Reproductive barriers in the intergeneric hybridization between Chrysanthemum grandiflorum (Ramat.) Kitam. and Ajania przewalskii Poljak. (Asteraceae)
Reproductive barriers in the intergeneric hybridization between Chrysanthemum grandiflorum (Ramat.) Kitam. and Ajania przewalskii Poljak. (Asteraceae)
复制标题
DOI：
10.1007/s10681-009-0113-3
复制
发表时间：
2010-07-01
期刊：
影响因子：
1.9
通讯作者：
Chang, Qingshan
中科院分区：
文献类型：
--
作者：
Deng, Yanming;Teng, Nianjun;Chang, Qingshan
为揭示大花菊属间杂交结实率低的原因。 “中山金贵”（母本）和 Ajania przewalskii Poljak。 （父本），我们使用石蜡切片以及光、荧光和扫描电子显微镜系统地研究了母本的大孢子发生和大配子发生、父本的花粉发芽性、花粉-雌蕊相互作用和杂种胚胎发育。结果表明，母本大配子体发育属蓼型，授粉期胚珠发育为正常8核胚囊的比例为84.6%；父本花粉离体发芽率为39.3%；授粉后24 h内，大量花粉粒正常萌发，雌性柱头上无胼胝质沉积。此外，大约75%的胚珠受精，而由于各个发育阶段的败育，只有17.2%的胚珠在授粉后15天发育成正常成熟胚胎。总而言之，这些结果表明母本的不育胚珠、花粉活力和花粉-雌蕊相互作用对杂交中的结籽没有显着影响。高比例的胚胎败育或退化，即受精后障碍，可能是种子产量低的主要因素。
In order to reveal the causes of low seed set in the intergeneric cross between Chrysanthemum grandiflorum (Ramat.) Kitam. 'Zhongshanjingui' (female parent) and Ajania przewalskii Poljak. (male parent), we systematically investigated megasporogenesis and megagametogenesis of female parents, pollen germinability of male parents, pollen-pistil interaction and hybrid embryo development using paraffin section and light, fluorescence and scanning electron microscopy. The results indicate that development of megagametophyte of female parent belongs to Polygonum type and 84.6% ovules developed to normal 8-nucleate embryo sac at the stage of pollination; the pollen germinability in vitro of male parent was 39.3%; a large number of pollen grains germinated normally and no callose deposited on the female stigmas within 24 h after pollination. Furthermore, about 75% ovules were fertilized, whereas only 17.2% ovules developed to normal maturing embryos at 15 days after pollination due to abortion at various developmental stages. Taken together, these results suggest that sterile ovules of female parent, pollen viability and pollen-pistil interaction have no significant influence on seed set in the cross. A high percentage of embryo abortion or degeneration, i.e. post-fertilization barrier, may be the main factor for low seed yield.