氮、钾、钙对柑桔幼苗生长与光合生理的影响

Effects of N,K and Ca on Growth and Photosynthetic Physiology of Citrus Seedlings

采用三因素五水平回归最优设计、砂培方法,研究了营养液中不同浓度 N、K、Ca 对椪柑实生苗生长与叶片叶绿素含量、光合强度及矿质养分吸收的影响,建立了相应的数学模型并对其进行了解析。结果表明;N 是影响柑桔叶片光合性状的重要因素,Ca、K 影响相对小些;叶片光合强度最大时的营养液组成是:N=230×10^(-6),K=130×10(-6),Ca=291×10^(-6);一定范围内,叶绿素含量、光合强度与叶片含 N、含 K 量成正相关;N 和 K 互相促进吸收,增施 K 时只有配合适量 N 才能更大程度地提高叶片的光合能力;叶片含 Ca 量随培养液与叶片中 N、K 含量升高而呈下降趋势。

The effects of N,K and Ca concentrations in culture solution on growth,chlorophyllcontent,photosynthetic rate and the nutrient element contents of orange seedlings(CitrusPoonensis Tanaka)were studied by means of three factors and five levels regression optimumdesign and sand culture.The corresponding regression equations were determined and anal-ysed.The results showed that:N is the main factor affected the leaf photosynthesis charac-ters.The optimum concentrations of N,K and Ca in nutrient solution for photosynthetic rateare 230×10^(-6),130×10^(-6),291×10^(-6)respectively;the positive correlation is found among thechlorophyll content,photosynthetic rate and the N,K contents in the leaves within a certainscope of N,K contents.The uptake of Ca by the roots is enhanced by low N,K levels,buthindered by high N,K levels in culture solution,the Ca content in the leaves gradually de-clines with the increase of N,K levels in both leaves and culture solution.The uptake of N,Kis enhanced by each other:more N should be used when increasing K was used,so that thephotosynthetic rate can be raised much more greatly.