马尾松种子园嫁接植株的分枝与结实特性探讨

A STUDY ON BRANCHING AND CONE-SETTING OF GRAFTED PLANTS IN CLONAL SEED ORCHARD OF MASSON PINE (PINUS MASSONIANA LAMB.)

对福建五一林场马尾松种子园嫁接植株分枝与结实特性及二者相互关系的分析表明：（１）每年侧枝数在无性系间未发现显著差异，但年度间差异显著；同一年份侧枝粗、侧枝断面积和两个性状在无性系间具显著差异，不同年度间差异极显著；（２）无性系球果以单果簇、二果簇、三果簇为主，可集中分布在树冠的上部、中部、下部或较均匀分布；（３）某一轮侧枝的球果产量与该轮侧枝总数无显著相关，但与该轮侧枝断面积和密切相关；单一侧枝的球果产量与基枝径密切相关。

Seed orchards play a very important role in forest genetic improvement.In China more than 1000 hectares of clonal seed orchard of masson pine has been established. Low and unstable seed yield is a main problem to be faced by scientists of tree improvement.The problem's long-time existance is due to two kinds of reasons,on one hand,characteristics of plants in the seed orchard are not well studied,on the other hand,few systematic studies on orchard management have been done.Obviously,the more about the plants have been learned,the more efficient the management measures can be taken.Most of studies on characteristics of plants in conifer seed orchard focus on strobili and cone yields and their distribution on crown of plant, anatomy traits of cones,and reproductive phenology. While branches on which cones grow have seldom been studied. The paper reported results from the study on banching and cone-setting characteristics of the grafted in clonal seed orchards of Masson pine.One hundred plants from 10 clones, 10 ramets from each clone,were randomly sampled from the clonal seed orchard in Wuyi Forest Farm.The number of branches growing annually(BN), average diameter of branches growing in the same year(BD),sum of cross-section areas of branches growing in the same year(BA),cone number(CN),and cone-cluster(CC) on branches of the same year were studied for 5 consecutive years.The results are as follows.1.Difference in NB was not significant among clone but significant among years. NB decreased from the top to the bottom of the crowns,but the trend might change with clones.2.For most of plants,BD and BA did not increase from the top to the bottem of crowns ,which was out of expectation. There were significant differences in BD and BA between years and between clones.3. Most of cones produced came from one-cone cluster,two-cone cluster,and three-cone cluster. Ramets of a clone had a similar cone cluster compound.4.Cones might occur mainly on top,central or bottom of crowns as well as evenly on different positions of crown.5.NB did not have a significant correllation with neither CN nor NB,while BA did; Diameter of branch instead of its cross-section area was significantly correlated with cone-setting on the branch.