Morpho-environmental strategies in the genus Ononis L. (subsections Natrix and Viscosae) in Western Mediterranean

Abstract

Very similar morphologies have always been pointed out for subsections Natrix and Viscosae of the genus Ononis L. Morphological, environmental and biogeographic approaches do not show significant differences between taxa of both subsections, and only life form was pointed out as biological descriptor to explain taxonomic and ecological strategies for these taxa: Natrix is composed by perennial life forms, while Viscosae is solely represented by annual life forms. The discussion of results was conducted through the insurance hypothesis, according to which resilient or resistant behaviours, here represented by taxonomic diversity and morpho-environmental variability, described the ecological strategies for these taxa. In this way, wider morpho-environmental variability induced more responses (higher taxonomic diversity and life forms), i.e. more resilience. On contrary, the narrower morpho-environmental variability induced less taxonomic diversity and only perennial life forms, i.e. more resistance. Two future climate change scenarios were also used to confirm these resilience and resistance strategies for both subsections.

Speciation and periodic restricted environments. The case of genus Ononis L. (subsections Natrix and Viscosae)

“…A remarkable similarity for both Natrix and Viscosae subsections, morpho-environmentally revealed by Rocha et al (2018), was confirmed again in this work (now at the genetic level). At the same time, two of the species of subsection Natrix, O. natrix and O. ramosissima, and two of the subsection Viscosae, O. pubescens and O. breviflora, were shown to have an important genetic role in explaining the short genetic distance between both subsections.…”

“…The relevant morphological similarity for the Ononis subsections analyzed here was already observed by Rocha et al (2018). Three morphological trends were suggested in this morpho-environmental approach, where taxa of subsection Natrix could be distinguished from those of subsection Viscosae without enough statistical significance (very low Fremove for the discriminant analysis).…”

“…Environmentally, subsection Natrix revealed the widest variability, in contrast to subsection Viscosae where just O. pubescens and O. breviflora showed high variations. In this sense, the molecular approach was necessary to confirm the hypothesis suggested by Rocha et al (2018). These authors proposed O. natrix and O. ramosissima as probable ancestors of both subsections, since the annual forms should be the mechanism to colonize inter-glacial environmental restricted areas.…”

“…In the case of subsections Natrix and Viscosae, no molecular analyses has been published. This characterization is essential to describe the correlation between the morpho-environmental analysis, previously elaborated by Rocha et al (2018), and the genetic information. Life forms, annuals or perennials, have traditionally been indicated as the way to distinguish these subsections.…”

“…The relation of these specimens and their original locations are shown in Table 1 and their geographic distribution is represented in Figure 1. According to Rocha et al (2018), and because of the extreme morpho-environmental similarity between O. sieberi and O. breviflora, both taxa were here considered as O. breviflora.…”