Physiological potential of Physalis peruviana L. seeds under different temperatures and light wavelengths

Physalis peruviana L. is a plant that produces small sweet berries of great nutritional and medicinal importance. This plant is propagated mainly through seeds, which requires information on germination response to temperature and light changes. Thus, the present study aimed to evaluate the use of different temperatures and light wavelengths on the physiological potential of P. peruviana seed batches. The experiment was conducted with seeds from plants cultivated in 2015/15 and 2016/16. The treatments applied were the following: two germination temperatures (constant temperature of 25 °C and alternated between 20/30 °C), two seed batches (2015/15 and 2016/16), and four forms of light exposure during germination (blue, red, white, and dark). The data were analyzed by principal component analysis using the correlation matrix obtained through the standardized mean equal to zero and variance 1 of the parameters evaluated for each treatment. The eigenvalues and eigenvectors of the matrix were obtained using the SAS University Edition® statistical software. The analyzed variables were: Germination test performed on the 7th and 28th day considering root protrusion, normal seedlings, shoot length, root length, and total dry matter mass. The data showed that the seed germination test of Physalis peruviana L. should be performed under a constant temperature of 25 °C, in the presence of light (white, blue, or red). When the option is the application of the test in the dark, it is necessary to use a thermoperiod of 20–30 °C to provide the expression of maximum physiological potential.