氮钙互作对设施栽培油桃叶片光合特性及叶绿素荧光参数的影响

The interactive effects of nitrogen and calcium on photosynthetic characteristics and chlorophyll fluorescence parameters of nectarine under protected culture

以设施栽培油桃"中油5号"为试材,采用营养液浇灌方式,研究了氮钙互作对设施油桃叶片光合色素含量、光合特性和叶绿素荧光参数的影响。结果表明,在不同氮水平处理下,随钙水平的提高,设施油桃叶片叶绿素a、叶绿素b、叶绿素a/b,叶片净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)、胞间二氧化碳浓度(Ci),PSⅡ最大光化学效率(Fv/Fm)、光化学猝灭系数(qP)、表观光合电子传递速率(ETR)和实际光化学效率(ΦPSⅡ)均呈先增加后降低的趋势,初始荧光(F0)、非光化学猝灭系数(NPQ)则均呈先降低后增加的趋势。其中在低氮水平(5mmol/L)下,以4 mmol/L钙水平处理对改善低氮水平时设施油桃光合作用效果最好,与其它钙水平处理差异显著(P<0.05);而在高氮水平(25 mmol/L)下,以8 mmol/L钙水平处理对改善高氮水平时设施油桃光合作用效果最好,与其它钙水平处理差异显著(P<0.05)。

Abstract：The interactive effects of nitrogen and calcium on leaf chlorophyll content, photosynthetic characteristics and chlorophyll fluorescence parameters of nectarine in protected cultivation were studied by using 3-yearsold nectarine （prunus persica var. nectariana cv. Zhongyou 5 ） trees which were watered by mixed solution of nitrogen and calcium at different levels. The results show that under different nitrogen levels, the chlorophyll contents, net photosynthetic rates （Pn）, stomatal conductances （Gs）, transpiration rates （Tr）, intercellular CO2 concentrations （Ci）, maximal photochemical efficiencies of PSⅡ（Fv/Fm）, photochemical quenching coefficients （qP）, apparent photosynthetic electron transfer rates （ETR）, and quantum yields of PSⅡ electron transport（￠PSⅡ） are increased firstly and then decreased with the increase of calcium levels, while the minimal fluorescence values （F0） and nonphotochemical quenching coefficients （NPQ） are decreased firstly and then increased. Under the low nitrogen level （5 mmol/L） the interactive effects of nitrogen and calcium on photosynthesis are the best with 4 mmol/L calcium level, which has significant differences （P〈0.05） compared with other calcium levels. Under the high nitrogen level （25 mmol/L） the interactive effects of nitrogen and calcium on photosynthesis are the best with 8 mmol/L calcium level, which has significant differences （P〈0.05） compared with other calcium levels.