Phylotranscriptomics reveal the spatio-temporal distribution and morphological evolution ofMacrozamia, an Australian endemic genus of Cycadales

• DOI: 10.1093/aob/mcac117
• Publication Date: 2022-09-16T15:33:33Z
• Authors: Sadaf Habib; Yiqing Gong; Shanshan Dong; Anders Lindstrom; Dennis William St...; Yang Liu; Hong Wu; Shouzhou Zhang
• Keywords: Coalescent theory; Lineage (genetic)

Cycads are regarded as an ancient lineage of living seed plants, and hold important clues to understand the early evolutionary trends plants. The molecular phylogeny spatio-temporal diversification one species-rich genera cycads, Macrozamia, have not been well reconstructed.We analysed a transcriptome dataset 4740 single-copy nuclear genes (SCGs) 39 Macrozamia species two outgroup taxa. Based on concatenated (maximum parsimony, maximum likelihood) multispecies coalescent analyses, we first establish well-resolved phylogenetic tree Macrozamia. To identify cyto-nuclear incongruence, plastid protein coding (PCGs) from data extracted using software HybPiper. Furthermore, explore biogeographical history genus shed light pattern floristic exchange between three distinct areas Australia. Six key diagnostic characters traced framework comparative methods, infra-generic classification is investigated.The topologies multi-species analyses SCGs mostly congruent with few conflicting nodes, while those PCGs show poorly supported relationships. contains major clades that correspond their distributional in crown group estimated around 11.80 Ma, expansion last 5-6 Myr. morphological homoplasy, traditional phenetic sectional division inconsistent this current phylogeny.This detailed investigation demonstrates promising prospects resolving relationships within cycads. Our study suggests once widely distributed Australia, underwent extinctions because fluctuating climatic conditions such cooling mesic biome disappearance past. close placement morphologically may be related neotenic events occurred genus.