DOI: 10.5061/dryad.4xgxd2564
title: Fine-scale spatial genetic structure, mating and gene flow dispersal patterns in Parkia biglobosa populations under different levels of habitat fragmentation

description: PREMISE: A good understanding of genetic variation and gene dispersal in
 tree populations is crucial for their sustainable management, particularly
 in a context of rapid environmental changes. West African Sudanian
 savannahs are undergoing fragmentation and degradation, partly due to
 expansion of crop cultivation and monocultures that reduce tree density
 and may impact pollinators. This could affect the population dynamics of
 important indigenous trees. We investigated the influence of habitat
 fragmentation on patterns of genetic diversity and gene dispersal of a key
 Sudanian agroforestry tree species, Parkia biglobosa. METHODS: Using ten
 highly polymorphic nuclear microsatellites, we genotyped 2475 samples from
 reproductive trees, seedlings and embryos in four tree populations
 presenting different levels of habitat fragmentation. RESULTS: Parkia
 biglobosa presented high genetic diversity, similar across the four
 populations studied. Genetic diversity and inbreeding were similar between
 adults and embryo cohorts. In all four populations the selfing rate was
 less than 1%. A high effective number of pollen donors per tree
 (NEP~18-22) and a high pollen immigration rate were observed (ranging from
 34 to 74%). Pollen dispersal was characterized by a fat-tailed
 distribution with mean estimates exceeding 200 m. In three populations,
 stem diameter had a pronounced effect on male reproductive success. Here,
 the highest male reproductive success was observed in trees with a
 diameter at breast height of between 60 and 75 cm. CONCLUSIONS: At the
 scale analyzed, fragmentation does not seem to pose limitations to gene
 flow in any of the sites investigated, regardless of the landscape
 configuration associated with the different tree stands examined. The
 study provides useful insights on the reproductive biology of an important
 tree species in the West African savannahs.
description: Overall, DNA was isolated from seed and leaflet samples of 2475
 individuals composed of 703 adult trees (167 small and 536 large trees),
 1747 embryos and 25 seedlings from Cassou and Saki. The total genomic DNA
 was extracted using the DNeasy 96 Plant Kit protocol (QIAGEN, Hilden,
 Germany), following the manufacturer’s instructions. DNA samples were
 genotyped using 10 nuclear microsatellite loci (nSSR) developed by Lassen
 et al. (2014) and following the method applied in Lompo et al.
 (2018). Lassen, K. M., Kjær, E. D., Ouedraogo, M. and
 Nielsen, L. R. 2014. Microsatellite primers for <i>Parkia biglobosa
 </i>(Fabaceae: Mimosoideae) reveal that a single plant sires all
 seeds per pod. <i>Applications in Plant Sciences</i><b>
 </b>2: 1-4. Lompo, D., Vinceti, B., Konrad, H.,
 Gaisberger, H., Geburek, T. 2018. Phylogeography of African locust bean
 (<i>Parkia biglobosa</i>) reveals genetic divergence and
 spatially structured populations in West and Central Africa.
 <i>Journal of Heredity</i> 109: 811-814.
description: Column names denote: Running No; sampleID;
 Population name; Marker data for 10 nuclear microsatellites (PbL03, PbL05,
 PbL22, PbL15, PbL04, PbL12, PbL11, PbL02, PbL09, PbL21) in
 “allele1-allele2” form; UTM coordinates and UTM zone (X_UTM, Y_UTM, Zone);
 DBH (cm); Total height (m); Crown height (m); Crown diameter (m); Tree
 location (Plot or Transect); Cohorts (Large Tree, small tree, seedling,
 embryo); Maternal tree (+ = yes). Lines 2-721 denote
 sampled trees Lines 723-2468 are embryos extracted from
 seed from mother trees (names are given as number of mother tree plus
 running number of seed).