荚相思子代林进行田间寒害调查测定,分析结果表明:所有参试家系均受到寒害影响,但两个地点试验林分的受害程度表现不同,大塘点受寒害严重,各家系平均寒害级值在2.67～4.00,平均寒害指数达92.3%;而钦州点受寒害较轻,平均寒害级值在0.60～1.93,平均寒害指数为26.0%。试点内家系间抗寒性差异极显著,家系内各株间变异量是家系间变异量的2～4倍,寒害级值的家系遗传力高于单株遗传力,抗寒性状呈强度遗传。试点间的寒害率和寒害指数均达到极显著正相关,但家系的抗寒水平与主要生长因子间无显著相关关系,根据田间抗寒表现初步筛选出10个抗寒性强的家系,两个试点选出家系其抗寒性状寒害级值的平均遗传增益分别可达10.23%和21.89%。

A survey on cold injury in one-year-old Acacia crassicarpa forest,subjected to a serious cold wave in 2008,was carried out in order to explore the variation in cold resistance between different families and screen out families with strong cold tolerance.Results indicated that all the families suffered from cold injury,but the injury degrees were different in the two investigated sites.The degree of cold injury was more serious in Datang than that in Qinzhou.The average cold injury level was 2.67-4.00,and the average cold injury index was 92.3% for all the investigated families in Datang,while the average cold injury level was 0.60-1.93,and the average cold injury index was 26.0% for the families in Qinzhou.There were extremely significant difference in cold resistance among families,and the variation among families was 2 to 4 times as much as that within families.It was found that the heritability of cold injury level of the families was higher than that of the individuals,and the cold resistance in families was strongly controlled by genetic factors.Extremely significant positive relationship was observed between cold injury rate and cold injury index in different sites,but no significant relationship between cold resistance and main growth factors among families in the same site.Ten families with strong cold resistance were preliminary screened out based on the average cold injury index and the performances of young trees in the field,and the average genetic gains of cold injury level of the families in Datang and Qinzhou were 10.23% and 21.89%,respectively.