A mixed genetic analysis of major gene plus polygene for purplish-black pericarp at mature-green stage in pepper
[Objective]Pericarp skin color is one of the important agronomic traits of chili peppers.In order to investigate the genetic pattern of peel color and provide a theoretical basis for the selection and breeding of new varieties of purple peppers at the green stage of ripening,a study was conducted to determine the mechanism of color expression in purple peppers.[Method]C152(purplish-black pericarp at green ripening stage)was used as the female parent and A37(green pericarp at green ripening stage)was used as the male parent in this study.Genetic populations were constructed for four generations,P1,P2,F1,and F2.A more precise classification was conducted for peppers at the green ripening stage,the peel color was investigated and counted for those peppers that developed normally and reached commercial maturity.Normal distribution was tested for the obtained data,different genetic models were obtained by joint analysis among the four different generations,Maximum Likelihood Value(MLV)of the respective genetic models and parameters of the distribution of the components of interest were computed,MLV were converted into Akaike's information criterion(AIC)values.The five models with the smallest AIC values in the genetic model were selected as the alternative models.The fitness test of the alternative models was conducted and the statistics were obtained.The alternative model with the least significant statistics was selected as the optimal genetic model.The first-order genetic parameters of the optimal genetic model were calculated,and the second-order genetic parameters of the optimal genetic model were estimated from the population variance and the distribution variance of the relevant components.[Result]The findings showed that the F1 generation was light purple black,which is between the purple black of the female parent and the green of the male parent,and it was more biased towards the female parent.Color transitions were abundant in the F2 population and the trait variation was continuous.The results of normality test showed that the median and the multitude of the obtained data were 4,the mean was 4.097,the coefficient of variation was 49.38%,the kurtosis of the fruit color trait was-1.117,the skewness was-0.321,and the absolute values of the two were in the range of 1.96,which was in line with the normal distribution.In the first order genetic parameters,the additive effect value of the main gene was 2.542 8,dominant effect value was 0.535 2 and dominance degree of the main gene was 0.220 1.The results of the second order genetic parameters showed that the total variance of the population phenotypes was 0.5626,the genetic variance of the main genes was 3.529 9,and the genetic variance of the polygenes and the heritability were 0.The heritability of the main genes in the population was 86.25%.[Conclusion]Purplish-black is incompletely dominant to green in green-ripe peppers;purplish-black pericarp is controlled by a pair of additive-dominant primary genes plus additive-dominant-superior polygenes,and the additive and dominant effects of the primary genes are both positive,and the additive effect is stronger than the dominant effect.Purplish-black pericarp shows a extremely high level of heritability,and the trait decision was influenced by genetic factors.
pepperfruit color during green ripening periodmajor gene plus polygenegenetic analysis
万方数据
维普
