506-513Rice is a staple food of human kind and its demand is ever increasing. Asia accounts for 91% of global rice production of which India contributes 23%. The increasing demand has led to the development of various high yielding varieties and cultivars. Rice cultivation in flooded fields is known to influence the atmospheric methane-budget. Here, we studied the effects of rice cultivars on methane (CH4) production, methanogenic archaeal diversity and abundance in Indian rice soils using six rice cultivars (IDR 763, HUR 3022, Sahbhagi, Swarna sub 1, MTU 7029 and BPT 5204). Methanogen community size and diversity was analyzed using qPCR and DGGE targeting mcr A and 16S rRNA gene fragments, respectively. Methanogenic community size varied among cultivars (1.65-97.6 × 105 copies g-1 dws). The diversity analysis revealed five methanogenic groups i.e., Methanocellaceae, Methanobacteriaceae, Methanomicrobiaceae, Methanosaetaceae and Methanosarcinaceae common to all the cultivar samples but with varying composition. Methane production of soil samples was in the order: Sahbhagi <HUR 3022 <IDR 763 <Swarna sub 1 <MTU 7029 <BPT 5204. It has been observed that rice cultivars with different plant biomass could provide favourable niche for the prevalence of methanogenic archaeal community that imparts differential effects on soil CH4 production
