Qtl Analysis for Eating Quality and Cooking Process Usinga Population Derived Froma Cross Between Minguhi63(Mh63) and Kkao Dawk Mali105(Kdml105)

摘要

The cooking and eating quality of the rice grain is one of the most serious problems in many riceproducing areas of the world. In this study, we performed a QTL analysis of rice cooking and eatingquality using a recombinant inbred line derived from a cross between Minghui 63 (MH63), theChinese best male sterility restorer in the hybrid rice programs, and Kkao Dawk Mali105 (KDML105), the Thai jasmine rice, known as the best quality rice. The traits analyzed include amylosecontent (AC), gel consistency (GC), alkali spreading value (ASV), and 13 parameters from theviscosity profile. Comparison of the QTL identified revealed 11 QTL clusters for these traits that aredistributed on six chromosomes. The QTL for the traits in same class often clustered into samechromosomal regions. A total of 29 distinct QTLs were identified for 16 traits (or parameters) in thetwo years at P=0.01 level. Our results clearly showed that the QTL corresponding to the Wx locuscontrolled seven of the viscosity parameters, and had no effect on AC, GC, and ASV The QTLcorresponding to the Alklocus played a role in ASV, GC, AC and all of the viscosity parametersexcept for PKV, FV and CS. This study showed that both AC and GC are not influenced by the Waxygene region and also could not classified in any group by principal component analysis; indeed, theprincipal component analysis used to analyze the correlation between all traits, showed that in 2009,all traits can be divided into two groups, the first group contain ASV, Atime, Atemp, Btime, Btemp,BAtime, PKV, SB, BD and V95, HPV, CPV, FV are in the second group. And in 2010, ASV, Atime,Atemp, BAtime, HPV, CPV, FV are in the first group, and PKV, SB are in the second group.Comparing the results of the two years, we found that ASV, Atime, Atemp and BAtime are always inthe same group, the same PKV and SB were always together, but they belong to group one and grouptwo respectively in 2009 and 2010. Another notable thing is that HPV, CPV and FV belong to the firstgroup in 2009 and to the second group in 2010; we can conclude that those traits are probablyinfluenced by environment. Our study investigates QTL analysis about the seven parameters of theviscosity profile, namely, Atemp, Atime, Btemp, Btime, BAtime, V95, and FV (most were theparameters in the heating period of viscosity analysis that had not been investigated previously), hadbeen reported in previous study by Wang et al. 2007 for the first time, and we located most of theQTLs already found by the previous study on chromosome 6 in the Waxy and Alk loci, onchromosome 5 and chromosome 7. Furthermore, we also mapped some new QTLs that never reportedbefore on the chromosomes 5, 6, 7, 8, 11 and 12. Nevertheless we can say that a fiirther deepinvestigation of these new QTLs or locus could bring more specific and comprehensive and probablycomplete information about them. However, we noted the instability of some of these QTLs across theenvironment and their small phenotypic variation value.