不同海拔高度对青脆李生理辐射光谱、光合特性及果实品质的影响

在横断山北段选取3个海拔梯度,研究不同海拔高度对生理辐射光谱、青脆李光合特性及品质的影响。结果表明:青脆李在低海拔表观量子效率α最高,达到0.091,且光补偿点(LCP)最低,叶片对弱光利用能力强,而在高海拔光饱和点(LSP)极显著高于低海拔,对强光的利用能力强。由于生理辐射随海拔升高而增强,短波光所占比例增大,表明青脆李对环境生理辐射光谱具有一定的适宜能力;在海拔1 786 m处,最大光合速率(Pmax)、暗吸收(Rd)、LCP和LSP均高,光合同化和代谢能力最强,果实综合品质最优;叶绿素a/叶绿素b(Chla/Chlb)与α显著正相关,而类胡萝卜素(Car)则与LSP显著正相关;生理辐射强、短波光多,利于果实可溶性固形物(TSS)、Vc及糖积累,但不利于有机酸积累和果实增大。

Studies on Physiological Radiation Spectrum and Photosynthetic Properties as well as Fruit Quality of Qingcui Plum at Different Altitudes

Different Qingcui plum habitats were selected from 3 altitudinal gradients in northern part of Hengduan mountains to study physiological radiation,photosynthetic properties and fruit qualities of Qingcui plum,especially analyze light response of photosynthesis(Pn-PPFD) response curve and the correlation between fruit qualities and physiological radiation and photosynthetic parameters of Qingcui plum.The results showed that the physiological radiation intensity and ratio of short wave light increased with altitude,apparent quantum yield(α) was highest,reaching 0.091,while light compensation point(LCP) was lowest at low altitude,which indicated Qingcui plum leaves had a good ability to utilize the low light.However,the light saturated point(LSP) was significantly higher at high altitude than at low altitude,which showed Qingcui plum leaves at high altitude had a good ability to utilize the strong light.Furthermore,low light was more at low altitude while strong light more at high altitude.Thus,they indicated that Qingcui plum was capable of adapting to low or strong light.In fact,the maximum photosynthetic rate(Pmax),dark respiration rate(Rd),LCP and LSP were the highest at 1 786 m,Pmax reached 21.12 μmol/(m2·s).Chla/Chlb was significantly and positively correlated with apparent quantum yield,and Car significantly and positively with LSP.The strong intensity of physiological radiation and short wave light helped to accumulate TSS,Vc and sugar content,but was detrimental to the accumulation of organic acid content and fruit mass.