黑樱桃与山樱桃幼苗光合作用的比较研究

Comparison on the Photosynthesis of Seedlings of Prunus serotina and Prunus serrulata

用LI-6400便携式光合作用系统对美国黑樱桃、加拿大黑樱桃、中国山樱桃苗木的净光合速率、气孔导度、胞间CO2浓度等进行了比较测定,结果表明:(1)日平均净光合速率、气孔导度和胞间CO2浓度均是中国山樱桃最大、美国黑樱桃居中、加拿大黑樱桃最小。3种苗木的净光合速率分别为6.381μmol.m-2.s-1、5.550μmol.m-2.s-1、4.952μmol.m-2.s-1,气孔导度分别为0.200 mol.m-2.s-1、0.151 mol.m-2.s-1、0.134 mol.m-2.s-1,胞间CO2浓度分别为251.7μmol.mol-1、234.7μmol.mol-1、230.1μmol.mol-1。(2)3种苗木的净光合速率、气孔导度、胞间CO2浓度均有显著差异。(3)3种苗木净光合速率的日变化相似,都呈单峰曲线,但美国黑樱桃达到峰值的时间在上午10时,早于加拿大黑樱桃和中国山樱桃,后两者达到峰值的时间都在中午12时。胞间CO2浓度的日变化都是从早晨开始逐渐下降,到下午降低到最小值,然后又有所增加,所不同的是,美国黑樱桃苗木下降到最小值的时间较早,在14时,而中国山樱桃和加拿大黑樱桃则较迟,都在16时。气孔导度的日变化趋势相似。

With LI-6400 portable photosynthesis systems, the net photosynthetic rate （Pn） , stomatal conductance （Gs）and intercellular CO2 concentration （Ci） under natural full light conditions were compared for Prunus serrulata from Guangshan County , Henan Province, P. serotina from Pennsylvania and Ontario. The resuits showed that： （ 1 ） P. serrulata had the maximum daily average amount of Pn, Gs, and Ci, which were 6. 381μmol·m^-2·s^-1 ,0. 200 mol ·m^-2·s^-1,and 251.7μmol·mol^-1 respectively,and the average amounts of seedlings of Pennsylvania provenances were the medium, they were 5. 550 μmol·m^-2·s^-1,0. 151 mol·m^-2 ·s^-1 , and 234.7 μmol·mol^-1 respectively, and the average amounts of seedlings of Ontario provenance were the least, they were 4.952 μmol·m^-2·s^-1 ,0. 134 mol·m^-2·s^-1 ,and 230. 1 μmol·mol^-1 respectively. （2） Pn, Gs and Ci had significantly differences among these species. （3）The daily variation of Pn was similar, there was only one peak of Pn in a day, but the Pn of plants of Pennsylvania provenance reached the peak earlier than that of the other two kinds of seedlings. The daily variation of Ci was similar, too. Ci decreased gradually from morning to the minimum in the afternoon and increased a little later, but the Ci of plants of Pennsylvania provenance fell the minimum earlier than that of the other two kinds of seedlings. The daily variation of Gs was similar, too.