Abstract:

The pollination experiments were carried out in Pinus tabulaeformis Carr. Seed orchard located at Lushi county in Henan province during 1993~1995, The pollination efficiencies of different pollination experiments were also analysed. The first pollen grain arriving at the integument arms was preferentially engulfed over pollen approaching later during female cone receptive period. The optimal time of pollination was the first 4 days after flowering. The controlled pollination carried out within 2~3 days after flowering gave the greatest efficiency with 54% of full seeds. The repeated pollination during receptive period could not significantly increase seed numbers over single pollination. The 45%~50% of full seeds in cone could be produced when 0.2~0.4 mL of pollen was applied to one pollination bag, and a markable decline in pollination efficiency be followed when less than 0.1 mL of pollen was applied. The mixtures of fresh pollen with dead pollen or talcum powder at the ratio of 1:1 could produce the same percentage of full seeds as pure fresh pollen applied. In addition, the pollination efficiencies of different treaments, the determination of weighted values for flowering synchronization indexes and changes of flowering synchronization indexes after weighting were preliminarily discussed.

Key words: Pinus tabulaeformis Carr., Seed orchard, Flowering period, Pollination mechanism, Pollination efficiency