Long-term changes in the inversion chromosomal polymorphism: Drosophila subobscura population from Rasht (North of Iran)

Drosophila subobscura is characterized by a rich chromosomal polymorphism for inversions. Many inversions are adaptive to global warming and can be classified as 'warm' or 'cold' adapted. However, most studies were carried out from European populations located in the central area of the species distribution or from American colonizing populations. For this reason, we aimed to analyse the isolated and marginal Rasht population, located in the Hyrcanian forests area (Iran). The chromosomal polymorphism for inversions was compared with previous Rasht samples (Rasht I and II) obtained 57 years ago. This polymorphism has changed regarding to the inversion composition and frequencies. Interestingly, the polymorphism for inversions was scarce and similar to that of Madeira, an isolated Atlantic island. Likely, this similarity is a consequence of the marginal location and isolation of Rasht population. Also, the CTI (Chromosomal Thermal Index) was 0.445, showing a significant increase over those from Rasht I (0.184) and II (0.210). All these observations were in agreement with global warming expectations. Moreover, the CTI was also computed for Russian Caucasus and Turkish populations collected more than forty years ago to better understand the adaptive potential of D. subobscura and to study the similarity between populations of different geographic areas. In summary, the inversions of D. subobscura changed also in marginal and isolated populations in agreement with global warming expectations, and an open question is to know where is the threshold for this evolutionary change

Global warming and chromosomal inversion adaptation in isolated islands: Drosophila subobscura populations from Madeira

Global warming is an environmental phenomenon to which species must adapt to survive. The chromosomal inversion polymorphism of Drosophila subobscura constitutes a genomic architecture that provides an adaptive capacity to this species. Until now, their populations studied were continental or in islands located near the coastline. In these conditions, gene flow could be a relevant mechanism allowing the movement of thermally adapted inversions between populations. For this reason, we obtained and compared the D. subobscura inversion polymorphism from Madeira, an Atlantic isolated island, with those reported there thirty eight and forty six years ago. Moreover, we studied whether global warming affected this island by measuring mean, maximum and minimum temperatures in a fifty-five years period. We detected significant increase of all these atmospheric parameters in agreement with climate change expectations. Focusing in thermal adapted inversions, their frequencies and the CTI (Chromosomal Thermal Index) values remained rather stable over years. Furthermore, J, U and O chromosomes almost present fixation for 'warm' adapted inversions. Thus, island populations of D. subobscura might be in the threshold of being endangered. However, apart from selection other evolutionary mechanism such as phenotypic plasticity or thermoregulatory behavior could be involved in the survival of the species populations. Finally, being a generalist species living in humanized environments could also favor the persistence of their Madeira populations

Genetic variability of high molecular weight glutenin subunits in bread wheat from continental Portugal, Madeira and Canary Islands

The genetic variability of high molecular weight glutenin subunits (HMWGS) composition at the Glu-1 loci in bread wheat (Triticum aestivum L.) was studied electrophoretically using the SDS–PAGE in 3,470 individuals representing 159 populations originated from the Canary Islands (Spain), the Archipelago of Madeira (Portugal) and the continental Portugal. A total of 25 alleles were detected, resulting in 69 different allele combinations. The geographical distribution of the high molecular weight glutenin alleles confirms historical data regarding circulation of wheat germplasm between the Iberian Peninsula and Madeira and between Madeira and the Canary Islands and vice versa.This research was supported by the European Community through the project AGRICOMAC and GERMOBANCO INTERREG III-B. We thank to Bank of Germplasm INIA (CRF, Alcala´ de Henares, Spain), to Maria Teresa Carvalho e Vasconcelos from Instituto Superior de Agronomia (Lisbon) and the National Small Grain Collection (Aberdeen, USA) for supplying the wheat accessions.info:eu-repo/semantics/publishedVersio

Phytogeographical origin of Madeiran common beans based on phaseolin patterns

The objective of this work was to determine the geographic origin of the Madeiran common bean (Phaseolus vulgaris) gene pool. Phaseolin patterns of 50 accessions representing the diversity of common bean collected in Madeira, Portugal, and conserved in the ISOPlexis Germplasm Bank, were analysed using the Experion automated electrophoresis system, based on lab-on-a-chip technology. Five common bean standard varieties with typical phaseolin patterns were used to determine the phytogeographical origin of the Madeiran common bean accessions. Ninety two percent of the accessions exhibited a phaseolin pattern consistent with the one of common bean types belonging to the Andean gene pool, while the origin of the remaining 8% of the accessions was indistinguishable. The application of a similarity coefficient of 85%, based on Pearson correlations, increases the number of accessions with uncertain pattern. The analytical approach used permitted the determination of the origin of the common bean gene pool, which is Andean in 98% of the cases, and clustering of the observed variability among the Madeiran common beans