| In this study, the genetic analysis population is crossed by two ornamental kale(Brassica oleracea var. acephala) inbred line(feathered leaved parent 0819 and flat leaved parent 0835) used to analysis the feathered leaved trait and other relative traits. Feathered leaved gene pool and flat leaved gene pool are conducted by BSA method combining with F2 population. The polymorphic primers linked to BoFeL are achieved through screening SSR and SRAP polymorphic primers. Utilizing the released Brassica Database, the candidate gene is predicted by homologous comparison.The main research results are as follows:1.F1 and RF1 are crossed by parents. In the rosette stage, investigating the phenotypic traits of parents, F1, RF1, F2, F2:3 and BC1. F1 and RF1 show as middle between parents. Feathered leaved, semi-feathered leaved and flat leaved plants in F2 population are 48,127 and 69, respectively. Segregation (x2=4.03<5.99) meets Chi-square ratio (1:2:1). Segregation (X2=0.63<3.84) of BC1 (F1× 0835) meets Chi-square ratio (1:1). Taking feathered leaved, semi-feathered leaved and flat leaved plants respectively 15 from F2 population at random, F2:3 of feathered leaved and flat leaved both unsegregated, segregation of semi-feathered leaved meets Chi-square ratio (1:2:1). All of the results can infer the gene of feathered leaf was controlled by a pair of alleles in nucleus, the feathered leaved trait for flat leaved trait showed incomplete dominance.2.In the semi-feathered populations, the number of serrated leaf margin is continuous. That is said, feathered leaved related traits are modified by some mirror genes. Four feathered leaved related traits, i.e. leaf length, leaf width, leaf index and number of serrated leaf margin, were investigated at rosette stage. The genetic segregation analysis is conducted by using four generations(P1、 P2、F1、F2) mixed major gene plus polygene inheritance model. The results show that there are prominent helerosis in the trait of number of serrated leaf margin. Meanwhile, these four characters show negative transgressive heterosis. Genetic analysis of quantitative traits indicate that leaf length and leaf width are both compatible with E-4 model characterized by two equal additive major gene plus additive-dominant polygene. The heritabilities of major gene and polygene are 83.80% and 1.05%, respectively, in leaf length. The heritabilities of major gene and polygene are 22.28% and 61.92%, respectively, in leaf width. Leaf index and number of serrated leaf margin both meet E-1 model showing two additive-dominant-epistatic major gene plus additive-dominant polygene. The heritabilities of major gene and polygene are 93.73% and 2.59%, respectively, in leaf index. The major gene heritability is 91.18% in number of serrated leaf margin trait.3.In order to achieve the feathered leaved trait gene BoFeL,538 markers are screened using BSA in parents. There are 104 pairs of the 288 SRAP markers show polymorphism between parents, polymorphic rate is 36.1%. There are 61 pairs of 250 SSR markers show polymorphism in parents, polymorphic rate is 24.4%.35 SRAP markers and 22 SSR markers which better linked between DNA pools are screened in F2 population. After calculating genetic distances, a genetic map of BoFeL locus is constructed using 7 markers, spanning a total interval of 50.4cM. Two markers O110E06 and M3E4 flanked BoFeL on either side at distances of 12.0cM and 7.7cM, respectively. The genetic distances of other markers M8E1, BN83B1-9, Ni3-C08, O110H12, FITO163-9 with gene BoFeL were 22.9cM,10.2cM,27.5cM, 11.3cM,16.9cM, respectively. Sequencing the specific amplification fragments of O110E06, BN83B1-9 and M3E4 are successful. Based on the results of the sequencing of PCR products and comparation of homologous gene sequence of similar trait, gene BoFeL may locus on the ninth chromosome of C genome. |
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