Establishment Of A Molecular Model For Different Ecotype Prediction In Brassica Napus

Based on the requirement of vernalization for transfering from vegetative growth to reproductive growth,Brassica napus has been divided into three types: winter type oilseed rape(OSR),semi-winter type OSR and spring type OSR.The winter type OSR,which mainly localized in Europe,needs to go through a cold month(temperature is lower than 4?).In our country,semi-winter type and spring type take the main part of growth area and there is no distinct resitriction between them,which allows the existance of widely adaptive variets.Semi-winter type OSR requires cold treatment for 15 to 20 days;however,the spring type does not need vernalization.Only sepcifc ecotype OSR could grow in specific zones.To develop the marker for ecotype identification and provide information for suitable growth area determination for a certain variet,we first conducted genome wide association analysis to discover the locus related with flowering time and develop primers based on those locus and published data,and finally get 7 PCR markers which could identify the ecotype.The main results are:With the natrual population composed of 495 Brassica napus inbred lines from our research group,the genotype data via De Novo sequencing from Prof.Guo Liang and flowering time data in 8 environments from Dr.Xu Liping,we found 166 potential flowering time related SNP/InDel.Among them,5 locus were detected in several environments and they are related in FLC,FRI and EMF2;in addition,we also characterized 21 regions constructed with closely localized flowering time related SNPs(the physical distance between them is lower than 150 kb)and there are also many homologenes related with Arabidopsis flowering genes in those regions.We selected 452 lines from the 495 inbred lines for ecotype classification,and the marker were developed from 166 markers in this study and candidate locus from other research.Finally,7 markers were identified with the ability to classify different ecotypes.Among them,BnA3-FRI-53-76 and BnaA3-FRI-69-20 could identify the winter OSR with 62% and 46% possibility respectively;BnaA3-FRI-53-78 could identify winter OSR with 92% possibility.We checked the haplotypes consisted of those markers,BnaA3-FRI-53-76,BnaA3-FRI-69-20 and BnaA3-FRI-53-78,which are localized in BnFRI.A3,constructed 5 haplotypes and Hap000 could identify spring ecotype with highest possibility.Bn-A10-p15106056 and BnvaAnn_random28331198 are localized in FLC and CDF1 respectively,and they constructed 4 haplotypes.The Hap00 could identify semi-winter ecotype with highest possibility.