干旱胁迫下施钾水平对油菜生长特性、籽粒品质和钾素利用的影响  

Effects of potassium fertilizer rate on growth,seed quality and potassium use efficiency in Brassica napus under drought stress

作　　者：朱波 徐绮雯 马淑敏[1] 刘帮艳 段美春 王龙昌[1] ZHU Bo;XU Qi-wen;MA Shu-ming;LIU Bang-yan;DUAN Mei-chun;WANG Long-chang(College of Agronomy and Biotechnology,Southwest University/Key Laboratory of Eco-environments in Three Gorges Reservoir Region,Ministry of Education/Engineering Research Center of South Upland Agriculture,Ministry of Education,Chongqing 400716,China;College of life Sciences,Chongqing Normal University,Chongqing 401331,China)

机构地区：[1]西南大学农学与生物科技学院/三峡库区生态环境教育部重点实验室/南方山地农业教育部工程研究中心,重庆400716 [2]重庆师范大学生命科学学院,重庆401331

出　　处：《植物营养与肥料学报》2021年第6期1016-1026,共11页Journal of Plant Nutrition and Fertilizers

基　　金：公益性行业(农业)科研专项(201503127);国家自然科学基金项目(31271673)。

摘　　要：【目的】探究长期干旱胁迫下不同施钾水平对油菜生长、籽粒品质、钾素利用的影响,旨在明确不同钾肥水平下油菜通过调节生长和营养分配应对干旱胁迫的机制,为油菜抗旱栽培提供科学依据。【方法】以抗旱油菜品种油研57和干旱敏感品种川油36为试验材料,采用盆栽土培试验,每盆装风干土10 kg,设置K_(2)O施用量0、80和160 mg/kg土3个水平,并于花期开始控制土壤水分保持45%~50%最大田间持水量直至油菜收获,分别记为DK0、DK80、DK160,以施K_(2)O 80 mg/kg土,全生育期保持65%最大田间持水量作为对照,记为CK,对比不同施钾水平下油菜生长、产量、籽粒品质和钾素利用特征的差异。【结果】干旱胁迫严重抑制油菜生长,与DK0处理相比,两个油菜品种在DK80和DK160处理下根干重、总根长、根表面积、干物重和籽粒产量均显著增加。干旱胁迫导致油菜品质降低,与DK0处理相比,DK80和DK160处理下油研57籽粒油酸含量显著增加且芥酸含量显著降低。干旱胁迫引起油菜叶片早衰,花期早衰落叶钾分配比例显著增加并呈DK160>DK80>DK0的趋势(P<0.05),角果皮和茎钾分配比例大幅降低并呈DK160<DK80<DK0(P<0.05)的趋势,导致油菜钾素利用效率显著降低。与川油36相比,抗旱品种油研57根、茎和角果皮维持较高钾分配比例,表现出更高的钾素利用效率,在干旱缺钾条件下籽粒产量和油酸含量显著高于川油36。【结论】干旱胁迫导致油菜根系生长受抑制,叶片早衰,进而影响产量和菜籽油品质。增施钾肥可在一定程度上缓解干旱的不利影响,提高钾素在叶片中的分配率,提高油菜籽粒中油酸含量并降低芥酸含量,从而提高籽粒品质。由于干旱胁迫引起油菜叶片早衰,大量钾素随叶片脱落未被再利用导致钾素利用效率降低。【Objectives】Under long-term drought stress,rate of potassium application could influence rape growth,seed quality,and potassium utilization.A pot experiment was conducted to clarify the mechanism of growth regulation and nutrient allocation of rape under drought stress in response to potassium fertilizer levels.【Methods】Two rape cultivars Chuanyou 36 and Youyan 57 differ in drought resistance were used in a pot experiment.The pot was filled with 10 kg of air-dried soil,and three K_(2)O rates of 0,80 and 160 mg/kg soil were applied,respectively,and the drought stress was conducted by controlling soil moisture at 45%-50%of field water capacity after flowering period,denoted as DK0,DK80,DK160,respectively.Applying K_(2)O 80 mg/kg soil and keeping soil moisture at 65%of field water capacity was used as control(CK).Rape growth,yield,seed quality and K utilization characteristics were investigated.【Results】Rape growth was inhibited significantly by drought stress.Compared to the DK0,the root dry mass,total root length,root surface area,total plant dry mass and seed yield increased significantly under DK80 and DK160 treatments for both cultivars.Drought stress reduced seed quality however,potassium fertilizer relatively alleviated it.Rapeseed oleic acid content in DK160 and DK80 treatments were significantly higher than that in DK0 in‘Youyan 57’,but the erucic acid content decreased with increasing rate of potassium fertilizer.Drought stress led to early senescence of leaves,the proportion of potassium in the early decayed leaves during flowering stage increased significantly as the rate of potassium fertilizer increased.Conversely,the proportion of potassium in the stem and pericarp decreased significantly and decreased with increasing rate of potassium application under drought stress,which led to the reduction of rape K-use efficiency.Drought-tolerant cultivar‘Youyan 57’maintained higher proportions of K in both stem and pericarp and conferred a superior K-use efficiency,improved yield and higher

关 键 词：油菜 钾肥 钾利用效率 抗旱性 籽粒品质 

分 类 号：S565.4[农业科学—作物学]