pH exudate test as a method to estimate viability and vigor of Citrus limonia Osbeck seeds

Abstract

Abstract: The pH exudate is a quick test used to check the seed membranes integrity; however, its performance is limited due to the singularity of each specie requiring adjustments about its methodology. In this sense, the aim of this study was to perform a quick and accurate physiological potential estimation of Citrus limonia Osb. (‘Rangpur Lime’) seeds through pH exudate test. First, there was carried out the characterization of five seedlots of ‘Rangpur Lime’ by determination of the thousand seed mass, water content, germination and emergence. Then, a complete randomized experimental design was installed in a factorial scheme: 5 × 3 × 2 (five seedlots, three indicator solutions, and two immersion periods), to evaluate the pH exudate. The seeds were individually distributed in polypropylene trays, and after the immersion periods, there were taken pictures and analyzed by a numeric scale. Despite the similarity, the emergence test showed to be more efficient for ‘Rangpur Lime’ seeds comparing to the germination test, because it promoted higher percentage of seedlings. Regarding the pH exudate test, there were not observed differences between the seedlots for both analysis, visual and image, not being efficient to discriminate lots of ‘Rangpur Lime’.