RESUMO
Nitrogen accumulation, translocation and allocation were investigated in a field experiment to find out the difference between six semi-winterness wheat cultivars and nine springness wheat cultivars that are mainly grown in Jiangsu. Results indicated that the average nitrogen accumulation amount (NAA) in the semi-winterness wheat cultivars was lower from the beginning of wintering to jointing stage, but higher from booting to maturity stage, compared with the springness wheat cultivars tested under the same rate of nitrogen fertilization. The amount of nitrogen accumulated between the beginning of wintering and jointing stage showed no significant difference between the two types of wheat cultivars, but that accumulated between anthesis and maturity in the semi-winterness wheat cultivars was higher than that in the springness wheat cultivars. The total N translocation amount (TNTA) and N accumulation amount to grains after anthesis (NAAA) were significantly higher in the semi-winterness wheat cultivars than those in the springness wheat cultivars, but the total N translocation efficiency (NTE), the contribution proportion of accumulated N (ANCP), and the contribution proportion of translocated N (TNCP) did not show significant difference between the two types of wheat cultivars. In leaves, the semi-winterness wheat cultivars showed lower TNTA, NTE and TNCP than the springness wheat cultivars, but in stem and sheath these N indexes were higher in the semi-winterness wheat cultivars, with a significant level for TNTA. These were significant differences in NAA, NAAA, TNTA and TNCP among cultivars with the same spring type or semi-winter type. According to the differences in nitrogen absorption, utilization and translocation among different wheat cultivars, nitrogen utilization efficiency could be improved by using approp-riate amount and reasonable proportion of nitrogen fertilizers at different developmental stages of wheat.
