不同品质类型小麦籽粒淀粉粒度的分布特征

选用小麦强筋品种德丰3号、德99-3和弱筋品种滨育535和鲁麦21，研究了籽粒中淀粉粒度、淀粉粒的体积、数目和表面积的分布特征，及其与小麦籽粒蛋白质和淀粉含量的相关性。结果表明，成熟期小麦籽粒含有A (＞9.8 μm)、B (＜9.8 μm)两种类型淀粉粒，其粒径为0.37~52.60 μm。淀粉粒的体积和表面积均表现为双峰分布；淀粉粒的数目表现为单峰分布，其中B型淀粉粒数目占总数的99%以上。在强筋品种中，B型淀粉粒所占体积和表面积百分比相对较高，而弱筋品种中A型淀粉粒体积、表面积百分比相对较高。籽粒直链淀粉和总淀粉含量与2.0~9.8 μm和＜9.8 μm的淀粉粒体积百分比分别呈显著和极显著负相关，与9.8~18.8 μm的淀粉粒体积百分比呈极显著正相关。籽粒蛋白质含量与2.0~9.8 μm和＜9.8 μm的淀粉粒体积百分比呈显著正相关，而与9.8~18.8 μm的淀粉粒呈极显著负相关。籽粒淀粉和蛋白质含量均与其他粒径范围的淀粉粒体积无显著相关性。

Starch Granule Size Distribution in Grains of Strong and Weak Gluten Wheat Cultivars

Granule size and structure of starch affects starch quality fatally in wheat (Triticum aestivum L.). The quantity and volume of starch granule and starch components in grain vary in different types of wheat. Many researches have unveiled the distribution of starch granule size in wheat grain, but rarely mentioned the relationship between grain quality and starch granule characteristics. In the present experiment, the purpose was focused on starch granule size distribution and the relationship between starch granule size and grain quality properties. Four winter wheat cultivars (Defeng 3 and De 99-3 as strong gluten type, Binyu 535 and Lumai 21 as weak gluten type) were planted at Tai’an and Dezhou experimental sites in Shandong Province, respectively, with randomized block design in 2004–2005 growing season. The starch granule in matured grain was 0.37–52.60 μm in diameter, containing smaller B-type (diameter <9.8 μm) and larger A-type (diameter >9.8 μm) granules. The distribution frequency showed typical two-peak curve in starch granule volume and surface area, and single peak curve in number of starch granule. The number of B-type granule accounted for over 99% of the total starch granule. The percentages of volume and surface area of B-type starch granules were higher than those of A-type granule in the strong gluten wheat cultivars, but on the contrary in the weak gluten cultivars. The contents of amylose and starch were negatively correlated with the volume of 2.0–9.8 μm (r = －0.483*, －0.679**) and <9.8 μm (r = －0.465*, －0.667**) starch granules, respectively, but positively correlated to 9.8–18.8 μm starch granule (r = 0.648**, 0.673**). The content of protein was positively correlated with the volume of 2.0–9.8 μm (r = 0.528**) and <9.8 μm (r = 0.514*) starch granules, respectively, but negatively correlated with that of 9.8–18.8 μm (r = －0.548**) starch granule. The contents of starch and protein had no correlation with volume percentage of starch granule with other size ranges.