基于颖果发育进程的杂草稻早熟机制的研究
时间:2018-08-02 16:25 来源:毕业论文 作者:毕业论文 点击:次
| 摘要：杂草稻与栽培稻相比存在明显的早熟现象，为明确杂草稻与栽培稻颖果发育进程差异，揭示杂草稻颖果发育特点及其与杂草稻早熟的关系，本研究以同质园种植的丹东、茂名、扬州和泰州杂草稻及相应栽培稻为材料，比较花后3-9d的颖果显微结构；并通过Evans blue 染色和 TTC染色，比较杂草稻与栽培稻颖果发育进程及胚乳细胞程序化死亡进程的差异。结果显示，杂草稻花后3d胚乳便完成细胞化，并开始积累淀粉，而栽培稻此时尚处于细胞化期，且无淀粉积累；花后5-9d杂草稻与栽培稻均进入生长分化期，开始大量积累淀粉，但杂草稻胚乳内的淀粉面积更大，排列更为紧密。杂草稻果皮内淀粉的消亡早于栽培稻，果皮失水收缩也早于栽培稻，其果皮生长期明显短于栽培稻。4种杂草稻胚乳细胞的死亡均早于相应栽培稻2-6d，胚乳细胞的脱氢酶活性丧失早于栽培稻3-11d，具有较快的胚乳PCD进程。综上所述，杂草稻颖果发育迅速、胚乳PCD进程加快可能是其早熟的机制之一。26616 毕业论文关键词：杂草稻；颖果发育；显微结构；细胞程序性死亡；早熟 The research on the mechanism of early-maturity of weedy rice based on caryopsis development Abstract：For exploring the difference on caryopsis development between weedy rice and cultivated rice, and revealing the characteristics of caryopsis development of weedy rice and its relationship with early-maturity, weedy rice and cultivated rice from Yangzhou, Taizhou, Maoming and Dandong were cultivated in the same experimental field at Nanjing Agricultural University. The microstructures of caryopsis were compared between the weedy rice and their respective cultivated rice from 3-9 DPA (days post anthesis). In order to definite the difference on the process of programmed cell death in starchy endoseprm between weedy rice and its cultivated rice, the viability and dehydrogenase activity of endosperm cells of both them from 3-21 DPA were determined by Evans blue staining and TTC staining. It was observed that the weedy rice had already finished celluarization and had some small amyloplasts stored in cells at 3 DPA, while the cultivated rice still was at celluarization stage with no starch grain storage at 3 DPA. From 5-9 DPA, weedy rice and its cultivated rice were at development and differentiation stage, and plenty of starch was accumulated during this period. However, the weedy rice stored more starch grains which arranged more closely in the starchy endosperm than their respective cultivated rice. Compared to cultivated rice, the degradation of starch in pericarp and the shrinkage of the pericarp occurred earlier in weedy rice, suggesting shorter pericarp growth duration of weedy rice. Furthermore, PCD of entire starchy endosperm and the loss dehydrogenase activity of entire starchy endosperm also occurred 2-6 days and 3-11 days earlier than that of the cultivated rice, respectively. The above results suggested a faster PCD progression of the starchy endosperm in weedy rice. In summary, the caryopsis of the weedy rice developed faster and displayed quicker endosperm PCD progression. This may be one of the mechanism of its early-maturity. Key words: the weedy rice; caryopsis development; microstructure; programmed cell death; early-maturity 目 录 摘要2 关键词2 Abstract2 Key words2 引言3 1 材料与方法4 1.1 试验材料4 1.2试验方法4 1.2.1栽培稻与杂草稻颖果的显微结构观察4 1.2.2 杂草稻与栽培稻胚乳细胞活性的检测 5 2 结果与分析6 2．1 杂草稻与栽培稻胚乳的显微结构差异6 2．2 杂草稻与栽培稻果皮的显微结构差异10 2．3 杂草稻与栽培稻果皮背部文管束的差异15 2．4 杂草稻与栽培稻胚乳细胞活性变化差异17 3 讨论17 3.1 杂草稻胚乳发育的结构特点17 (责任编辑：qin) |