2年生不同油茶品种树体养分对缺钾胁迫的响应差异

Variations of tree nutrient response to potassium deficiency stress in different two-year-old Camellia oleifera cultivars

【目的】试验研究了不同品种油茶缺钾胁迫下的养分响应差异,为油茶钾素养分管理及耐低钾品种选育提供理论依据。【方法】以当前主栽的赣无1(G1)、赣石83-4(G83-4)、赣无11(G11)2年生油茶苗作为试验材料,设置缺钾(K0)及施钾(K1、K2)3个钾水平处理,探究生长过程中叶片养分含量变化及收获期各器官养分含量、生物量差异。【结果】缺钾胁迫明显影响各品种叶片对钾养分的积累,G1叶片7月氮含量显著高于施钾处理18.13%以上,而8月磷含量和9月钠含量下降,G83-4和G11叶片氮、磷、钠含量对缺钾响应则不明显。缺钾使收获期G83-4根氮含量显著低于施钾处理33.48%以上,各组织品种间氮积累量差异显著;G1根磷含量、积累量高于施钾处理,且分别是K2处理2.17、2.12倍,G83-4叶磷含量较K2提升78.73%;各品种钾含量、积累量降低,品种间钠含量、积累量差异增大。缺钾胁迫使G83-4的氮养分利用率显著提高,且较K2处理显著提升78.73%,G11叶磷分配量高于另外两个品种,G1的磷养分利用率降低,且显著低于K2处理34.16%;G1、G83-4钾养分分配规律相似,各品种钾养分利用率显著提高。缺钾胁迫对钠元素的吸收与分配受影响最大,而对G83-4钠养分利用率影响不明显。缺钾使G1、G83-4茎、叶组织生物量减少,而G11更高,但影响均没有达到显著水平。【结论】缺钾胁迫使2年生油茶钾养分利用率提高,并使钠代替部分钾营养功能;树体的氮、磷含量、积累量以及各组织生物量对缺钾胁迫的响应因品种存在差异,G11低钾条件下能积累更多养分和生物量,更耐低钾。

【Objective】The experiment investigated the nutrient response differences of different varieties of Camellia oleifera under potassium deficiency stress to provide a theoretical basis for potassium nutrient management and selection and breeding of low potassium tolerant varieties of C.oleifera.【Method】Two-year old C.oleifera seedlings of G1,G83-4 and G11,which were mainly planted,were used as the test materials.Three potassium level treatments,potassium deficiency(K0)and potassium application(K1,K2),were set to investigate the changes of leaf nutrient content during growth and the differences of nutrient content and biomass of each organ during harvesting.【Result】The potassium deficiency stress significantly affected the accumulation of potassium nutrients in the leaves of each variety.The nitrogen content of G1 leaves in July was significantly higher than that of the potassium application treatment by more than 18.13%,while the phosphorus content in August and sodium content in September decreased,while the nitrogen,phosphorus and sodium content of G83-4 and G11 leaves did not respond significantly to potassium deficiency.Potassium deficiency caused G83-4 root nitrogen content to be significantly lower than that of the potassium treatment by more than 33.48%at harvest,and the difference in nitrogen accumulation among varieties was significant;G1 root phosphorus content and accumulation were higher than that of the potassium treatment,and 2.17 and 2.12 times higher than that of the K2 treatment,respectively,and G83-4 leaf phosphorus content increased by 78.73%compared with K2;potassium content and accumulation decreased among varieties,and the difference in sodium content and accumulation among varieties increased.Potassium deficiency stress significantly increased the nitrogen nutrient utilization of G83-4 and 78.73%compared with K2 treatment,the phosphorus distribution of G11 leaves was higher than the other two varieties,the phosphorus nutrient utilization of G1 decreased and was significantly lower than that of K2 treatment by 34.16%;the nutrient distribution pattern of potassium was similar for G1 and G83-4,and the potassium nutrient utilization of each variety increased significantly.The uptake and distribution of sodium were most affected by potassium deficiency stress,while the effect on sodium nutrient utilization of G83-4 was not significant.Potassium deficiency reduced the biomass of G1 and G83-4 stem and leaf tissues,while G11 was higher,but none of the effects reached significant levels.【Conclusion】The potassium deficiency stress increased the potassium nutrient utilization of biennial C.oleifera,making sodium replace part of the potassium nutrient function;the response of nitrogen and phosphorus content,accumulation and biomass of each tissue to potassium deficiency stress in C.oleifera varied by species,with G11 accumulating more nutrients and biomass under low potassium conditions and being more tolerant of low potassium.