磷元素对受铝胁迫的高州油茶幼苗光合作用的影响

摘要

Camellia oleiferais is fit to grow in acid soil,which always exists Al stress.In order to find the optimum P concentration to alleviate Al stress,using C.gauchowensis seedlings as research objects,Al stress and P alleviating Al stress experiments of C.gauchowensis seedlings were put forward by using soil culture method,Al concentration was 1.01 cmol · kg-1,and P contents were set four treatments of 0.00 cmol · kg-1 (Ⅰ),0.16 cmol · kg-1 (Ⅱ),0.33 cmol · kg-1 (Ⅲ),0.50 cmol · kg-1(Ⅳ),and 1.00 cmol · kg-1(Ⅴ).The results showed that 0.50 cmol · kg-1 (Ⅳ) and 1.0 cmol · kg-1 (Ⅴ) of P could effectively alleviate inhibition of Al stress to net photosynthesis of C.gauchowensis and could recover intercellular CO2 concentration to CK level.Lower P content could significantly enhance water use efficiency in C.gauchowensis.When P content was ≥ 0.50 coml · kg-1,it could not effectively decreaseinitial fluorescence in C.gauchowensis under Al stress.1.0 cmol · kg-1 p could effectively alleviate inhibition of Al stress to actual photosynthesis efficiency,electron transport efficiency and maximal photosynthesisrate in C.gauchowensis.%油茶适宜生长在酸性土壤中,但酸性土壤容易产生铝胁迫作用.为了寻找磷缓解油茶铝胁迫作用的最适宜浓度,以高州油茶幼苗为试验对象,设铝浓度为1.01 cmol·kg-1,并设磷含量分别为0.00(处理Ⅰ)、0.16(处理Ⅱ)、0.33(处理Ⅲ)、0.50(处理Ⅳ)、1.00(处理Ⅴ)cmol·kg-1,采用土培法对油茶幼苗进行了铝胁迫和磷抗铝胁迫的试验研究.结果表明:磷含量分别为0.50和1.00 cmol·kg-1的处理Ⅳ与Ⅴ均能有效缓解铝胁迫对高州油茶净光合作用的抑制,均能使其胞间CO2浓度恢复到CK水平(P＞0.05);较低含量的磷处理能显著提高高州油茶的水分利用效率;当磷含量≥0.50 coml·kg-1时,磷处理不能完全降低受铝胁迫的高州油茶的初始荧光值:含量为1.00 cmol·kg-1的磷处理能完全有效地缓解铝胁迫对高州油茶实际光合效率、电子传递效率和最大光合效率的抑制作用.