Browsing by Author "Slaski, Jan J."
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- Abscisic acid phytohormone estimation in tubers and shoots of Ipomoea batatas subjected to long drought stress using competitive immunological assayPublication . Gouveia, Carla S. S.; Ganança, José F. T.; Slaski, Jan J.; Lebot, Vincent; Carvalho, Miguel Â. A. Pinheiro deSweet potato (Ipomoea batatas L.), typically cultivated in temperate climates under low inputs, is one of the most important crops worldwide. Abscisic acid (ABA) is an important plant stress-induced phytohormone. Hitherto, few works analyzed the ABA function in sweet potato tissue growth. Very scarce information is available concerning the ABA role in sweet potato response to water scarcity conditions. Here, we show the ABA content var iation in shoots and tubers of eight sweet potato accessions subjected to drought stress. ABA was also related to other resistance traits, such as chlo rophyll content index (CCI), carbon isotopic discrimination (Δ13C), oxalic acid (OA) and water use efficiency (WUE), to assess stress response mecha nisms to water deficit between their organs. The most resilient drought stressed sweet potato plants accumulated ABA-shoot, and significantly decreased the ABA-tuber content. ABA signaling was related to Δ13C and CCI decrease and WUE increment, as an attempt to cope with water stress by partially closing the stomata. The partial closure of stomata could be in part due to the presence of OA-shoots, known to affect the intensity of the ABA-shoot signal in stomatal closure. Higher CCI content and minimal Δ13C-shoot differences indicated good carboxylation fractionation, with higher Δ13C-tuber content as an indicator of efficient tuber 13C fixation and growth. Our work demonstrated that ABA could be used in conjunction with the other traits studied for the assessment of sweet potato whole-plant responses to environmental stresses, and thus aid the selection of the best drought tolerant genotypes for breeding programs.
- 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.
- Cereal landraces genetic resources in worldwide GeneBanks. A reviewPublication . Carvalho, Miguel A. A. Pinheiro de; Bebeli, Penelope J.; Bettencourt, Eliseu; Costa, Graça; Dias, Sonia; Santos, Teresa M. M. dos; Slaski, Jan J.Since the dawn of agriculture, cereal landraces have been the staples for food production worldwide, but their use dramatically declined in the 2nd half of the last century, replaced by modern cultivars. In most parts of the world, landraces are one of the most threatened components of agrobiodiversity, facing the risk of genetic erosion and extinction. Since landraces have a tremendous potential in the development of new cultivars adapted to changing environmental conditions, GeneBanks holding their genetic resources potentially play an important role in supporting sustainable agriculture. This work reviews the current knowledge on cereal landraces maintained in GeneBanks and highlights the strengths and weaknesses of existing information about their taxonomy, origin, structure, threats, sampling methodologies and conservation and GeneBanks’ documentation and management. An overview of major collections of cereal landraces is presented, using the information available in global metadatabase systems. This review on winter cereal landrace conservation focuses on: (1) traditional role of GeneBanks is evolving beyond their original purpose to conserve plant materials for breeding programmes. Today’s GeneBank users are interested in landraces’ history, agro-ecology and traditional knowledge associated with their use, in addition to germplasm traits. (2) GeneBanks therefore need to actively share their germplasm collections’ information using different channels, to promote unlimited and effective use of these materials for the further development of sustainable agriculture. (3) Access to information on the 7.4 million accessions conserved in GeneBanks worldwide, of which cereal accessions account for nearly 45 %, particularly information on cereal landraces (24 % of wheat, 23 % of barley, 14 % of oats and 29 % of rye accessions), is often not easily available to potential users, mainly due to the lack of consistent or compatible documentation systems, their structure and registration. (4) Enhancing the sustainable use of landraces maintained in germplasm collections through the effective application of recent advances in landrace knowledge (origin, structure and traits) and documentation using the internet tools and data providing networks, including the use of molecular and biotechnological tools for the material screening and detection of agronomic traits. (5) Cereal landraces cannot be exclusively conserved as seed samples maintained under ex situ conditions in GeneBanks. The enormous contribution of farmers in maintaining the crop and landraces diversity is recognised. Sharing of benefits and raising awareness of the value of cereal landraces are the most effective ways to promote their conservation and to ensure their continued availability and sustainable use. (6) Evaluation of costs and economic benefits attributed to sustainable use of cereal landraces conserved in the GeneBanks requires comprehensive studies conducted on a case-by-case basis, that take into consideration species/crop resources, conservation conditions and quality and GeneBank location and functions.
- 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.
- Factors contributing to the development of aluminum resistance in the Madeiran maize germplasmPublication . Carvalho, Miguel Â. A. Pinheiro de; Slaski, Jan J.; Abreu, Ivo; Ganança, Filipe T.; Santos, Teresa M. M. dos; Freitas, Lurdes; Vieira, Maria R. Clemente; Nunes, Antonieta; Domingues, Ana; Taylor, Gregory J.
- 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.
- Identification of aluminum resistant genotypes among Madeiran regional wheatsPublication . Carvalho, Miguel Â. A. Pinheiro de; Slaski, Jan J.; Santos, Teresa M. M. dos; Ganança, Filipe T.; Abreu, Ivo; Taylor, Gregory J.; Vieira, Maria R. Clemente; Popova, Tatyana N.; Franco, EmanuelForty-eight genotypes representing wheat diversity from the Island of Madeira were screened for resistance to aluminum (Al) in nutrient solution. Seeds of wheat used in the experiments were obtained from local farmers. The soil pH and content of ionic Al of plots cultivated with wheat were analyzed. The pH of topsoils varied between 3.83 and 6.59. The amount of ionic Al in soil samples varied between 0.38 and 1.36 cmol Al3 + per kg of soil and was positively correlated with the altitude of a plot. Eriochrome cyanine staining was used to evaluate the effect of Al ions on the root elongation. Seventy-two hour exposure of 3-day-old seedlings to 100 and 200 mM Al in nutrient solution revealed a high number of Al resistant genotypes among wheat germplasm. After withdrawal of Al stress, survival and root regrowth was observed in 28 and 23 genotypes screened at 100 and 200 mM Al in nutrient solution, respectively. Enhanced resistance to Al among Madeiran genotypes was associated with the amount of ionic Al in the soils. Complexity and various patterns of responses of tested cultivars to Al stress may suggest that Madeiran germplasm could be a valuable source of genes controlling Al resistance for conventional breeding programs and for studies of molecular bases of mechanisms of Al resistance.
- Involvement of abscisic acid and other stress indicators in taro (Colocasia esculenta (L.) Schott) response to drought conditionsPublication . Gouveia, Carla S. S.; Ganança, José F. T.; Slaski, Jan J.; Lebot, Vincent; Carvalho, Miguel Â. A. Pinheiro deTaro (Colocasia esculenta (L.) Schott) is a staple food and represents an important food security role in most tropical regions. It is, unfortunately, susceptible to prolonged drought conditions. Abscisic acid (ABA) is a well-documented stress-induced phytohormone that tolerant crops usually accumulate in leaves to induce stomatal closure, preventing water loss through inhibition of transpiration. Hitherto, exists very scarce information regarding the ABA role in taro response to drought. Here, we determined the ABA content in the shoots and corms of taro subjected to seven months of water scarcity and linked ABA to other drought resilience traits, including carbon isotopic discrimination (Δ13C), oxalic acid (OA), chlorophyll content index (CCI), water use efciency (WUE), and biomass (B). The Δ13C-shoot content showed partially open stomata in all accessions, and signifcant correlation with Δ13C-corm, CCI, and WUE. The osmotically active OA-shoot decrease seemed not to interfere with the stomatal aperture. The tolerant accessions subjected to drought stress had higher B-corm, ABA shoot, Δ13C-shoot, CCI, OA, and WUE. However, the observed under drought conditions increase of ABA in the shoots, and its decrease in the corms were not signifcantly correlated, nor with other traits, suggesting that ABA was not the main regulator of taro physiological processes under stress. The information gained should be considered in breeding programs to predict taro’s response to climate change.
- Morphological characterization of wheat genetic resources from the Island of Madeira, PortugalPublication . Santos, Teresa M. M.; Ganança, Filipe; Slaski, Jan J.; Carvalho, Miguel Aˆ . A. Pinheiro deThis paper presents the first comprehensive morphological characterization and identification of the wheat populations collected on the Archipelago of Madeira and preserved at the ISOPlexis Germplasm Bank, the University of Madeira, Funchal. Fifty-two wheat populations representing Madeira’s Triticum diversity and a wide range of ecological conditions were evaluated based on the biometrical and cytometrical traits. Forty-six traits related to plant morphology, cytological and grain characteristics were included in a multivariate analysis. Taxonomic identification of the collected materials revealed the presence of 3 species, 2 subspecies and 16 botanical varieties among the Madeiran wheat germplasm. The obtained results were confirmed by the multivariate analysis since all accessions were grouped in clusters corresponding also to different taxonomic levels. The detailed description of the Madeiran wheat landraces may contribute also to the protection of the existing Triticum diversity as well as support efforts of conservation of landraces, proper germplasm preservation and utilization.
- Morphological evaluation of common bean diversity on the Island of MadeiraPublication . Freitas, Gregório; Ganança, José F.T.; Nóbrega, Humberto; Nunes, Élvio; Costa, Graça; Slaski, Jan J.; Carvalho, Miguel Â. A. Pinheiro deThe variability of fifty populations of common bean (Phaseolus vulgaris L.), representing a wide range of ecological conditions on the Island of Madeira, was evaluated based on morphological and reproductive traits. Individual data of 58 traits related to earliness, plant and tassel structure and the shape of the ear and grain were analysed using multivariate analysis. The populations belonging to two major common varieties were clustered into fifteen groups by their degree of dissimilarity, based on discriminant analysis. The dissimilarity of these groups was con- firmed by one way ANOVA. The racial rank of these groups was proposed and a brief description of the common bean landraces was presented. This work represents the first morphological characterization and analysis of diversity of bean germplasm from the Archipelago of Madeira, where the traditional agricultural practices are still keeping this Portuguese region free from improved bean varieties. The description of the Madeiran bean landraces allows the preservation of the existing bean biodiversity and could be used for their registration as conservation landraces, or for conservation and breeding purposes worldwide.