间作对安吉白茶生长与叶绿素荧光动力学特性的影响

Growth and chlorophyll fluorescence kinetics of Camellia sinensis(L.)under forest tea intercropping

探讨薄壳山核桃与茶间作后安吉白茶生长和叶绿素荧光动力学特性差异,为构建薄壳山核桃和安吉白茶高效复合栽培提供理论依据。薄壳山核桃与安吉白茶间作分别以乔木树冠下(T1)、树冠缘(T2)、树冠外(T3)和纯安吉白茶园(T0)等4个测定点,测定10年生安吉白茶茶树新芽数、新稍生长量和单位面积产量等生长指标,结合茶树速生期(7-9月)叶绿素荧光动力学参数指标,分析探讨林茶间作不同光照条件下安吉白茶生长与叶绿素荧光动力学特征。结果表明(1)林茶间作茶树的新芽数、新梢长度等生长指标均显著高于纯茶园,其中乔木冠缘茶树生长指标较优;间作茶园茶树的百芽鲜(干)质量显著高于纯茶园,单位面积茶树新芽鲜质量以冠缘、冠外显著高于冠下和纯茶园,茶树新芽干质量为冠缘处最高,其次为冠外,冠下与纯茶园较低;(2)通过各测定点叶绿素荧光动力学OJIP曲线分析,7-8月高温强光下薄壳山核桃冠缘处茶树的荧光信号强度较强,8月纯茶园茶树的荧光点位显著低于间作茶树,9月各测定点茶树荧光曲线重合度较高。薄壳山核桃冠缘、冠外茶树相对可变荧光差异曲线(ΔV_(t))波动较小,冠下茶树荧光的J相在7月快速下降但在9月却陡然升高,表明此时茶树叶片PSⅡ反应中心电子传递受阻,电子传递的能量配额减少。(3)间作茶园中茶树S_(m)、N、φP_(o)均高于纯茶园茶树,7-8月高温强光时期,纯茶园的茶树M o升高受到了光抑制,林茶间作茶树吸收(ABS/CS_(m))、捕获(TR_(o)/CS_(m))、传递(ET o/CS_(m))的能量均高于纯茶园,纯茶园茶树反应中心量子效率(ABS/RC)和热耗散(DI_(o)/CS_(m))显著升高,致使PSⅡ电子传递和能量转化异常。薄壳山核桃冠缘附近茶树的光合能力(PI_(abs))较高。表明林茶间作冠缘下散射光有利于安吉白茶生长和光合同化作用,冠外次之,冠下和纯茶园较差。强光对安吉白茶产生了明显的光抑制,过度遮阴也不利于茶树的光合与生长。

To learn the growth and photosynthesis-environment relationship of tea(Camellia sinensis L.)under different shade of hickory pecan-tea plantation intercropping,and to provide theoretical basis for the construction of efficient compound cultivation,four tests under the crown(T1),at the crown margin(T2),outside the crown(T3)of hickory pecan and single tea cropping(T0)were carried out.Such growth indexes as the number of new buds,the amount of new growth and the yield per unit area of 10-year-old tea were determined,and the chlorophyll fluorescence kinetic characteristics analyzed in the rapid growth from July to September.The results showed that(1)the number and length of new shoots of intercropping were significantly higher than those of single tea cropping,and the growth indexes of the tea trees sited at crown margin were better than those of single tea cropping.The fresh(dry)weight of 100 tea buds in intercropping was significantly higher than that in single tea cropping,and the fresh weight of new shoots per unit area at the margin of and outside the crown significantly higher than that under the crown and in single tea cropping.The dry weight of tea bud was the highest at the crown margin,followed by that outside the crown,lowest under the crown and single cropping.(2)The analysis of the OJIP curves of chlorophyll fluorescence kinetics showed that the fluorescence signal intensity of the tea tree at the crown margin was stronger from July to August under high temperature and strong light,the fluorescence point location of the tea tree in single cropping in August was significantly lower than that of the intercropping tea tree,and the coincidence degree of the fluorescence curve of the tea tree at each measured point in September was higher.The relative variable fluorescence difference curve(ΔV_(t))at the crown margin and outside the crown fluctuated little.The J phase of fluorescence in tea trees under the crown decreased rapidly in July but increased sharply in September,indicating that electron transfer was blocked in the PSⅡreaction center of tea leaves at this time,and the energy allocation of electron transfer was reduced.(3)S_(m),N,andφP_(o)of intercropped tea plantations were all higher than those of single tea cropping.In the period of high temperature and strong light from July to August,the increase of Mo of singly-cropped tea trees was inhibited by light.The energy absorption(ABS/CS_(m)),capture(TR_(o)/CS_(m))and transfer(ET o/CS_(m))of interplanted tea trees were all higher than those of singly-cropped tea trees,and the quantum efficiency(ABS/RC)and heat dissipation(DI_(o)/CS_(m))of reaction center were significantly increased,resulting in abnormal electron transfer and energy conversion of PSⅡ.The photosynthetic capacity(PI_(abs))of tea tree near the crown margin was higher.It was concluded that the light scattered under the crown margin was beneficial to the growth and photosynthetic assimilation of tea tree,followed by outside the crown,and poor under the crown and single cropping.Strong light had obvious photo-inhibition on tea tree,and excessive shading was not conducive to the photosynthesis and growth.