%0 Journal Article
%T Genotypic differences in nitrogen uptake by maize inbred lines its relation to root morphology<br>玉米氮素吸收的基因型差异及其与根系形态的相关性
%A WANG Yan
%A MI Guohu
%A CHEN Fanjun
%A ZHANG Fusuo
%A <br>王艳
%A 米国华
%A 陈范骏
%A 张福锁
%J 生态学报
%D 2003
%I 
%X Five maize inbred lines, (478,H21,Wu312, Zong31,Baici), selected from previous field and pot experiments were used in order to compare the genotypic variations in total N uptake, N partition between shoot and root and its relation to root morphology at four nitrate levels (0.04,0.4,2, 4mmol/L). Seedlings were grown in solution cultures. The results showed that 478, a N efficient variety, partitioned a larger amount N to its root in comparison with the other inbred lines. The percentage of root N accumulation to total N accumulation was increased by 18.34% and 17.08%, respectively in comparison with N inefficient lines, Wu312 and Zong31, when it was grown in N-deficient treatment (0.04mmol/L), whereas there was no significant difference between 478, Baici and H21. As the NO- 3 concentration increased, the percentage of total N partitioned to root declined for all the genotypes. Genotypic variation of N partitioning was not detected among the five maize inbred lines at high nitrate supply. ;The highest N accumulation in 478 at low nitrate supply was mainly due to its large root biomass which was 0.10, 0.74, 0.6 and 0.18 times larger than H21, Wu312, Zong31 and Baici respectively. When nitrate concentration increased from 0.04 to 2 mmol/L, root and shoot biomass of all the lines increased to various degrees. At the high nitrate level (4 mmol/L), however, shoot biomass keep increasing whereas root growth was inhibited. The genotypic variation in root dry weight among the five varieties was larger than that of shoot dry weight at low nitrate concentration. Total N uptake was significantly and positively correlated to root dry weight, total root length and length of root axis at 0.04 mmol/L, the coefficients of which were 0.9590, 0.9345 and 0.9050 correspondingly, but not at 4 mmol/L nitrate level. This indicates that genotypes with large root systems are able to obtain more N from low N medium. When N is not a limiting factor for plant growth, root morphology becomes less important in N uptake.
%K maize
%K genotype
%K nitrate
%K root
%K N uptake<br>玉米
%K 氮素吸收
%K 基因型差异
%K 根系形态
%K 相关性
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=90BA3D13E7F3BC869AC96FB3DA594E3FE34FBF7B8BC0E591&jid=FE163E5DB2274E5937319DE98913EC37&aid=D9FEAD5DBFA0ED5D&yid=D43C4A19B2EE3C0A&vid=EA389574707BDED3&iid=0B39A22176CE99FB&sid=E42CAFB11D4BE21A&eid=119B6C0AA09DE6B9&journal_id=1000-0933&journal_name=生态学报&referenced_num=38&reference_num=9