【目的】以2个不同品质类型的小麦品种为供试材料,分析小麦胚乳中淀粉粒的分布特征和变化特点。【方法】选用鲁麦21(弱筋)和济南17(强筋)两个小麦品种,利用激光衍射粒度分析仪研究其胚乳发育过程中淀粉粒的积累动态。【结果】花后不同时期小麦胚乳淀粉粒数目的变化均呈单峰曲线,峰值出现在0.5~1.1μm。花后7d,A-型淀粉粒已经出现,最大直径20μm;花后10d,淀粉粒直径范围扩大到30μm;至花后14d,B-型淀粉粒开始产生;花后21d又产生了一个新淀粉粒群体,即C-型淀粉粒;花后24~28d,籽粒中新淀粉粒的产生仍在继续;花后35d,主要是最小粒径淀粉粒直径的扩大。与强筋小麦济南17相比较,花后7~14d,弱筋品种鲁麦21胚乳中小于0.6μm的淀粉粒数目百分比较低,大于0.6μm的淀粉粒数目百分比较高,花后17~28d则相反。【结论】灌浆前期鲁麦21胚乳中淀粉粒的增长速率较快,而灌浆后期新淀粉粒合成能力较强。成熟期,济南17籽粒中的B-型淀粉粒所占体积和表面积百分比较高,而弱筋小麦鲁麦21的A-型淀粉粒体积和表面积百分比较高。
[ Objective ] The present study was carried out to characterize the distribution and development of starch granules during grain filling in two wheat cultivars differing in gluten. [Method] Two wheat cultivars, Lumai 21 (weak gluten winter wheat) and Jinan 17 (strong gluten winter wheat) were used as materials to investigate the distribution of starch granule size with laser-diffraction particle-size analyzer during endosperm development at Tai'an of Shandong Province in 2004-2006 growing season. [ Result] At different days after anthesis (DAA), the percent number distribution of starch granules in wheat endosperm exhibited single peak curves with peaks at 0.5-1.1 μm. The starch granules initiated before 7 DAA and increased in size to maximum diameter of 20 μm at 7 DAA. These early synthesized granules (A-type) continued to enlarge to their maximum diameter of 30 μm at 10 DAA. By 14 DAA, a burst of synthesis created a new population of small starch granules (B-type), which reduced the number proportion of big starch granules. A third group (C-type) of small granules was initiated at 21 DAA. From 24 to 28 DAA, the percent number of 〈 0.6 μm starch granules increased and those of 〉9.8 μm starch granules decreased continuously, indicating that new granules were still synthesized, however, the magnitude of increase reduced. These small granules continued to enlarge in diameter by 35 DAA. The percent number of 〈0.6 μm starch granules and that of 〉0.6 μm in Lumai 21 was lower and higher, respectively, than in Jinan 17 at 7-14 DAA. However, there were opposite changes at 17-28 DAA. [Conclusion] It is concluded that Lumai 21 has higher starch granule accumulation rate and stronger capacity of new starch granule synthesization than Jinan 17, respectively, at early and late grain filling stage. At maturity, the percentages of volume and surface area of B-type starch granules in Jinan 17 are higher than those in Lumai 21, but on the contrary in the percentages of A-type starch granu