What Is the Cultivation Temperature for Small-Fruited Papaya? With an Introduction to the Hongling Papaya Variety
Papaya is a fruit commonly seen in our daily lives, and there are quite a lot of papaya varieties. Let us take a look below at some of the characteristics of Hongling papaya and small-fruited papaya!
The quality requirements and grading standards for fresh small-fruited papaya fruit are proposed for the first time, and corresponding technical requirements are put forward for the entire process of harvesting and post-harvest handling of fresh small-fruited papaya fruit, to guide the commercial production and market circulation of small-fruited papaya.
Papaya has long enjoyed the reputation of being a "fine fruit of Lingnan", and has developed rapidly in recent years, especially the small-fruited red-fleshed papaya, which has become the main cultivated variety. However, judging from the current production situation, there are few orchards with large-scale commercial production, and most orchards fail to organize production and management in accordance with food safety standards, resulting in low planting efficiency. To enhance the competitiveness of papaya in domestic and international markets and ensure its sustainable and healthy development, it is necessary to establish and improve a standard system for papaya product quality standards and production technology regulations.
Using the red-fleshed small-fruited papaya variety ‘Meizhonghong’ as explants, a study was conducted to investigate the induction of somatic embryos from immature embryos at different maturity levels, with different concentrations of 2,4-D and under different culture conditions, as well as the process of somatic embryo formation. The results showed that papaya immature embryos (90-120 d) with cotyledons and both inner and outer seed coats all white and relatively large in size had the best callus induction effect in a medium containing 10 mg·L^-1 2,4-D under dark conditions, and the callus induction rate increased with increasing 2,4-D concentration. Papaya callus first appeared at the lower end of the morphological radicle, and somatic embryos mostly occurred at the upper end of the morphological plumule.
The optimum growth temperature for small-fruited papaya is 22-25°C. At an air temperature of 10°C, growth basically stops; at 5°C, young and tender tissues suffer chilling injury; and at 0°C, the leaves suffer freezing injury.
