摘要
【目的】探明不同水稻品种胚乳发育过程的异同。【方法】以日本晴(粳)、扬稻6号(籼)、武育糯16号(粳糯)和扬辐糯4号(籼糯)4个水稻品种为试验材料,通过精确标记颖果受精后的发育天数,观测颖果的生长;采用碘-碘化钾、TTC染色法观察胚乳细胞发育过程中淀粉的积累和生理活性的变化差异;采取树脂包埋法制作半薄切片,用光镜详细观察水稻内胚乳细胞和糊粉层细胞在颖果发育过程中结构的变化差异;用扫描电镜研究水稻成熟籽粒断面的超微结构,并使用能谱仪对其相关部位元素组成的差异进行探测。【结果】粳稻与籼稻颖果长、宽、高的变化存在明显区别,二者粒型存在显著差异,是否为糯性并不影响颖果的外形发育。供试的4种水稻颖果中,2个籼稻品种,扬稻6号与扬辐糯4号发育要快于粳稻品种;2个糯稻品种,武育糯16号与扬辐糯4号有着近乎一致的干重增长曲线;随着细胞内淀粉体和蛋白体的充实,内胚乳细胞在发育的中后期会发生核变形而衰亡;细胞核衰亡以后,胞内淀粉体仍可膨大生长。4种水稻内胚乳细胞所含淀粉体均为复粒;直链淀粉含量高的非糯品种,其胚乳淀粉充实程度高;2个籼稻品种的糊粉层细胞体积要大于2个粳稻品种;粳糯品种武育糯16号P、K、Mg、S等矿质元素含量低于其他3个供试品种;籼糯品种扬辐糯4号糊粉层含有少量单粒淀粉体,O元素含量高于其他品种。【结论】水稻颖果胚乳发育是一种特殊的细胞程序性死亡方式,细胞核的死亡并不影响胚乳同化产物的积累,淀粉体在内胚乳细胞内都是以复粒淀粉形式存在。以上这几点,供试的4个品种水稻之间几乎没有区别。而在总体发育进程、分化、细胞形态、活性变化、同化产物积累、淀粉体形态大小及在不同部位的分布上,4种水稻品种各自呈现了一定程度的差异与联系。粳稻2个品种与籼稻2个品种间差异更多体现在颖果发育进程上;而糯稻与非糯稻的区别则更多体现在淀粉体的形态与灌浆的充实程度上。
【Objective】The objective of this research is to clarify the difference of rice endosperm of different varieties during the development process.【Method】Four rice varieties, Nipponbare, Yangdao 6, Wuyunuo16 and Yangfunuo 4 were used as the experimental materials, and their caryopsis development days precisely were precisely recorded and their caryopsis development was closely observed. Starch accumulation and physiological activities were observed by I2-KI and TTC staining. Structure changes of rice starch endosperm cells were observed by applying spur resin embedding and semi-thin sectioning, and light microscopy. The ultrastructure and element analysis of full ripe rice caryopsis were observed under scanning electron microscope and EDS. 【Result】Four stages occurred in caryopses development of all the rice varieties tested： formation stage, milky stage, dough stage, and full maturity stage. Compared to development stages of the endosperm, formation stage runs in parallel to the coenocyte and cellurization stages, which are the initial stage of endosperm formation; milky stage corresponds to the differentiation stage of endosperm cells, while the last two stages, dough and full maturity stages, are equivalent to that of the endosperm maturity stage. The shape of two rice sub subspecies, japonica and indica, varies significantly. Of the four rice varieties tested, two indica varieties showed a relatively faster growth rate than two japonica cultivars; Wuyunuo16 and Yangfunuo 4 had almost identical growth rate of dry matter accumulation. Nuclei of starch endosperm cells degenerated with the extension of amyloplasts, while amyloplasts were still enlarging and growing. Amyloplasts in the endosperm cells were compound granules, and their development pattern possibly affected a certain quality of endosperm. Amyloplast in endosperm cells was spherical or elliptic in shape during early developmental stage, but turns to polyhydric during the late development stage. Two glutinous rice cultivars tended to have a loosely stacked endosperm and as a result, caused the appearance to be less transparent. Aleurone cell volume of two indica cultivars were bigger than japonica ones, mature aleurone cells were rich in minerals like P, K, Mg, and S. Cultivar Yangfunuo 4 had some single amyloplast detected in aleurone cells and, showed a higher level of O element content.【Conclusion】The development of starchy endosperm is autonomous and is independent of the existence of endosperm nuclei. The two non-glutinous rice cultivars have a more densely packed endosperm, The types of starch contents in cells from scutellum, pericarp and endosperm are relatively distinct in two glutinous rice cultivars, which stresses the disparate set of mechanism of starch synthesis between maternal tissue, endosperm and embryo.
出处
《中国农业科学》
CAS
CSCD
北大核心
2014年第19期3757-3768,共12页
Scientia Agricultura Sinica
基金
国家自然科学基金(31270228
31071341)
