Identification Of The Prostrate Gene La1-a In Rice And Mapping Of Quantitative Trait Loci For Indica-Japonica Differentiation

There are two parts to this paper,part 1 is on mapping and cloning the lal-a that controlled the rice prosprate trait,part 2 is on mapping of QTLs for certain traits in indica and japonica subspecies.The proceduce that rice from creeping growth to erected growth is an indispensable in the process of domestication from wild rice to cultivated rice.Analysis of this process will provide important clues and evidences to clarify the origin and evolution of cultivated rice.In this study a mutant of prostrate growth was found in early indica restorer line Jinhui 2689 in our laboratory.Genetic analysis shows that the trait is controlled by a single recessive gene located in chromosome 11 between RM287-RM7275 in approximately 240kb range by analysis of a F2 population between mutantion and Nipponbare.There was a cloned gene LAI(LAZY1),located in this region which control rice upright growth.Comparing the sequences of LA1 in wild type and mutant,we found a nucleotide mutation in the coding region,causing a amino acids substitution.in conserved regions,so named lal-a.Compared with LAI,lal-a is a new allele of the LA1.The nucleotide mutation does not cause a significant effect the expression in mutant.Further analysis of the LAI sequenc in 30 accessions of wild rice,failed to find the mutation like lal-a.There are much differcnce Between indica and japonica subspecies in cultivated rice,including not only the phenotypic characteristics such as the first internode length,apiculus length,but also the genomic sequence.Further studying of these traits genetic characteristics can provide the theoretical basis clarified the molecular mechanism of differentiation in indica and japonica.Building genetic linkage map and QTL analyses of nine main traits include plant height,panicle length,the first internode length,apiculus length,heading date,grain length,grain width,outer glume length and inter glume length using F2 population derived from typical japonica Mudanjiang 8(MDJ8)and typical indica Minghui 63(MH63).24 QTLs have been detected in the 12 lingkage groups,including 3 QTLs controlling plant height in chromosome 1?6?10;4 QTLs controlling panicle length in chromosome 3?6?7;4 QTLs controlling the first intemode length in chromosome 6?8?12;5 QTLs controlling apiculus length in chromosome 3?4?5?6;3 QTLs controlling heading date in chromosome 7?10?12;1 QTL controlling grain length in chromosome 6;2 QTLs controlling grain width in chromosome 3?4;1 QTL controlling the outer glume length in chromosome 6;1 QTL controlling inter glume length in chromosome 4.