DOI: 10.5091/plecevo.147801

Authors: Pablo Dupiol, Armel Chakocha, Marie-Louise Avana Tientcheu, Mohamed Mahamoud Charahabil, Cedric Mariac, Adeline Barnaud, Jérôme Duminil

Abstract: Background and aims – We developed a new set of nuclear microsatellite markers for Cola acuminata (Malvaceae), an important African food tree species commonly known as the kola nut. Probably originating from the tropical rainforests of the Congo Basin, C. acuminata is widely cultivated in the humid savannahs of the region where its nuts are sold throughout Central and West Africa for their stimulant properties. Nuclear microsatellite markers (SSRs) are well suited for assessing the genetic diversity and population structure of plant species due to their high variability. Material and methods – Leaf samples were collected from 84 C. acuminata cultivated individuals across three sites in Cameroon, two in the savannah zone, one in the forest zone. SSR markers were developed by sequencing genomic DNA from two individuals using an Illumina HiSeq platform. Genetic diversity was assessed based on 14 SSR markers genotyped in 84 individuals, and marker transferability to the closely related species Cola nitida was tested. Key results – Forty-eight new microsatellite loci were developed, of which 14 were polymorphic in C. acuminata. The results demonstrated a high level of genetic diversity with the presence of two to 33 alleles per locus (with an average of 14.14) across the three sites. The transferability of these markers was confirmed with 13 out of the 14 SSRs successfully amplifying in the closely related species, Cola nitida. Conclusion – These newly developed SSRs will be useful for assessing genetic diversity, genetic differentiation, and gene flow patterns of C. acuminata in the tropical forests of Central Africa. Preliminary results suggest genetic similarity between the two savannah sites. However, these two sites were significantly differentiated from the site in the forest zone. This suggests that the propagation material introduced in the savannah zone did not originate from the forest in southern Cameroon.

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DOI: 10.5091/plecevo.94921

Authors: Thales Silva Coutinho, Mariela Analía Sader, Andrea Pedrosa-Harand, Marccus Alves

Abstract: Background – Waltheria marielleae is a new species of Malvaceae endemic to north-eastern Brazil that occurs only in the states of Pernambuco and Alagoas, in areas of Atlantic Forest and Caatinga. It is characterized by cinereous leaves, axillary and sessile to subsessile inflorescences, pallid yellow corollas with apically eciliate petals and fan-plumose stigmas. Material and methods – DNA was extracted from leaf tissue and the markers matK, ndhF, and ITS were amplified using universal primers, with PCR products purified and sequenced. Phylogenetic analysis was performed, including DNA sequences obtained from GenBank. Morphological studies were based on the analysis of specimens deposited in seven herbaria and specimens collected in Pernambuco state, Brazil. Results – Waltheria marielleae is morphologically and phylogenetically related to pantropical W. indica and W. ackermanniana, with these three species forming a well-supported clade. Overall, phylogenetic molecular analysis suggests the monophyly of Waltheria, with the two currently proposed sections also being monophyletic, and Melochia as its sister group. The new species is assessed here as Endangered, according to IUCN criteria. In addition, we formally present new occurrences of W. ackermanniana and W. rotundifolia. Conclusion – In this study, a complete morphological description, illustration, distribution map, and phylogenetic tree are provided for Waltheria marielleae. This species is compared with morphologically and phylogenetically related species (W. ackermanniana, W. indica, and W. rotundifolia) and an identification key to the species occurring in Alagoas and Pernambuco is provided.

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