RESUMO
In 2008 and 2009, vine decline symptoms were observed in three watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai) fields located in the municipalities of Mossoró (Rio Grande do Norte State) and Quixeré (Ceará State) in northeastern Brazil. Symptoms included yellowing of crown leaves just prior to harvest and collapse of many of the vines. Mean maximum daily temperatures for the first and second half of the season were 28.6 and 25.1°C, respectively. Affected plants exhibited necrotic root systems and lacked most of the secondary and tertiary feeder roots. Numerous perithecia on the roots contained asci and ascospores characteristics of Monosporascus cannonballus Pollack & Uecker (1,2). Small pieces of primary and secondary roots were surface disinfected and plated onto potato dextrose agar (PDA) medium with 0.5 g liter-1 of streptomycin sulfate and incubated for 7 days at 25°C in the dark. Hyphal tips from all colonies were transferred to PDA and further incubated for 30 to 40 days at 25°C in the dark for subsequent growth and sporulation. Isolations consistently yielded colonies of white mycelium, which became dark grayish after 10 to 15 days, and perithecia with one-spored asci. The internal transcribed spacer regions of ribosomal DNA of isolates 18-5 and 19-1 were sequenced (GenBank Accession Nos. GQ891544 and GQ891545). These sequences were identical to sequences of M. cannonballus (GenBank Accession Nos. AM167936 and AM167937). Pathogenicity of these two isolates was confirmed on watermelon cv. Crimson Sweet in a greenhouse maintained at 25 to 30°C. Inoculum was produced in a sand-oat hulls (Avena sativa) medium (0.5 liter of sand, 46 g of ground oat hulls, and 37.5 ml of distilled water) and incubated at 25°C for 1 month. CFU were quantified by serial dilution using 1% hydroxyethyl cellulose. A sterilized mixture of equal portions (vol/vol) of sand and peat moss was used to fill 17-cm-diameter plastic pots and inoculum was added to produce an inoculum concentration of 20 CFU g-1. Five watermelon seeds planted in each pot were later thinned to one seedling per pot. There were five replicated pots for each treatment with an equal number of noninfested pots. Plants were evaluated for disease 45 days after sowing. All isolates of M. cannonballus were highly aggressive and caused severe root necrosis compared with the noninoculated controls. M. cannonballus was reisolated from symptomatic plants, confirming Koch's postulates. In 2004, M. cannonballus was reported in the same Brazilian cucurbit-growing areas causing root rot and vine decline of muskmelon (Cucumis melo L.) (3), but to our knowledge, this is the first report of M. cannonballus on watermelon in Brazil. References: (1) R. D. Martyn and M. E. Miller. Plant Dis. 80:716, 1996. (2) F. G. Pollack and F. A. Uecker. Mycologia 66:346, 1974. (3) R. Sales Jr. et al. Plant Dis. 88:84, 2004.
RESUMO
The ovarian characteristics of pregnant and non pregnant zebu cows (Bos taurus indicus) were studied. The ovaries were obtained in slaughterhouses, identified and divided into: group I, non pregnant animals (GI, n=43) and group II, pregnant animals (GII, n=43). The ovaries were measured and cut in their lenght for measuring and evaluation of the corpus luteum (CL) characteristics. For the GI the measures for the left ovary were 2.5 ± 0.70, 1.61 ± 0.32 and 1.22 ± 0.39cm, respectively for length, width and thickness, and 2.62 ± 0.54, 1.71 ± 0.36 and 1.21 ± 0.31cm for the right ovary. For the GII the measures for the left ovary were 2.78 ± 0.48, 1.80 ± 0.33 and 1.23 ± 0.35cm, respectively for length, width and thickness and 2.84 ± 0.50, 1.74 ± 0.45 and 1.21 ± 0.40cm for the right one. Both groups presented 51.2 percent of CL in the left ovary and 48.8 percent in the right one, with high incidence of CL enclosed and without cavity. The mean for the diameter of the CL was 1.59±0.32cm for GI e 1.82±0.35cm for GII. The results suggest the need to consider carefully the size of the ovary and the enclosed characteristics of the CL when performing gynecological examination of zebu cows via rectal palpation
Assuntos
Animais , Feminino , Bovinos , Corpo Lúteo , OvárioRESUMO
The preservation of the goat genital organs with a fixed solution of paraformaldehyde 10 per cent and a saturated solution of Bouin during 4, 8, 12 and 24 hours of fixation, included in paraffin and stained with hematoxylin-eosin was evaluated. The Bouin solution with four hours of fixation showed to be the best protocol of fixation for the ovary, oviduct, uterus and vagina, resulting in little tissue retraction and better cellular integration when compared to the other fixing times (8, 12 and 24 hours). The fixation with paraformaldehyde showed significant alteration in the tissue architecture of the oviduct and vagina. Althouh paraformaldehyde is not the most adequate solution for the goat genital system preservation, its use can be considered in the absence of Bouin solution
