Genetic Analysis of Plant Height and Allelic Variation of SD1 in Oryza glumaepatula
In order to investigate the reasons for the differences in plant height between SSSL-B50 and HJX74,an F2 population was constructed by backcrossing SSSL-B50 with HJX74 for genetic analysis and gene map-ping of the plant.The genetic analysis showed that F,plants exhibited tall plant height.And the separation ratio within F2 was 3:1(x2=0.18<3.84)between the tall plant individuals and the semi-dwarf ones,which indicated that the tall plant height of SSSL-B50 was a dominant trait.Based on the linkage analysis between the marker genotypes and pheno-types of plant height in the F2 population,the gene controlling tall plant height was mapped between markers S18 and X161 within the 38.38-39.07 Mb interval of the substituted segment on chromosome 1.Moreover,it was found that the known gene of"Green revolution",SD1,fell to the mapping interval.Through amplification and sequence alignment of SD1 gene in Oryza glumaepatula,SSSL-B50,and HJX74,it showed that a 280 bp deletion in CDS in HJX74 compared with Oryza glumaepatula and SSSL-B50.The qRT-PCR results showed that the expression level of SD1 was significantly higher in the second,third,and fourth sections of SSSL-B50 stem than in HJX74.The comparison of the SD1 gene se-quence of Oryza glumaepatula with the previous reported results showed that the base substitutions occurred at two sites(E100G,Q339R)in the encoded amino acid.The results revealed that the tall plant height of SSSL-B50 was controlled by SD1.Furthermore,a new allelic type of SD1,SD1 Glu,was identified in Oryza glumaepatula.
Oryza glumaepatulaPlant heightSingle segment substitution lineGene mappingAllelic type