小麦穗离体培养下干物质及锌元素的积累规律

Study on Dry Matter and Zinc Accumulation of Detached Wheat Spikes in vitro Culture

以花后2 d的济麦20为试验材料,利用离体穗培养的方法,研究了低锌(19.5μg/mL Zn)和高锌(195μg/mL Zn)处理下离体穗各器官干物质及锌元素的积累规律,以探讨锌对籽粒建成和籽粒锌积累的影响。结果表明,随培养天数的增加,离体穗干物质积累总量呈增加趋势。高锌处理有利于倒二节、穗下节、旗叶、旗叶鞘、穗轴和颖壳干物质的积累,其籽粒干物质量却明显降低,仅为低锌处理的十分之一。因此,高锌处理离体穗干物质积累总量低于低锌处理。随培养天数的增加,离体穗各器官锌含量呈增加趋势,且高锌处理下各器官锌含量均明显高于低锌处理。不同器官锌含量存在差异,表现为旗叶较高,而籽粒较低。随培养天数的增加,离体穗锌积累量呈"快-慢-快"的递增趋势,高锌处理除籽粒外其他器官锌的积累量远高于低锌处理。低锌处理下锌主要积累于颖壳、籽粒和旗叶,籽粒锌积累量占总量的20%;而高锌处理下锌主要积累于颖壳和旗叶,在籽粒中积累较少,仅占总积累量的3%。

In order to study the effect of Zinc （Zn） on the grain development and Zn accumulation, dry matter and Zn content in organs of detached wheat spikes in vitro culture were determined under two levels of Zn application （19.5 and 195 μg/mL, respectively）. The experiment material was Jimai 20, which grew in the field 2 days after anthesis. The results showed that with the days of culture added, dry matter accumulation of detached spikes increased. Under high Zn treatment （195μg/mL Zn）, dry weight of internode next to peduncle, peduncle, flag leaf, flag leaf sheath, rachis and glumes were more than those under low Zn treatment （19. 5 μg/mL Zn）. However, dry matter accumulation in grains under high Zn treatment was only as one tenth as those under low Zn treatment. Therefore, low Zn treatment was more benefit to the dry matter accumulation of detached spikes. With the days of culture added, Zn concentration in organs tended to rise. Furthermore, Zn concentrations in organs under high Zn treatment were all significantly more than those under low Zn treatment. And there were significant differences in Zn concentration among organs. Zn concentration was greater in flag leaves, and less in grains. With the days of culture added, Zn accumulation of detached wheat spikes also increased. And the adding trend can be described as fast-slow-fast. There was a slow increase in the number of Zn accumulation of detached spikes form 15d to 20d after culture. Zn concentration in organs except grain under high Zn treatment tended to jump sharply compared with low Zn treatment. Under low Zn treatment, there was more Zn accumulation in glumes, grains and flag leaves, the proportion of Zn accumulation in grains was 20 percent. Moreover, there was more Zn accumulation in glumes and flag leaves under high Zn treatment. But under high Zn treatment, Zn accumulation in grains was the least, and it was only 3 percent of total Zn accumulation.