橡胶树优良品种云研76-235的选育报告OA

High yield with cold resistance clones is the core objective of rubber tree breeding in Yunnan.In this study,the cold-resistant clone GT1,which exhibits strong tolerance to radiative chilling injury,was selected as the female parent,and the widely cultivated fast-growing,high-yielding variety Yunyan 277-5 was used as the male parent.Through artificial isolated pollination,hybrid offspring were obtained.After a sexual family trial,individual plants with potentials were selected from the progeny population and entered into small-scale and large-scale clone comparative trials.This process led to the selection of an excellent clone,Yunyan 76-235,which is characterized by high yield and fast growth with the cold resistance and latex production type comparable to the clone RRIM600.Thirty years of sys-tematic evaluation demonstrated that Yunyan 76-235 exhibits rapid early growth,with an average annual girth incre-ment of 6.0 cm by the 6th year after planting in the primary trial area,which is 115.4%of the clone RRIM600.It also shows high yield of dry rubber,with an average annual dry rubber yield per tree of 2.64 kg in years 1-5 of tapping in the small-scale clone comparative trials,representing 149.26%and 168.54%of the RRIM600 and GT1,respectively.In the large-scale clone comparative trials,the average annual rubber production per tree in years 1-13 of tapping was 4.6 kg,which is 140.12%of the RRIM600.Its cold resistance is stronger than that of RRIM600 but weaker than that of GT1 and Yunyan 77-4.The successful breeding of clone Yunyan 76-235 enriches the genetic resources for rubber cultivation in areas of Yunnan where prone to mild and moderate cold damage,providing variety support for the development and enhancement of the local rubber industry.