Morphological Characters Genetic Variation of Yunnan Rice Core Collection BC_1F_2

458 accessions hybrid BC1F2 were backcrossed,with two elite parents Diantun502(Indica) and Hexi35(Japonica) widely cultivated in Yunnan as recurrent parent,while 548 accessions core collection in Yunnan rice landrace as donors.Under natural low temperature 18.1℃ at booting stage,the genetic variation to main morphological characters of core collection hybrids in Yunnan rice landrace was analyzed between indica and japonica,rice cropping regions.The result showed that:(1)The hybrid BC1F2 had high morphological diversity among accessions,such as seed setting rate,filled grain no.per panicle,unfilled grain no.per panicle, peduncle length have and the average diversity index was high.(2)The variation trend of single characters was consistent between indica and japonica,rice cropping regions;There was great difference on diversity index among characters.