Fine Mapping Of The Petal Color Gene (fc) And Identification Of The Candidate Gene In Eggplant

Eggplant?Solanum melogena L.,2n=24?is one of the important Solanaceous crops and cultivated worldwide.It is originated in India,and China is the secondary evolution center with the largest cultivation area and yield in the world.Eggplant is rich in vitamins and minerals which benefits to human nutrition and healthcare.The trait of white petal in eggplant is linked with the characters of the vigorous growth,strong adaptability,good fruit colouration and high yield.It wil be time-consuming and space-occupied to select for white petal at the flowering stage.However,marker-assisted selection at seedling stage could solve this problem.This study fine-mapped the fc gene for petal color in eggplant using an F₂ population derived from the cross of‘Blacknite'and‘Yunnan small round eggplant'.Furthermore,the candidate gene was identificated by sequencing PCR amplicons and its expression levels were analyzed with real-time PCR.The results are as follows:?1?The petal color in the F₂ population segregated into purple and white clearly with a ratio of 137:37 that fit a ratio of 3:1??2=1.295,P=0.255?,suggesting that this trait was controlled by a single locus and the purple petal was dominant over the white.?2?A linkage map was constructed with SSR markers.This genetic map consisted of 14linkage groups and 52 SSR markers.The map covered 211.1 cM and the petal color gene?fc?was located onto the neighborhood of the marker EMJ316 on the eggplant chromosome8.?3?The fc gene was fine-located within marker InDel8-11 and EFc8-32 using a large population.The physical distance between the two markers was 165.5 kb.?4?The candidate gene was predicted to be a anthocyanidin synthase?ANS?and the gene sequence was obtained by sequencing PCR amplicons.Sequence comparasion showed that a insertion/deletion exsited in the ANS gene,which could explain the function loss due to the early termination of translation.The real-time PCR confirmed that the expression level of the ANS gene in flower of male parent"Blacknite"increased 3.65 fold to the female parent.