Genetic divergence among populations and accessions of the spineless peach palm from Pampa Hermosa landrace used in the heart-of-palm agribusiness in Brazil

Abstract

Although originally domesticated for its fruit, exploitation of the peach palm (Bactris gasipaes Kunth) in the production of gourmet heart-of-palm has also become an important activity, hence the need for improved material for large-scale production, on employing the Pampa Hermosa landrace as the seed source. In this study 11 microsatellite markers were used to evaluate genetic divergence among 96 elite plants representing four populations of spineless peach palm from the above cited source. Genetic variability was high (HT = 0.82). The low levels of divergence [FST (0.023), GST’ (0.005)] and the high number of migrants (Nm - 3.8 to 52.2) indicated significant interpopulation gene flow. Some of the plants presented high levels of genetic divergence, but the plants were grouped independently of their geographic origins. When combined with morpho-agronomic evaluation, the results found could substantially contribute towards mounting an efficient tool for obtaining superior genotypes with wide genetic variability for improvement programs.

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

“… Cole et al (2007) detected considerable inbreeding ( F = 0.105–0.210) in peach palm populations belonging to peasant and indigenous communities in northeastern Peru, confirming that traditional practice favors a certain level of biparental inbreeding, even though there is significant gene flow mediated by farmer seed sourcing ( Adin et al , 2004 ). Alves-Pereira et al (2012) found similar levels (0.156–0.210) within the Pampa Hermosa landrace with a larger sample. Generations of generally unconscious selection for yield will maintain productivity even as heterozigosity decreases due to inbreeding ( Hancock, 2004 ).…”

“…The estimated total variance effective size ( N e ( v ) t ) of the population samples (maximum 30.6) of these three river basins in the Pampa Hermosa landrace is lower than what is considered acceptable for genetic conservation at the population level (minimum 50, Frankel and Soulé, 1981 ). However, the high gene flow among these populations ( Adin et al , 2004 ; Alves-Pereira et al. , 2012 ; and Rodrigues DP (2007) PhD Thesis, Universidade Federal do Amazonas, Manaus, AM, Brazil) suggests that conservation should be planned at the landrace level, where the estimated N e ( v ) = 86.8 is well above the minimum for short term conservation.…”

“…In this study, it was slightly more than 24% (mean N e ( v ) t / N = 86.6/359), likely due to high pollen donor number at peak flowering season. The progeny trials at INPA ( Alves-Pereira et al , 2012 ; Clement et al , 2012 ) and Embrapa ( Kalil Filho et al , 2010 ; Clement et al , 2012 ) in Brazil, and in Peru ( Cornelius et al , 2006 ) are adequately dimensioned to handle genetic conservation based on these estimates. The major peach palm germplasm collections in Brazil (375 accessions, with a maximum of 9 plants/accession) and Costa Rica (1,200 accessions with 9 plants) do not have the requisite numbers even of this important landrace, and have much smaller numbers of other landraces; all other collections are smaller ( Mora Urpí et al , 1997 ; Graefe et al , 2013 ).…”

“…Commercial propagation of peach palm uses open-pollinated seeds ( Mora Urpí et al , 1997 ). The majority of seeds available in the market today originate from the Pampa Hermosa landrace, Yurimaguas, Peru ( Alves-Pereira et al. , 2012 ), as the spineless plants are more easily handled and more productive than those of other landraces ( Mora Urpí et al , 1999 ).…”