Conservation implications of the mating system of the Pampa Hermosa landrace of peach palm analyzed with microsatellite markers

Abstract

Peach palm (Bactris gasipaes) is cultivated by many indigenous and traditional communities from Amazonia to Central America for its edible fruits, and is currently important for its heart-of-palm. The objective of this study was to investigate the mating system of peach palm, as this is important for conservation and breeding. Eight microsatellite loci were used to genotype 24 open-pollinated progenies from three populations of the Pampa Hermosa landrace maintained in a progeny trial for genetic improvement. Both the multi-locus outcrossing rates (0.95 to 0.99) and the progeny level multi-locus outcrossing rates (0.9 to 1.0) were high, indicating that peach palm is predominantly allogamous. The outcrossing rates among relatives were significantly different from zero (0.101 to 0.202), providing evidence for considerable biparental inbreeding within populations, probably due to farmers planting seeds of a small number of open-pollinated progenies in the same plot. The correlations of paternity estimates were low (0.051 to 0.112), suggesting a large number of pollen sources (9 to 20) participating in pollination of individual fruit bunches. Effective population size estimates suggest that current germplasm collections are insufficient for long-term ex situ conservation. As with most underutilized crops, on farm conservation is the most important component of an integrated conservation strategy.

Mating system and intrapopulational genetic diversity of Copernicia prunifera (Arecaceae): a native palm from Brazilian semiarid

“…Furthermore, the single-locus outcrossing rate was high (t s = 0.738). These values were consistent with those found for other tropical palms, which are predominantly outcrossing, such as Acrocomia aculeata (Abreu et al, 2012) and Bactris gasipaes (Picanço-Rodrigues et al, 2015). Ward et al (2005) in 36 studies surveyed found > 90% outcrossed mating for 45 hermaphroditic or monoecious species.…”

“…The mating system of hermaphroditic species can combine selfing with outcrossing, through which both random or correlated mating occurs (Ritland, 2002). Furthermore, most palm species present mixed mating systems, being preferentially allogamous (Ramos et al, 2011;Abreu et al, 2012;Picanço-Rodrigues et al, 2015). Due to the effects of anthropization in the natural populations, and because the species occurs in monodominant groups at high densities, it is expected that C. prunifera presents a mixed mating system, with a high rate of outcrossing between related individuals.…”

Natural and human-mediated drivers of microevolution in Neotropical palms: a historical genomics approach

“…Independently from site-specific hybridization patterns, estimates of intra-population genetic diversity revealed high heterozygosity ( H o ) and significantly negative F is , indicating the absence of inbreeding. These estimates are in line with previous knowledge about the breeding system in Arecoideae that are known to be monoecious and predominantly outcrossed due to protandry and/or genetic incompatibility (Henderson 1986; Eguiarte et al 1992; Consiglio and Bourne 2001; Picanço-Rodrigues et al 2015; Gaiotto et al 2003; Ottewell et al 2012). The genetic structure and diversity of populations on ring ditches was further close to populations in the surrounding natural forests, indicating the absence of pre-Columbian impacts on population genome-wide diversity and divergence.…”

Mating system analysis of Açaí-do-Amazonas (Euterpe precatoria Mart.) using molecular markers

“…Studies of the mating system can be based on microsatellite markers or simple sequence repeats (SSRs), which are an adequate tool for this purpose, due to the high polymorphism in terms of number of alleles, co-dominant inheritance and low cost of the method (Wadt et al 2015). Simple sequence repeat-based studies to determine the mating system were carried out for different Amazonian and tropical tree species (Ramos et al 2011, Medina-Macedo et al 2015, Picanço-Rodrigues et al 2015Moraes et al 2018).…”