Possible association of glaucoma with pectinate ligament dysplasia and narrowing of the iridocorneal angle in Shiba Inu dogs in Japan

The purpose of the study was to describe the shape of the pectinate ligament (PL) and to estimate the width of the iridocorneal angle (ICA) in glaucomatous and non-glaucomatous eye of Shiba Inu dogs in Japan. One hundred fourteen Shiba Inu dogs were presented to the Veterinary Medical Center at the University of Tokyo between June 1998 and June 2003. Among these, 46 dogs had glaucoma; the remaining 68 dogs were presented for routine vaccinations or heartworm testing and were used as a control population. Complete ophthalmic examination and gonioscopy were performed in all the dogs. PL and ICA were evaluated by gonioscopy and goniophotographs. Of the 46 dogs with glaucoma, 17 (37%) were affected bilaterally, and 29 (63%) were affected unilaterally. Of the 29 dogs with unilateral glaucoma, the ICA of the normotensive eye was slightly narrow in 2 eyes (7%), narrow in 12 eyes (41%), and closed in 15 eyes (52%). Among the normotensive control group, the ICA was open in 13 dogs (19%), slightly narrow in 29 (43%), narrow in 22 (32%), and closed in 4 (6%). In dogs with narrow and slightly narrow ICAs, the PLs were thickened, and in some cases, formed a solid sheet. The majority of dogs with glaucoma had changes in both ICA and PL. A narrow or slightly narrow ICA was also detected in the majority of normotensive control dogs. This study suggests that ICA narrowing and PL thickening is a common abnormality in Shiba Inu dogs in Japan and may predispose those dogs to glaucoma.     

Improved control of black rot of broccoli caused by <Emphasis Type="Italic">Xanthomonas campestris</Emphasis> pv. <Emphasis Type="Italic">campestris</Emphasis> using a bacteriophage and a nonpathogenic <Emphasis Type="Italic">Xanthomonas</Emphasis> sp. strain

We examined the potential for biological control of black rot of broccoli, caused by Xanthomonas campestris pv. campestris (Xcc), using nonpathogenic Xanthomonas sp. strain 11-100-01 (npX) mixed with bacteriophage XcpSFC211 (pXS). Inoculation of intact broccoli plants in greenhouse trials with either npX or pXS did not control black rot. After injured plant inoculation, however, npX alone or npX with pXS significantly controlled black rot. When a mixed suspension of npX with pXS was placed on a membrane filter, then washed with distilled water and air-dried, a substantial amount of pXS adsorbed to the surface of npX. In a field trial, broccoli plants were sprayed with a suspension of npX with pXS, then inoculated with Xcc. A meta-analysis of the results from five field trials showed an integrated risk ratio (IRR, the ratio of disease incidence in inoculated broccoli plants to the incidence in control plants) of 0.69 after treatment with only npX and 0.59 with npX with pXS, indicating that black rot incidence was significantly reduced by each treatment. The difference between these two treatments was also significant. IRR was 1.24 when comparing suppression by npX with pXS and that by basic copper sulfate wettable powder; thus, their control was comparable. The combination of npX with pXS improved the preventive effect against black rot. This is the first report describing that a nonpathogenic Xanthomonas sp. strain mixed with a bacteriophage effectively controlled black rot of broccoli in field trials.     

Plant growth inhibitory activity and active substances with allelopathic potential of cogongrass (Imperata cylindrica) rhizome

Cogongrass (Imperata cylindrica [L.] Raeusch.) is a perennial rhizomatous grass that belongs to the Poaceae and is widely distributed in tropical, subtropical and temperate regions over the world. The grass is strongly invasive and is suggested to have allelopathic potential. However, limited information is available on allelopathic substances in cogongrass rhizomes. Therefore, the allelopathic potential and substances in cogongrass rhizomes were investigated. The extracts of cogongrass rhizomes inhibited the root and shoot growth of barnyard grass, ryegrass, timothy, cress, lettuce and alfalfa. After bioassay‐guided separations of the extracts, four growth inhibitory substances, 5‐methoxyflavone, 5,2′‐dimethoxyflavone, methyl caffeate and abscisic acid, were isolated. 5‐Methoxyflavone, 5,2′‐dimethoxyflavone and methyl caffeate significantly inhibited the root and shoot growth of cress at concentrations of ≥0.03–0.3 m mol L^?1 and their concentrations required for 50% growth inhibition were 0.079–0.24, 0.23–1.1 and 0.59–0.88 m mol L^?1, respectively. The other isolated substance, abscisic acid, has been reported to have strong growth inhibitory activity. Its concentrations required for 50% growth inhibition on cress were 0.31–0.61 μ mol L^?1. The present study suggests that cogongrass rhizomes might have allelopathic potential and that those four substances might contribute to that potential.