不同水分条件下源库调节对小麦营养器官可溶性碳水化合物和籽粒千粒重的影响

Effects of source-sink regulation on water soluble carbohydrates of vegetative organs and thousand-grain mass of wheat under different water conditions

以抗旱性有显著差异的两个冬小麦品种为材料,在干旱胁迫(DS)和正常灌溉(WW)条件下,研究了源库调节对小麦营养器官中可溶性碳水化合物(WSC)和籽粒千粒重(TGM)的影响.结果表明:缩库处理显著增加了小麦各营养器官WSC含量,且正向促进WSC的相对转运;减源处理反之.源库调节WSC含量及其相对转运量/率的效应为:干旱胁迫显著高于正常灌溉,抗旱品种(陇鉴19)显著高于水分敏感品种(Q9086),缩库处理对WSC含量的影响强度显著高于减源处理,穗下节和倒二节普遍高于倒三节、叶鞘和叶.减源处理下,陇鉴19的总WSC相对转运率的强势器官主要为叶鞘、穗下节和倒二节,而Q9086主要表现在倒二节和倒三节;两小麦品种果聚糖相对转运率的强势器官均为叶鞘、穗下节和倒二节.减源处理使陇鉴19和Q9086的TGM在干旱胁迫下分别下降27.3%和31.7%,在正常灌溉下分别下降25.3%和12.1%.缩库处理的WSC含量及其相对转运与TGM的相关系数显著大于减源处理;干旱胁迫处理显著高于正常灌溉处理,不同器官中WSC总含量和果聚糖含量与TGM普遍表现出较高的相关系数(r2>0.900);小麦WSC含量及其相对转运与TGM关联度较为密切的器官主要集中在叶鞘和穗下节.在干旱胁迫条件下,WSC总含量有关性状与TGM表现出较高关联度,而在正常灌溉条件下,蔗糖和葡聚糖有关性状与TGM普遍表现出较高关联度.源库关系对小麦不同营养器官WSC及籽粒千粒重的调节易受水分环境、基因型和营养器官位置的显著影响.

Two winter wheat cuhivars with different drought tolerance were selected to investigate the effects of source-sink regulation on the vegetative organs water soluble carbohydrates （WSC） content and 1000-grain mass （TGM） of wheat under drought stress （DS） and well watered （WW） conditions. Sink-cutting increased the WSC content of different vegetative organs significantly, and promoted the relative transportation of the WSC positively; while source-cutting caused opposite responses. The effects of source-sink regulation on the WSC content and its relative transportation amount （TA） and transportation rate （TR） were significantly higher under DS and sink-cutting than under WW and source-cutting, for drought-resistant cuhivar （Longjian 19 ） than for drought-sensitive Q9086, and for peduncle internode and PedI than for penultimate internode and PenI. Under source-cutting, the superior organs of Longjian 19 in the TR of total WSC were sheath, PedI, and PenI, which also contributed to the fructan TR of the two cultivars, while those of Q9086 were the PenI and the third intenode from top （ThiI）. Source-cutting decreased the TGM of Longjian 19 and Q9086 significantly, with the decrement being 27.3% and 31.7% under DS and 25.3% and 12.1% under WW, respectively. The correlation coefficients of the WSC content and its TA and TR and the TGM were significantly higher under sink-cutting than under source-cutting, and also, under DS than under WW. There existed a higher correlation coefficient （r2 〉 0.900） of the TGM and the total WSC and fructan contents in different vegetative organs. The vegetative organs with closer correlation between their WSC content and its TA and TR and the TGM were mainly sheath and PedI. Under DS, the traits associated with the total WSC content had a higher correlation with TGM; under WW, the traits associated with sucrose and glucan contents generally showed a higher correlation with TGM. It was suggested that the effects of source-sink regulation on the WSC content of vegetative organs and the TGM were significantly affected by soil waterwater environment, wheat genotype, and vegetative organs location.