Influence of maturity stage on physical and chemical characteristics of fruit and physiological quality of seeds of Physalis angulata L.

Abstract Physalis angulata L. is an annual herb of the Solanaceae family, known in Brazil as camapu. Its fruits are widely eaten due to their high nutritional content and various plant parts are also used for medicinal purposes plant. The objective of this study was to evaluate the physiological maturity of P. angulata seeds during fruit development and maturation, as well as to identify the tolerance method for seed desiccation, contributing to the conservation of this species. Fruits and seeds were harvested at 15, 22, 29, 36 and 43 days after anthesis (DAA). The fruits were characterized regarding length, diameter, weight, total soluble solids, epicarp color, total number of seeds, and fresh seed weight. For determination of the seed physiological quality at different maturation times, freshly harvested seeds were dried at room conditions for 72 h and evaluated for water content, dry weight, germination percentage, germination index and seedling emergence. The desiccation tolerance was analyzed through fast and slow methods utilizing silica gel and saline solution of CaCl2. Significant increases were found in all physical and chemical traits of the fruits during development. Epicarp, nervure and calyx color can be used as good indicators of the degree of maturity, allowing identifying the best fruit harvest time. The seed physiological maturity of P. angulata was reached at 36 days after anthesis. The drying speed did not influence the seed germination percentage, germination index and vigor. P. angulata has orthodox seed storage behavior and can tolerate water content below 7%, which contributes to the maintenance of high viability (above 90%) for prolonged periods. Our findings can guide the conservation of P. angulata in seed banks and their use in breeding programs to obtain new hybrids.