移植和钾肥对降香黄檀光合特性与叶绿素含量的影响

以降香黄檀(Dalbergia odorifera T. Chen)为材料,分析不同移植方式和外施钾肥等培育措施对其光合参数和叶绿素(Chl)含量的影响。结果显示,断根处理后植物的最大净光合速率(Pnmax)比去冠、全冠移、对照(CK)和去冠移4种处理方式分别提高了19.25%、34.79%、40.88%和219.86%。光合参数分析结果显示,光饱和点(LSP)最高的为去冠处理,光补偿点(LCP)最高的为断根处理。断根处理后植物的净光合速率(Pn)和蒸腾速率(Tr)最大。断根、去冠、全冠移3种处理的Chla、Chlb、Chl(a+b)含量及胡萝卜素均高于CK,且断根处理后上述各指标达到最高值。外施钾肥处理中,降香黄檀最大净光合速率随钾肥用量的增加而增加,K2处理下的LSP值最大。随着钾肥施用量的增加,植物叶片的Pn、气孔导度呈上升的趋势,且植株的Chla、Chlb和Chl(a+b)含量均随钾肥用量的增加而增加,CK处理下Chla/Chlb比值显著高于K1、K2处理。研究结果表明断根、去冠、施用钾肥等处理均可显著提升降香黄檀叶片的叶绿素含量,有利于植株进行光合作用,促进生长发育。

Effects of transplantation and potassium fertilizer on the photosynthetic characteristics and chlorophyll content of Dalbergia odorifera

Dalbergia odorifera T. Chen was used to analyze the effects of transplantation and potassium fertilizer on its photosynthetic characteristics and chlorophyll content. Results showed that the maximum net photosynthetic rate of plants after root pruning was 19.25%, 34.79%, 40.88%, and 219.86% higher than that of de-crowning, full-crown transplantation, CK, and de-crown transplantation. The maximum light saturation point(LSP) occurred under de-crowning treatment, and the maximum light compensation point(LCP) occurred under root pruning. The net photosynthetic rate(P_n) and transpiration rate(T_r) were highest under root pruning treatment. Compared with CK, the contents of Chla, Chlb, Chl(a + b), and Car were all higher under root pruning, de-crowning, and full-crown transplantation. Chla, Chlb, and Chl(a + b) all increased with the increase in potash fertilizer. The maximum net photosynthetic rate increased with the increase in potassium fertilizer dosage. The LSP value was largest under K₂ treatment. As the amount of potash fertilizer increased, P_n and Cond showed a tendency to increase. The Chla/Chlb ratio under CK treatment was significantly higher than that under K₁ and K₂. Root pruning, de-crowning, and applying potash fertilizer significantly increased the chlorophyll content of D. odorifera, which was beneficial for photosynthesis and the promotion of plant growth.