克服甘薯组(Section batatas)种间杂交不亲和性研究再报

甘薯组Ａ系列野生种Ｉ．ｔｒｉｌｏｂａ和Ｂ系列栽培种徐薯１８杂交授粉后１１～２０天的胚珠培养获得了试管苗和杂种植株，观察比较了杂种和两亲的形态特征，进行了细胞学鉴定。同时一植株的不同细胞中，染色体数均多于３０，但有变异，变动在３８～５６范围内，杂种植株的花器中，雌雄蕊结构发生变异，全部花朵没有出现雄蕊，雌蕊却有１～５套。用Ｂ系列２个野生种和栽培种的６个品种的花粉与杂种植株回交授粉，均不结实，这些异常

The Second Report of Studies on Overcoming the Interspecific Incompatibility and Hybrid Abortion between Series A and B in the Section batalas of the Genus Ipomoea

Ovule culture of a cross between I. triloba(2n=30, series A)and I. batatas (2n=90, series B)resulted in regenerated hybrid plantlets. It was found that the suitable stage for treatment of hybrid ovule was 11~20 day after pollination, and the best media for ovule cul ture were MS medium or MS supplement with 6-BA. The plantlets were transplanted into pots, and grew into adults plants. Observation of somatic chromosome number in root tip cells of the hybrid plants showed that they were aneuploids with chromosome numbers ranging from 38 to 56, It was also found that the anthers and filament of the stamen disappeared from the flower, while the structure of the pistil varied with different flowers, having from 1~5 sets of stigma- style-ovary. When the hybrid was backcrossed with wild species and cultivar of the B series as the male parents, all combinations became sterile, further, the results of identification using RAPD markers, were obtained; the DNA amplification fingerprinting showed that in the differ ent area of interspecific hybrid there are many bands distribution, some bands were same as that of I triloba while some were same as that of Xu-18, indicating that the hybrid plants were gen uine interspecific hybrid.