3个扁桃品种的光合特性

Photosynthetic Characteristics of Three Cultivars of Almond(Amygdalus communis)

在盆栽条件下对3个引种扁桃品种3#、4#和7#的光合作用、荧光参数生理生态特点进行研究。结果表明:1)扁桃叶片的净光合速率(Pn)日变化均呈双峰曲线型,峰值在10:00,次峰值在16:00,10:00—15:00有“午休”现象;在10:00—15:00时4#和7#叶片的Pn显著高于3#,15:00差值最大。2)扁桃不同品种的光合生理生态参数有显著差异:4#的光饱和点和补偿点都比3#和7#高,分别为1206μmol.m-2s-1和25.82μmol.m-2s-1,说明4#品种能适应较高的光照强度;4#和7#的CO2补偿点和饱和点都比3#高,扁桃在CO2饱和点以下,Pn随CO2浓度的增加呈线性增长,说明增大CO2浓度可大大提高光合生产力。3)叶绿素荧光参数的日变化显示:4#和7#的Fv/Fm、光化学猝灭系数(qP)均高,且正午过后Fv/Fm恢复较快,不仅能较强地吸收光能,同时还具有较高的PSⅡ活性和光能转化效率,从而将所吸收的光能有效地转化为化学能,提高光合电子传递速率,形成更多的ATP和NADPH,为光合碳同化提供充分的能量和还原能力。

The photosynthetic characteristics and chlorophyll fluorescence characteristics of introduced three almond （ Amygdalus communis） cultivars 3^# ,4^# and 7^# were studied. The curves of diurnal variation of net photosynthetic rate（Pn） in leaves of almond showed two peaks, occurring at 10 ： 00 and 16 ： 00 respectively. Midday depression of P, （ 10 ： 00- 15 ： 00） was found in leaves of almond. Pn of leaves of 4 ^# and 7^ # almond was significantly higher than that of 3 ^# during 10 ： 00- 15 ： 00. Some physioecological parameters showed significant difference among different cuhivars. The light compensation and saturation points of P, in 4^# leaves were higher than those in 3^# and 7^# , 25.82 μmol·m^-2s^-1 and 1 206 μmol·m^-2s^-1 respectively The C02 compensation and saturation points of P, in 4^# leaves were higher than those in 3^# and 7^# . Pn was increased linearly with the increase of CO2 concentration below the CO2 saturation point, thus increasing CO2 concentration could improve productivity greatly. And the results of diurnal variations of chlorophyll fluorescence showed that Fv/Fm and qp of 4^# and 7^# were higher than 3^# , and Fv/Fm restored very fast after noon. The leaves of 4^# and 7^# not only could absorb the light energy more effectively, but also had higher PSⅡ activity and light energy transform efficiency, which could turn light energy absorbed into chemical energy effectively, then the transmit speed of electrons was improved. So more ATP and NADPH were formed, which could offer abundant energy and reduction ability for CO2 assimilation.