V. Carnide

Towards allelic diversity in the storage proteins of old and currently growing tetraploid and hexaploid wheats in Portugal

Using sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS–PAGE), the different alleles encoded at the 6 glutenin loci and 3 ω-gliadin loci were identified from a set of 134 hexaploid and 128 tetraploid wheat accessions mainly grown in Portugal. In the hexaploid wheats (T. aestivum L.), a total of 56, 42 and 36 patterns were observed for high molecular weight-glutenin subunits (HMW-GS), low molecular weight-glutenin subunits (LMW-GS) and ω-gliadins respectively. For HMW-GS encoded at Glu-A1, Glu-B1 and Glu-D1 loci, 4, 10 and 6 alleles were observed, respectively. LMW-GS displayed similar polymorphism, as Glu-A3,Glu-B3 and Glu-D3 loci, which comprises 5, 9 and 3 alleles. Twenty-four alleles were observed for ω-gliadins found at Gli-A1, Gli-B1 and Gli-D1 loci with, 5, 16 and 3 alleles respectively. For tetraploid collection fifty different alleles were identified for the seven loci studied Glu-A1 (3), Glu-B1 (13), Glu-A3 (6), Glu-B3 (7), Glu-B2 (2), Gli-A1 (5) and Gli-B1 (14). The genetic distances within hexaploid and tetraploid wheats were presented using cluster representation. The mean value of genetic variation indices (H) for wheat storage protein loci was slightly lower in current commercially available varieties (0.592) and highest for old varieties (0.574).

Nucleolar organiser activity in Lolium and Festuca. 1. Lolium multiflorum, Festuca arundinacea and Lolium—Festuca Hybrids

Lolium multiflorum, Festuca arundinacea and L. multiflorum-F. arundinacea hybrids were analysed by phase contrast, C-banding and silver-staining methods. Although the number of secondary constrictions detected by phase contrast was always six in L. multiflorum, it was very variable in F. arundinacea (4–12) and Lolium-Festuca hybrids (3–7); in these cases most of the constrictions appeared as euchromatic or c-hetero chromatic material when the C-banding technique was applied. By contrast the number of Ag-NORs was virtually constant in all plant varieties: six interstitial in L. multiflorum, two interstitial and two telomeric in F. arundinacea and three interstitial in the hybrids. These results indicate that not all the secondary constrictions detected by phase contrast are in fact nucleolar organiser regions. In addition a suppression of the nucleolar organisers of F. arundinacea by those of L. multiflorum was detected in the hybrids analysed.

Cowpea: a legume crop for a challenging environment

Cowpea is a grain legume native from Africa and is a primary source of protein for millions of people in sub-Saharan Africa and other parts of the developing world. The main important characteristics of this crop include a good protein quality with a high nutritional value, its nitrogen-fixing ability, and an ability to be more drought- and heat-tolerant than most of its legume relatives. In a research perspective, studies of cowpea are relatively scarce, despite its relevance to agriculture in the developing world and its resilience to stress. The present review provides an overview of different aspects of cowpea, with a special emphasis on the molecular markers for assessing genetic diversity, as well as on biochemical and transcriptomic data with respect to evaluating cowpea drought stress tolerance. The integration of both datasets will be useful for the improvement of cowpea because research on drought stress tolerance is of major interest for this crop in a challenging environment.

Chloroplast SSR genetic diversity indicates a refuge for Corylus avellana in northern Portugal

The genus Corylus, a member of the birch family Betulaceae, includes several species that are widely distributed throughout temperate regions of the Northern Hemisphere. The development of microsatellites or simple sequence repeats (SSRs) for non-coding regions of the chloroplast genome and their higher sequence variation compared with coding regions has provided a higher resolution tool for the study of cultivars and closely related taxa. Chloroplast polymorphisms provide a marker system to evaluate the genetic structure of plant populations. This study investigated genetic diversity in three cultivars and 32 genotypes of Corylus avellana L. from Portugal: 13 wild genotypes and 19 Portuguese landraces. Four of ten cpSSR loci were polymorphic, with diversity indices ranging from 0.111 to 0.244. Eleven chlorotypes were detected, and their relationships were analyzed using a network model. Haplotype A was most frequent in landraces and cultivars. Four chlorotypes (H, I, J and L) were found only in wild hazelnuts. The diversity of chlorotypes in the wild hazels, and the limited number reported in cultivars, suggests that northern Portugal was a refuge for hazel during the last ice age.

Phenotypic diversity and evaluation of fresh pods of cowpea landraces from Southern Europe: Fresh pod variability of cowpea landraces

BACKGROUND Cowpea fresh pods are consumed as green vegetables in many countries in Southern Europe. Among cowpea cultivated material, a relatively large number of landraces can be found, maintaining species genetic diversity. To assess the value of these landraces in breeding programs, the characterization and estimation of diversity levels is therefore required. In the present study, an estimation of the diversity and evaluation of cowpea landraces originating from Portugal, Spain and Greece, in terms of their fresh pod traits, was performed, aiming to assist with the problem of low cowpea production in Southern Europe. RESULTS A notable mean total phenotypic diversity (HT = 0.57) was observed in the whole collection. The Spanish cv. - gr. unguiculata collection exhibited the highest value of total phenotypic diversity (0.56). Landraces did not differ significantly from each other regarding the three countries of origin. Landraces such as Cp4906, Vg60 and BGE038478 presenting higher values of some traits studied could contribute to the breeding of new cowpea varieties for fresh pod production. Positive correlations were observed, indicating the feasibility of breeding for preferable traits regarding fresh pod consumption. CONCLUSION The present study has revealed a wide diversity among and within cowpea landraces that could enhance fresh pod production in South European countries.

Morpho-agronomic characterization and variation of indigo precursors in woad ( Isatis tinctoria L.) accessions

Woad (Isatis tinctoria L.) was the most important source of natural blue indigo, a pigment used mainly for dyestuff until the beginning of the 20th century, when the increased use of synthetic dyes by the industry lead to a decrease in the interest of natural dyes and to the abandonment of dye crops. The aim of this study was to characterize, according to morphological and agronomical traits, 11 woad accessions from different countries and to quantify the indigo precursor content by high-performance liquid chromatograph-diode array detection (HPLC-DAD). Qualitative traits revealed a low variability and a great variation was observed in quantitative traits. Principal component analysis (PCA) diagrams divided the accessions into four groups, primarily according to their geographic origin. The first three components of the PCA accounted for 76.8% of the total variation. Reciprocal interactions between indigo precursors and fresh leaf weight were compared through genetic diversity, with significant differences in isatan B (0.5‐5.1 g/kg), indoxyl (0.3‐2.0 g/kg) and residual indigo (0.3‐0.5 g/kg). This information, together with genetic data, can be used to assist local farmers to re-introduce Isatis species in the European agricultural system, not only indicating the higher indigo yielding genotypes, but also the most suitable harvest time.

European cowpea landraces for a more sustainable agriculture system and novel foods

BACKGROUND Genetic diversity is fundamental to breeding programs and consequently has an important role in obtaining new varieties. To properly use the genetic diversity present in germplasm collections, a good knowledge of the agro-morphological traits of each accession is needed. The aim of this study was to explore the production capacity of 24 cowpea landraces from southern Europe, through phenotypic characterization and evaluation in three different locations in Greece and Portugal. RESULTS Most qualitative parameters tested showed a high stability among the three locations. A wide difference was observed among the three locations with respect to number of days to flowering, ranging from 55 to 99 days. Quantitative traits showed a higher genotype × environment than genetic variance component. In general, an inverse relationship between σ2ge /σ2g ratio (where σ2ge is genotype × genotype interaction and σ2g is genotype impact) and heritability value was observed. Principal component analysis was able to group accessions based on their origin. The first two principal components explained 97.52% of variation, being the number of seeds per plant, plant height and seed protein content, the traits which contributed most to variability. CONCLUSION The results show that sufficient variation exists in different traits within landraces in the studied cowpea germplasm to pursue a breeding program. However, the quantitative traits showed a higher genotype × environment component.

Effect of Harvest Year and Altitude on Nutritional and Biometric Characteristics of Blueberry Cultivars

In recent years the consumption of small fruits has increased continuously and knowledge about the more suitable production requirements is essential. This study aims to evaluate the influence of harvest year and altitude on chemical composition of four blueberry cultivars, in order to create rentable opportunities for producers and minimize eventual losses in quality fruits. Dry mass, protein, fat, energy, free sugars, organic acids, and vitamin C contents were determined using HPLC-UV-DAD and spectrophotometric methods. Differences () in the concentrations of free sugars, organic acids, and vitamin C were found among years, while the altitude had no () influence. Citric acid was the main organic acid and fructose the most abundant sugar in blueberries. Fruits of “Ozarkblue” had the highest mass and volume whilst the “Bluecrop” was the cultivar with highest crude protein and fat contents. “Goldtraube” showed the highest content of sucrose and organic acids and “Duke” had the highest content of fructose.

Genetic diversity and structure of Iberian Peninsula cowpeas compared to world-wide cowpea accessions using high density SNP markers

BackgroundCowpea (Vigna unguiculata L. Walp) is an important legume crop due to its high protein content, adaptation to heat and drought and capacity to fix nitrogen. Europe has a deficit of cowpea production. Knowledge of genetic diversity among cowpea landraces is important for the preservation of local varieties and is the basis to obtain improved varieties. The aims of this study were to explore diversity and the genetic structure of a set of Iberian Peninsula cowpea accessions in comparison to a worldwide collection and to infer possible dispersion routes of cultivated cowpea.ResultsThe Illumina Cowpea iSelect Consortium Array containing 51,128 SNPs was used to genotype 96 cowpea accessions including 43 landraces and cultivars from the Iberian Peninsula, and 53 landraces collected worldwide. Four subpopulations were identified. Most Iberian Peninsula accessions clustered together with those from other southern European and northern African countries. Only one accession belonged to another subpopulation, while two accessions were ‘admixed’. A lower genetic diversity level was found in the Iberian Peninsula accessions compared to worldwide cowpeas.ConclusionsThe genetic analyses performed in this study brought some insights into worldwide genetic diversity and structure and possible dispersion routes of cultivated cowpea. Also, it provided an in-depth analysis of genetic diversity in Iberian Peninsula cowpeas that will help guide crossing strategies in breeding programs.

Genetic diversity and phaseolin variation in Portuguese common bean landraces.

A collection of 18 landraces of common bean ( Phaseolus vulgaris L.) from northern Portugal was evaluated for both phaseolin pattern and a set of qualitative and quantitative traits. The phaseolin Contender and Tendergreen types were the most commonly occurring, with Boyaca and Huevo de Huanchaco present, but rare. The colour of the flower standard and wing, and seed shape, colour and size were all highly variable. On the basis of morphological traits, the landraces and testers clustered into two main groups. No relationship was found between phaseolin profile and any of the quantitative traits measured. Based on phaseolin patterns, the origin of Portuguese common bean populations was probably the Andean region of South America.