Analysis Of Pericarp’s Phenotype,Genotype,and Habitat Factors Effect On Proanthocyanidin Content In Weedy Rice’s Caryopsis

Weedy rice and Oryza sativa L belong to the Gramineae,Oryza,and AA genome,can occur gene flow.The red pericarp is one of the characteristics of weedy rice,which is different from cultivated rice.And the red pericarp is due to the proanthocyanidins accumulating in the caryopsis pericarp layer.The pericarp is green before the weedy rice caryopsis is immature,red only appeared in the late stage of seed maturity.Rc and Rd genes are the key genes that control the synthesis of proanthocyanidin.Studies on the relationship between proanthocyanidin content and pericarp color phenotype,geographical habitat factor and Rc/Rd genotype are helpful to explore the mechanism of weeds to adapt to the environment,as well as to provide a genetic source for the cultivation of rice varieties in plateau proanthocyanidin.This study is mainly carried out from the following two aspects:Study of 1.weedy rice proanthocyanidin content in caryopsis and pericarp color phenotype and habitat factorsProanthocyanidins are polyphenols derived from the condensation of flavane-3alcohol.They are widely found in plants and found in the pericarp,shells,seeds,kernel,flowers and leaves of many plants.Objective:To investigate whether there is correlation between the proanthocyanidin content of weedy rice caryopsis and pericarp color、habitat factors.The results were as follows:weedy rice lines from 69 populations in the country were randomly selected to form 207 weedy rice materials,planted in the homogeneity garden,and extract the proanthocyanidins from the mature seeds.There are no proanthocyanidins in the white colour caryopsis,There are proanthocyanidinsing in the reddish brown and red black colour caryopsis,and the content of proanthocyanidins in the reddish brown caryopsis is higher than the the red black ones.On the other hand,the content of proanthocyanidins in the weedy rice caryopsis is significant negtive correlation with the average annual temperature,the average temperature of two months before harvest and the annual rainfall.There was a significant negative correlation(P<0.01)and has the average temperature of two months before harvest latitude(P<0.01).Study of 2.The relationship between the weedy rice pericarp color phenotype,proanthocyanidin content and Rc/Rd genotypeRc and Rd genes are the key genes controlling the synthesis of proanthocyanidins.Rc is a regulatory gene in the synthesis pathway of proanthocyanidins.The transcriptional product is a protein with an alkaline spiral-loop-helix(bHLH)structure,and the Rd gene is a structural gene and encodes Dihydroflavonol-4-reductase(DFR).The alleles of Rc and Rd genes were detected in 207 weedy rice samples.Analysis the realation between pericarp color phenotype,proanthocyanidin content and the Rc/Rd genotypes.There were six genotypes in the 207 samples:RcRcRdRd,RcRcRdrd,RcrcRdRd,RcrcRdrd,rcrcRdRd and rcrcRdrd.The main genotype was RcRcRdRd,accounting for 79.23%of the total sample,and the content of proanthocyanidins was higher than the other five genotypes.