Abstract:

Generally the fruiting ability of interspecific crossing in Larix is high, although there are differences between different crosses. The fruiting ability of the cross between L. kaempferi and L. gmelini was the lowest. It was revealed that the emptied seeds were mainly due to the self pollination through the experiments of open and self pollination. Some clones were almost total self incompatibility. The possible usage of these clones in seed orchard was discussed. Compared the process of pollen capture with different pollen (open-, self-pollens of L. principis rupprechetii and pollen of Pinus tabulaeformis) under control pollination, there was no selection between ovule and pollen at the pollination stage, and all kinds of pollen could enter into ovule canal. About 4 weeks after pollination, the tip cells of nucellus broke and secreted liquid into ovular canal, which promoted pollen movement to the nucellus and played important role for pollen germination. Through the histo chemical analysis, the distribution of protein changed from pollination to fertilization stage. At pollination stage, protein almost distributed in whole ovule, while at fertilization stage it gradually transferred to the upper tissue of nucellus. The specialties between ovule and pollen during pollen germination and fertilization were detected.

Key words: Larix, Interspecific crossings, Self-depression, Pollen recognition