The freezing method combined with enzymolysis was used to determine the content of stone cells of 70 pear varieties for the purpose of identifying the relationship between the content of stone cells and pulp quality. The results demonstrated that the content of stone cells was strongly correlated with pear quality. The majority of the stone cells in all the varieties had diameters of 0.25-0.5 mm; the weight of the stone cells with diameters in this range differed significantly among pear varieties. In addition, the varieties with a higher content of stone cells contained a higher content of coarse pulp than the varieties with a lower content of stone cells.
Xiaogang Li, Ling Jin, Zhongchun Jiang*, Nianjun Teng, and Baolong Sheng
Chun-Qing Sun, Zhi-Hu Ma, Guo-Sheng Sun, Zhong-Liang Dai, Nian-jun Teng, and Yue-Ping Pan
Reproductive barriers exist in some water lily crosses that result in low seed set and low breeding efficiency. We investigated pollen morphology, pollen viability, microspore development, pistil receptivity, and embryo and endosperm development in six water lily crosses using paraffin section as well as light and scanning electron microscopy (SEM) techniques. The results indicated that the percentage of pollen with normal morphology ranged from 8.9% to 55.2%. The pollen viabilities of ‘Fen Zhuang’, ‘Bai Lu’, and ‘Hong Ying’ were 33.9%, 3.3%, and 20.7%, respectively. Stigmatic pollen germination peaked at 12 h after pollination and varied from 0.3 to 65.7 grains per stigma among the crosses. The production of embryos with normal morphology ranged from 0% to 43.6% at 5 days after pollination, from 0% to 31.4% at 15 days after pollination, and from 0% to 19.7% by 20 days after pollination. The seed sets of the six crosses were from 0% to 10.9%. Our results suggest that the low seed set in some crosses is the result of low pollen viability, low pistil receptivity, and embryo abortion.