The effect of temperature on the germination of Melocactus violaceus Pfeiff. (Cactaceae), a threatened species in restinga sandy coastal plain of Brazil

Abstract

Melocactus violaceus is an endangered species due to habitat destruction and the overcollection of this species for ornamental use. The aim of this study was to test the effect of different temperatures on the germination of M. violaceus. Three treatments were conducted: a constant temperature of 25°C, a 20-35°C alternating temperature, both inside germination chamber, and an alternating temperature under room temperature (mean temperature ranged from 25-37°C). The fi nal seed germination rates at the alternating temperature treatments were not signifi cantly different (65% in the seed germinator and 62.5% at room condition). However, both treatments with alternating temperatures had signifi cantly higher germination rates compared to the treatment kept at the constant temperature (8%). Our study showed that alternating temperatures between 20 and 37°C provides satisfactory conditions to induce a high percentage of seed germination of M. violaceus, without the passage of seeds through the digestive tract of its natural disperser, the lizard Tropidurus torquatus. This condition contributes to effi ciently producing seedlings that can be reintroduced into conservation areas or used as ornamentals that may help reduce the overcollection of the remaining native populations.

Evolutionary change in the germination niche between related species within Neoporteria clade (Cactaceae) is idiosyncratic to habitat type

“…day: 4˚C / night: 9˚C) at any water potential. Similar effects have been reported for cacti in Brazil (Zamith et al 2013). This result suggests that suitable conditions (presence of rainfall) for germination of E. subgibbosa seeds are achieved almost throughout the year (Fig.…”

Técnicas para superação da dormência de sementes de guanandi

“…Assim, há, na literatura, uma grande quantidade de trabalhos que avaliam aspectos do processo germinativo de sementes florestais, como as de ucuúba (Virola surinamensis) (Limas et al, 2007), cariru (Talinum triangulare) (Brasileiro et al, 2010) e coroade-frade (Melocactus violaceus) (Zamith et al, 2013).…”

<em>Melocactus violaceus</em> Pfeiff. (Cactaceae) growth rate and abundance in a sandy terrace of Atlantic Rain Forest (REBIO Guaribas, Paraíba, Brazil)

“…seeds, where the high nectar concentration would explain the lizard's attraction for the flowers, which themselves have a high carbohydrate budget, being a source of food throughout the year (Gomes et al 2014). Despite the mutualistic relationship found between Melocactus and its pollinizer and seed disperser, Tropidurus (Gomes et al 2014), it is possible to obtain excellent germination rates even with seeds that had not passed through the lizard's digestive tract (Zamith et al 2013). Also known as "button cactus", Melocactus violaceus Pfeiff.…”