Detection of rice panicle blast with multispectral radiometer and the potential of using airborne multispectral scanners

ABSTRACT Rice reflectance was measured to determine the spectral regions most sensitive to panicle blast infection. Reflectance increased in the 430- to 530-, 580- to 680-, and 1,480- to 2,000-nm regions at the dough stage both in the laboratory and the field as the percentage of diseased spikelets increased. The wavebands of the greatest sensitivity were in the visible region, located near 485 and 675 nm. After the yellow-ripe growth stage, near-infrared rather than visible reflectance responded to panicle blast infections. Ratios of rice reflectance were evaluated as indicators of panicle blast. R470/R570 (reflectance at 470 nm divided by reflectance at 570 nm), R520/R675, and R570/R675 decreased significantly as the incidence of panicle blast increased at the dough stage. At the yellow-ripe stage, R550/R970 and R725/R900 were used to estimate panicle blast severity as measured in terms of the percentage of diseased spikelets. According to the simulation that uses ground-based sensor data, airborne multispectral scanners may be effective in detecting the occurrence of panicle blast using a band combination of 530- to 570- and 650- to 700-nm regions at the dough stage.     

The Helper Component-Proteinase of Sweet potato feathery mottle virus Facilitates Systemic Spread of Potato virus X in Ipomoea nil

ABSTRACT When Ipomoea nil was coinfected with Sweet potato feathery mottle virus (SPFMV), a member of the genus Potyvirus, and Potato virus X (PVX) typical symptoms caused by PVX were observed on those by SPFMV on the first upper true leaves at 14 days postinoculation (dpi). On the other hand, no PVX-induced symptoms were observed on the first upper true leaves at 14 dpi when plants were infected with PVX alone. In the case of coinfection with PVX and SPFMV, PVX RNA was detected not only in the inoculated cotyledonary leaves but also in the first upper true leaves at 14 dpi. In the case of single infection with PVX, PVX RNA was detected in the inoculated cotyledonary leaves but not in the first upper true leaves at 14 dpi. The accumulation of SPFMV remained unchanged, regardless of whether the inoculum consisted of SPFMV alone or a mixture of SPFMV and PVX. Although recombinant PVX engineered to express the helper component-proteinase (HC-Pro) of SPFMV (PVX.HC) enhanced symptoms severity in Nicotiana benthamiana, PVX.HC induced the synergism characterized by an enhanced viral movement in Ipomoea nil. Immunofluorescence microscopic examination revealed that the HC-Pro was present in phloem of SPFMV-infected I. nil. These results suggest that SPFMV HC-Pro acts as an enhancer of long distance movement for PVX in I. nil.     

Effects of medetomidine and xylazine on intraocular pressure and pupil size in healthy Beagle dogs

ObjectiveTo determine the effects of intramuscular (IM) administration of medetomidine and xylazine on intraocular pressure (IOP) and pupil size in normal dogs.Study designProspective, randomized, experimental, crossover trial.AnimalsFive healthy, purpose-bred Beagle dogs.MethodsEach dog was administered 11 IM injections of, respectively: physiological saline; medetomidine at doses of 5, 10, 20, 40 and 80 μg kg⁻¹, and xylazine at doses of 0.5, 1.0, 2.0, 4.0 and 8.0 mg kg⁻¹. Injections were administered at least 1 week apart. IOP and pupil size were measured at baseline (before treatment) and at 0.25, 0.50, 0.75, 1, 2, 3, 4, 5, 6, 7, 8 and 24 hours post-injection.ResultsA significant decrease in IOP was observed at 6 hours after 80 μg kg⁻¹ medetomidine compared with values at 0.25 and 0.50 hours, although there were no significant changes in IOP from baseline. In dogs treated with 8.0 mg kg⁻¹ xylazine, significant reductions in IOP were observed at 4 and 5 hours compared with that at 0.25 hours after administration. In dogs treated with 5, 10, 20 and 40 μg kg⁻¹ medetomidine and 0.5, 1.0 and 2.0 mg kg⁻¹ xylazine, there were no significant changes in IOP. Pupil size did not change significantly after any of the medetomidine or xylazine treatments compared with the baseline value.Conclusions and clinical relevanceLow or moderate doses of medetomidine or xylazine did not induce significant changes in IOP or pupil size. In contrast, high doses of medetomidine or xylazine induced significant changes up to 8 hours after treatment, but values remained within the normal canine physiological range. The results of this study suggest a lack of significant change in IOP and pupil size in healthy dogs administered low or moderate doses of xylazine or medetomidine.     

Identification of rRNA gene loci in the wild mouse (Mus musculus molossinus) captured at Hachioji, Tokyo

Mus musculus (M. m.) molossinus has been considered an independent subspecies of Mus musculus. To elucidate the evolutional origin of this subspecies, we carried out double-color FISH using 18s-28s ribosomal DNA and mouse chromosome paint probes. Among eleven rDNA loci detected, five loci on chromosomes 12, 15, 16, 18 and 19 were common to both Mus musculus (M. m.) musculus and M. m. molossinus and the other six loci, on chromosomes 1, 5, 10, 11, 13 and 17, were characteristic in M. m. molossinus. As M. m. molossinus is thought to originate from a hybrid between ancestral colonies of M. m. musculus and Mus musculus castaneus, we supposed that these six rDNA loci might have evolved after geographical isolation of the ancestral hybrid animals from M. m. musculus and M. m. castaneus.     

Reproduction of a Robinia pseudoacacia population in a coastal Pinus thunbergii windbreak along the Kujukurihama Coast, Japan

We investigated reproduction of the clonal tree Robinia pseudoacacia in a Pinus thunbergii windbreak. Microsatellite polymorphism analysis revealed that asexual reproduction through horizontal root elongation and ramet formation was the primary mode of reproduction in this population. Germination experiments indicated that the inability of established genets to produce viable seeds inhibited sexual reproduction. The boundaries between genet areas were relatively distinct, indicating that ramets within genets spatially excluded one another. Analyses of the number of annual rings and thickness of excavated horizontal roots provided new insight regarding photosynthate transfer through horizontal roots. The number of annual rings and thickness were highest for horizontal roots near the base of ramets and decreased along portions far from ramets. This result indicates that the new horizontal root is supplied with photosynthate from the mother ramet for a few years only, and that resource translocation between neighboring ramets within the same clone ceases after several years. Hypotheses about horizontal root expansion and cessation were considered to explain the exclusive distribution pattern of the horizontal root between genets.     

Gel permeation chromatography of anthocyanin pigments from Rosé cider and red wine.

Anthocyanin pigments from rosé cider and red wine, which is a sparkling wine made from apples, were separated by gel permeation chromatography (GPC) using a TSK-GEL Toyopearl HW-40 (F) column with a 6:4 mixture of acetone and 8 M urea (pH 2.0) as the eluent. Under this condition, all phenolic compounds containing monomeric anthocyanins (mainly, cyanidin-3-galactoside; Cyn-3-gal), oligomeric and polymeric anthocyanins, chlorogenic acid, catechin, epicatechin, procyanidin B2 (PB2), and procyanidin C1 (PC1) in the apples and rosé cider were found to elute according to molecular weight. Bleaching of the anthocyanin pigments by SO(2) was gradually effective in the fractions separated by GPC according to elution volume. In the case of rosé cider, the levels of Cyn-3-gal decreased markedly during fermentation and then decreased gradually during maturation. We confirmed that anthocyanin polymers are not detectable in apple juice; these polymers are produced during fermentation and maturation as determined by GPC. The polymeric anthocyanins from red wine could be separated by this method, too.     

Two Amino Acid Substitutions in the Coat Protein of Pepper mild mottle virus Are Responsible for Overcoming the L(4) Gene-Mediated Resistance in Capsicum spp

ABSTRACT The Capsicum spp. L genes (L(1) to L(4)) confer resistance to tobamoviruses. Currently, the L(4) gene from Capsicum chacoense is the most effective resistance gene and has been used widely in breeding programs in Japan which have developed new resistant cultivars against Pepper mild mottle virus (PMMoV). However, in 2004, mild mosaic symptoms began appearing on the leaves of commercial pepper plants in the field which possessed the L(4) resistance gene. Serological and biological assays on Capsicum spp. identified the causal virus strain as a previously unreported pathotype, P(1,2,3,4). PMMoV sequence analysis of the virus and site-directed mutagenesis using a PMMoV-J of the P(1,2) pathotype revealed that two amino acid substitutions in the coat protein, Gln to Arg at position 46 and Gly to Lys at position 85, were responsible for overcoming the L(4) resistance gene.     

Comparisons of ribosomal DNA-internal transcribed spacer sequences and biological features among <Emphasis Type="Italic">Olpidium bornovanus</Emphasis> isolates from Cucurbitaceae-cultivating soil in Japan

The chytrid fungus Olpidium bornovanus is an obligate plant parasite that acts as a vector to transmit Melon necrotic spot virus in cultivated soil. Here, we conducted a molecular phylogenetic analysis of 16 isolates of O. bornovanus taken from soil in which Cucurbitaceae plants had been grown in various locations throughout Japan. The ribosomal DNA and internal transcribed spacer region sequences of the 16 O. bornovanus isolates were divided into four molecular phylogenetic groups, designated O.bor-A to O.bor-D. Biological features of O. bornovanus isolates such as host specificity varied consistently with their molecular phylogenetic groups.