| Fructan accumulation,concentration,partitioning,translocation and their heterosis in different tissue organ at various growth stages in wheat and its relationships to the grain yield(GY), grain nitrogen yield(GNY) and content(GNC) were studied using six hybrids of wheat as well as their seven parents by a split plot design with two replications and two levels of nitrogen application viz.O kg N /hm~2 (0 N) and 200 kg N/hm2(200 N).The main results are as follows.1. Significant N fertilizer level variation existed for Fructan accumulation,concentration and translocation in different tissue organ at most sampling dates,but the genetic variation were different in different tissue organ at various sampling dates .2. The change tendency of fructan accumulation and concentration in plants and stems were very similar at different N levels applied,but thats were difference in leaves and chaffs. its increased step by step in plants from jointing to a maximum at milk-ripe stage(0 N) or maturity(200 N).Except for fructan concentration of stems decreased from flag leaf emergence to maturty at 0 N level,stems fructan accumulation and concentration increased fast to a peak at anthesis,and decreased sharply again to maturity.That of leaves presented decrease tendency at 0 N,but its remained static at 200 N.For chaffs,its peaked at anthesis(0 N) or milk-ripe stage (200 N). Without leaves fructan accumulation at 0 N were lower than that at 200 N, leaves fructan concentration, fructan accumulation and concentration of stems and plants at 0 N were higher than that at 200 N,this indicated that N deficit had disadvantages on fructan accumulating in leaves,but stimulated fructan accumulating in stems.3. The pattern of fructan distibution in different tissue organ were also very similar at different N levels applied, Stems, containing about 73.3%~87.8% of plants fructan accumulation during vegetative growing stages, were the major storage tissue organ for fructan.4. The heterosis for fructan accumulation of leaves and chaffs were nagetive direction at most sampling dates; that of stems were positive direction at vegetative growth stages(5.8%~30.0%),but after anthesis its were nagetive; for plants that were positive direction(4.2%~22.0%) without at maturity at 0 N. However,there were no regular for fructan concentration heterosis in different tissue organ at various growth stages.5. Fructan translocation of total straws were 56.18 g/m~2 (0 N) and 71.6 g/ m~2 (200 N), stems accounted for more than 85%. Fructan translocation efficiency of leaves and chaffs at 200 N (23.9%, 2.4%) were lower obviously than that at 0 N (43.9%, 16.7%) ,that for stems and total straws were steady, 49.5% and 47.4% for stems , and 41.7% and 44.7% for totalstraws at 200 N and 0 N respectively. Fructan translocation of stems made more contribution to grain yield,which were more higher than that of leaves and chaffs.6. There were positive heterosis of fructan translocation, translocation efficiency and contribution ratio of various tissue organs, Nitrogen application increased notably the heterosis of fructan translocation and contribution ratio of chaffs at two N levels, but no remarkable effects of leaves and stems. This indicated that hybrids wheat had more powerful capacity of fructan translocation in leaves and stems than their parents.7. Fructan accumulation of plants and stems were positive significantly correlated with GY and GNY at most sampling dates at two N levels,but not significant with GNC at 0 N,while significant negatively correlated with GNC at 200 N.There were no. significant correlation between fructan accumulation of leaves and chaffs with GY.GNY and GNC.Fructan concentration of plants and its tissue organ also were not significantly correlated with GY,GNY and GNC at 0 N, but, fructan concentration of leaves,stems and plants were positively correlated with GY, negatively with GNC and not significant with GNY at 200 N.8. There was a positive significantly correlation between the heterosis of plants and stems fructan accumulation with the heterosis of GY and GNY,and not significant with the heterosis of GNC at 0 N,also positive significantly with GY heterosis,negative significantly with GNC heterosis and not significant with GNY heterosis at 200 N.The heterosis of plants and stems fructan concentration significant negatively correlated with the heterosis of GY,GNY and GNC at most sampling dates at 0 N,but not significant with GY and GNY heterosis,and negative significantly with GNC heterosis at 200 N.9. There were no significant relationships between fructan translocation of various tissue organs and grain yield, grain nitrogen concentration and their heterosis. |
