摘要
为了探究镁对茶树的光合及光保护的响应及茶树的适宜镁肥用量,以‘陕茶1号’为试材,采用水培法,研究不同镁营养水平对茶树生长、光合特性及光保护作用的影响。结果表明:随着镁素浓度的升高,茶树幼苗的叶绿素含量、生物量、净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)、PSⅡ最大光化学效率(Fv/Fm)、PSⅡ潜在光化学效率(Fv/Fo)、PSⅡ实际光化学量子产量[Y(Ⅱ)]均呈现先增加后降低的趋势,PSⅡ非调节性能量耗散量子产量[Y(NO)]则呈现相反的趋势;相关性分析显示,总鲜质量与Pn、Gs、Tr、Fv/Fm、Fv/Fo呈显著或极显著正相关,与总叶绿素、Y(Ⅱ)呈不显著正相关,与Y(NO)呈不显著负相关;0.1 mmol/L镁素处理的茶树生物量高于0.4 mmol/L,而缺镁(0 mmol/L)和0.8 mmol/L镁素处理的生物量显著降低。究其原因,缺镁和0.8 mmol/L镁素处理可能抑制PSⅡ反应中心光能利用效率和电子传递速率,热耗散等保护性调节机制和光化学反应不足以将叶片吸收的所有光能完全消耗,茶树可能受到光抑制或光破环,导致茶树光合器官遭受到损伤,光合能力降低,抑制茶树生物量的积累;而适宜浓度的镁素(0.1 mmol/L)可能通过提高叶绿素含量进而加强光合作用和光保护作用,促进茶树生长。因此,缺镁茶园可通过适量施镁促进茶树生长,具体用量需结合茶园土壤的镁素水平等因素再行确定。
In order to explore the response of magnesium to photosynthesis and photoprotection of tea plant,andthe proper application amount of magnesium fertilizer,Camellia sinensis cv.‘Shancha 1’was used in this study as the test material to study the effect of magnesium nutrition levels at different concentrations on the growth,photosynthetic characteristics and photoprotection of tea plant through hydroponic cultivation.The results indicated that seedlings chlorophyll content of the tea plant,biomass,net photosynthetic rate(Pn),stomatal conductance(Gs),transpiration rate(Tr),maximum quantum yield of PSⅡ(Fv/Fm),maximum primary yield of photochemistry of PSⅡ(Fv/Fo)and yield of photochemistry of PSⅡ[Y(Ⅱ)]showed increasing trend at first,and then decreasing trend with the increase of magnesium concentration,while the yield of non-regulated dissipation losses of PSⅡ[Y(NO)]showed an opposite trend.Correlation analysis indicated that the total fresh mass was in significantly or very significantly positive correlation with Gs,Gs,Tr,Fv/Fm and Fv/Fo,inapparently positive correlation with the total chlorophyll and Y(Ⅱ),but obviously negative correlation with Y(NO).The biomass of tea plant treated with 0.1 mmol/L magnesium was higher than that under 0.4 mmol/L treatment,while the biomass of tea plant treated with magnesium deficiency(0 mmol/L)and 0.8 mmol/L magnesium was significantly reduced.The restriction of light energy utilization efficiency of the PSⅡreaction center and electron transfer rateunder the 0 mmol/L and 0.8 mmol/L treatment of magnesium may be the reason,which caused insufficiently protective regulation mechanism such as heat dissipation and light chemical reactions for competing consumption of all the light energy absorbed by the leaves.Thus,the tea plant might be photodynamically inhibited or damaged,and the photosynthetic organ was damaged,which led to the poor photosynthetic capacity to inhibit the accumulation of biomass.In contrast,treatment of proper magnesium concentration(0.1 mmol/L)might promote the growth of tea plant by increasing the chlorophyll content and enhancing the photosynthesis and photoprotection.Therefore,for the magnesium-deficient teagardens,appropriate amount of magnesium canbe applied to promote the growth of tea plants.The exact dosage depends on the magnesium contentin tea garden soil and other factors.
作者
唐磊
肖罗丹
黄伊凡
孟阳
肖斌
杨亚军
TANG Lei;XIAO Luodan;HUANG Yifan;MENG Yang;XIAO Bin;YANG Yajun(College of Horticulture,Northwest A&F University,Yangling Shaanxi 712100,China;Tea Research Institute,Chinese Academy of Agricultural Sciences,Hangzhou 310008,China)
出处
《西北农业学报》
CAS
CSCD
北大核心
2021年第8期1210-1219,共10页
Acta Agriculturae Boreali-occidentalis Sinica
基金
陕西省茶产业技术体系(K3370219029)
陕西省重点研发计划(K3300220087)。
关键词
茶树
镁
光合作用
叶绿素荧光
光保护
Tea plant
Magnesium
Photosynthesis
Chlorophyll fluorescence
Photoprotection
