Physiological quality of pitaya seeds subjected to different methods of mucilage extraction

Abstract

The selection of seed extraction methods from flesh fruits depends on the characteristics of the fruit and the seed to ensure their physiological quality, viability, vigor and sanity within the acceptable percentage for each species. The present study aimed to assess the physiological quality of pitaya seeds subjected to different extraction methods of the mucilage surrounding the seeds. The assessed methods were M1 – friction in sieve under running water; M2 – friction in sieve under running water, with addition of CaO; M3 – fermentation for 24 h; M4 – fermentation for 24 h, with addition of sucrose; M5 – fermentation for 48 h; M6 – fermentation for 48 h, with addition of sucrose; M7 – immersion for 2 h in 2.5% HCl solution; M8 – immersion for 2 h in 5.0% HCl solution and M9 – immersion for 2 h in 10.0% HCl solution. The experimental design was entirely randomized. The analyzed variables were germination percentage (%), germination speed index (GSI) and mean germination time (MGT - days), as well as identification and quantification (%) of plant pathogenic fungi based on germination and accelerated aging tests; percentage of viable seeds (%) based on tetrazolium test; and vigor (μS cm-1) based on electrical conductivity test. The method of immersion for 2 h in 10.0% HCl solution (M9) has proven to be advantageous for the extraction of H. undatus seeds to favor seeds with higher physiological quality in a short period.