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通过 45个基因型的小麦 (TriticumaestivumL .)幼胚培养 ,发现有 1 1 .1 %的基因型从靠近再生芽基部的愈伤组织上分化形成花器官。再生花芽呈裸露的、多子房丛生的、具有茂盛羽毛状柱头而缺乏雄蕊、外稃、内稃和颖片的单性雌花。组织切片观察发现 ,其雌蕊起源于再生芽附近的分生组织细胞 ,并通过次生雌蕊再生的方式形成丛生状 ,其羽毛状结构的发育先于子房中胚珠的分化。除正常的单胚珠外 ,还发现双生胚珠分化。χ2 独立性检验结果显示 ,花芽再生率存在强烈的基因型效应。小麦品种YA_1表现突出 (4 4 .4% ) ,其花芽再生潜力能在不同年份间较好地再现 ,说明YA_1的花芽再生能力具有相对稳定性。与脱分化培养基的效应相比 ,YA_1的花芽再生效率主要受继代培养基成分的影响。其中 ,6_BA、NAA和加倍无机铁盐的配比较 2 ,4_D和正常浓度无机铁盐的配比更有利于YA_1的幼胚培养再生花芽。同时 ,外植体实验表明 ,YA_1的幼穗和成熟胚培养无任何成花反应 ,而其幼胚外植体具有特异的花芽再生能力。据此认为 ,YA_1的幼胚培养有助于为小麦花发育机理研究建立理想的实验系统。
Immature embryos were cultured in 45 genotypes of wheat (Triticum rasum L.) and found that 11.1% of the genotypes differentiated from the callus near the base of regenerative buds to flower organs. Regeneration flower buds were bare, many-celled tufted, with lush feathered stigma lacking stamens, nephew, inflorescence and glumes of unisexual female flowers. Histological observation showed that the pistil originated from meristematic cells in the vicinity of regenerative buds and developed into clusters through secondary pistil regeneration. The development of feathery structures preceded the differentiation of ovules. In addition to the normal single ovules, twin ovules are also found to differentiate. The results ofχ2 independent test showed that there was a strong genotype effect on flower bud regeneration rate. The performance of wheat variety YA_1 was outstanding (44.4%), and its flower bud regeneration potential could be well reproduced in different years, indicating that YA_1 had relatively stable flower bud regeneration ability. Compared with the effect of dedifferentiation medium, the efficiency of flower bud regeneration of YA_1 was mainly affected by the composition of subculture medium. Among them, the ratio of 6_BA, NAA and double inorganic iron salt was more favorable to the regeneration embryo culture of YA_1 than that of 2, 4_D and normal inorganic iron salt. At the same time, the explant experiments showed that there was no flower-forming reaction in the young ear and mature embryo of YA_1, but the embryo explant of YA_1 had the ability of flower bud regeneration. Accordingly, YA_1 immature embryo culture help to establish the ideal experimental system for the development of wheat flower.