The generic relationships within the core Millettieae have not been well resolved to date. Millettia is considered one of the most problematic genera to classify within the core Millettieae, with approximately 150 species found in Asia and Africa. Recent molecular evidence has indicated that Millettia is highly polyphyletic. In this study, we utilized plastomes and single-copy nuclear genes from genome skimming sequencing to reconstruct the generic relationships and estimate the divergence time for the core Millettieae, focusing on the Asian species of Millettia. Our results revealed a broader circumscription of the core Millettieae with the inclusion of the Phaseoleae subtribe Ophrestiinae, consisting of 7 clades and 14 subclades within two main groups (canavanine and non-canavanine). The Asian species of Millettia were grouped into three distinct, well-supported subclades, leading us to propose a much narrower generic concept of Millettia, along with the reinstatements of the genera Pongamia and Otosema. Millettia s.str. was restricted to include only seven species. Pongamia was recognized as a medium-sized genus that includes Fordia and Ibatiria, with approximately 56 species. Otosema, usually treated as a subgenus or section of Millettia, was resurrected as a distinct genus with three species. Our findings also indicated that the sampled African Millettia species belong to three subclades distinct from the Asian Millettia subclades, warranting further investigation in future studies. The dating result showed that the early rapid diversification of the core Millettieae during the Mid-Miocene Climatic Optimum involved several major problematic genera, including Derris s.lato, Lonchocarpus s.lato, and Millettia s.lato, which may explain why these plant groups are difficult to classify. These results offer new insights into the phylogeny and taxonomy of the core Millettieae.
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http://dx.doi.org/10.1016/j.ympev.2024.108254 | DOI Listing |
Mol Phylogenet Evol
November 2024
Key Laboratory of National Forestry and Grassland Administration on Plant Conservation and Utilization in Southern China, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, PR China; South China National Botanical Garden, Guangzhou 510650, PR China. Electronic address:
Mol Phylogenet Evol
May 2024
Instituto de Biologia, Universidade Federal da Bahia, Rua Barão de Jeremoabo, s.n., Ondina, 40170-115 Salvador, Bahia, Brazil; Instituto de Pesquisas Jardim Botânico do Rio de Janeiro, Rua Pacheco Leão, 915 22460-030 Rio de Janeiro, Brazil. Electronic address:
Our knowledge of the systematics of the papilionoid legume tribe Brongniartieae has greatly benefitted from recent advances in molecular phylogenetics. The tribe was initially described to include species marked by a strongly bilabiate calyx and an embryo with a straight radicle, but recent research has placed taxa from the distantly related core Sophoreae and Millettieae within it. Despite these advances, the most species-rich genera within the Brongniartieae are still not well studied, and their morphological and biogeographical evolution remains poorly understood.
View Article and Find Full Text PDFFEMS Microbiol Ecol
February 2015
Department of Biological Sciences, University of Cape Town, Private Bag X3, Rondebosch 7701, Cape Town, South Africa.
Rhizobial diversity and host preferences were assessed in 65 native Fynbos legumes of the papilionoid legume tribes Astragaleae, Crotalarieae, Genisteae, Indigofereae, Millettieae, Phaseoleae, Podalyrieae, Psoraleeae and Sesbanieae. Sequence analyses of chromosomal 16S rRNA, recA, atpD and symbiosis-related nodA, nifH genes in parallel with immunogold labelling assays identified the symbionts as alpha- (Azorhizobium, Bradyrhizobium, Ensifer, Mesorhizobium and Rhizobium) and beta-rhizobial (Burkholderia) lineages with the majority placed in the genera Mesorhizobium and Burkholderia showing a wide range of host interactions. Despite a degree of symbiotic promiscuity in the tribes Crotalarieae and Indigofereae nodulating with both alpha- and beta-rhizobia, Mesorhizobium symbionts appeared to exhibit a general host preference for the tribe Psoraleeae, whereas Burkholderia prevailed in the Podalyrieae.
View Article and Find Full Text PDFAm J Bot
March 2000
Section of Evolution and Ecology, University of California, Davis, California 95616 USA;
Phylogenetic relationships in the tribe Millettieae and allies in the subfamily Papilionoideae (Leguminosae) were reconstructed from chloroplast trnK/matK sequences. Sixty-two accessions representing 57 traditionally recognized genera of Papilionoideae were sampled, including 27 samples from Millettieae. Phylogenies were constructed using maximum parsimony and are well resolved and supported by high bootstrap values.
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