不同生理老化程度杉木外植体的组培效果

从12株28年生杉木树冠上取条，嫁接在1年生实生苗根系上作为复壮母株，用同一株树的基部萌条杆插苗作为对照母株，上述2种母株经过几次在地面下切割，使其重新萌条和长出根系，然后用新的萌条作外植体进行组培试验，即第1组材料，同时，直接从10株20年生杉木上采取上部萌条作外植体进行同样的组培试验为第2组。共进行了9次继代培养，用成对样本T检验法比较同一无性内两种外植体的差异用成组样本T检验法比较两组无性系间的差异。结果表明，成树上部侧枝外植体的芽分化数量、嫩梢数量、嫩梢长度、生根率、根长等性状均始纳税极显地低于树干基部萌条和经复壮处理的外植体；复壮外植体与基部萌条的差异在最初的3次继代培养中仍然存在，但在以后的继代培养中消失了，谤些结果表明，嫁接、切割、生根和组培对杉木有明显的复壮作用。

Results of In-vitro Explants with Different Maturation Status from the Same Gene -types of Chinese fir

Upper branches of each of 12 28-year-old trees of Chinese fir were grafted onto root systems of one-year-old seedlings as donors for rejuvenation. Basal sprouts of the same trees were rooted as donors as controls. Sprouts of these donors were cut in earth, which allows new sprouts to develop their own roots. Cutting process were done several times and then new shoots were taken as explants for tissue culture in a group. In addition, upper branches and basal sprouts were taken directly from each of 10 20-year-old trees as explants and cultured in-vitro as second group. A total of 9 subcultures were conducted. Paired sample T test method was used to compare the difference between the two explants of the same trees. Independent sample T test method was used to determine the difference between the two groups. It was found that the average number of buds and shoots per explant, the average shoot length, the rooting percentage and average root length of the upper branch explants were lower than those of the grafted explants at 0.01 level. The differences of these characteristics between graft-origin and basal-sprout explants remained in the first 3 subcultures, however, they disappeared in the late. The results indicate that grafting scion, cutting stems, rooting and tissue culture itself have some functions of rejuvenating mature tissues of Chinese fir.