Genetic Analysis And Molecular Tagging Of A New Gene Of Amylose Content Of Soft Rice In Yunnan And Quality Characters Of Soft Rice In Sichuan Ecosystem

Soft rice is a kind of special resources of quality rice in the district of Yunnan.Amylose content of soft rice is generally ranged from 9.0% to 15.0%, belongs low amylosecontent rice resources. Soft rice is characterized by sheer or semi-sheer appearance of grain,fluffy texture of cooked rice, soft texture of cooled rice, and some is aromatic, excellenteating quality. It is a kind of important rice resources that improve the quality of hybridrice in the nation, and have great potential for breeding.1, Research to soft rice grain characters showed that soft rice, non-glutinous rice andglutinous rice was different in appearance, eating quality and texture. Soft rice wascharactered by the appearance of semi-sheer almost, higher alkali spreading value rangedfrom 6.8-7 scale and 7 scale at average, lower amylose content ranged from 9.8%-12.8%and 11.1% at average, lower gel consistence ranged from 34mm-49mm and 41.5mm ataverage, higher protein content ranged from 8.2%-12.9% and 11.0% at average.Non-glutinous rice was charactered by the appearance of sheer almost, and the sideline ofchalkiness was clearly. Glutinous rice was charactered by extremely high gel consistenceof 100mm and low amylose content of 2.1% at average. Judge analysis to the soft rice,high amylose content and low amylose content type non-glutinous rice varieties showedthat translucency, gel consistency, amylose content and end viscosity are the main actorsfor judging the soft rice, low and high amylase content type non-glutinous rice varieties,and the correct rate was 100%.2, Soft rice had polymorphism at Wx gene locus. Using molecular marker 484/485 totest Wx genotype of soft rice, the genotypes of soft rice were Wx³ genotype and Wx²genotype. Another tested result using molecular marker PCR-Accâ… showed that soft ricewere G nucleotide type almost at the 5' splice site of intron 1 in waxy gene and was Tnucleotide type also.3, Genetic analysis of soft rice. The amylose content test result to soft rice and it'soffsprings showed that amylose content of soft rice was ranged from 9.8-12.8%, amylosecontent of the hybrids and F₁ rice from soft rice and non-soft rice trended it's female parent,and the appearance of grain trended it's female parent also. Cross was made betweenHaomulv and G46B which has the same Wx genotype as Haomulv. As a result, frequencydistribution curve of amylase content of F₂ had obvious double apex which were 16% and22%. The ratio of high amylase content individuals and low amylase content individualsfitted well to 3:1 by x² test. And the frequency distribution curve of amylase content ofcontra-cross F₂ between Haomulv and G46B had obvious double apes also. The ratio of high amylase content individuals and low amylase content individuals fitted well to 3:1 too.It showed that the inheritance of amylose content of soft rice was controlled by a recessivegene which was a non-allelic gene with waxy gene.4, The F₂ population of Haomulv/G46B was analysed as mapping population bybulked segregation analysis. Analysis result indicated that SSR makers, RM254, RM224,RM5349, RM4601, RM7654, were linked tightnessly with the du-cl(t) gene in soft rice.And it was located at 11th chromosome with distance 10.2 cM to RM5349 and withdistance 17.3 cM to RM224.5, Research to rice quality of three types of rice showed that the stability of head rice,chalky grain and chalkiness were worse than other characters of rice quality on fourecosystem points, and the stability of brown rice, length/width ratio and grain length werebetter in all characters of rice quality.6, Analysis results to soft rice's RVA profiles showed that the peak viscosity of softrice was lower than low amylose content type varieties or series, but higher than glutinousrice. The valley viscosity of soft rice was lower than non-glutinous rice and higher thanglutinous rice. The breakdown viscosity was higher than glutinous rice and lower than lowamylose content type varieties or series, parts of soft rice varieties were higher than highamylose content type non-glutinous rice varieties. End viscosity and consistency viscosityof soft rice were between the non-glutinous rice and glutinous rice. The consistency ofstarch of soft rice was between of non-glutinous rice and glutinous rice.