Identification of a Kunitz-type proteinase inhibitor from Pithecellobium dumosum seeds with insecticidal properties and double activity

A trypsin inhibitor, PdKI, was purified from Pithecellobium dumosum seeds by TCA precipitation, trypsin-sepharose chromatography, and reversed-phase-HPLC. PdKI was purified 217.6-fold and recovered 4.7%. SDS-PAGE showed that PdKI is a single polypeptide chain of 18.9 kDa and 19.7 kDa by MALDI-TOF. The inhibition on trypsin was stable in the pH range 2-10 and at a temperature of 50 degrees C. The Ki values were 3.56 x 10(-8)and 7.61 x 10(-7) M with competitive and noncompetitive inhibition mechanisms for trypsin and papain, respectively. The N-terminal sequence identified with members of Kunitz-type inhibitors from the Mimosoideae and Caesalpinoideae subfamilies. PdKI was effective against digestive proteinase from Zabrotes subfasciatus, Ceratitis capitata, Plodia interpunctella, Alabama argillaceae, and Callosobruchus maculatus, with 69, 66, 44, 38, and 29% inhibition, respectively. Results support that PdKI is a member of the Kunitz inhibitor family and its insecticidal properties indicate a potent insect antifeedant.     

Influence of agronomic variables on the macronutrient and micronutrient contents and thermal behavior of mate tea leaves (Ilex paraguariensis)

The influence of agronomic variables (light intensity, age of leaves, and fertilization type) on the content of macronutrients and micronutrients (potassium, calcium, sodium, magnesium, manganese, iron, zinc, and copper) of tea leaves was assessed by acid digestion, followed by flame atomic absorption spectrometry (FAAS). The thermal behavior of mate tea leaves (Ilex paraguariensis) was also studied in this work. Samples of mate (Ilex paraguariensis) were collected in an experiment conducted under agronomic control at Erva-Mate Bar?o Commerce and Industry LTD (Brazil). The results showed that the mineral content in mate is affected by the agronomic variables investigated. In general, the content of mineral compounds analyzed is higher for younger leaves and for plants cultivated in shadow. Thermal analysis of samples indicated a similar behavior, with three typical steps of decomposition: loss of water, degradation of low-molecular weight compounds, and degradation of residual materials.     

Influence of drying methods and agronomic variables on the chemical composition of mate tea leaves (Ilex paraguariensis A. St.-Hil) obtained from high-pressure CO2 extraction

The main objective of this work is to assess the influence of two drying methods (microwave and vacuum oven) and some agronomic variables (plant fertilization conditions and sunlight intensity) on the characteristics of mate tea (Ilex paraguariensis) leaves extracts obtained from high-pressure carbon dioxide extractions performed in the temperature range from 20 to 40 degrees C and from 100 to 250 bar. Samples of mate were collected in an experiment conducted under agronomic control at Ervateira Bar?o LTDA, Brazil. Chemical distribution of the extracts was evaluated by gas chromatography coupled with a mass spectrometer detector (GC/MS). In addition to extraction variables, results showed that both sample drying methods and agronomic conditions exert a pronounced influence on the extraction yield and on the chemical distribution of the extracts.     

Seroprevalence of caprine arthritis-encephalitis virus in goats in the Cariri region, Paraiba state, Brazil

The seroprevalence of caprine arthritis–encephalitis virus (CAEV) in the Cariri Region of Paraíba State, Brazil, was determined in 60 goat herds using the agar gel immunodiffusion test. The overall seroprevalence was 8.2%, with seropositivity in 21/60 (35%) herds and 13/15 (86.6%) municipalities. Bucks had a significantly higher frequency of infection (28.3%) than does (5.9%), and bucks that originated in other states had a significantly higher frequency of infection (76.5%) than those from Paraíba State (9.3%).     

Sublethal effects of propiconazole on the metabolism of lambari Deuterodon iguape (Eigenmann 1907), a native species from Brazil

Fish Physiology and Biochemistry - The objective of this study was to analyze the sublethal effects of propiconazole on Deuterodon iguape, a native fish common in Brazil, which has potential for...     

Genome-wide selection in cassava

The main objective of this study was to estimate the selection accuracy and to predict the genetic gain in cassava breeding using genomic selection methodologies. We evaluated 358 cassava genotypes for the following traits: shoot weight (SW), fresh root yield (FRY), starch fraction amylose content (AC), dry matter content (DMC), and starch yield (S-Y). Genotyping was performed using 390 single nucleotide polymorphisms (SNPs), which were used as covariates in the random regression-best linear unbiased prediction model for genomic selection. The heritability values detected by markers for the SW, FRY, AC, DMC, and S-Y traits were 0.25, 0.25, 0.03, 0.20, and 0.26, respectively. Because the low heritability detected for AC, this trait was eliminated from further analysis. Using only the most informative SNPs (118, 92, 56, and 97 SNPs for SW, FRY, DMC, and S-Y, respectively) we observed higher selection accuracy which were 0.83, 0.76, 0.67, and 0.77, respectively to SW, FRY, DMC, and S-Y. With these levels of accuracy and considering a selection cycle reduced by half the time, the theoretical gains with genomic selection compared to phenotypic selection for DMC, FRY, and SW would be 39.42 %, 56.90 %, and 73.96 %, respectively. These results indicate that in the cassava, genomic selection can substantially speed up selection cycles, thereby increasing gains per unit time. Although there are high expectations for incorporating this strategy into breeding programs, we still need to validate the model for other traits and evaluate whether the selection accuracy can be improved using more SNPs.     

Confirmation and characterization of interspecific hybrids of <Emphasis Type="Italic">Passiflora</Emphasis> L. (Passifloraceae) for ornamental use

Three new varieties of Passiflora hybrids were developed from crosses between P. sublanceolata J. M. MacDougal (ex P. palmeri var. sublanceolata Killip) versus P. foetida var. foetida L. Twenty putative hybrids were analyzed. Hybridizations were confirmed by RAPD and SSR markers. The RAPD primer UBC11 (5′-CCGGCCTTAC-3′) generated informative bands. The SSR primer A08FP1 amplified species-specific fragments and heterozygote status was observed with the two parent bands 240 and 280 bp. The molecular markers generated by primers were analyzed in terms of the presence or absence of specific informative bands. The morphological characterization of the hybrids enabled their differentiation into three groups, identified as: (1) Passiflora ‘Alva’, composed of five hybrid plants with white flowers, large corona, light purple filaments at base, white and purple/white banding to apex; (2) P. ‘Aninha’, composed of six hybrid plants with pale pink flowers, corona filaments reddish/purple at base, white, purple/white banding to apex; (3) P. ‘Priscilla’, composed of nine hybrid plants with white flowers, small corona, filaments dark purple at base, white and purple to apex. The genomic homology of parent plants was verified by cytogenetic analysis. Both parents were 2n = 22. Meiosis was regular in genitors and hybrids. Aneuploidy was observed at hybrid groups P. ‘Alva’ and P. ‘Priscilla’ (2n = 20). Other authors had already observed the same number of chromosomes for some P. foetida genotypes. Obtaining valuable interspecific hybrids opens up new perspectives to offer opportunities in agribusiness for producers and to arouse the interest of consumers into using passion flowers in the Brazilian ornamental plant market.     

Heritability and genetic correlation in daylily selection

Daylily (Hemerocallis × hybrida Hort.) is a popular ornamental plant and hybrid cultivars are frequently selected for medium size, large number of flowers per stem, and flower color diversity. However, daylily selection is limited due to the lack of information on genetic parameters and their correlation to phenotypic characteristics. This study aimed at estimating genetic parameters and genetic correlations among full sib families of 13 daylily cultivars using REML/BLUP (restricted maximum likelihood/best linear unbiased prediction) and to select families with high genotypic values for plant height and number of floral buds per stem. Crosses were performed among those cultivars and 24 families were obtained. In the third year, plant height, leaf length and width, stem number, number of floral buds per stem, and number of floral buds per plant were evaluated. The estimates of average heritability of families were superior to the estimates of restrict individual heritability for all characters evaluated. High heritability estimates were obtained for plant height, leaf length, leaf width, stem number, and number of floral buds per plant. Selected families showed genetic gain of 19.80% for plant height, 32.48% for stem number, and 38.64% for number of floral buds per plant.     

Selection of pathometric variables to assess resistance and infectivity in the passion fruit woodiness pathosystem

The objective of this work was to compare the efficiency of four pathometric variables, i.e., grading scale, infection intensity index, global leaf disease index, and global incidence and severity index, in evaluations of the passion fruit/Cowpea aphid-borne mosaic virus (CABMV) pathosystem. In ??yellow?? passion fruit plants, mechanically inoculated with CABMV isolates, the degree of association between leaf symptoms and the total fruit yield was determined, as well as the relative infectivity between viral isolates. Only infection intensity index and the global incidence and severity index presented significant regressions with yield (p?=?0.007 and 0.006, respectively). These two pathometric variables could also distinguish groups of viral isolates inducing different severity levels (0.001 and 0.002, respectively). The results indicate that infection intensity index and global incidence and severity index are equally efficient in early identification of passion fruit populations with a higher resistance/susceptibility level to CABMV, and can be helpful in identifying more severe CABMV isolates, both useful aids in breeding programs.