Scientific Journals of INIA (Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria)
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Genotype by environment interaction in sunflower (Helianthus annus L.) to optimize trial network efficiency
Get PDFModeling genotype by environment interaction (GEI) is one of the most challenging aspects of plant breeding programs. The use of efficient trial networks is an effective way to evaluate GEI to define selection strategies. Furthermore, the experimental design and the number of locations, replications, and years are crucial aspects of multi-environment trial (MET) network optimization. The objective of this study was to evaluate the efficiency and performance of a MET network of sunflower (Helianthus annuus L.). Specifically, we evaluated GEI in the network by delineating mega-environments, estimating genotypic stability and identifying relevant environmental covariates. Additionally, we optimized the network by comparing experimental design efficiencies. We used the National Evaluation Network of Sunflower Cultivars of Uruguay (NENSU) in a period of 20 years. MET plot yield and flowering time information was used to evaluate GEI. Additionally, meteorological information was studied for each sunflower physiological stage. An optimal network under these conditions should have three replications, two years of evaluation and at least three locations. The use of incomplete randomized block experimental design showed reasonable performance. Three mega-environments were defined, explained mainly by different management of sowing dates. Late sowings dates had the worst performance in grain yield and oil production, associated with higher temperatures before anthesis and fewer days allocated to grain filling. The optimization of MET networks through the analysis of the experimental design efficiency, the presence of GEI, and appropriate management strategies have a positive impact on the expression of yield potential and selection of superior cultivars
Short communication: Melatonin implantation during the non-growing period of cashmere increases the cashmere yield of female Inner Mongolian cashmere goats by increasing fiber length and density
Get PDFThis study aimed to evaluate if melatonin implantation at the end of April and June was able to increase cashmere production in female Inner Mongolian cashmere goats and to search for contributing factors accounting for the melatonin increasing in cashmere production. One hundred and fifty female Inner Mongolian cashmere goats (initial body weight 37.2 ± 3.3 kg) were randomly assigned to either a control (n=75) or a treatment (n=75) group. Goats in the treatment group were implanted with melatonin (2 mg/kg of body weight) on April 30 and June 30, 2014 while goats in the control received no treatment. Melatonin implantation increased cashmere yield by 23.4% while increasing the length and density of the cashmere fiber by 19.8% and 11.4%, whereas it decreased cashmere fiber diameter by 4.4%. Melatonin treatment had no effect on doe growth, litter size or birth and weaning weights of kid. Melatonin implantation promoted cashmere yield by increasing fiber length and density without impacting the performance of goats and their offspring. Therefore, melatonin implantation during the cashmere non-growing period (late April and June) is an effective way to increase cashmere yield and improve cashmere characteristics of goats
Identification of epiphytic yeasts and bacteria with potential for biocontrol of grey mold disease on table grapes caused by Botrytis cinerea
Get PDFThe objective of this study was to identify grapevine epiphytic yeasts and bacteria for biocontrol of Botrytis cinerea on grapes. Antagonistic yeasts and bacteria were isolated from the epiphytic flora associated with grape berries and leaves cv. ‘Thompson seedless’ from vineyards in Iran and identified by sequencing the conserved genomic regions. A total of 130 yeast and bacterial isolates from the surface of grapevine were screened in vitro for determining their antagonistic effect against B. cinerea and used to control postharvest gray mold. Among the 130 isolates, five yeasts and four bacterial isolates showed the greatest antagonistic activity in vitro against B. cinerea. Two yeasts species including Meyerozyma guilliermondii and Candida membranifaciens had high antagonistic capability against the pathogen. Also, 4 bacterial isolates belonging to Bacillus sp. and Ralstonia sp. showed significant biocontrol effect against B. cinerea. The isolates were capable of producing volatile and non-volatile substances, which suppressed the pathogen growth. The antagonistic activity of selected yeasts and bacteria against the pathogen was investigated on wounded berries of ‘Thompson seedless’. On small clusters with intact berries, all of the antagonistic isolates considerably reduced the decay on grape berries and inhibition of gray mold incidence on fruits treated by these isolates was less than 50%, except for the isolate N1, which had higher capability in inhibiting the disease incidence. These results suggest that antagonist yeasts and bacteria with potential to control B. cinerea on grape can be found in the microflora of grape berries and leaves
Reproduction, longevity and life table parameters of Monosteira unicostata (Hemiptera: Tingidae) at constant temperatures
Get PDFInformation on the effect of temperature on biological parameters of phytophagous insects is one of the tools in IPM programs, as it allows prediction of risk situations in the field. This work reports the effect of temperature on reproductive parameters and longevity of one of the most important current pests of almond orchards in the Mediterranean basin, the poplar lace bug, Monosteira unicostata (Mulsant & Rey) (Hemiptera: Tingidae). The temperatures tested were 22, 25, 28, 31, 34 and 37ºC, always at 60 ± 10% relative humidity and under a L16:D8 photoperiod. Extreme temperatures had an adverse effect on preoviposition period, total fecundity and daily fecundity while increasing values of oviposition period and adults longevity were registered for decreasing temperatures. Male longevity was higher than female longevity, and mortality pattern differed between sexes for all temperatures but 37ºC. The nonlinear Lactin model described accurately the effect of temperature on the intrinsic rate of natural increase of M. unicostata populations and predicted the optimum temperature for population increase at 34.1ºC, at which the population doubling time is 3.6 days. Produced values of lower and upper thresholds for M. unicostata populations were 14.8 and 38.8ºC, respectively. This characterizes the poplar lace bug as a very important pest in the Mediterranean basin, with an increasing potential risk in a global warming scenario
Dietary supplementation with papaya (Carica papaya L.) leaf affects abundance of rumen methanogens, fermentation characteristics and blood plasma fatty acid composition in goats
Get PDFThe objective of this study was to test the effect of feeding papaya leaf (PL) on rumen microbial population, fermentation characteristics, blood fatty acid composition and antioxidant activity in goats. Three rumen fistulated male goats were assigned in a 3×3 latin square design using three levels of PL: no addition of PL in basal diet (control, CON, 50% concentrate + 50% alfalfa hay), 25% of alfalfa hay in basal diet replaced by PL (medium PL, MPL) and 50% of alfalfa hay in basal diet replaced by PL (high PL, HPL). Rumen fluid and blood plasma were sampled from the animals at the end of feeding trial (third week). Papaya leaf treatments (MPL and HPL) showed significant differences (p<0.05) in terms of rumen fermentation parameters as compared to the CON group at different times of measurement. The concentration of methanogenic archaea (log10cell/L) decreased (p<0.05) in both PL treatment groups as compared with CON group at all sampling times. The concentration of α-linolenic acid and total conjugated linoleic acid (CLA) were also higher (p<0.05) in the blood of goats fed PL especially HPL, compared to the CON. Blood plasma malondialdehyde concentration (mM/mL) of PL treatment groups showed a significant reduction as compared with CON. Supplementation of PL allowed the modulation of rumen characteristics which might represent a feeding strategy to reduce methane emission by directly inhibiting methanogens while improving the health benefits of ruminant products
Effects of antioxidant activity of black maize in corn borer larval survival and growth
Get PDFAntioxidant activity (AA) of black maize kernels attributed mainly to polyphenols has potential effects on health and possible defense functions against pests. Our objective was to evaluate the effects of maize polyphenols and AA in survival and growth of larvae of the corn borer Sesamia nonagrioides. We carried out two bioassays with S. nonagrioides larvae grown in artificial diet with white and black maize flour and control. AA was tested spectrophotometrically on each of the diets using four methods. The different measurements of AA were strongly correlated, indicating that these measurements were highly reliable. The control diet, the white-maize-diet and black-maize-diet with vitamin C and without H2O2 had the highest antioxidant activity. The processing of the maize flour altered the AA of the polyphenols. The control treatment had the highest AA, and vitamin C had stronger AA than polyphenols. AA of vitamin C hides that of polyphenols probably due to environmental effects, dilution of polyphenols, or interactions with other substances. Larvae grew more in the control diet and the addition of H2O2 had not significant effects on weight. There was a weak rank correlation between AA and larval weight. Mortality was lowest for the control diet with or without H2O2 followed by white maize with or without H2O2 and black maize without H2O2. Effects of polyphenols depend on other substances that might interact with them. The results indicate that antioxidant activity has insecticide effects on young larvae and, as the larvae grow, antioxidants have positive effects on larvae
Molecular characterization of the cucumber (Cucumis sativus L.) accessions held at the COMAV’s genebank
Get PDFThe cucumber (Cucumis sativus L.) is an important crop worldwide. In the present study, the molecular genetic diversity of 131 Spanish accessions was analyzed using 23 simple sequence repeat (SSRs). Eighteen of these SSRs were polymorphic; the mean number of alleles, mean observed heterozygosity and mean polymorphic information content were 3.2, 0.065 and 0.229, respectively. Seven SSRs showed a polymorphic information content (PIC) ranging from 0.31 to 0.44, therefore they were reasonably informative. Around 60% of the alleles showed a frequency higher than 0.05, and only one allele in the SSR31399 showed a frequency lower than 0.01. In addition, three accession-specific alleles were found. A high proportion of variation among accessions was obtained. In no case all plants of any accession showed the same genotype and only 18 of 131 Spanish accessions had at least two plants with the same genotype. A cluster analysis did not show any relation with morphological types or geographical area. Therefore, these results demonstrated that molecular diversity of the cucumber did not reflect its phenotypic variability. Finally, this study provided information for the rationalization of the cucumber collection of the COMAV. Morphological traits, origin and molecular data were taken into account to select 47 accessions, six belonging to ‘French’ type, 15 to ‘Long’ type, and 24 to ‘Short’ type. Phenotypic and molecular variability contained in the complete collection was conserved in the selected accessions
Descriptive epidemiology of endemic Classical Swine Fever in Cuba
Get PDFIn Cuba, Classical Swine Fever (CSF) has become an endemic disease since 1993 with several outbreaks each year despite the compulsory vaccination program implemented. To deepen the disease characterization is essential for improving the CSF control measures and to achieve its eradication. The aim of this study was to describe the epidemiological characteristics of CSF occurrences in Cuba during a seven-year period within the endemic situation. Data on CSF occurrence from January 2010 to December 2016 were analyzed. The seven-year period shows a tendency of the number of affected premises to increase (r=0.31, p=0.005) over time (month). Directional distribution (1SD ellipse) indicated a great dispersion of affected premises by year across the country with a trend to a higher occurrence to the west. It was demonstrated by the negative correlation (r=-0.893, p=0.007) between the longitude of the mean center of the ellipses over the years. The Kernel density indicated that the disease was spatially distributed across the whole country, but four hot spots were found in the western (Pinar del Río and Artemisa) and eastern (Guantánamo and Holguín) regions. The clinical sign most frequently reported in affected premises was fever, followed by loss of appetite, conjunctivitis, and diarrhea. The most frequent observed clinical signs were non-specific, which complicates the disease recognition in the field. The obtained results have a practical importance for improving the efficiency of the CSF control program implemented in the country and contribute to enhance epidemiological surveillance taking into account the risk based principles
Short communication: Morphometric characterization of Lidia cow (Bos taurus) reproductive apparatus
Get PDFTo study Lidia cow reproductive apparatus traits, a total of 90 organs were collected after slaughtering the cows from different Bos taurus breeds: (i) Lidia cattle breed - Brava dos Açores population (n=10) and Domecq lineage (n=11); (ii) Holstein Friesian females – 10-14-month-old heifers (n=15); 15-20-month-old heifers (n=10), 21-19-month-old heifers (n=18), and (iii) cows ≥ 30 months (n=26). The length and width were measured for five portions of the female reproductive apparatus (vulva and vagina, cervix, uterine body, uterine horns and ovaries). One-way ANOVA was performed with Tukey test. The level recognized to assume differences was p<0.05 to less. Differences were not shown between Lidia groups. In general, the Lidia cow reproductive apparatus was small in size that that of the matured cows in terms of all traits, with the exception of cervix rings (5.10 ± 0.17 rings) with p≤0.01 for all the groups (averages ranged from 3.33 ± 0.11 rings to 3.50 ± 0.15 rings). The vulva and vagina (L= 27.31 ± 0.53 cm; W=2.07 ± 0.14 cm), the uterine body width (3.01 ± 0.18 cm) and the uterine horns (L= 12.24 ± 0.32; W= 1.13 ± 0.10) showed were smaller in size than those of the evaluated heifers from HF breed that ranged in age from 10 to 14 months (p≤0.01). This study was the first to perform a morphometric characterization on the Lidia cow reproductive apparatus, and the results provide useful information for understanding reproductive approaches to be used with this breed
