日本落叶松插穗生根力的变异和选择效应

VARIATION IN ROOTING ABILITY OF CUTTINGS AND SELECTION EFFECTS OF LARIX LEPTOLEPIS SIEB.ET ZUCC.) GORD

用１２个６．５年生半同胞家系和２个１０．５年生杂种群体的１４０个单株的半木质化插穗在全光自动喷雾装置条件下扦插，研究了生根率，每穗生根数目，最长根的长度，当年插条苗高和根系分布状态（偏向一侧或环基均匀分布）的家系内变异程度，各生根性状间的表型相关关系，遗传力及方差分量等。看到参试１４个家系间各生根性状差异显著，但家系内无性系间的差异比家系间更大，由于生根率与其它生根性状相关很强，可把生根率做为主导选择标准。

An investigation was undertaken in the variations in rooting ability of Larix leptolepis(Sieb.et Zucc.)Gord.using fullsunshine and auto-spray system. The materials used were softwood cuttings which were taken from 10seedlings,at 6.5 year age,of each half-sib families of L.leptolepis and from 140 plants,at 10.5 year age,of two hybrids between L.leptolepis×L.principisrupprechtii Mayr and L.olgensis Henry,respectively.The research results showed that significant phenotypic variations existed in genetic variance,heritability and rooting rates between different families and clones, however,the variations between clones within a family were even more significant than those between families. Therefore,the combined selection based on the performances of both family and clone would be better than that based on family or clone means.Genetic gains could be estimated with combined selection of multitraits.Rooting percentage could be ncreasad by 47.5% through selecting 15% of the best clones other than using the overall mean of 140 individual clones.