小麦×玉米诱导小麦单倍体的形态学及细胞学鉴定

IDENTIFICATION OF MORPHOLOGY AND CYTOLOGY IN WHEAT HAPLOID THROUGH WHEAT×MAIZE

为了鉴定小麦(Triticum aestivum L.)×玉米(Zeamays L.)产生的杂种子代的单倍性,采用形态学和细胞学鉴定相结合的方法对杂种幼胚及胚拯救产生的植株进行表型分析与染色体记数。结果表明,小麦×玉米诱导的杂种子房内均无胚乳,仅在少数子房内观察到1个游离的球形幼胚,这些幼胚发育成植株后在花期花药退化或花粉败育,这一特征可作为小麦×玉米杂交后代单倍性的形态学标记。研究同时表明,杂种子代植株体细胞染色体数目为2n=21,在整个染色体组中无可同源配对的成对染色体,并且未发现玉米染色体,结合麦族植物染色体基数x=7的特点,确定该杂种子代为小麦单倍体(三元单倍体),这是小麦×玉米杂交后代单倍体鉴定最重要的细胞学标记。文中同时对小麦×玉米杂交后代单倍体鉴定的重要性,及与以前相关研究结果的差异进行了讨论。

In order to identify the haploidy of hybrid progeny through wheat × maize, phenotype and chromosome number of hybrid embryo and plants produced by embryo rescue were analyzed on the method of combining morphology and cytology identification. The results showed that： there were no endosperm in the hybrid ovary, sometimes one dissociative globular young embryo could be found in few ovaries, which maybe grew into wheat plants, but their anthers were obsolete or pollens are yeld in the blooming period, which could be looked as a kind of morphology mark. In this study, the chromosome number of all hybrid progeny plants through wheat ×maize were 2n = 21, there was no homologous chromosome in whole genomes, and there was no maize chromosomes, also. On the basis of all above results and combining the character of chromosomal base number in Triticum L. plant is × = 7, the hybrid progeny plants were identified as true wheat haploid （allotriploids）, which was the most important cytology mark to identify haploid through wheat and maize cross. The importance of haploid identification in wheat × maize and the differences of previous relative results were also discussed in this paper.