Abstract:

In this study, three breeds of cultivated hawthorns(Crataegus pinnatifida var.Major )with extremely low fertilization rates `Mianzha', `Changkou' and `Dajinxing' were pollinated by the pollen of wild hawthorns(C.pinnatifida) with high fertilization rates, and some physiological and biochemical indexes of pollen and pistil were compared between wild hawthorns and cultivated hawthorns. The results showed that the kernel contents of the seeds of cultivated hawthorns were increased significantly by the treatment of pollination with the pollen of wild hawthorns. There was no significant difference between cultivated hawthorns and wild hawthorns in pollen viability, but the germination rate of the pollen and the growth speed of pollen tubes of the former were lower than those of the latter. The pollen of `Dajinxing' could not germinate after cultivated for 24 h at 25℃. The germination of the pollen of wild hawthorns and cultivated hawthorns was inhibited by the pistil extracts of the cultivated hawthorns. Compared with wild hawthorns, cultivated hawthorns were of lower carotenoid, free proline and soluble protein contents,and higher phenolic compound content and POD activity in the pollen, of which the `Dajinxing' was of the lowest carotenoid and soluble protein contents, and the highest phenolic compound content and POD activity in the pollen, and higher IAA oxidase activity and lower soluble sugar content in pistil. The POD isozymes in pistil of `Dajinxing', `Changkou' and `Mianzha' had 2, 3 and 4 bands respectively more than that of the wild hawthorns, however, there was no difference between cultivated hawthorns and wild hawthorns in the POD isozymes in pollen.

Key words: Hawthorn, Pollen, Pistil, Physiological and biochemical characteristics, Fertilization