Inheritance and incrossability studies in papaya

Abstract

All the plant and fruit characters studies showed higher phenotypic variance than genotypic variation which indicated the importance of environment in the manifestation of these characters. The phenotypic and genotypic variance were higher for plant height, fruit weight and fruit cavity index, it was moderate for plant spread, fruit length and low for stem diameter, fruit breadth, pulp thickness, TSS, total carotenoids and total sugars. The phenotypic coefficient of variation was higher than the genotypic coefficient of variation for all the characters. The coefficient of variation was high for fruit weight, fruit volume, fruit cavity index, fruit length and medium for fruit height, stem diameter, fruit breadth and total carotenoids. Plant spread, pulp thickness, TSS and total sugars had low coefficient of variation. Maximum fruit set was noticed when 3% sucrose was used irrespective of then cross combinations involving papaya varieties as female parents. However, among the cross combinations maximum fruit set was noticed in Pusa Dwarf x Carica cauliflora. In all cross combinations where Carica cauliflora was the female parent, the average fruit set was maximum with the use of 3% sucrose and among the cross combinations maximum fruit set was recorded in the cross Carica cauliflora x Lucknow Collection. Average number of seeds set was maximum under 5% sucrose level in crosses where Carica papaya was used as female parents. Maximum number of seeds set was recorded in the cross Washington x Carica cauliflora at 5% sucrose level. percentage of variable seeds was maximum 2% sucrose level in all the cross combinations studies. percentage of variable seeds was highest in the cross combination Pusa Dwarf x Carica cauliflora at 5% sucrose level. Cross combinations involving Carica cauliflora as female parent did not yield any viable seed. Varietal differences were observed in the crossability of Carica papaya with Carica cauliflora. The cultivar Pusa Dwarf was found to be the best as female parent in crosses with Carica cauliflora.