Abstract: In order to expand the new purple material resources and breed our own purple Chinese cabbage varieties in China,we focused on a new purple germplasm 15NG28,its F₁ back-crossing F₁ and self-bred progenies to study characteristics,distribution of anthocyanins in leaf,ploidy modes in genome,chromosome patterns and differentially expressed genes of these progenies.Results showed F₁ hybrids crossed by 15NG28 and Chinese cabbage could be obtained,which segregated purple and green colors.At the seedling and adult stages,15NG28 and purple F₁ plants had purple colors in adaxial leaf,abaxial leaf,vein,while the F₁ plants owned purple colors in adaxial,abaxial blade of leaf and 15NG28 had purple color in adaxial blade,green color in abaxial blade.Meanwhile purple F₁ hybrids had different ploidy modes,i.e.,3n,4n,6n,etc.and chromosome patterns,i.e.,24,28,36,etc.Among them,16M-170-21 was similar as B.juncea.16M-170-21 self-bred seeds could be gotten,which showed distinctly different characteristics.While 16M-170-22 was similar as Chinese cabbage.Characteristic of 31 BC₁F₁ progenies of 16M-170-22 were the same as Chinese cabbages,and purple to green ratio was 14:17.Especially self-bred seeds of 14 purple lines were better.RNA-seq results showed twelve genes involved in flavonoid,flavone,flavonol and anthocyanin biosynthesis pathway were apparently up-regulated in purple lines.Interestingly Bra013652 (as LDOX gene) and Bra027457 (as DFR gene) were structural genes,which were up-regulated apparently in purple lines compared to green lines.Especially the two genes were differently from c3563g1i2,a regulator factor R2R3-MYB reported before.Therefore 15NG28 and its progenies could be new germplasm resources and 15NG28 might origin from B.juncea.

Key words: Chinese cabbage, Purple leaf germplasm 15NG28, RNA-seq, Functional genes, Breeding

CLC Number: 

• Q78

• S634.03