Studies On Characteristics Of Reproductive Biology Of Two Pear Varieties

The reproductive biology of zao su pear and bartlett were researched in the paper, such as: flower bud morphological differentiation, blooming phenophase, pollen viability and pollen germination rate, self-pollination and cross pollination and effect of bagging to fruit qulity were also researched . The results are as follows:1. Zao su pear flower bud morphological differentiation began at mid-June, prime of differentiation initial stage began at early July, stage of sepal formation began at mid-July, petal formed in late July and early August. Bartlett flower bud morphological differentiation began at late June, prime of differentiation initial stage began at mid-July, stage of sepal formation began at late July, petal formed in early and middle August .The overlap of different stage in bartlett and zao su pear is obvious between and in the varieties.2. Pollen germination rate of zao su pear and bartlett were all in the high level. In condition with 0.1% boric acid and 10% Sucrose, the average pollen germination rate of bartlett was 89.6% and higher than others. In condition with 0.1% boric acid and 10% Sucrose, the average pollen germination rate of zao su pear was higher than other rate, and the rate is 92.3%. The pollen germination rate of zao su pear and bartlett were improved because of 0.1% boric acid, but the improving degree was not significant.3. The pollen viability of zao su pear and bartlett was decreased owing to prolonged saving time. In condition with 20℃, the pollen germination rate of zao su pear decreased obviously in the first 5 days, the pollen germination rate was 70.5%, the rate was 11.3% in 60th day, and there was no germination in 90th day. The pollen germination rate of bartlett was also decreased obviously in the 5th day, the pollen germination rate in 60th day was 0%.4. 4℃can hold the pollen germination rate of two pears for longer time and higher viability. Under 4℃condition, the pollen germination rate of zao su pear was not change significantly in the first 15 days, and it can hold 28.5% viability in the 90th day. The bartlett pollen germination rate was 27.8% in 90th day under 4℃.5. There was almost no seed setting in condition with self-pollination of zao su pear and bartlett. The seed setting rate of zao su pear was 90% when xue hua pear as male parent, the seed setting rate of bartlett was 94% when jin hua pear as male parent.6. Yellow paper bag and 1/2 black non-woven fabric + 1/2 white film improved the fruit weight of zao su pear and bartlett.Bagging decreased the soluble solids of pear.Yellow paper bag and 3 kinds of non-woven fabrics increased the appearance quality of pears but yellow film bag.