不同小麦品种的灌浆生理特性对后期青枯影响的研究

Influence of Physiological Characteristics at Grain Filling Stage on Dying Green of Wheat Plants in Different Varieties

在小麦灌浆期,剧烈的气温变化会导致一些品种和麦田发生青枯危害,表现为茎杆青灰发暗,不能正常落黄;籽粒灌浆不足,千粒重大幅度下降,造成减产.品种间对此反应不一,受害程度大小不同.研究表明,抗青枯品种具有较强的根系活力,体内可溶性总糖量高,而总氮量低,花后灌浆期,茎鞘叶物质分解转运量大,转运速率高,植株体内碳氮比较高,灌浆进程衰退缓慢.穗和籽粒发育充分,籽粒占穗重的比例较高.不抗青枯的品种茎杆物质积累量高,分解转运早,穗和籽粒在灌浆早期发育快,但在剧变气温出现后,根系活力迅速衰退,茎、鞘、叶物质分解缓慢,转运量低,植株体内碳氮比值较低,穗和籽粒发育不充分,籽粒占穗重的比例较低.

The dramatically changed temperature at grain filling often caused dying green of plants in some wheat varieties, which symptomatized dark-glaucous stems,unusual yellow ripening and un-fully filling grains,and finally resulted in a substantially decreased grain weight and yield. Simultaneously other wheat varieties,however,displayed yellow ripening naturally and little damage in developing grains. The variety difference may be explained by that of physiological characteristics between the plants. The resistant varieties had more vigourous roots. high total soluble carbohydrates and low total nitrogen concentrate, The substances in shoots were degraded more transported rapidly. Thus a higher carbon-nitrogen ratio was maintained in shoots. Espesially at filling the spikes and grains developed complemently. The grain DM accumlates accounted for a great proportion of spike wight. On the contrary, the sensitive varieties had a high accuml ates in shoots. Substance degration and transportation occured early. Spikes and grains developed fast in early stages. but substance degration and transportation reduced after the violent temperature at filling. The carbonnitrogen ratio was low in plants. Spike and grain could not developed fully. The grain wight accounted for a less proportion of spike weight.