Exploitation of molecular markers for erect panicle trait and study on breeding Indica erect panicle varieties in rice.

Erect panicle(EP) gene was the one with great practice value related to plant type in rice.In this research program,inheritance of the EP,exploitation of molecular markers for the gene,marker-assisted selection(MAS) for the trait in the hybrid progenies and the comparison of the characters between erect and bended panicle breeding lines were studied.Results indicated that the EP trait was incompletely dominant single gene inheritance with dominant effect up to 73.3 %-93.7 %.The EP gene was found to be close linkage with SSR markers RM566,RM24423 and RM7048 with map distances 5.8,0.43 and 0.85cM.Exploiting the three markers for maker-assisted selection(MAS) showed a correct select rate of 66.7 %-100 % for the EP trait and the rate reached as high as 100 % by use of RM24423 for the MAS in the breeding progenies.As compared with the bended panicle type breeding lines,the EP lines selected presented little shorter in plant height,lower number of effect panicles and shorter panicle length;significantly larger grain number per panicle and higher density of spikelets in the panicle;significantly lower filled grain rate and a little but not significant lower 1000-grain weight and single-plant yield in the Indica rice.Therefore,designing ideal Indica EP plant type against the EP effect in these characters and researching the breeding methods would be a significant step for breeding Indica EP varieties.