Reproductive biology and hybridization of Physalis L. species

The hybridization of the species belonging to the Physalis L. genus has been seldom to date, preventing the combination of distinct characteristics. Thus, assessments concerning basic reproductive biology and inter-specific compatibility of crosses are required for breeding. The present study aimed to evaluate pollen viability, stigmatic receptivity, and the compatibility of self-pollinations and inter-specific crosses in Physalis species. P. angulata L., P. ixocarpa Brot., P. pruinosa L., P. peruviana L., P. pubescens L., P. minima L., and P. daturifolia Lam, were investigated, each represented by one accession. The viability of pollen grains was determined through in vitro germination. Stigma receptivity was determined using 3% hydrogen peroxide (H2O2) with flower buds in pre-anthesis and anthesis, every two hours, from 6:00 am to 6:00 pm, a’. A total of 50 artificial crosses were performed for each hybrid combination and self-pollination. Pollen germination ranged between 43.65 and 75.30% among Physalis species. Stigma receptivity was greater during anthesis for all species and the time of day influences receptivity. Self-compatibility for all Physalis species was observed, and fruit fixation occurred in most inter-specific crosses, except when P. daturifolia was used in hybrid combinations.