不同供水条件对小麦强、弱势籽粒中淀粉粒度分布的影响

以3个淀粉含量不同的冬小麦品种山农12、鲁麦21和济南17为材料,设灌溉和旱作2种栽培处理,对不同水分条件下小麦强、弱势籽粒中淀粉粒的体积、数目和表面积的分布特征进行了研究.结果表明,小麦强、弱势籽粒均含有A(＞9.8 μm)、B(2.0～9.8 μm)、C(＜2.0 μm)3种类型的淀粉粒,但不同类型淀粉粒的分布状况存在明显差异.在强势籽粒中,淀粉粒的体积和表面积分布均表现为三峰分布,而弱势籽粒中淀粉粒的体积和表面积分布则表现为双峰分布.与弱势粒相比较,强势粒中C型淀粉粒(＜2.0 μm)的体积百分比为7.25%～9.31%,表面积百分比为34.88%～41.51%,而弱势粒的体积和表面积百分比分别为5.33%～6.40%和26.31%～33.54%.强、弱势籽粒中＜0.6 μm和0.6～2.0 μm范围内的淀粉粒数目存在明显差异,强势粒为1.86%～6.13%和83.77%～87.77%,而弱势粒为25.72%～37.42%和52.77%～58.48%.与灌溉栽培相比较,旱作栽培条件下籽粒中B、C型淀粉粒体积和表面积百分比显著增加,而A型淀粉粒体积和表面积显著减少;弱势粒中＜0.6 μm的淀粉粒数目显著增加,强势籽粒中淀粉粒的数目无显著变化.与弱势粒相比较,强势粒中的蛋白质含量较高,C型淀粉粒的体积和表面积所占比例较大,而强势粒中的淀粉含量较低,且A、B型淀粉粒比例也较小.与灌溉栽培相比较,旱作栽培条件下强、弱势籽粒中B、C型淀粉粒体积和表面积百分比增加,蛋白质含量也显著增加,淀粉含量降低.表明水分亏缺能提高籽粒中B、C型淀粉粒体积和表面积百分比及蛋白质含量.

Effect of water regime on starch granule size distribution in superior and inferior grains of wheat

The present study was carried out to investigate the starch granule size distribution in grains of wheat. This information will help to elucidate the characterization of starch granule in the superior and inferior gains in winter wheat. The volume%, surface area% and number% distribution of starch granules were investigated in three winter wheat cultivars (Shannong12, Lumai21 and Jinan17), differing in starch content, in Tai'an experimental location in Shandong Province during the 2004-2006 growing season. The results showed that both superior and inferior grains contained three types of starch granules: smaller C-type granules with diameters ＜2.0 μm, medium B-type granules with diameters 2.0-9.8 μm and large A-type granules with diameters ＞9.8 μm at maturity. Both volume% distribution and surface area% distribution of starch granules in superior grains showed the typical three populations, and those in inferior grains exhibited the two peak curve. The volume% and surface area% of starch granules with the ranges of ＜2.0 μm in superior grains were 7.25%-9.31% and 34.88%-41.51%, respectively, and those in inferior grains were 5.33%-6.40% and 26.31%-33.54%. Significant differences were seen among the superior and inferior grains for number% of starch granules with the ranges of ＜0.6 μm and 0.6-2.0 μm. The number% in inferior grains was 25.72%-37.42% and 52.77%-58.48%, and that in superior grains was 1.86%-6.13% and 83.77%-87.77%, respectively. Compared with irrigation, the volume% and surface area% of B, C-type starch granules were significantly increased, and those of A-type were evidently decreased. The number% of starch granules with the ranges of ＜0.6 μm in inferior grains under rainfed condition was significantly increased, and that in superior grains had no evident difference. The volume percentage and surface area percentage of C granules and protein content in superior grains were higher than that in inferior grains, but those of A, B granules in superior grains were lower than that in inferior grains. Compared with irrigated condition, rainfed condition can increase the volume percentage and surface area percentage of B, C granules and protein content in superior and inferior grains.