广东桑多倍体育种研究的进展

RECENT PROGRESS IN THE STUDY OF POL YPLOIDY BREEDING OF Morus atropurpurea Roxb.

普查了广东桑（ＭｏｒｕｓａｔｒｏｐｕｒｐｕｒｅａＲｏｘｂ．）３２４份材料染色体数，获得三倍体桑１５份；建立了应用秋水仙素处理广东桑杂种实生苗（有性系）诱导四倍体的技术程序，提出“苗期选择法”，从４个生态型中选择，可提高诱导率１．３３倍，选出的高产、优质材料也提高１．８３倍；研究了其主要性状，选出具有优质、高产、种子量多的种质资源一批，克服了从白桑、山桑、鲁桑等桑种的无性系获得的四倍体桑生长缓慢、生产量少、孕性差等缺点。利用四倍体桑为亲本，初步育成优良三倍体杂交组合７个，定名粤桑１号至７号，简介其性状，提供生产鉴定、示范及参加广东省桑树新品种区域性试验；并探索四倍体桑杂交组合的实用性。

Chromosome numbers in 324 materials of M. atropurpurea were investigated and 15 triploids were obtained. Among these“Lun 40”had gained significant result in commercial production,and “Da 10”showed great potentiality in beverage production. Technical procedures for inducing tetraploids by colchicine treatment of M. atropurpurea seedlings ware established.By selecting from the four ecolgical types at the nursery stage,the inducing ratio could be increased 33%,the high yielding and good quality materials selected could be increased 83% over that of the normal methods.Through studies on their main agronomic characters,a group of plasmic resources with good quality,high yielding and seeding ability was selected.These tetraploids were superior to those induced from asexual system of Morse alba,Morus bombycis and Morus muticaulis,which are slow growing yieldin and of poor seeding ability.By using these tetraploids as parental stocks for crossing,7 hybrid combinations have been bred, which are nameky Yuesang No. 1 to No.7. Their characters are briefly described. They have been provided for assessment in demonstrative production:tnd regional comparative test of new mulberry variieties inthe province. The practial utilization of the tetraploid hybrid combinations is being hfther studied.