Genetic analysis of salt-tolerance of cucumber at seedling stage

【Objective】 The research discussed the genetic mechanism of salt-tolerance of cucumber at seedling stage.【Method】 The salt tolerance inheritance of the seeding cucumber treated with 150 mmol/L NaCl solution was analyzed by applying the joint segregation analysis of a mixed genetic model of major gene plus polygene in six generations(Pl,P2,F1,B1,B2 and F2) from the cross between highly tolerable inbred line M8(P1)and not tolerable inbred line M7(P2).【Result】 The salt injury grades of segregating population B1,B2 and F2 presented skew distribution showing that salt-tolerance of cucumber at seedling stage belonged to quantitative genetic character,and there existed major gene.The inheritance of salt-tolerance was fitted by one major genes plus polygenes mixed model(D model),in B1,B2 and F2 populations,the estimated heritability of major genes was 42.409 2%,28.917 1%,63.245 6%,respectively.The heritability of poly-genes was 17.673 6%,36.505 0% and 0,respectively.The proportion of environmental variance in phenotypic variance was 39.917 2%,34.577 9% and 36.754 4%.The environmental factors had strong effect on salt-tolerance of cucumber.【Conclusion】 The salt-tolerance of cucumber at seeding stage was controlled by one major gene plus poly-genes,affected by environment easily and not fit to earlier choice.