ABSTRACT

A fertility obstacle exists in hybrid production between distant related species, particularly from different genera. In the present study, by using tissue culture and chromosome doubling technology, radish (Raphanus sativus L.) and kohlrabi (Brassica oleracea L. var. caulorapa DC.) were subjected to intergeneric distant hybridisation. Through a combination of bud pollination and ovary rescue technology, five putative hybrids were obtained, and three of which were identified as true hybrids with the hybrid acquisition frequency of 0.85%. After tissue culture propagation and colchicine doubling treatment, ×Brassicoraphanus allotetraploids were obtained. Chromosome counting confirmed one plant as allotetraploid with a chromosome doubling rate of 2.70% and 14 seedlings with partial chromosome doubling at a chimaeral rate of 37.8%. The allotetraploid hybrid exhibited normal morphological characteristics, fertile pollen, fuller flower buds and developed pods, compared with the primary hybrid plants. In the present study, the distant hybrid plant that combines the R and C genomes was created to provide basic materials for producing new radish germplasm and to act as a useful bridge for gene transfer between the vegetable species of Brassica and Raphanus.

摘要

远缘物种之间的杂交生产存在生育障碍，特别是来自不同属的物种。本研究利用组织培养和染色体加倍技术，对萝卜（Raphanus sativus L.）和大头菜（Brassica oleracea L. var. caulorapa DC.）进行属间远缘杂交。通过芽授粉和子房挽救技术相结合，获得了5个假定杂种，其中3个被鉴定为真杂种，杂种获得频率为0.85%。经过组织培养繁殖和秋水仙碱加倍处理后，× Brassicoraphanus获得异源四倍体。染色体计数证实1株为异源四倍体，染色体加倍率为2.70%，14株幼苗部分染色体加倍，嵌合率为37.8%。与原代杂种相比，异源四倍体杂种表现出正常的形态特征、可育的花粉、更饱满的花蕾和发达的豆荚。在本研究中，创建了结合R和C基因组的远缘杂交植物，为生产新的萝卜种质提供基础材料，并作为芸苔属和萝卜属蔬菜物种之间基因转移的有用桥梁。