A Dynamic Model and Its Characteristics Analysis for Nitrogen Accumulation after Heading in Yongyou 538 Dynamic Model and Its Characteristics Analysis for Dry Matter Production after Heading of Indica/JaponicaHybrid Rice of Yongyou Series Abnormalities Occurring during Female Gametophyte Development Result in the Diversity of Abnormal Embryo Sacs and Leads to Abnormal Fertilization in indica/japonica Hybrids in Rice Distorted Segregations of RFLP Markers and Their Distribution on Chromosomes in an indica/japonica F2 Population of Rice (Oryza sativa L.)