[Objective] The aim of this study was to explore the differences in photosynthetic characteristics of Korla fragrant pear among different planting densities,providing a basis for the improvement of fruit yield and quality of Korla fragrant pear in production. [Method] The net photosynthetic rates, photoresponse curves and CO2 response curves of Korla fragrant pear under six different planting densities were determined using Li-6400 XT portable photosynthesis system. [Result] There were significant differences in photosynthetic parameters of Korla fragrant pear among six different planting densities. The net photosynthetic rate of Korla fragrant pear was highest under the planting density of 4.0 m × 6.0 m. At the planting density of4.0 m×6.0 m, when the light intensity reached 1 800 μmol/（m^2·s）, the net photosynthetic rate of Korla fragrant pear reached the peak [19.326 μmol/（m^2·s）], and the apparent quantum yield, carboxylation efficiency and dark respiration rate all reached the maximum values; at the planting density of 6.0 m ×7.0 m, Korla fragrant pear showed lower light compensation point and CO2 compensation point, but higher light saturation point. At the planting density of 3.0 m ×5.0 m, Korla fragrant pear had higher light saturation point. [Conclusion] Among the six different planting densities,Korla fragrant pear with planting density of 4.0 m ×6.0 m showed the highest net photosynthetic rate. It suggested that Korla fragrant pear, at the planting density of4.0 m ×6.0 m, had stronger utilization capacity for low light and low-concentration CO2. Therefore, the Korla fragrant pear with the planting density of 4.0 m ×6.0 m has the highest photosynthesis efficiency, and the planting density of 4.0 m ×6.0 m is the most ideal planting density for Korla fragrant pear.
[Objective] The primary aims of this study were to understand the characteristic of floralorgan development in ‘Dongxing＇, and analyze its differences with other apricot varieties. [Method] Floral organ morphology, pollen quantity, pollen viability and stigma receptivityof ‘Dongxing＇ and other apricot varieties were observed and measured. [Result] The ratio between the medium style and long style of‘Dongxing＇ was 82.4%, and the ratio of pistillode was lower than that in the other apricot varieties. Its pollen quantity was 32 183.2 grains per flower, and was fewer than the others. The pollen germination of ‘Dongxing＇ in optimum medium（1% agar ＋15% sucrose ＋ 0.01% boric acid） was 53.0%, i.e. its pollen viability was low. The pollen viability increased at first and then decreased following the period of the bud stage to flowering stage, and pollen viability reached maximum value at the 1st d after flowering. Meanwhile the stored pollen viability continuously decreased with the extension of storage time, and pollen viability of the both vivo or vitro stored was decreased to the half of the maximum value at the 3rdd after flowering or storage.The stigma receptivity of ‘ongxing＇ enhanced at first then weakened, maximum stigma receptivity was found at the period of 2 h to 4 h after flowering. The optimum time for artificial pollination was 1 h to 8 h after flowering and it was shorter than the other apricot varieties was. [Conclusion] The ratio between the medium style and long style of ‘Dongxing＇ was higher than the other apricot varieties, while the pollen viability of ‘Dongxing＇ on the contrary. Its pollen viability reached maximum value at the 1st d after flowering and the optimum time for artificial pollination was1 h to 8h after flowering.
