Use of culture-derived Fusarium oxysporum f. sp. cubense, race 1 filtrates for rapid and non-destructive in vitro differentiation between resistant and susceptible clones of field-grown banana

Banana and plantain are among the most important food crops in developing countries but production is threatened by increasing virulent forms of Fusarium oxysporum f. sp. cubense. Chemical control is not economically effective and,therefore, breeding programs are necessary. Traditional field studies of new genotype resistance to this disease are time-consuming and destructive. Therefore,we developed a rapid and non-destructive procedure to differentiate field-grown banana resistant from susceptible clones. This procedure implicates application of culture filtrates of Fusarium oxysporum f. sp. cubense race 1 onto banana leaves. The relationship between duration of the fungal in vitro incubation, and the fungal culture fresh mass, the culture filtrate absorbency, and the Gross Michel (susceptible cultivar)leaf lesion area (after application of the culture filtrate) were similar and at 24day-incubation the highest values of the recorded indicators were observed. A comparison between Gross Michel and FHIA-01(resistant) was also performed. The most relevant differences between cultivars were observed at 48 hours after application of the culture filtrate, and in the middle-aged leaves. The position of the culture filtrate application in the leaf limb (distal, middle, proximal) was not determinant. A wider comparison among banana cultivars confirmed previous results informed by other researchers using different systems to study this plant-fungus interaction. Such a confirmation validates the effectiveness of the procedure described here to select rapid and non-destructively banana resistance to this disease at field level. This revised version was published online in August 2006 with corrections to the Cover Date.     

Identification of sex in Carica papaya L. using RAPD markers

Brazil is currently the worlds largest producer of papaya (Carica papayaL.), producing fruits for both the domestic market and export. Only fruits from hermaphrodite plants are marketed because they have the necessary commercial characteristics, i.e. they are pear-shaped and have thicker flesh and a smaller internal cavity. Increased papaya yield has been limited mainly by the ratio of female to hermaphrodite (1: 2) plants normally occurring in orchards. This ratio causes great losses to papaya producers and the identification of the sex of seedlings during the nursery stage would be an important advance. In our study random amplified polymorphic DNA (RAPD) analysis was used to differentiate between the sexual forms of three commercial C. papaya cultivars belonging to the Solo group. RAPD assays using the BC210 primer were able to detect hermaphrodites in all of the cultivars tested. The BC210₄₃₈molecular marker was much better at papaya sex differentiation than other markers described in the literature. This revised version was published online in August 2006 with corrections to the Cover Date.     

Arabinogalactan proteins may facilitate the movement of pollen tubes from the stigma to the ovules in Actinidia deliciosa and Amaranthus hypochondriacus

Sexual plant reproduction is a complex process that involves a series of interactions between the male gametophyte and the different cell types of the pistil. These interactions are believed to direct the pollen tube growth until its final target, the embryo sac. Arabinogalactan proteins are complex proteoglycans that are believed to be involved in these processes. The pistil is enriched in these highly glycosylated proteins and we provide results that show the selective presence of different AGP epitopes at the surface of the cells or in the ECM of the tissues that correspond exactly to the pollen tube growth pathway in Amaranthus hypochondriacus and Actinidia deliciosa. We also show that in Actinidia deliciosa, which is a dioecious plant with the male flowers having rudimentary ovaries where fertilization does not occur, there is no presence at all of the epitopes recognised by the monoclonal antibodies utilized in this study. This revised version was published online in July 2006 with corrections to the Cover Date.     

Implications of early selection for grain colour on iron and zinc content and productivity of common bean

Brazilian consumers prefer beans of the beige grain colour. Common beans help supply dietary requirements for iron and zinc. The objectives of this study were (i) to determine whether early selection for grain colour affects the iron and zinc content and the grain yield in common beans and (ii) if an association between these characteristics was found, to obtain lines of carioca‐type grains with a high iron and zinc content and good grain yield. We evaluated 96 F_3:4, F_3:5 and F_3:6 progeny at two locations for iron and zinc content and grain yield. We selected 48 progeny for grain colour and chose 48 others at random. We found that early selection for grain colour does not affect the zinc content and grain yield. A positive and high association was found between iron and zinc content, and both iron and zinc content were slightly negatively correlated with grain yield. It is possible to obtain common bean lines combining a high iron and zinc content with good grain yield as long as a selection index is used.     

A methodology for evaluating a location as a selection site for an international plant breeding program

Summary A method for comparing locations as selection sites based upon their abilities to predict yield and disease reaction over a target region is proposed. The probability of coincidence in selection for a site is defined as the probability for a line selected at the site to be selected at other sites within the region. The probability of divergence in rejection is defined as that associated with regional selection of a line given that is discarded by the site where selection is being conducted. The ideal selection site would maximize the probability of coincidence in selection and minimize the probability of divergence in rejection. The method is illustrated using a set of data from the rice yield nurseries of the International Rice Testing Program for Latin America planted under the rainfed conditions of Central América and México during the period 1978–1984. Five locations were compared for their predictive ability in selecting for the rainfed rice growing region, based on yield and disease reaction. Selection for yield was defined as performance superior to the best check in each location. Selection for disease reaction was based on an index derived from the Standard Evaluation System for Rice for diseases of regional importance. Locations varies 10–15 percent in their selection coincidence with the region for both yield and disease selection criteria applied independently.     

E-cinnamic acid derivatives and phenolics from Chilean strawberry fruits, Fragaria chiloensis ssp. chiloensis

Three E-cinnamic acid glycosides, tryptophan, and cyanidin-3-O-beta-D-glucopyranoside were isolated from ripe fruits of the Chilean strawberry Fragaria chiloensis ssp. chiloensis. 1-O-E-Cinnamoyl-beta-D-xylopyranoside, 1-O-E-cinnamoyl-beta-D-rhamnopyranoside, and 1-O-E-cinnamoyl-alpha-xylofuranosyl-(1-->6)-beta-D-glucopyranose are reported for the first time. The cinnamic acid glycosides and aromatic compound patterns in F. chiloensis fruits were determined by high-performance liquid chromatography (HPLC). HPLC analyses of extracts showed that cyanidin-3-O-beta-D-glucopyranoside and free ellagic acid are present in achenes while the E-cinnamoyl derivatives and tryptophan were identified only in the thalamus. The free radical scavenging effect of the fruit extract can be associated with the anthocyanin content.     

Evaluation of biomass age in activated sludge processes

The effect of chronic exposure of sublethal concentration (5%) of vegetable oil factory effluent on ovarian maturation of Channa punctatus was studied. The process of ovarian recrudescence was significantly retarded as evidenced by the low ovarian weights and low occurrence of Stage III (Yolky) oocytes in the ovaries of effluent-exposed fish. A high incidence of atresia was also noticed in the ovaries of fish exposed to the effluent.     

Diversity in White Lupin (<Emphasis Type="Italic">Lupinus albus</Emphasis> L.) Landraces from Northwest Iberianplateau

All the accessions (35) of white lupin (Lupinus albus L.) landraces collected from northwest Iberian plateau and maintained at the Spanish germplasm collection (CRF of INIA), were studied with the general objective of assessing the biodiversity of these landraces and to ascertain their value as genetic resources for the development of germplasm adapted to the areas where they were collected with long and chilly winters. The characterization study comprised 51 qualitative and 50 quantitative characters. Quantitative parameters were analyzed by Principal Components Analysis (PCA). The 2-dimensional plot (49.3% of cumulative variability) formed a main group of accessions and 4 outliers (#1, #9, #27 and #28) separated in the first PC. The characters with a higher contribution to the first PC were inflorescence length, leaf petiole length and leaf central foliole area. The presence of alkaloids, the percentage of plants killed by soil borne fungal diseases, the phenology, the yield per plant and yield components were also assessed. Twenty six accessions (the main group in the PCA plot) showed high homogeneity, with the following highlights: bitterness, indeterminate growth habit, early ripeness and spring sowing with the exception of #18, in which seeding date is unknown and it had a later phenology. By contrast accessions #9 and #27 were bitter of autumn sowing with determinate growing habit and they had the longest values of primary inflorescence length and a later phenology when they were sown in spring. Average values for yield and yield components showed a broad range of variation between accessions. The main yield component was the number of pods per plant. Accession #22 had the highest mean seed mass, although this had not significant influence in yield. Accession #17 showed the highest yield and #1 the lowest. This last also had the lowest values of inflorescence length, leaf petiole length and leaf central foliole area. No significant differences of resistance to soil-borne fungi were found between accessions. The year had a significant effect in the phenology, yield and yield components except for number of seeds per pod. The studied material might be of interest for the development of spring sowing germplasm adapted to north Iberian peninsula.     

Behavior of Cd,Pb, and Cu in the marine deltaic area of the Po River (North Adriatic Sea)

An analysis of the spatial trend of concentrations and of the correlation between heavy metals and total suspended matter was performed in a multidisciplinary study of transport of pollutants in the marine coastal area involving in situ investigations, remote sensing techniques and modeling. This paper presents results concerning the chemical behavior of heavy metals (Cu, Cd, Pb) in the North Adriatic Sea and in particular in the marine deltaic area of the Po river. The samples were collected during the JRC Remote Sensing Campaigns ADRIA 84 and ADRIA 85, carried out in the entire North Adriatic Sea and in the selected area in front of the Po when passing from the fluvial to the marine environment. In the dissolved phase, Cu undergoes a dilution process consistent with the mixing theory, while there is a tenfold increase in Pb concentrations. A pronounced tendency to augment the level in the dissolved phase is observed for all three elements in the pelagic waters. In the particulate phase, Cd and Cu, after a diminution in the nearshore stations, their concentration increases as the pelagic area is approached. The total amount of heavy metals in solid phase of the water decreases according to the dispersion and the sedimentation processes of the fluvial load in the marine water. A satisfactory correlation was found between the Cu and Pb with the total suspended matter (TSS). An attempt was made to characterize sediments and suspended matter in order to assess the role of the organic and mineralogical components on heavy metal behavior.     

Effect of kilning on the antioxidant and pro-oxidant activities of pale malts

Pale malts were prepared using standard and rapid kilning regimes that differed in the temperature and moisture profiles in the kiln. Samples were taken over the last 9 h of kilning, that is, at 18, 20, 22, 25, and 27 h. Antioxidant activity, assessed by redox potential, scavenging of the 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS*+), and ferric reducing/antioxidant power (FRAP), increased at moisture levels below 6.7% for both regimes. The 27 h malt exposed to the rapid regime (moisture content of 4.8%) had a higher activity than the 27 h standard regime sample (moisture content of 4.8%). None of the malts scavenged oxygen. Pro-oxidant activity profiles were different for the malts obtained using each regime and, at 27 h, the rapid procedure gave malt with higher activity. Levels of (+)-catechin and ferulic acid (the most abundant phenolic compounds identified) generally increased as the moisture content of malt fell below 6.7%. Differences in antioxidant and pro-oxidant activities of the 27 h malts are partly attributed to the Maillard reaction, as evidenced by lower L* and higher b* values and higher levels of Maillard-derived flavor compounds, in the sample obtained by the rapid procedure. Levels of lipid-derived flavor compounds were significantly higher after 27 h of kilning using the rapid procedure.