Temporal expression of QTLs for plant height and tiller number in rice (Oryza sativa L.)

Abstract

A double haploid population of 80 lines derived from IR 64/Azucena cross was used for identifying quantitative trait loci (QTL) underlying the development of plant height and tiller number in rice (Oryza sativa L.). The composite interval mapping revealed a total of nine QTLs for plant height and six QTLs for tiller number on four chromosomes (3, 6, 8 and 10). On chromosome 3, a common QTL flanked by RZ284 and RG179 markers was detected with its peak expression (4.35 LOD) at 75 days after sowing (DAS) indicating varied level of gene expression for plant height. No QTL could be detected for tiller number at 60 days after sowing (DAS), while the remaining stages were found to be associated with six QTLs, of which the QTL detected on chromosome 6 (RM225-RM253) was a common QTL. Thus the QTLs identified at successive growth stages were different while some QTLs were common for all growth stages for both traits explaining the differential patterns of gene expression.