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The evolution and morphology of this new species have been studied in two scientific articles published in the American Journal of Botany and Taxon, as part of Marta Nieto Lugilde's doctoral thesis.
Researchers from the University of Murcia (UMU) have described a new species for science, which they have called Ceratodon amazonum.
The name refers to the Amazons, a tribe of Greek mythology formed and governed in its entirety by women warriors, since no males have been found.
"Everything arose when we imagined the Sierra Nevada populations formed by daring warriors fighting alone to survive," says Nieto Lugilde, who adds that although the new species is very abundant in Sierra Nevada (Spain), it is usually more rare as we we move away from the mountain massif;
In spite of this, samples have been found in the Region of Murcia.
In addition to the PhD student, the UMU scientists involved in these findings were Olaf Werner, Samah Mohamed Rizk and Rosa María Ros Espín who directs the research group "Molecular Systematics, Phylogeography and Conservation in Briophytes".
Other researchers from the University of Florida (USA) and the University of South Bohemia (Czech Republic) have also collaborated in this work.
The results show that these "warriors" are closely related to the species C. purpureus.
"We showed that during the evolution of this new moss the size of its genome has increased by 25% in comparison with the cosmopolitan C. purpureus and that the frequency of males has decreased significantly", explains Ros Espín, co-director of the thesis.
Although neither males nor evidence of recent sexual reproduction have been found in the new species, genetic diversity among the plants is relatively high.
All this suggests that it does not need the male to reproduce, but probably propagates asexually.
That is to say, "it multiplies by fragmentation of the plants, since each piece of them has the capacity to regenerate a whole new plant, which is genetically identical to the plant from which it comes", adds the main researcher, who maintains that no other cases are known in mosses in which the loss of males has been associated with the processes by which new species originate.
This highlights the complexity of the mechanisms of speciation in these plants.
These investigations have been financed by the Ministry of Science and Innovation and the Ministry of Economy and Competitiveness.
Molecular biology at the service of botany
The current techniques of molecular biology have allowed UMU scientists to carry out an in-depth study of the populations of the genus Ceratodon in the mountainous areas of the Mediterranean region and compare them with those of other mountain ranges and lowlands, mainly from southern Europe.
"We did genetic analysis of kinship, we measured the amount of DNA in the nuclei of the cells and we determined the sex of the plants collected in the field, we also studied and measured at the microscopic level many morphological characters, both in plants grown in the field and cultivated in the laboratory ", describes the researcher Olaf Werner.
The researchers are hypothesizing that C. amazonum has gained DNA on the sex chromosome, which comprises almost a third of its genome.
In other organisms sex chromosomes also accumulate genomic material quickly, which has important evolutionary and ecological consequences.
In addition, a group of samples has been detected that present a hybrid genome between C. amazonum and C. purpureus, in which the size of the genome is approximately the sum of the genomes of both species.
The comparative study of the samples collected in the field with those cultivated in vitro leads to the conclusion that C. amazonum is morphologically distinguished from C. purpureus and even from the hybrid group.
Although the results conclude that the observed morphological differences are mainly due to environmental factors, genetic factors are also important.
Centuries of research focused on mosses
Mosses belong to the group of plants called bryophytes (non-vascular plants).
They perform important functions in ecosystems: they cushion desertification, they regulate water levels in riverbeds, they constitute the habitat where many microorganisms and small animals feed and protect themselves.
Researchers dedicated to the delimitation of moss species have devoted much effort to the genus Ceratodon since its description in 1826 by the Swiss botanist Samuel Élisée von Bridel.
However, the great morphological diversity of C. purpureus, its wide distribution across all continents and its growth on a wide variety of substrates have made this task difficult for a long time.
Stuart F. McDaniel, of the University of Florida, and co-author of the studies carried out at the UMU, has spent years studying different aspects of the biology of C. purpureus, and in 2005 he published that the gene flow between the populations of the Northern Hemisphere and the Southern Hemisphere was frequent, but the tropical populations (including those of the Mediterranean region) were more genetically isolated.
These observations suggested that the sampling level was insufficient to detect the structure of the populations of this species and encouraged the UMU researchers to address this study.
At present we observe that climate change affects the proportion of females in animal species such as the turtle and therefore its evolution, but how it will influence the evolution of the plants is still a field of research in which to deepen.
Source: Universidad de Murcia
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