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- Genetic variability of high molecular weight glutenin subunits in bread wheat from continental Portugal, Madeira and Canary IslandsPublication . Santos, Teresa M. M. dos; Nóbrega, Humberto; Ganança, José Filipe Teixeira; Silva, Emanuel; Afonso, Desire; Gutiérres, Abílio F. M.; Slaski, Jan J.; Khadem, Manhaz; Carvalho, Miguel Â. A. Pinheiro deThe 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.
- Evidences of organic acids exudation in aluminium stress responses of two Madeiran wheat (Triticum aestivum L.) landracesPublication . Rodrigues, Marta; Ganança, José F.T.; Silva, Emanuel M. da; Santos, Teresa M. M. dos; Slaski, Jan J.; Zimny, Janusz; Carvalho, Miguel Â. A. Pinheiro deTwo wheat (Triticum aestivum L.) Madeiran landraces were subjected to 100 μM and 200 μM of aluminium (Al) in hydroponic culture, assessing the organic acid exudation role in plant’s responses to this metal. Samples of initial landrace populations (F0), F3 and haplodiploid lines (DH) were evaluated using standard tests: eriochrome cyanine R staining, root elongation and callose accumulation in roots. Root exudates were obtained to determine if the accumulation of malic and citric acids in hydroponic medium was a response to Al exposure. Additionally, the presence of ALMT1 gene was determined using five microsatellite markers. Standard tests confirmed that ISOP 76 was Al tolerant and ISOP 239, Al susceptible. ISOP 76, in the presence of 100 μM Al, exuded substantially more malic acid (12.87 to 43.33 mg/L), than ISOP 239 (3.65 to 7.72 mg/L). The levels of both organic acid exudation were substantially lower in ISOP 239 than in the ISOP 76. In the presence of 200 μM Al, ISOP 76 F0 shows a higher root elongation ratio (better tolerates Al), but the DH line was the one that exuded higher content of malic acid. Different gene alleles and promoters were detected in both landraces. Molecular differences could explain the observed dissimilarity in organic acid exudation response to Al stress.
- Aluminium tolerance in bean traditional cultivars from MadeiraPublication . Domingues, Ana Maria; Silva, Emanuel da; Freitas, Gregório; Ganança, José Filipe; Nóbrega, Humberto; Slaski, Jan J.; Carvalho, Miguel Ângelo Pinheiro deCommon bean (Phaseolus vulgaris L.) is the most important legume crop in the world, providing low-cost, high quality protein, minerals and dietary fiber for human nutrition. The crop was originated from diversity centers in America and exhibits adaptation abilities to different environmental conditions, including soil with low pH. Acid soils occupy 30% of the agro ecosystem areas in the world. In Madeira, acid Andosols and unsatured Cambisols are the dominant groups of soils. Generally, under acidic and infertile conditions, besides of H+ toxicity, soluble aluminium (Al) is the most important abiotic factor limiting plant development and crop productivity. In the field, the hidden roots are also affected and the reduction of root growth under Al stress can be clearly observed in early stages. Seedlings of fifty bean accessions from the Archipelago of Madeira were tested under controlled conditions in the presence of 50 mM Al at pH 4.4. In general, the tested germplasm appeared to be sensitive or very sensitive to Al toxicity. However, fifteen traditional cultivars clearly exhibited elevated Al-tolerance, with an average root relative elongation (RRE) exceeding 50%, while top six accessions surpassed the 60% RRE mark. The Madeira bean germplasm is a valuable resource for sustainable crop production in acid soils and it could be used as parental lines in breeding programs aimed for Al tolerance in common beans.