| 摘要: |
| 【目的】深入研究玉米种子内部因脱粒产生机械裂纹的机理及其对种子发芽和幼苗发育的影响，为进一步优化设计玉米种子脱粒机提供参考。【方法】以辽宁主栽的辽单526、辽单565和郑单958 3个玉米品种为材料，利用体视显微技术分析玉米种子内部机械裂纹的形态结构、生成位置和扩展方向等特征，探讨内部机械裂纹对玉米种子发芽和幼苗发育的影响。【结果】（1）3个品种玉米种子中单裂纹发生率最高，达到19%～33%，其次为龟裂纹，双裂纹发生率最低，仅为2%～5%；裂纹主要产生于冠部，并向背部、侧面和腹部扩展。（2）内部机械裂纹对玉米种子发芽率、子叶长、胚根长、胚根数影响明显，其中龟裂纹对玉米种子的发芽和幼苗发育影响最大，发芽率最高仅为48%，并且幼苗子叶及胚根发育较差。（3）种胚中存在裂纹是影响玉米种子发芽的主要因素，发芽弱和未发芽玉米种子的种胚和胚乳存在不同程度的损伤。【结论】玉米种子在脱粒过程中产生的内部机械裂纹严重影响种子发芽及幼苗的后期发育。发芽弱和未发芽玉米种子内部存在不同程度的机械裂纹。 |
| 关键词: 玉米种子 机械裂纹 发芽 幼苗发育 |
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| 基金项目:安徽科技学院博士启动基金项目（ZRC2013397） |
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| Effects of internal mechanical cracks in corn seeds on germination and seedling development |
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ZHANG Xin-wei,GAO Lian-xing
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| Abstract: |
| 【Objective】This study investigated the characteristics of mechanical damages in corn seeds and the impact on germination and seedling development to optimize the design of corn seed threshers.【Method】Using Liaodan 526,Liaodan 565 and Zhengdan 958,which were the main varieties cultivated in Liaoning Province,the characteristics including morphological structure,location,and extending direction of mechanical cracks in corn seeds were studied using stereomicroscope system to investigate the effects of inner mechanical cracks on corn seed germination and seedling development.【Result】(1) Single crack had the highest occurrence rates in corn seeds (19%-33%) followed by multiple cracks,while double cracks had the lowest rates (2%-5%).Cracks mainly distributed in crown,expanding to back,belly and side.(2) Inner mechanical cracks in corn seeds had significant effects on germination ratio,cotyledon length,radicle length and number of radicle.Multiple cracks had the greatest influence on germination and seedling development with a germination rate of 48% and week cotyledon and radicle.(3) Mechanical cracks in embryo were the mainly reason that affected corn seeds germination,and damages with different levels were observed in embryos of weak sprouts and no germination corn seeds.【Conclusion】Internal mechanical cracks produced during threshing which significantly affected seed germination and seedling development of corn seeds.Mechanical cracks were observed inside week sprouts and no germination corn seeds. |
| Key words: corn seeds mechanical cracks germination seedling development |
