摘要
我们依据油松受松干蚧危害后的表型特征和松干蚧无肢若虫显露数量的变化,进行受害等级的划分,并对受害级与树木生长及立地条件的关系、幼树受害的过程和抗性优树选择的标准等进行了研究。结果表明:油松受松干蚧危害后,可以根据表型特征直观地划分为四个等级,各级之间株率呈9:3:3:1的比例关系、与立地条件无关;树木生长量与若虫显露量呈负相关,但不显著,以Ⅰ级树生长最好且无受害症状。Ⅰ级树与Ⅲ、Ⅳ级树之间的生长差异极显著;受害树6龄即可表现症状,从15年生后受害明显减轻,因此,选择抗性优树林龄定为15年生以上,以5株优势木法在Ⅰ级树中选择优树,优树须大于5株优势木平均值:胸径在15％、树高在5％以上。
Based on the investigation of symptoms of the infected Chinese pine tree and the amount of their nymph, the infected trees are graded into four classes. There is in the ratio of 9:3:3:1 among the four classes of trees. The gradation is not related to the environment. There is a negative correlation between the tree growing capacity and the amount of the nymph, but not significant. The trees of class Ⅰ grow normally without symptoms. The difference of growth between Ⅰ and Ⅲ, Ⅳ class of trees is very significant. The symptoms occured on the infected trees which are six years old. If no symptoms occured on such trees they will not occur ever. The chances of infection will become much less when the trees are over 15 years old. For this reason, the age of stand in which the plus trees with the resistance are selected will be over 15 years old. By using the method of 5 dominant trees, the plus trees shall be selected among the trees of class Ⅰ and its DBH and H must be larger than the average by 15% and 5% respectively.
出处
《林业科学》
EI
CAS
CSCD
北大核心
1989年第1期7-13,共7页
Scientia Silvae Sinicae
关键词
松干蚧
油松
优势木
抗性
Dominant tree
Allele
Dominant gene
