Integrative approaches to ex situ conservation of endangered Melocactus from Brazilian ecosystems

Summary: Melocactus Link & Otto is one of the most representative and endangered genera of Cactaceae in Sergipe. This study evaluates ex situ conservation under two integrative approaches: the rescue of adult plants to set a germplasm bank and the analysis of different substrates to establish a seedling bank of rescued species. We collected thirty individuals of each species and cultivated them in a greenhouse for twelve months. We evaluated the number of flowers, fruits, and seeds daily, as well as the mortality rate of adult plants. We evaluated five substrates to establish the seedling bank 1 – sand, 2 – sand + commercial soil (1:1), 3 – sand + goat manure (1:1), 4 – soil (100% volume) and 5 – soil + goat manure (1:1). We found mortality rates of 0%, 10% and 50% for M. zehntneri, M. violaceus subsp. margaritaceus and M. sergipensis, respectively. We found two phenological patterns for the species in the germplasm bank: a continuous production of flowers, fruits and seeds throughout the year and another pattern, with periods of greater production of flowers, fruits, and seeds. We also found positive correlations between the environmental factors and the phenological stages of the species. We conclude that substrates ‘sand’ and ‘sand + soil’ are the most suitable to produce seedlings of the three species of Melocactus.