Variationin Rooting Ability of Cuttings and Selective Effects among Ortets in A Japanese Larch Cutting Garden──A Case Study

Variation of rooting percentage,number of root per cutting,one side rootingpercentage and correlativities of phenotypes between different rooting characters of cuttingscollected from 3.5-year-old ortets were studied in a Japanese larch [Larix kaempferi(Lamb.)Carr. ]hedged cutting garden,which was established by planting seedings of half-sib families. Selection of ortets with superior rooting ability were also done based on thecombined value of rooting percentage and number of roots per cutting in average. The research showed that there was wide range of variation in different rooting parameters amongcuttings taken from the different families and ortets,but significant variations can only befound among cuttings taken from different ortets. The heritahility of ortets was more important than that of the family in rooting percentage,average number of roots per cutting andthe rate of One side rooting. The significances of correlativity of rooting parameters varied among different families. Significant negative correlativity was found hetween the rootingnumber per cutting and one-side rooting percentage. However,significance of correlativitybetween rooting percentage,number of root per cutting,and one-side rooting percentage varied among some families. According to the results of the combined selection,routing out 50% of ortets which showed lower rooting ability from the garden,or forming new secondcircle garden by using rooted cuttings of 50% selected ortets,rooting percentage and rootnumbers would increase 20% and 28.6% respectively without obviously reducing genetic diversity of the hedged garden.