[Objective] This study was conducted to evaluate three training systems for Korla fragrant pear trees by comparing the characteristic parameters of light response curve and CO2 response curve, and to provide some theoretical basis for improving the pruning techniques of Korla fragrant pear trees. [Method] The light response curve and CO2 response curve of the trees trained to three systems were measured by LI-6400 portable photosynthesis system. The SPAD value was measured using SPAD-502 chlorophyll meter, and specific leaf weight was calculated, to evaluate the effects of the three training systems. [Result] The CO2 response curves of the three training systems were basically in agreement with their light response curves, but there were some differences in their characteristic parameters. Among the three training systems, the maximum net photosynthetic rate, apparent quantum yield and light compensation point of espalier trained trees were the highest, while their light saturation point was the lowest. The CO2 saturation point of delayed-open central leader trained trees and open center trained trees were 1 752 and 1 665 μmol/mol, both of which were much higher than that of espalier trained trees. In addition, the carboxylation efficiency and photorespiration rate of espalier trained trees were both higher than those of delayed-open central leader trained trees and open center trained trees, while the CO2 compensation point of espalier trained trees was the lowest. The leaf SPAD value of espalier trained trees was the largest, followed by that of open center trained trees, and the leaf SPAD value of delayed-open central leader trained trees was the smallest. In addition, the leaf area and specific leaf weight of espalier trained trees were both the highest, followed by those of open center trained trees. [Conclusion] Among the training systems for Korla fragrant pear trees, the espalier training system had better ability to capture light, higher photosynthetic productivity and strongest adaptability to light en
[Objective] The aim of this study was to understand the flowering biological characteristics of different varieties Prunus domestica L. in Aksu Jiamu Experi- ment Station. [Method] Three varieties of plum as Prunus domestica L. cv. ＇French＇, Prunus domestica L. cv. ＂Victoria＇ and Prunus domestica L. cv. ＂Stanley＇ were the research subjects. The phenophases of blooming, and the morphological and developmental characteristics of floral organs were observed. The amount and viability of pollen and the stigma receptivity were measured. [Result] Three varieties of plum all blossomed in early April, and the florescence had lasted for 9-10 d. The average number of anthers was 28.48%. The average number of pollen grains in each flower was 28 700.0. The pollen germination rate was 27.4%. 86.75% of the flowers were medium-styled or long-styled. There was no significant difference in the petal shape, color, anther number, calyx color, and flower ovary among the three varieties of plum. The stigma receptivity was strongest on the first day of flowering, and then dropped gradually. Therefore, the flowers of plum were manual pollinated on the first day of flowering. The duration time of stigma receptivity of Prunus domestica L. cv. ＇Victoria＇ was longer than the other cultivars, the duration time of stigma receptivity was about 5 d. [Conclusion] The pollen number and pollen germination rate of Prunus domestica L. cv. ＇Stanley＇ were higher than the other cultivars, which be considered the most suitable pollinizer for plum. In contrast, the complete flower rate of Prunus domestica L. cv. ＇French＇ and Prunus domestica L. cv. ＇Victoria＇ was relatively high, but the pollen number and pollen germination rate of Prunus domestica L. cv. ＇French＇ and Prunus domestica L. cv. ＇Victoria＇ were lower than Prunus domestica L. cv. ＇Stanley＇, which are not suitable to use as a pollinizer for plum.
[Objective] This study aimed to investigate the photosynthetic characteristics of different Prunus domestica × armeniaca cultivars, thereby providing some theoretical basis for high-yield and high-quality cultivation of P. domestica × armeniaca. [Method] Total three cultivars（Konglongdan, Fengwei Huanghou and Weiwang）of P. domestica × armeniaca were selected as the test materials, and their leafphotosynthetic parameters were measured with Li-6400 portable photosynthesis system.The light response curve and CO_2 response curve were drawn. [Result] There were significant differences in photosynthetic rate among the three cultivars of P. domestica × armeniaca（P〈0.01）. The photosynthetic rate of Konglongdan [14.76 μmol/（m^2·s）]was highest. When the light intensity reached 1 800 μmol/（m^2·s）, the maximum net photosynthetic rate of Konglongdan was up to 27.27 μmol/（m^2·s）, and its apparent quantum yield reached the peak. Konglongdan showed lower light compensation point [43.069 μmol/（m^2·s）] and higher light saturation point [697.684 μmol/（m^2·s）].Weiwang showed the lowest CO2 compensation point（68.264 μmol/mol） and the highest carboxylic efficiency [0.072 μmol/（m^2·s）]. [Conclusion] Konglongdan showed the highest light utilization efficiency and photosynthetic potential, and it had the strongest utilization ability for weak light. The utilization ability of Weiwang for lowconcentration CO2 was strongest, followed by those of Fengwei Huanghou and Konglongdan.
