Characterization of Vasconcellea cauliflora for morpho-horticultural traits under climatic conditions of Pune, India

Abstract

Vasconcellea cauliflora is one of the few species in the family Caricaceae that have shown resistance against Papaya ringspot virus strain papaya (PRSV-P) which is a global limiting factor in papaya (Carica papaya L.) cultivation. V. cauliflora has a potential role in introgression of gene(s) of PRSV-P resistance in C. papaya. It was introduced in India for academic and research purposes. Therefore, very little information is available about its morpho-horticultural traits under Indian climate and its reaction against local isolates of PRSV-P. V. cauliflora plantation maintained at ICAR-Indian Agricultural Research Institute, Regional Station, Pune since 2011 provided valuable information on morpho-horticultural traits under climatic conditions of Pune and its reaction against local isolate of PRSV-P. Plants gained a height of 0.89 m and collar diameter of 6.94 cm in one season which increased in subsequent years. Yellowish white and waxy female flowers were 3.9 cm long. Pollen viability was 86%. Average fruit yield was 4.3 kg/plant in the first year, which increased to 8.4 kg/plant in the third year. Berry type fruits were long, round or intermediate in shape with smooth skin texture. The average fruit length and width was 6.8 cm and 3.7 cm, respectively. Ridges and grooves were prominent in long fruit shape as compared to intermediate and round ones. Seedlings showed resistance against PRSV-P under field conditions and when infected by challenge inoculation in glasshouse. The plants remained disease-free even when exposed to severe disease pressure under field conditions for more than three years. There is a renewed interest in V. cauliflora as a source of gene(s) for resistance against PRSV-P infection, especially after overcoming the crossing barrier with C. papaya in India.