研究水稻同一穗上不同粒位、不同开花日序籽粒的发育动态,对阐明秕粒形成的规律是很有意义的。过去研究表明,同一稻穗上的颖花开花的早迟与籽粒灌浆的早迟及粒重有很密切的关系,开花早的优势粒不仅灌浆起步早,并且充实速度快,最后粒重也高。我们的研究也曾指出,杂交水稻开花日序越迟的颖花结实率越低。但这些研究都未曾对各个籽粒的灌浆动态进行连续观察,而是采用取样称重的方法进行研究, It is significant to elucidate the rule of grain formation when studying the development of different grain positions on the same ear of rice and the different flowering date kernels. Past studies have shown that the early flowering of spikelets on the same ear is closely related to the early grain filling rate and grain weight. The early flowering superiority grains are not only infested early, but also have high filling speed and high final grain weight . Our research also pointed out that the lower the flowering rate of hybrid rice is at the later flowering stage. However, none of these studies have continuously observed the grain filling dynamics of individual grains, but studied the method of sampling weighing,