Research on Superior Family Selection and Genetic Stability of Rooting of Green-wood Cuttings of Hybrid Larches

Different hybridized combinations between intraspecies and interspecies of larches showed different heterosis,and genetic characteristics could be maintained by asexual propagation.The results of experiments on growth and cuttings of superior families of hybrid larches in 3 successive years indicated that the best hybridized combinations were Korean Larch 14×Japanese Larch and Korean Larch 4c×Japanese Larch,the rooting rates of cuttings and development of root systems were increased compared with maternal plants,which indicated that hybridization of Korean Larch with Japanese Larch increased not only growth but also rooting characteristics.Japanese Larch yong8×Korean Larch increased not only growth but also rooting characteristics compared with maternal plants.However, the number of roots and the length of the longest root were lower than Korean Larch×Japanese Larch compared with hybridized combinations of Korean Larch ×Japanese Larch except for growth of 3 years was higher and the rooting rates were lower than Korean Larch 14×Japanese Larch and Korean Larch 4c×Japanese Larch.So much emphasis should be put on higher rooting rates in selection of superior clones.Propagation of cuttings of hybrid larches could bring the inheritance potentials into full play.The heritability for most characteristics was much higher except for lower heritability of one-side rooting percentage,thus stability of superior genetic characteristics of maternal plants were maintained.