氮素水平对不同氮效率基因型苎麻根系性状的影响  

Effects of nitrogen levels on root characteristics of ramie genotypes possessing different nitrogen recovery efficiency

作　　者：陈继康[1] 谭龙涛[1] 喻春明[1] 朱爱国[1] 陈平[1] 王延周[1] 朱涛涛[1] 熊和平[1] 

机构地区：[1]中国农业科学院麻类研究所,湖南长沙410205

出　　处：《草业科学》2017年第11期2316-2324,共9页Pratacultural Science

基　　金：湖南省科技计划重点研发计划项目(2016NK2205);国家麻类产业技术体系建设专项(CARS-19);中国农业科学院科技创新工程多年生麻类作物遗传改良团队资金(ASTIP-IBFC04)

摘　　要：根系是苎麻(Boehmeria nivea)吸收氮素的主要器官,开展苎麻根系对不同氮素水平的响应研究对其品种改良和农艺调控具有重要意义。针对以往研究的不足,本研究设置了0、6、9、12和15 mmol·L^(-1)氮素水平处理进行盆栽试验,分析了不同氮效率苎麻根系性状对氮素水平的响应特征,及其与氮素利用效率的关系。结果表明,增施氮素可显著提高苎麻根系总吸收面积、活跃吸收面积及比表面积(P<0.05),但对根长影响不显著(P>0.05)。增施氮肥可显著促进苎麻根系体积与活力的增长,其中氮高效基因型苎麻H2000-03根系体积在12mmol·L^(-1)处理时达到最大,为未施处理的3.06倍,氮低效基因型苎麻册亨家麻根系体积在9mmol·L^(-1)时达到最大,为未施处理的2.38倍;而过量施氮则会导致指标下降,其中旺长期册亨家麻根系活力下降达67.5%。各性状的综合表现导致苎麻氮素回收率在9mmol·L^(-1)时达到最大值。氮高效苎麻H2000-03较氮低效苎麻册亨家麻具有显著较高的根长、根系体积、总吸收面积、活跃吸收面积,且能够随生长发育维持较高水平。但二者根系比表面积和根系活力没有显著差异,是其根系性状改良的重点。影响苎麻氮素回收率、地上部氮素累积量的关键时期为生长中后期,且关键因素为根量及根系表面特性。The root is the main organ of ramie for absorbing nitrogen. It is therefore, important to study the responses of ramie root under different nitrogen levels for variety improvement and agronomic trait modification. This paper focused on root characteristics and response by root, and their relationship to nitrogen recovery efficiency （NRE）. A potted experiment was conducted using two ramie varieties with different nitrogen utilization efficiency, and there were： 0, 6, 9, 12 and 15 mmol·L-1 nitrogen levels. The results showed that different parameters of ramie root had different responses under different nitrogen levels. The total absorption area （TAA）, active absorption area （AAA） and root area∶volume ratio （A∶V）, all were found to increase with the increasing nitrogen levels, but no significant effect was detected on root length （RL） in the experiment. Ramie root volume （RV） and activity （RA） were enhanced by increasing nitrogen levels. RV of H2000 03 with high NRE peaked at 12 mmol·L-1, which was 3.06 times of unfertilized N. RV of Ceheng Jiama with low nitrogen efficiency peaked at 9 mmol·L-1, which was 2.38 times of unfertilized N. RV and RA reduced after exceeding a certain amount of nitrogen, among which the RA of Ceheng Jiama was reduced by 67.5% at the rapid growth stage of the plant. Highest NRE was detected for 9 mmol·L-1 due to the significant changes in root parameters measured. H2000 03 showed significantly higher RL, RV, TAA and AAA than Ceheng Jiama. These parameters also could be maintained at a higher level in H2000 30 along its growth stages. Unfertilized N significant difference was detected in A∶V and RA between the two varieties, which was key for improvement of ramie root characteristics. The key periods which affected NRE and nitrogen accumulation of ramie shoots mostly were the later stages of plant growth and the key attributes were root quantity and root surface characteristics.

关 键 词：苎麻 氮素水平 氮素回收率 根系形态 根系活力 

分 类 号：S563.1[农业科学—作物学]