Study On The Consumption Of Endosperm And Changes Of Amyloplast Shape During The Germination Process Of Rice Seed

Seed germination is the beginning of agricultural production, and many scientific researchers, home and abroad, are interested in it. Whether the rice seed could germinate rapidly and become sound seedling after paddy planting is closely related to the growth vigor and high yield of the seedling when bedded out, and it is also related to the grain security. Other researchers who studied rice seed germination focused on the outside factors, and those who studied rice seed endosperm focused on the its formation and input pathway of nutrients during its development. So far there is no systematic report about the consumption of endosperm and changes of amyloplast shape during the germination process of rice seed. This dissertation stated our study on the changes of the endosperm morphology and changes of the physiological activities during the germination process. The focus of our study was the consumption of endosperm and the shape changes of amyloplast. The main results were as follows.(1) The nutrient in the seed can sustain the seedling growth for about 12 days at room temperature. In this process, the grain weight decreased; the seedling height increased; and roots grew well. The seedling stopped growing after 12 days.(2) Comparied with Yangdao number 6, Xiang zao xian 33 had some advantages, for example, during the seed development, the dry matter accumulated faster; the seedling height increased more rapidly; and the grow vigor was better. Besides, the supply, absorption and the use of the endosperm nutrients were good.(3) During the process of seed germination, the starch content in the grain decreased gradually, while the soluble sugar showed the"up, stable, down"change.(4) The respiration rate of the two different rice variety both had a"peak", which was positive correlated with the peroxidase content in the seed. And the respiration activities of scutellum increased along with the germination of seed.(5) The amyloplast in rice endosperm cell was made up of polygon-like compound starch granules, and one compound starch granule included several small granules. When endosperm was consumed, many small pits and holes emerged on the surface of the amyloplast, and the starch granule was degraded gradually showing an irregular shape.(6) In the process of seed germination, the consumption of rice endosperm inclusion started from the site near the embryo. Then the endosperm inclusion far from the embryo was transported to the site near the embryo. At last the endosperm inclusion in the whole seed was totally consumed.