Analysis of morphological variation in wild beet (Beta vulgaris L.) from Sicily

Summary In this paper the variation pattern of the Sicilian Beta germplasm collection is analysed. Accessions from Sicily were grown under controlled conditions and were evaluated morphometrically. Geographical distribution patterns of morphological characters are identified and the putative classification of the collection into coastal and inland populations is reassessed. Between adjacent populations significant variation was found for Petiole length, Leaf length, Leaf width and Biomass, however no one variable unambiguously reflected a geographical pattern. Overall differences between coastal and inland populations were small. Petiole length and rate of generative development were found to be important for distinguishing between these groups. Interferences are drawn on how the collection from Sicily could be rationalized to avoid excessive duplication.     

A new variant of arcelin in wild common bean, Phaseolus vulgaris L., from southern Mexico

Arcelin, a seed protein discovered in wild Phaseolus vulgaris L. accessions, gives high levels of resistance to the Mexican bean weevil [MBW; Zabrotes subfasciatus (Boheman)]. Six variants of arcelin have been described. In this paper we report on a new variant, arcelin 7, found in six wild bean accessions collected in the southern state of Chiapas in Mexico. The new variant is clearly distinct from previously reported ones. It confers high levels of resistance to MBW, comparable to those due to the presence of arcelin 1, arcelin 2 and arcelin 4. Accessions containing arcelin 7 were not as resistant as the one containing arcelin 5 but significantly better in terms of resistance than arcelins 3 and 6. Arcelin 7 was found in a poorly sampled area of Mexico threatened with genetic erosion due to expanding agricultural operations. This exemplifies the need for urgent additional collecting efforts.     

Foliar response of wild and domesticated Phaseolus vulgaris L. to water stress

It is surmised that domestication has reduced geneticvariability in the common bean (Phaseolusvulgaris L.). However, little is known about leaf anatomy responses to water stress in wild or domesticated forms ofP. vulgaris. In this study,anatomical variation was evaluated in watered and water stressed plants of wild and domesticated genotypes of P.vulgaris from Mexico, growing under greenhouse conditions. Five terminal leaflets of completely expanded leaves wereused to evaluate leaf area (LA) and theirmiddle-regions to evaluate leaf thickness (LT), and various anatomical features. Domesticated genotypes showed bigger LAthan that of the wild ones; there was an effect due to the origin of materials, LA being bigger in genotypes from warm and humid lands that those from dry and temperate ones. No differences were detected in LT among materials; however, in domesticated plants the palisadeparenchyma predominated over the spongy one, contrasting with thewild genotypes. Under drought conditions, stomatal abortion was observed in wild and domesticated genotypes, especially on theabaxial surface. We conclude that, in fact, there are contrasting differences in leaf anatomy among wild and domesticated forms of Mexican Phaseolus vulgaris. Results suggest that domestication not only favours the enlargement of the LA, but also an increase in palisade parenchyma, suggesting a divergence toward assimilation in domesticated forms, in contrast with a better internal gas diffusion in wild forms. Domestication seems to have accentuated stomatal abortion as means of a transpirational control mechanism to counteract the effects of drought.     

Guava fruit (Psidium guajava L.) as a new source of antioxidant dietary fiber.

Guava (Psidium guajava L.) is a tropical fruit, widely consumed fresh and also processed (beverages, syrup, ice cream, and jams). Pulp and peel fractions were tested, and both showed high content of dietary fiber (48.55-49.42%) and extractable polyphenols (2.62-7.79%). The antioxidant activity of polyphenol compounds was studied, using three complementary methods: (i) free radical DPPH* scavenging, (ii) ferric reducing antioxidant power assay (FRAP), and (iii) inhibition of copper-catalyzed in vitro human low-density lipoprotein (LDL) oxidation. All fractions tested showed a remarkable antioxidant capacity, and this activity was correlated with the corresponding total phenolic content. A 1-g (dry matter) portion of peel contained DPPH* activity, FRAP activity, and inhibition of copper-induced in vitro LDL oxidation, equivalent to 43 mg, 116 mg, and 176 mg of Trolox, respectively. These results indicate that guava could be a suitable source of natural antioxidants. Peel and pulp could also be used to obtain antioxidant dietary fiber (AODF), a new item which combines in a single natural product the properties of dietary fiber and antioxidant compounds.     

Morphotype relationships in Lima bean (Phaseolus lunatus L.) deduced from variation of the evolutionary marker phaseolin

Summary Variation of the seed storage protein phaseolin was analysed in a collection of 100 accessions of Phaseolus lunatus L. using one-dimensional SDS/PAGE. Cultivated small-seeded genotypes belonging to Sieva and Potato morphotypes and intermediate Sieva-Potato and Sieva-Big Lima morphotypes showed the M (Mesoamerican) pattern, confirming their origin in the same gene pool. Cultivated Big Lima morphotypes showed the A (Andean) pattern, confirming that they belong to a distinct gene pool.     

A note on the variation of phaseolin among common bean landraces collected in Eastern Asia

Summary Phaseolin seed protein was used as a marker to reveal the origin, Mesoamerican or Andean, of common bean (Phaseolus vulgaris) accessions cultivated in some countries (Korea, China, and Japan) of eastern Asia. Andean cultivars (T and C phaseolin patterns) are predominant in this geographical area. Introductions from Middle America, represented by cultivars with S phaseolin type, also occurred at lower rate. In all cases, genotypes with larger seeds have been favoured.     

Codigested dairy slurry as a phosphorus and nitrogen source for Zea mays L. and Amaranthus cruentus L.

Residues from biogas production contain essential plant nutrients such as nitrogen (N), phosphorus (P), and potassium (K) but also organic matter, and should be recycled in crop production. For efficient re‐use as fertilizers, the availability of nutrients for crops and the effect of the residues on soil fertility need to be evaluated. Focusing on the element P, we compared effects of codigested slurry with dairy slurry, highly soluble mineral NPK fertilizer, and a control without any P supply (NK). Codigested slurry used in this experiment was based on anaerobic digestion of dairy slurry, maize silage, and wheat grain. The fertilizing effects were tested in an 8‐week pot experiment on a sandy and a loamy soil using two crop species (Zea mays L., Amaranthus cruentus L.). The plant P uptake was up to 64% greater in the slurry treatments than in the treatment without P. The effect of codigested slurry on P uptake was comparable to that of dairy slurry and mineral P. Plant N uptake from codigested slurry was lower than that from mineral N (NK, NPK), but tended to be higher than from dairy slurry. The water‐soluble and double lactate–soluble P content of the soil was lower in the slurry treatments than in the mineral‐P treatments and accompanied by higher contents of microbial‐bound P. Differences between both organic fertilizers were detected for dehydrogenase activity which was up to 32% lower in soils fertilized with codigested slurry than it was in soils fertilized with dairy slurry. Our results indicate that codigestion of slurries in biogas plants does not substantially alter their fertilizer value as P and N sources for crops.     

The collection of wild oat species of C.I.S. as a source of diversity in agricultural traits

This work presents the results of studying (1990–1992) such wild oat species as Avena clauda Dur., A. pilosa M.B., A. bruhnsiana Grun., A. wiestii Steud., A. barbata Pott.; weedy species – A. sterilis L., A. fatua L. and A. ludoviciana Dur. The range of variability by agricultural traits has been shown and plant forms have been identified by such traits as earliness, dwarfness, productive tillering, resistance to lodging, crown and stem rusts, powdery mildew, tolerance to BYDV and other morphological characters. The author has defined parameters of interrelation between the duration of the vegetation period and its separate phases as well as between other agricultural and morphological traits.     

Miscanthus sinensis and wild flowers as food resources of Lumbricus terrestris L.

Senescent leaves of Miscanthus sinensis contained 36% soluble polysaccharides, 26% cellulose and had a C/N ratio of 45. In 11 wild flower species contents of soluble polysaccharides (21–30%), cellulose (3–16%) and C/N ratio (13–31) were lower. Decomposing leaves of M. sinensis lost weight at a rate of 0.002 day⁻¹, increased the C/N ratio from 45 to about 100, the bacterial biomass from 0.4 to 1 μg C mg⁻¹ dry weight, and decreased the tensile strength from 35 to 10 N. The withdrawal rate of Lumbricus terrestris with senescent leaves of M. sinensis was 30 mg g⁻¹ week⁻¹; the feeding rate was lower. With most senescent wild flowers withdrawal and feeding rates were higher. During decomposition of M. sinensis withdrawal rates increased to about 90, and feeding rates to about 30 mg g⁻¹ week⁻¹. The rates were not related to soluble polysaccharides, cellulose, acid-insoluble residue, C/N ratio and the presence of trichomes on the leaves. The abundance of L. terrestris decreased in a meadow turned into a field of M. sinensis from 55 to 26 earthworms m⁻² and increased in a rotational maize field turned into wild flower strips from 28 to 46 earthworms m⁻². The species richness of earthworms decreased with M. sinensis from 7.2 to 4.7 and increased with wild flowers from 4.7 to 6.7 species per sampling unit.     

Particulate organic matter as a source of variation in denitrification in clods of soil

Existing mechanistic models of denitrification in clods of soil describe the anaerobic activity in the centres of the clods, but they neglect the role of particulate organic materials. We therefore studied the effect of particulate organic matter on denitrification in soil both under pasture and in arable cultivation. Clods were separated into two compartments: (i) particulate organic matter and adhering soil exceeding 200 μm (coated POM), and (ii) the matrix (the rest of the soil). Potential denitrification and production of CO₂ were then estimated on coated POM, matrix and unfractionated soil. The quantity and the quality of coated POM were assessed individually in 100 clods from the pasture and 100 from the arable land. The rate of potential denitrification was similar in unfractionated soil from these treatments. However, it was 70 times greater in the coated POM than in the matrix from the arable soil. Production of CO₂ was nine times greater in the coated POM than in the matrix from the pasture soil and 33 times greater in the arable soils. These observations were the basis for a mechanistic model of denitrification, taking into account contributions from coated POM and the matrix. Denitrification rates in a computerized representation of clods from both pasture and arable soil had approximately the same distribution as experimental data both in the matrix and coated POM contributions in the cropped soil and in the matrix alone in the pasture soil. Coated particulate organic matter can explain more than half of the denitrification and most of the variation in denitrification when it increases microbial activity sufficiently and the soil structure limits the supply of O₂.     

Valorization of cauliflower (Brassica oleracea L. var. botrytis) by-products as a source of antioxidant phenolics

The present study reports the development of two extraction protocols, with potential industrial applicability, to valorize cauliflower (Brassica oleracea L. var. botrytis) byproducts as a source of antioxidant phenolics. In addition, the nonionic polystyrene resin Amberlite XAD-2 was used to obtain purified extracts. The extract yield, phenolic content, phenolic yield, and correlation between the antioxidant activity and the phenolic content were studied. The water and ethanol protocols yield a phenolic content of 33.8 mg/g freeze-dried extract and 62.1 mg/g freeze-dried extract, respectively. This percentage increased considerably when the extracts were purified using Amberlite XAD-2 yielding a phenolic content of 186 mg/g freeze-dried extract (water extract) and 311.1 mg/g freeze-dried extract (ethanol extract). Cauliflower byproduct extracts showed significant free radical scavenging activity (vs both DPPH(*) and ABTS(*)(+) radicals), ferric reducing ability (FRAP assay), and capacity to inhibit lipid peroxidation (ferric thiocyanate assay). In addition, the antioxidant activity was linearly correlated with the phenolics content. The results obtained indicate that the cauliflower byproducts are a cheap source of antioxidant phenolics very interesting from both the industrial point of view and the possible usefulness as ingredients to functionalize foodstuffs.     

Flavonoid glycosides of Barbarea vulgaris L. (Brassicaceae)

Seven flavonoid derivatives were for the first time isolated from aerial parts of an alimentary and medicinal plant of the Brassicaceae family, Barbarea vulgaris L. The products were characterized on the basis of spectroscopic NMR ((1)H, (13)C, COSY, HMQC, HMBC) and FAB-MS data. The occurrence of flavonoids in this plant is interesting for their important nutritional properties and for chemotaxonomical pourposes.     

Characterization of betacyanin oxidation catalyzed by a peroxidase from Beta vulgaris L. roots

A protein fraction with peroxidase (EC 1.11.1.7) activity against guaiacol from Beta vulgaris L. roots oxidized both betanidin and betanin (betanidin 5-O-beta-D-glucoside), the former being the more efficient substrate for the enzyme. The protein fraction contained three strongly basic perxidase isoenzymes. Betanidin quinone was formed as the only product in the course of enzymatic betanidin oxidation, whereas betalamic acid and several oxidized cyclo-DOPA 5-O-beta-D-glucoside polymers were generated during the oxidation of betanin. In accordance with the catalytic properties of peroxidase, a possible mechanism for betanidin oxidation is proposed. This mechanism includes the formation of a betanidin radical, which, by further dismutation, yields betanidin quinone and betanidin. The betanidin oxidation rate showed a Michaelis-type dependence on the substrate concentration. The apparent K(M) for the reaction was 0.46 mM. On the basis of the spectral properties of the enzyme responsible for both betanidin and betanin oxidations, its peroxidase nature is suggested.     

Analysis of anthocyanin variation in wild populations of bilberry (Vaccinium myrtillus L.) in Finland

The berries of Vaccinium myrtillus L. are characterized by 15 anthocyanins. To study the variation in the anthocyanins on a south-north axis of about 1000 km in Finland, the berries from 179 individual bilberry plants in 20 populations were analyzed using an optimized RP-HPLC-DAD method. The mean content of the total anthocyanins was 2878 mg/100 g dry weight. There was extensive variation in the anthocyanin contents within and between the populations, suggesting differences in berry raw material. A significantly lower content of the total anthocyanins was observed in the berries of the southern region compared to those in the central and northern regions. Differences in the proportions of anthocyanins were also observed. The delphinidin glycosides dominated in the northern berries whereas the cyanidin glycosides were most common in the southern ones. Exceptional bilberry individuals were found mainly from eastern Finland with very low amounts of anthocyanidin glucosides. This is the first systematic study to reveal the extremely high variation in the content and distribution of anthocyanins in wild bilberries.     

Karyotypic and genome size variation in Cajanus cajan (L.) Millsp. (pigeonpea) and some wild relatives

Detailed karyotypes and 4C DNA amounts have been studied in five cultivars of Cajanus cajan and 20 species belonging to Cajanus, Rhynchosia, Dunbaria, Flemingia and Paracalyx. C. cajan shows intraspecific variability and its karyotype is most similar to that of C. cajanifolius (sect. Cajanus) in the morphology and number of satellite chromosomes and the lack of any correlation between chromosome size within the complement and asymmetry. Karyotypes of C. lineatus and C. sericeus belonging to sect. Atylia are similar with respect to maximum r-index and the ratio of longest and shortest chromosomes in their respective complements. C. acutifolius (sect. Frutocosa) is distinct in having a very low ratio (1.44) between the longest and the shortest chromosomes, while in C. albicans, C. goensis, C. scarabaeoides (sect. Cantharospermum) there is no chromosome pair with r-index >2.0. C. mollis and C. volubilis (sect. Volubilis) show similarity with regard to ratio between the longest and the shortest chromosomes and a distinct chromosome pair with an arm ratio of 2.7 and C. platycarpus is distinct (sect. Rhynchosoides) in having the smallest ratio (1.36) between the longest and the shortest chromosomes. 4C DNA amounts in Cajanus and Rhynchosia vary between 3.28 pg to 11.69 pg and 4.92 pg to 11.13 pg respectively, while in Dunbaria, Flemingia and Paracalyx these vary between 4.70 and 7:06 pg. In the genus Cajanus karyotypic features and 4C DNA amounts agree with the sectional classification and bring out a close relationship between C. cajan and C. cajanifolius. This is supported by studies based on seed protein patterns, isozyme analysis, trypsin and chymotrypsin inhibitor patterns, RFLP and RAPD data and crossability relationships. A clear relation between DNA amount and abnormalities effecting the extent of pairing and recombination in interspecific hybrids shows the importance of this study in developing future breeding programme involving C. cajan and its wild relatives that are of potential value.     

Artichoke (Cynara scolymus L.) byproducts as a potential source of health-promoting antioxidant phenolics

The present study reports a fast, economical, and feasible way to extract antioxidant phenolics from artichoke byproducts: raw artichoke (RA), blanched (thermally treated) artichoke (BA), and artichoke blanching waters (ABW). These byproducts represent a huge amount of discarded material in some industries. Two protocols, with possible industrial applicability, based on both methanol and water extractions were used. Phenolic contents (expressed as caffeic acid derivatives) (grams per 100 g of dry extract) were 15.4 and 9.9 for RA when extracted with methanol and water, respectively; 24.3 and 10.3 for BA when extracted with methanol and water, respectively; and finally, 11.3 g of phenolics/100 mL of ABW. Therefore, methanol extracts yielded more phenolics than water extracts, especially when BA byproducts were used. The higher amount of phenolics in BA could be due to the inactivation of polyphenol oxidase (PPO) at the industrial scale (due to blanching process), avoiding PPO-catalyzed oxidation of these phenolics, a phenomenon that could occur in RA byproducts. Artichoke extracts from industrial byproducts showed a high free radical scavenging activity (versus both DPPH* and ABTS*+ radicals) as well as capacity to inhibit lipid peroxidation (ferric thiocyanate method). According to these results, the use of artichoke extracts from industrial byproducts as possible ingredients to functionalize foodstuffs (to decrease lipid peroxidation and to increase health-promoting properties) is suggested.