The Gene Effects for Reaction To Powdery Mildew and Some Related Biochemical Characters in Muskmelon

Information regarding the genetics of disease resistance and related characters obtained from a diallel set of F₁ crosses involving six parental varieties is reported. Only the additive component of variance was significant for disease intensity and water soluble phenols, while both the additive and the dominance components were significant for total sugars. The variability of the total sugars appeared to be dependent on non-reducing sugars rather than the reducing ones. The variability with respect to crude protein could not be attributed to either additive or dominance effects directly. The recessive alleles affecting crude protein content were more frequent than their dominant counterparts in the population. The observed regression lines depicted partial domi nance of all the characters studied. There were more dominant alleles for reducing sugars and resistance to disease in Florida-67 and more recessives in Parlita and Jacumba. It is suggested that selection could be quite instrumental to modify the expression of the characters studied.