茶叶科学
茶葉科學
다협과학
2013年
6期
505-511
,共7页
余海云%石元值%马立锋%伊晓云%阮建云
餘海雲%石元值%馬立鋒%伊曉雲%阮建雲
여해운%석원치%마립봉%이효운%원건운
茶树%冠层%光合作用%光合有效辐射
茶樹%冠層%光閤作用%光閤有效輻射
다수%관층%광합작용%광합유효복사
tea plant%canopy%photosynthesis%photosynthetically active radiation
茶树树冠整体的光合能力是决定茶树生产力的主要因素。本文研究了10龄龙井43投产茶园茶树树冠表层(受光率100%)、中层(受光率50%~70%)、下层(受光率0%~15%)叶片的光合作用特性、生理生态指标的特点及其相互关系。结果表明,从树冠表层至下层叶片接受到的光合有效辐射显著降低,但空气 CO2浓度以树冠下层最高;叶片比叶重、单位面积全氮和全碳含量、叶绿素含量均以表层显著高于下层,而以重量为基础的全氮和全碳含量没有表现出明显的冠层分布差异;表层和中层叶片的光响应曲线表现为典型的Farquhar 模型,但下层叶片无类似特征;光饱和速率、气孔导度、蒸腾速率均以表层叶片最高、下层叶片最低,但胞间 CO2浓度以下层叶片最高;表层和中层叶片光合氮效率差异不大,但显著高于下部叶片。这表明,冠层下部叶片光合作用速率下降的主要原因是光照强度减弱使光合系统活性和羧化效率明显降低,而气孔导度的下降可能不是主要影响因素。因此,如何采取科学的栽培技术,进而调节树冠叶片分布以提高茶树群体光合能力值得深入研究。
茶樹樹冠整體的光閤能力是決定茶樹生產力的主要因素。本文研究瞭10齡龍井43投產茶園茶樹樹冠錶層(受光率100%)、中層(受光率50%~70%)、下層(受光率0%~15%)葉片的光閤作用特性、生理生態指標的特點及其相互關繫。結果錶明,從樹冠錶層至下層葉片接受到的光閤有效輻射顯著降低,但空氣 CO2濃度以樹冠下層最高;葉片比葉重、單位麵積全氮和全碳含量、葉綠素含量均以錶層顯著高于下層,而以重量為基礎的全氮和全碳含量沒有錶現齣明顯的冠層分佈差異;錶層和中層葉片的光響應麯線錶現為典型的Farquhar 模型,但下層葉片無類似特徵;光飽和速率、氣孔導度、蒸騰速率均以錶層葉片最高、下層葉片最低,但胞間 CO2濃度以下層葉片最高;錶層和中層葉片光閤氮效率差異不大,但顯著高于下部葉片。這錶明,冠層下部葉片光閤作用速率下降的主要原因是光照彊度減弱使光閤繫統活性和羧化效率明顯降低,而氣孔導度的下降可能不是主要影響因素。因此,如何採取科學的栽培技術,進而調節樹冠葉片分佈以提高茶樹群體光閤能力值得深入研究。
다수수관정체적광합능력시결정다수생산력적주요인소。본문연구료10령룡정43투산다완다수수관표층(수광솔100%)、중층(수광솔50%~70%)、하층(수광솔0%~15%)협편적광합작용특성、생리생태지표적특점급기상호관계。결과표명,종수관표층지하층협편접수도적광합유효복사현저강저,단공기 CO2농도이수관하층최고;협편비협중、단위면적전담화전탄함량、협록소함량균이표층현저고우하층,이이중량위기출적전담화전탄함량몰유표현출명현적관층분포차이;표층화중층협편적광향응곡선표현위전형적Farquhar 모형,단하층협편무유사특정;광포화속솔、기공도도、증등속솔균이표층협편최고、하층협편최저,단포간 CO2농도이하층협편최고;표층화중층협편광합담효솔차이불대,단현저고우하부협편。저표명,관층하부협편광합작용속솔하강적주요원인시광조강도감약사광합계통활성화최화효솔명현강저,이기공도도적하강가능불시주요영향인소。인차,여하채취과학적재배기술,진이조절수관협편분포이제고다수군체광합능력치득심입연구。
The canopy photosynthetic capacity is one of the dominant factors determining the productivity of tea plants. The photosynthetic traits, physiological and ecological factors as well as their interactions of 10-year old tea plant (Longjing 43 cultivar) at surface, middle, low positions in the canopy receiving 100%, 50%~70%, 0%~15%photosynthetically active radiation (PAR) were investigated in this paper. The received PAR decreased sharply from the surface to low canopy, while CO2 concentration was the highest at low canopy. There were magnificent decreases of leaf mass area ratio (LMA), total nitrogen (NA), total carbon (CA), chlorophyll contents based on leaf area from the surface to low canopy. However, the contents of total N and C were not significantly different among positions in tea plant when calculated based on leaf mass. Leaves at the surface and middle positions, but not low canopy showed typical light response curves fitting well to the Farquhar model. The light-saturated photosynthesis rate (Pn), stomatal conductance (Gs), transpiration rate (Tr) also decreased markedly from surface canopy to low canopy, while concentration of intercellular CO2 (Ci) was the highest at low canopy. Photosynthetic nitrogen use efficiency (PNUE) of surface canopy and middle canopy were significantly higher than that of low canopy. The overall results suggested that the decreased Pn within the leaves of tea plant from surface to low canopy was mainly related to the reduced capacity of photosystem and carboxylation efficiency caused by decreased light intensity instead of low Gs. More research is needed to illustrate the optimum canopy structure shaped by rational agronomical management which could improve the canopy photosynthetic capacity of tea plants.