摘要
对栽培小麦'康选9号'和超甜玉米'SS7700'杂交后的受精作用和胚胎发育进行了研究。在经玉米花粉授粉的180个小麦子房中,34个(占18.9%)发生了双受精,具有胚和胚乳;46个(占25.6%)只发生了卵细胞单受精,形成了胚而无胚乳;12个(占6.7%)只发生了极核受精,形成了胚乳而无胚。以'中国春'小麦为母本(父本相同)的对照中,观察了192个子房,相应的数字为23(12.0%);30(15.6%)和2(1.0%)。表明我国栽培小麦'康选9号'和玉米杂交的受精率(51.2%)和成胚率(44.5%)都比国外做这类杂交惯用的模式小麦品种'中国春'显著要高,后者和玉米杂交的受精率和成胚率分别为28.6%和27.6%。观察发现'康选9号'小麦和玉米杂交后形成的胚和胚乳的核型极不稳定,其中来自玉米的染色体在合子和胚乳核的早期分裂中很快被排除,最后产生的是单倍体小麦胚。讨论了这一方法在小麦单倍体诱导和玉米基因(包括玉米可转移因子)向小麦转移的可能性。
The fertilization and embryo development in crosses of hexaploid wheat 'Kangxuan 9' X maize 'SS 7700' were studied.Of 180 florets fixed after pollination 34(18.9%) had embryo and endosperm,46(25.6%) had only embryo and 12(6.7%) had only endosperm.Percentages of single or double fertilization were higher than that in control ('Chinese Spring' X maize). The hybrid embryos and endosperms obtained were karyotypically unstable and characterized by rapid elimination of the maize chromosomes to produce haploid wheat embryos.The potentials for wheat haploid production and transfer of DNA segments,including transposable elements,from maize to wheat is discussed.
基金
国家自然科学基金资助项目
关键词
小麦
玉米
受精
胚胎
发育
Wide crosses
Wheat
Maize
Chromosome elimination
