Abstract

Successful crosses have been achieved in intergeneric hybridization between Carica papaya and wild Vasconcellea cauliflora, to break post zygotic barriers by using various nutrients. Among the nutrients used, sucrose 5 per cent, sucrose 5 per cent + boron 0.5 per cent and sucrose 5 per cent + CaCl 2 0.5 per cent improved the fruit set and seed set percentage. A total of 1197 flowers were pollinated resulted 308 fruits. On extraction, 721 seeds were obtained from CO 7, Pusa Nanha and CP 50. Out of twenty nine F 1 hybrid plants of CO 7 x Vasconcellea cauliflora, only six plants namely CO7V1 to CO7V6 were found free from PRSV symptoms. Similarly, out of fifty five F 1 hybrid plants of Pusa Nanha x Vasconcellea cauliflora only twenty three plants namely PNV1 to PNV23 were found free from the symptoms and seventy plants namely CPV1 to CPV70 out of 335 plants of CP50 x Vasconcellea cauliflora were found free from PRSV symptoms. F 1 hybrids exhibited very clear morphological marker in the form of pink vein colour. The number of days for first flowering, first flowering height (cm), plant height (cm), stem girth (cm), number of leaves, first fruiting height (cm), fruit set (%), days to first harvest, fruit yield per tree (kg), were intermediate between the two parents.

Keywords: Carica papaya, Vasconcellea cauliflora, intergeneric hybrids, papaya ring spot virus (PRSV)