Genetic Analysis Of Major Genes And Polygenes Of 10 Traits In Pepper

Pepper has now become the vegetable with the largest planting area,consumption and output value in my country.It is rich in nutrition and is welcomed by consumers.Therefore,in this study,the F₂generation population was constructed with pepper lines"AA5"and"CK18"provided by the vegetable Germplasm Resources Innovation Laboratory of Northwestern University of Agriculture and Forestry as parents,and the segregation of each character of the population was investigated statistically.The major gene model and genetic effect of each character of pepper were analyzed by correlation analysis and major gene+polygene genetic model.It provides a theoretical reference for the fine mapping of related genes and more efficient and targeted molecular marker development and molecular design breeding of pepper.The results are listed below:1.Population segregation:10 quantitative characters of pepper F₂population crossed between AA5 and CK18 showed varying degrees of variation.Among them,the variation of single fruit weight was the largest（46.1%）,while that of plant height was the lowest（13.71%）.All characters showed continuous changes,which were in line with normal distribution or partial normal distribution,indicating that the characters were quantitative characters controlled by major genes.The trait of plant surface hairs was controlled by a single gene,with hairs as dominant traits and non-hairs as recessive traits.2.The results of correlation analysis:fruit transverse diameter,fruit shape index was extremely significantly positively correlated with fruit longitudinal diameter.And so was the correlation between pulp thickness and fruit longitudinal diameter,stem diameter,fruit transverse diameter,peel hardness,single fruit weight;between single fruit weight and fruit transverse diameter,fruit longitudinal diameter;between main stem length and plant height.Moreover,fruit shape index was extremely significantly negatively correlated with fruit transverse diameter,main stem length,single fruit weight.And the same was true between peel hardness and plant height,initial flower node position,fruit shape index.Single fruit weight and stem diameter showed significant positive correlation;pulp thickness and plant height showed significant negative correlation.3.The results of genetic model analysis:there were two groups of additive major genes in five traits of pepper,such as fruit transverse diameter,pulp thickness,fruit shape index,initial flowering node position and stem diameter,which belonged to 2MG-EA model.Fruit longitudinal diameter,main stem length and single fruit weight had two groups of additive-dominant major genes,which belonged to 2MG-AD model.The inheritance of peel hardness and plant height characters need to be further studied.4.The results of major gene genetic effects:the major gene additions of all traits were positive.The two major gene additive effects of fruit shape index,stem diameter,fruit transverse diameter,initial flowering node position and pulp thickness were basically the same;the major gene additive and dominant effects of main stem length,fruit longitudinal diameter and single fruit weight traits were dominated by the first pair of major genes,while the major gene dominant effects of fruit longitudinal diameter,and single fruit weight traits were negative,while the major gene dominant effects of stem diameter and main stem length were positive.The heritability of main stem length of pepper in F₂generation was very high,breeding in the early generation can meet the breeding target needs,and other traits will be stable in the higher generation.