低磷胁迫对不同油茶无性系幼苗生长及养分利用效率的影响

Effects of low phosphorus stress on the growth and nutrient utilization efficiency of different Camellia oleifera clones

选择砂培处理的油茶无性系幼苗为对象,采用裂区设计,以0、0.05、0.5 mmol/L 3种磷处理水平(P0、P1、P2)模拟低磷胁迫,研究低磷胁迫对5个油茶优良无性系生长及氮、磷、钾吸收利用效率的影响差异。结果表明:不同油茶无性系间耐低磷胁迫差异显著;随低磷胁迫的加剧,各无性系的生物量和氮、磷吸收量减少,而利用率增加。无磷和低磷时湘林67和湘林69两个无性系的生物量和磷吸收量、利用效率均较高,叶片氮磷比(N/P)和叶片Δ(N/P)均较低,表明这两个无性系具有较好的体内磷养分循环利用机制,具备良好的耐低磷胁迫能力。

A sand culture experiment with a split design was conducted to study the responses of seedlings of five Camel-lia oleifera clones under three levels of P stress （P0（0 mmol/L）, P1（0.05 mmol/L）, P2（0.5 mmol/L））. The results showed that five clones were significantly different in tolerance to low phosphorus stress. With low P stress exacerbating, the biomass and the N and P absorption of tested clones decreased, whereas the nutrient utilization efficiency increased. In low P and P deficiency treatments, the biomass and the P absorption and utilization efficiency of Xianglin67 and Xianglin69 were higher. Leaf （N/P）and leafΔ（N/P） ratio were lower. There were better phosphorus nutrient recycling mechanism in Xianglin67 and Xianglin69.Those clones could be considered to be excellent low P stress resistant clones.