不同倍性山楂资源的胚胎发育特性研究

Study on the Characteristics in the Embryonic Development ofHawthorn Resources with the Different Ploidy

以二倍体山楂资源山东红面楂和三倍体资源磨盘山楂的盛果期树为试材,通过定期调查方法观测了种仁率变化,并利用石蜡切片方法对胚胎发育过程及特性进行了研究。结果表明:在自然授粉条件下,2份资源的种仁率均呈下降趋势;但磨盘山楂的种仁率明显低于山东红面楂,特别是在花后25～40天种仁率迅速下降,最终只有9.8%;而山东红面楂的种仁率最终为58.3%。2份山楂资源的胚珠均为倒生胚珠,其胚囊在开花前成熟、发育方式为蓼型;种胚发育方式为藜型,核型胚乳。花后8天左右合子开始分裂;花后1个月左右可形成球形胚,球形胚的位置仍然靠近珠孔端。此外,在磨盘山楂中发现了部分棒状原胚,这与山东红面楂的球形原胚形状不同。

In this experiment, with the material of the diploid hawthorn resources of Shandong Hong Mian Zha and the triploid resources of Mo Pan Shan Zha in full fruit period, the change of kernel rate was surveyed by regular observation, and the embryonic development process and characteristics were studied using paraffin method. It was found that in the condition of opening pollination, the kernel rates of both resources appeared in downtrend. The kernel rate of Mo Pan Shah Zha was significantly lower than the kernel rate of Shandong Hong Mian Zha, and especially during 25 days to 40 days after anthesis, the kernel rate declined rapidly and finally reached to 9.8% only. The final kernel rate of Shandong Hong Mian Zha reached to 58.3%. The ovule of two accessions of the hawthorn resourees grew in the anatropous way. Their embryo sac matured before the flowering phase, and the developmental type of the embryo sac was Polygonum type. Hawthorn endosperm was the one of nuclear type. The manner of their embryonic development was Chenopodiad type. The zygote divided at about 8 days after the blossom, and the globular embryo, which still located near the micropyle end, was formed one month after the flowering stage. Some proembryos of Mo Pan Shah Zha were virgulate which were different from Shandong Hong Mian Zha.