Phylogenetic implication of seed coat sculpturing in subtribe Agrimoniinae (Rosaceae)

Abstract

Seed morphology in the subtribe Agrimoniinae (Rosaceae) was examined using scanning electron microscopy to identify distinct characters and evaluate their evolution in a phylogenetic framework for five genera in the subtribe: Agrimonia L., Aremonia Neck. ex Nestl., Hagenia J.F. Gmel., Leucosidea Eckl. & Zeyh., and Spenceria Trimen. All genera have one or two mature achenes in a fruiting hypanthium. In the seed coats, the cell shape, size, wall features, and sculpturing vary across genera. Of most significance is the presence of papillae structures in both Agrimonia and Aremonia. Through the mapping of papillae features onto phylogenetic trees, either one or two changes in seed coats are hypothesized. The phylogenetic tree inferred from four nuclear and six chloroplast regions of sequence data suggests that at least two steps of papillae sculpturing on seed coats are required. On the other hand, in the phylogenetic tree of a low-copy nuclear gene, one independent evolutionary step is postulated to explain the current character states. In the latter hypothesis, the seed coat sculpturing also supports a monophyletic relationship for cosmopolitan Agrimonia and European endemic Aremonia. The seed coat sculpturing provides valuable information for inferring phylogenetic relationships at the generic level in the subtribe Agrimoniinae.

Light and scanning electron microscopy observations on morphological diversity of Rosaceae stigma and its taxonomic significance

“…Many scholars have explored the morphological characteristics of seeds (Chung et al, 2002; Dowidar et al, 2003; Maciejewska‐Rutkowska & Bednorz, 2004; Song et al, 2020a; Song & Hong, 2020; Ullah et al, 2021), leaf epidermis (Ganeva, 2009; Ganeva et al, 2011; Ganeva & Uzunova, 2010; Kumachova et al, 2021; Shaheen et al, 2021; Song & Hong, 2016a; Zamani et al, 2017) and petals (Sharifnia & Shakib, 2012; Song et al, 2020b; Song & Hong, 2016b; Sulborska et al, 2012; Tahir & Rajput, 2010) in Rosaceae. However, only Heslop‐Harrison and Shivanna (1977) have studied the stigma morphology of several species in family Rosaceae.…”