‘燕山红栗’坚果不同发育时期淀粉粒显微结构变化

The microstructure of starch granule during nut development in ‘Yanshanhongli’ (Castanea mollissima Bl.)

【目的】为板栗品种的筛选、资源利用以及加工特性的改良调控提供理论依据。【方法】以‘燕山红栗’为试验试材,通过碘染法、切片法和淀粉粒提取法,及显微镜观察淀粉粒,分析坚果不同发育时期淀粉颗粒变化。偏光显微镜观察淀粉颗粒偏光特性;X射线衍射法分析淀粉颗粒晶型;扫描电镜观察淀粉颗粒表面形态。【结果】淀粉颗粒几乎占据板栗子叶细胞的所有空间,淀粉颗粒粒度分布不均匀,大小淀粉粒同时存在于细胞中,小淀粉粒直径3~5μm,大淀粉粒直径可达到20μm,随着坚果发育大淀粉颗粒比例不断增多。淀粉颗粒呈鹅卵石状,表面光滑。淀粉颗粒为单粒淀粉,晶型为C型,具有明显的马耳他十字。【结论】为淀粉特性的变化提供形态、分布的理论依据,为板栗加工、品种改良、良种选育提供依据。

[Objective]Study on starch granule properties in different period might provide insights into chestnut starch synthesis and contribute to germplasm utilization and proceeding quality enhancement. [Methods]Samples were collected from the Chinese chestnut cultivar ＇ Yanshanhonglity. X-ray diffraction Light-microscope, scanning electron microscope and polarizing microscope were used to observe the morphological characteristics of starch granule. Distribution of starch granule in cells was observed by iodine-stained thin sections. [Results]Starch granules almost occupied all the spaces in cotyledon cell. Various types were observed when the morphology of the starch granules was visualized. Particle size distribution was inhomogeneous and starch granules grew in size during cotyledon development. Starch shapes were irregular spheroids or ellipsoids with smooth surfaces and starch granules were single grain, C-type crystal with clear Maltese cross. [Conclusion]This study provides theoretical basis for the morphological properties and distribution of starch, and lays foundation for postpartum processing, quality improvement and seed breeding.