Genetic evidence of multiple reproductive strategies in a microendemic and threatened cactus (Cactaceae: Discocactus Pfeiff) in Bahia, Brazil

Abstract

Discocactus zehntneri subsp. petr-halfari, an endangered taxon, is represented by a single population in an anthropized area of Bahia, Brazil, where it is suffering due to extreme extractivism. Thus, information about this cactus, such as its reproductive patterns, is urgently needed to support conservation strategies. A population genetics approach was used to determine if this subspecies has a preferential pattern of reproduction. We sampled 18 individuals, both with and without connection to parental plants, from five clumps and assessed their diversity and genetic structure using five ISSR markers. The results revealed two clumps that are genetically supported by the presence of genetically equal individuals. The other three groups presented individuals that are genetically different and similar to individuals in other clumps. These findings suggest that this subspecies has sexual and clonal reproduction and that its environmental distribution might be shaped by events of dispersion. In addition, a possible hybrid origin may explain its rates of genetic diversity. Despite all these factors, this taxon is in danger and so the development of conservation strategies to preserve its population are urgently needed, including in situ and ex situ actions such as the micropropagation in vitro, living collections and cryopreservation.

Micropropagation of Opuntia and Other Cacti Species Through Axillary Shoot Proliferation: A Comprehensive Review

“…The number of cladodes per plant has been estimated for vegetatively propagated cochineal carmine cactus pear forage-resistant species to be around 15.64 cladodes per plant after 540 days after planting (Lopes et al, 2013 ). Moreover, some cacti genera suffer from extreme extractivism, illegal trades and unsustainable harvesting, and the degradation of their natural habitat due to anthropic action (Jesus et al, 2019 ). These disturbances are largely responsible for the extinction threat of local populations and drastic changes in cacti distribution and abundance and can be exacerbated by slow growth and dependence on reproductive individuals for population maintenance (Hughes, 2017 ).…”