Study On The Relation Between Rice Plant Type And Yield And Quality

Five single cross combinations of which had two parents from eight Japonic rice. Cultivors (or lines) with different plant type and their progenies of F2. .generations were analyzed genetically in various statistic analysis methods . Using 33 agronomic traits the results showed as following:1.The variation of straw and leaves.traits: the blade radix angle is highest,height is lowest; panicle type:the highest is number of subordinate branch shrivel grain and number of main branch shrivel grain, the lowest is panicle length and main branch number. Among milled quality: coefficient of variation is: the highest is Ratio of head rice the lowest is Ratio of brown rice .Physical quality: coefficient of variation of Ratio of length and width is lowest ,and core rate is highest; Steamed wheatenquality; Gelatination consistency is highest,Amylose content is lowest;2.Panicle curved degree, panicle length, panicle weight, grain of subordinate rachisbranches. seed-sectoring rate of subordinate rachisbranches affect the more conspious to yield ,3.Correlation analyse showed: quality characters is relative to straw and leaves.traits and panicle type. Characters with lower height, fewer tillers, narrower blade width, lower grain density can select offspring with high milled quality; lower grain density, fewer grain number can select offspring with high physical quality; fewer grain number and high subordinate branch seeding rate can select offspring with high steamed wheaten quality.4.Ratio of head rice,ratio of length and width ,core rate,amylose content gelatination consistency are important traits of quality.5.In the course choosing the straw and leaves. traits and panicle type,blade leaf width and highness should be choosen in the early generation, grain density,grain number and tillers should be choosen in the late generation, heredity change differently among combinations ,so combination effect should be considered.6.There are contradictions in highness and tillers between high yield colony and high quality colony,we should enhance the choice of number of subordinate branch grain and rate of subordinate rachisbranches grain7.Ideal quality plant type model: (1)heught 85cm～95cm, (2)tillers : 10～15 (3) blade leaf width: 1.1cm～1.4cm (4) grain density 5.5～6.5 (5) average grain number 100～120. (grain number withrmain haulm: 120～135.) (6)the seed-setting rate of subordinate rachisbranches is more than 90%.