Genetic Interaction of Hd1 with Ghd7, DTH8 and Hd2 Largely Determines Eco-Geographical Adaption of Rice Varieties in Southern China

摘要

Although cultivated rice originated from the tropical region,a long process of domestication and human selection has enabled cultivated rice to grow in a wide range of geographical regions.Diversification of photoperiodic flowering provides a foundation for this diverse adaptation.Intensive studies have focused on elucidating how japonica varieties lost photoperiodic sensitivity(PS)to expand their cultivation areas to high latitudes,where rice is grown in a short season when day-length is long(Fujino et al,2013;Naranjo et al,2014;Gomez-Ariza et al,2015;Li et al,2015,2018;Goretti et al,2017;Ye et al,2018).By contrast,limited attention has been paid to the genetic architecture of heading date(HD)variation among varieties in middle and low latitudes.The southern China rice region,located in middle and low latitudes,occupies the most important rice cultivation region in China.This region is predominantly planted with indica varieties,which presents a rich diversity of regional and seasonal adaptations.In the present study,improved varieties and landraces used in this region were analyzed for allelic variations of 12 cloned QTLs controlling HD,as well as for the genotypic effects of these genes on HD and PS.Our objective was to clarify predominant genetic factors influencing ecogeographical adaption of rice varieties in southern China by comparing improved varieties with landraces.