硅对杉木幼苗生长和光合特性的影响

Effects of Silicon on the Growth and Photosynthetic Characteristics of Cunninghamia lanceolata Seedlings

为从光合生理角度揭示杉木对不同施硅量的响应特征。于2021年在福建省洋口国有林场田间大棚,以0.5 a的杉木优良无性系“洋061”为材料,在施用复合肥30 g·株^(-1)基础上添加不同量的硅肥(0、0.4、0.8、1.2 g·株^(-1)),以不施肥为对照,比较不同硅肥用量对杉木幼苗生长和光合特性的影响,并结合隶属函数法对各生长和生理指标进行综合评价。结果表明:与对照和单施复合肥处理相比,施硅能不同程度促进杉木幼苗苗高、地径生长,且在硅肥用量为0.8 g·株^(-1)时苗高和地径达到最大值。施硅可显著促进杉木叶片叶绿素和光合色素的积累,提高叶绿素a/b值,提高叶片最大荧光(F_(m))、可变荧光(F_(v))、PSⅡ最大光化学效率(F_(v)/F_(m))、PSⅡ潜在光化学效率(F_(v)/F_(o))、实际量子产量(QY)值和叶片净光合速率(Pn),且各指标均在硅肥用量为0.8 g·株^(-1)时达到最大;施硅处理叶片初始荧光(F_(o))、非光化学猝灭(NPQ)和胞间二氧化碳浓度(Ci)则低于对照。隶属函数法分析结果表明,当硅肥用量为0.8 g·株^(-1)时其隶属值最大,表明该处理下苗木综合生长状况最好。综合结果表明,在施用复合肥30 g·株^(-1)的基础上添加硅肥0.8 g·株^(-1)是适宜杉木“洋061”幼苗生长的施肥处理。

In order to unravel the response characteristics of Cunninghamia lanceol ata to different amounts of silicon from the perspective of photosynthet ic physiology,a pot experiments were conducted in greenhouses in Yangkou state-owned forest far m in 2021 to investigate the effects of different amounts of silicon(Si)fertil izer(0,0.4,0.8,1.2 g·plant^(-1))on the growth and ph otosynthetic characteristics of C.lanceolata seedlings by using 6-month-old su perior clone seedlings″Yang 061″supplied with 30 g·plant^(-1) of compoun d fertili zer(CF).Moreover,subordinate function value method was employed as well to compr ehensive analyzed the growth and physiological indexes,thus selecting the suita ble Si fertilizer level for C.lanceolata seedlings growth.The results showed t hat compared with the control and solely CF supplied treatment,Si applicati on could promote the growth of seedling height and ground diameter to different degrees,and the seedling height and ground diameter reached their maximum at 0.8 g·plant^(-1) Si treatment.Si application also significantly promote the a ccumu lation of chlorophyll and photosynthetic pigments in C.lanceolataleaves,incre ase chlorophyll a/b value,maximum fluorescence(F_(m)),variable fluorescence(F_(v)),maximum photochemical efficiency of PSⅡ(F_(v)/Fm),potential photochemical effi ciency of PSⅡ(F_(v)/F_(o)),actual quantum yield(QY)and net photosynthetic rate(P n)in leav es,and all of the above indexes reached their maximum at 0.8 g·plant^(-1) Si treatm ent.While the initial fluorescence(F_(o)),non-photochemical q uenching(NPQ)and intercellular carbon dioxide concentration(C i)of the silicon-appli ed leaves were lower than control.The subordinate function value method result s showed that the membership value was the highest when the dosage of Si was 0.8 g·plant^(-1),indicating that this is the most suitable Si concentration fo r the growth of C.lanceolata seedlings.In conclusion,compound fertilizer with 30 g·plant -1 plus 0.8g·plant -1 Si fertilizer is the appropriate fertilization treatment for the growth of C.lanceolata seedlings.