2种氮素的分根处理对木薯幼苗生长发育和氮效率的影响  

Effects of root-split treatments with two forms of nitrogen on the growth and nitrogen use efficiency of cassava seedlings

作　　者：戴云鹏 潘晋龙 吴宇垚 韩昊祥 张怀方 陈新[2] 曾长英[1,2] DAI Yunpeng;PAN Jinlong;WU Yuyao;HAN Haoxiang;ZHANG Huaifang;CHEN Xin;ZENG Changying(College of Tropical Crops,Hainan University,Haikou,Hainan 570208,China;Institute of Tropical Bioscience and Biotechnology,Chinese Academy of Tropical Agricultural Sciences,Haikou,Hainan 571101,China)

机构地区：[1]海南大学热带作物学院,海口570228 [2]中国热带农业科学院热带生物技术研究所,海口571101

出　　处：《热带生物学报》2023年第6期614-621,共8页Journal of Tropical Biology

基　　金：国家自然科学地区基金项目(32060714,32260509);国家重点研发计划子课题(2018YFD1000500);海南省自然科学基金高层次人才项目(2019RC042)。

摘　　要：为了解氮源分根处理对木薯(Manihot esculenta)氮利用的影响,通过土培盆栽试验,以单侧加氮(-N/+N)与两侧加氮(+N/+N)的方式对2个木薯品种(‘华南16号’和‘华南205号’)根系进行分根处理,1个月后,比较‘华南16号’和‘华南205号’在不同氮源(NO_(3)^(-)、NH_(4)^(+))下农艺性状(生物量、株高、根长等)及氮生理指标(氮含量、氮积累量、氮生理利用率)的差异。结果表明:总施氮量减少1/2(-N/+N),并不会影响冠根比及全株干物质的积累,反而会促进木薯株高的增长,同时地上部氮累积量、地下部截留氮的能力及根的氮利用效率显著增加。-N/NH_(4)^(+)处理后,有氮侧的根系发育受到抑制;与之相比,-N/NO_(3)^(-)分根处理后,有氮一侧的根形态更好,同时还提升植株地上部氮积累量、根系氮利用效率。在同氮源异质分根条件下,‘华南205号’的株高、地上和地下部生物量、氮积累量、根形态均优于‘华南16号’;-N/NO_(3)^(-)分根处理后,‘华南205号’地上部和地下部氮利用效率高于‘华南16号’,而在-N/NH_(4)^(+)分根处理后‘华南16号’的氮利用效率更高。本研究结果显示,2种氮形态的减氮分根处理均能提高2个木薯品种的氮利用效率,硝态氮异质分根处理更有利于苗期‘华南16号’、‘华南205号’的生长,后者的氮效率更高生长更旺盛。An attempt was made to analyze the impact of a split root treatment using two forms of nitrogen on efficiency of two varieties of cassava('SC16'and'SC205')in using nitrogen.Cassava roots were treated unilaterally with nitrogen(-N/+N)or bilaterally with nitrogen(+N/+N),and the differences in agronomic traits(biomass,plant height,root length,etc.)and nitrogen physiological indicators(nitrogen content,nitrogen accumulation,and nitrogen physiological use efficiency)between the cassava varieties SC16 and SC205 under different nitrogen sources(NO_(3)^(-),NH_(4)^(+))after one month of split root treatment were compared to find out the effect of split root treatment with two N forms on nitrogen use efficiency of the two cassava varieties.The results showed that the reduced total N application to cassava by half(-N/+N)did not affect the shoot/root ratio and whole plant weight,but promoted cassava plant height and at the same time increased obviously the root nitrogen accumulation,the ratio of nitrogen to root and the nitrogen use efficiency.The root development of the cassava on the N-added side was inhibited in the-N/NH_(4)^(+)treatment.Conversely,the–N/NO_(3)^(-)root-split treatment resulted in better root morphology on the NO_(3)^(-)-side,and it also increased shoot N accumulation and root N use efficiency.Under the unilateral root-split treatment with the same nitrogen source,the plant height,the biomass of shoot and root,the nitrogen accumulation of root and shoot,and root morphology of SC205 were better than those of SC16.The nitrogen use efficiency of the-N/NO_(3)^(-)treated SC205 was higher than that of SC16 in the shoot and root,while the nitrogen use efficiency of the-N/NH_(4)^(+)-treated SC205 was lower than that of SC16.All these results showed that unilateral root-split treatment with two forms of nitrogen at a halfreduced rate could improve the N use efficiency of the two varieties of cassava.The unilateral split root treatment with nitrate nitrogen was more conducive to the growth of SC16 and SC205 at the

关 键 词：木薯 均质 异质 不同氮源 种质差异 氮效率 表型性状 

分 类 号：S533[农业科学—作物学] Q945.3[生物学—植物学]