Abstract:

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 Shan 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 resources 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 Shan Zha were virgulate which were different from Shandong Hong Mian Zha.