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Vera Lygia El Id Bárbara Vale da Costa Daiane Salete Broch Mignoni Marina Belloni Veronesi Kelly Simoes Marcia Regina Braga Nelson Augusto dos Santos Junior 《林业研究》2015,26(2):339-346
Sesbania virgata(Cav.) Pers.is a pioneer species native to South America able to release allelochemicals that affect germination and development of other plant species.The aim of this work was to evaluate the allelopathic effect of S.virgata on the germination and development of co-occurring species from gallery forest and on agronomic species.Two forest native species,Enterolobium contortisiliquum(Vell.) Morong and Sapindus saponaria L.,and two agronomic species(these as control),Oryza sativa L.and Solanum lycopersicum L.were used in the lab and greenhouse assays with seeds and leaf extracts of S.virgata.Agronomic species were more affected than native species when co-germinated with seeds of S.virgata.The germination percentage and speed germination index of the agronomic species were reduced in both in vitro and greenhouse assays.In the same assays,the seeds of native species showed no significant differences in the parameters mentioned.However,the initial growth of the four species assayed was affected,with reduction in plant length and shoot diameter followed by significant reduction in plantlet shoot and root weights.In the assays with irrigation of S.virgata leaf extracts,no significant inhibitory effects on germination were observed for all species.Height and shoot diameter of the native species were not affected by the leaf extracts,nor were fresh and dry weights.However,these parameters increased in the agronomic species as they were irrigated with leaf extracts.Based on our data we conclude that seed leachates of S.virgata affect germination and seedling development of other species,suggesting that its invasive behavior is due mainly to seed allelochemicals.Although with less pronounced effects on native species,allelopathy of S.virgata might also influence Interspecific competition in its natural environment. 相似文献
54.
In order to establish an appropriate breeding programme, the reproductive system of a population of Lolium rigidum Gaud, from Sardinia was analyzed to determine the mechanisms operational in this species. A dual approach was adopted of genotype assay, exploiting the polymorphism at the Pgi-2 locus, and an assessment of the effects of inbreeding on agronomic characters. The statistical analysis showed highly significant differences for the number of plants due to selfing among the 35 progenies obtained by controlled crossing of genotypes homozygous for different alleles at the Pgi-2 locus. The greatest inbreeding effect was on dry matter yield. Although at a bulk population level the species is outbreeding, highly self-compatible plants can be found within this naturally-derived population. 相似文献
55.
Rota A. Veronesi M. C. Volpe S. Riccardi A. Battocchio M. 《Veterinary research communications》2007,31(1):197-199
Veterinary Research Communications - Rota, A., Veronesi, M.C., Volpe, S., Riccardi, A. and Battocchio, M., 2007. Estradiol-17β, progesterone and testosterone plasma concentrations during... 相似文献
56.
Up to date, information concerning the Anaplasma phagocytophilum infection in fallow deer is scant, therefore, to verify its prevalence in these ungulates serological and PCR screenings were performed on blood of 72 fallow deer hunted in a Central-Northern Italian preserve. Molecular analyses were also performed on 90 ticks removed from the animals.A. phagocytophilum infection in fallow deer was confirmed in 20 out 72 by IFA assay and in 11 out 72 by PCR. The sequence obtained revealed a complete genetic homology among the blood samples and strong degrees of homology with other European isolates. Considering the 90 ticks collected we found that 7.3% of Ixodes ricinus harboured A. phagocytophilum specific DNA. The data obtained confirmed that fallow deer can be a competent host for A. phagocytophilum and, therefore, that may represent a biological reservoir playing an important role in the epidemiological scenarios of the infection, in the geographical areas where is widespread. 相似文献
57.
E. Veronesi G.J. Venter K. Labuschagne P.S. Mellor S. Carpenter 《Veterinary parasitology》2009,163(4):370-373
This laboratory study investigates the sub-adult developmental cycle of field collected Culicoides (Avaritia) imicola Kieffer (Diptera; Ceratopogonidae). The period required from blood-feeding field-collected females to the production of progeny adults occupied 34–56 days at 20 °C, 15–21 days at 25 °C and 11–16 days at 28 °C, demonstrating clear temperature dependence. When reared at 28 °C, C. imicola demonstrated higher variability in fecundity (between 2.4 and 20.6 eggs/female) and lower hatching rates (50.0–62.2%), although larval survival rates to pupation were low at all temperatures (20–30%). Similarly, the mean emergence rate from pupae was the highest at lower temperatures. These results highlight the difficulty in establishing and maintaining a laboratory colony of this species from field-collected material and results are discussed in reference to future research directions that may aid this process. 相似文献
58.
Rebecca Veronesi Marina Morach Ella Hübschke Claudia Bachofen Roger Stephan Magdalena Nüesch‐Inderbinen 《Zoonoses and public health》2021,68(1):8-11
Hepatitis E virus (HEV) is the causative agent of an acute and in most cases self‐limiting hepatitis. Of the four major HEV genotypes that infect humans, genotype 3 and 4 are zoonotic and have been identified in humans but predominantly in pigs and wild boar, which are considered the main reservoirs. However, the known host range of zoonotic HEV may be increasing to comprise additional species, including companion animals. Several studies have identified contact with dogs as a risk factor for HEV infection in humans, yet information on the occurrence of HEV in Swiss dogs is lacking. To examine a possible risk of exposure, this study was designed to assess the seroprevalence of HEV in 84 Swiss dogs. Serum and plasma samples collected from four veterinary clinics were screened for HEV‐specific antibodies by HEV‐antibody ELISA test kit. In addition, information of 22 dogs regarding the country of origin, the type of dog feed and any history of hunting was recorded. Samples from seropositive animals were also screened for the presence of HEV RNA by quantitative real‐time RT‐PCR (qRT‐PCR). Overall, 38% (32 of 84) of the dogs tested seropositive for anti‐HEV, indicating exposure to HEV. Among the 22 dogs for which information was available, HEV‐specific antibodies were detected in three of five dogs that were born abroad, in one of two dogs that were fed a raw meat‐based diet, and in one hunting dog. No viral RNA could be detected in any of the serum and plasma samples; thus, the genotype of the strains remained undetermined. This study provides further evidence for canine exposure and susceptibility to HEV and highlights the need to further assess the risks of HEV transmission to humans with contact to dogs. 相似文献
59.
The objective of the present study was to evaluate the fertility of tetraploid plants obtained from diploid mutants that produced
2n gametes via bilateral (BSP) and unilateral sexual polyploidization (USP) schemes. Controlled matings between selected plants
from BSP and USP were carried out according to a complete diallel. The level of male and female fertility of each plant was
estimated within full-sib, half-sib and non-inbred crosses. Crosses with unrelated self-fertile and male-sterile testers were
also performed. Pollen size and stainability were determined by acetocarmine staining. The number of ovules per ovary was
counted and the callose deposition within ovules examined to evaluate embryo sac fecundity. Cross-fertility was generally
much higher for USP than BSP plants (on average, 0.3 vs. 0.03 seeds per flower pollinated). Both male and female fertility
were inversely related to the inbreeding level of cross combinations. The in vitro pollen germinability was positively correlated
to male fertility of BSP plants. The level of in vivo embryo sac sterility was not correlated to female fertility in either
BSP or USP plants. Female fertility was restored in both BSP and USP groups when plants were crossed with unrelated tetraploid
testers. Male fertility also increased in USP plants but remained rather low in the BSP plants. Scaling up the ploidy level
by means of 2n gamete union resulted in tetraploid plants with low fertility. In particular, the BSP process yielded virtually
self-sterile and highly cross-sterile plants. The well documented positive effect of sexual tetraploidization on forage yield
was accompanied by worsening of fertility traits.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
60.
F. Veronesi 《Plant Breeding》1990,105(4):321-326
The objective of the study was to determine the effect of selection for large root dimension on root and shoot characteristics of an Italian variety of Lolium perenne L. (cv. ‘Vejo’). Two cycles of recurrent restricted phenotypic selection (RRPS) were carried out in 1983 and 1984 at Perugia (Italy). In each cycle, 20 out of 1,500 plants were selected and intercrossed under isolation. In 1985, 120 plants from‘Vejo selected’ and an equal number of plants from‘Vejo’ initial seed-lot were grown hydroponically for 92 days; at the end of the experiment, the plants were measured for their number of leaves and stems, leaf length, length of the longest root, root volume and shoot and root dry weight. Sufficient genetic variability existed among plants of cv. ‘Vejo’ to allow highly significant responses to selection for root dimension (+25 % in root length, +39 % in root volume, + 67 % in root dry weight and +31 % in root: shoot dry weight ratio). Furthermore, two cycles of RRPS for root dimension did not show negative responses of the above-ground parts of the plant. 相似文献