Subspecies Classification Of Indica And Japonica System And Relationship Of Subspecies Differentiation And Rice Quality Characters

A recombinant inbred line(RIL) population of F₈ and F9 generations derived from a cross between Qishanzhan(typical indica) and Akihikari(typical japonica) were used as materials to study the morphological differentiation based on phenotype and genetic differentiation based on indica and japonica specific SSR markers and evaluate if vascular bundles characters can be a supplement for the method based on Cheng's index to discriminate indica and japonica.Based on QTL Analysis of Cheng's index,34 markers linked to Cheng's index were found.94 F8 lines and 142 F9 lines of the RILs(Recombinant Inbred Lines) derived from the cross between Qishanzhan(typical indica) and Akihikari (typical japonica) were used as materials to study the relationship of morphological characters differentiation with genetics differentiation by investing Cheng's index,shorted as ChI,and Dj value based on indica and japonica diagnostic SSR markers,and rice quality in 2006 year and 2007 year.The result showed:1.The frequency distribution of morphological differentiations and genetic differentiations were all japonicalinous.The population was more japonicalinous based on the frequency distribution of genetic differentiation than morphological differentiation.The consistent degree of classification based on the vascular bundles characters or Cheng's index was about 50%,compared with genetic differentiation.The consistent degree of classification based on the total scores of Cheng's index and the scores based on vascular bundles characters was about 80%,compared with genetic differentiation.The Vascular bundles characters can be used as a helpful supplement for subspecies classification.2.The consistent degree of classification based on the 28 indica and japonica specific SSR markers and 34 markers or all of 122 SSR markers were 96%and 90%by the limit of 50%blood relationship of indica and japonica.The consistent degree of classification based on 34,65,90 markers were 91%,97%and 99%.The consistent degree of classification based on 28 indica and japonica specific SSR markers and 65 markers or 122 markers were more than 95%.Using few SSR markers can analyse blood relationship of indica and japonica on the population derived from indica and japonica crossing.3.RILs' population were divided into indica type and japonica type based on morphological differentiation,there was no significant difference in the most of quality traits between the two types except milled rice width.RILs' population was devided into japonica-cline type and japonica type,brown rice rate and milled rice rate and grain wide from japonica type were significant higher than that ofjaponica-cline type,and the ratio of milled rice length to milled rice width was significant lower than that of japonica-cline type.The relationship between Cheng's index from two generations and all the quality traits were not significant.The Dj value and brown rice rate and milled rice rate and milled rice width existed a significant positive correlation,whereas Dj value and the ratio of milled rice length to milled rice width showed more significant negative correlation.It showed there were no significant correlation between the morphological differentiation and rice quality trait in northern japonica.It could improve the milled quality through increasing the japonica component in genetic differentiation.