Suitability of different mealybug species as hosts to solitary endoparasitoid,Aenasius arizonensis (Girault) ( = Aenasius bambawalei Hayat)

We investigated the suitability of six mealybug species, namely Phenacoccus solenopsis, Saccharicoccus sacchari, Paracoccus marginatus, Drosicha mangiferae, Nipaecoccus viridis and Ferrisia virgata as hosts to Aenasius arizonensis ( = Aenasius bambawalei). The study was conducted to ascertain a viable parasitic relationship between a parasitoid species and different mealybug hosts. Successful parasitization, complete development of immature stages within the host and adult emergence was observed only in P. solenopsis, whereas, other mealybug species were not found suitable as hosts by the parasitoid in both choice and no-choice tests. The development studies of A. arizonensis on P. solenopsis showed that the mean duration from oviposition to mummy formation was 6.13 days, while, from mummy formation to adult emergence, it was 5.43 and 7.05 days for male and female, respectively. The total development period from oviposition to adult emergence was 11.28 days for males and 13.13 days for females. Female adults (19.96 days) live longer as compared to male adults (7.83 days). Among different mealybug species, P. solenopsis was observed to be the only ecological and fundamental host of A. arizonensis.     

Unraveling the multilevel aspects of least explored plant beneficial <Emphasis Type="Italic">Trichoderma saturnisporum</Emphasis> isolate GITX-Panog (C)

Species of Trichoderma offer an eco-friendly and economical solution to the management of plant pathogens in agricultural crops. The secretion and spectrum of different bioactive molecules by Trichoderma spp. is known to follow adaptive and species/strain behavior, depending upon the edaphic conditions. In present study, GITX-Panog (C), an antagonistic isolate of Trichoderma saturnisporum against Fusarium oxysporum was screened for the production of different glycosyl hydrolases and secondary metabolites. The evaluation of antagonistic isolates for lytic enzymes and secondary metabolites revealed their significance as plant probiotics. Profiling of lytic enzymes such as chitinases and β-glucanases secreted by T. saturnisporum GITX-Panog (C) in the presence of autoclaved mycelium of F. oxysporum and colloidal chitin or laminarin showed increased enzyme activities. Production of bioactive secondary metabolites such as siderophore, peptaibols, 6-pentyl-α-pyrone, and the known potential of these compounds in mineral acquisition and suppression of plant F. oxysporum, revealed the potential significance of Trichoderma saturnisporum isolate GITX-Panog C in agricultural application against biotic and abiotic stresses. The antagonistic isolate also showed significant increases in fresh biomass and seed production in Arabidopsis thaliana in the greenhouse compared to controls. Thus, the current study highlights the multiple attributes of an antagonistic isolate of T. saturnisporum for future agricultural applications as a plant probiotic agent.     

Genetic analysis and conservation of endangered medicinal tree species <Emphasis Type="Italic">Taxus wallichiana</Emphasis> in the Himalayan region

Taxus wallichiana is one of the most important medicinal tree species of the Himalayan region. Leaf and bark of the species yield an important drug called taxol, which is used for treatment of many types of cancer. There is a serious threat to the existence of the species due to over exploitation in its native habitat. Adequate information on the nature and the extent of genetic diversity in this important species is required for developing suitable strategy for its conservation. Random amplified polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP) were used to assess genetic variation in nine natural populations of T. wallichiana from western part of the Himalayan ranges. Both the markers revealed low genetic diversity in these populations. Average heterozygosity for AFLP and RAPD were 0.3715 and 0.3072, respectively. Φ_ST values derived from molecular variance were 0.0855 and 0.1005 for AFLP and RAPD, respectively, whereas the corresponding G_ST values were 0.1796 and 0.2140. Most part of the genetic variation was present within the populations. However, between population variation was low but statistically significant, which suggested that the sampled populations might not constitute a single panmictic population. Cluster analysis and Mantel’s correlation revealed that genetic differentiation broadly followed geographic distribution of the populations. T. wallichiana thus urgently needs to be conserved using both in situ and ex situ conservation approaches.     

Expression of resistance to Atherigona soccata in F1 hybrids involving shoot fly-resistant and susceptible cytoplasmic male-sterile and restorer lines of sorghum

In recent years, cytoplasmic male‐sterility (CMS) has been recognized as a potential danger to the stability of crop production and resistance to insect pests in sorghum. Therefore, the influence of CMS on the expression of resistance to sorghum shoot fly was studied at the ICRISAT, Patancheru, India using the interlard fishmeal technique. The experimental material consisted of 12 restorer, 12 CMS and the maintainer lines, and their 144 F₁ hybrids. Shoot fly‐resistant CMS lines were preferred for oviposition and had more damage because of deadhearts than the corresponding maintainer lines. The hybrids based on shoot fly‐resistant CMS × resistant restorer lines were significantly less preferred for oviposition than the hybrids based on other cross combinations and exhibited the highest frequency (69.1%) of shoot fly‐resistant hybrids. The hybrids based on glossy and trichomed parents had the highest frequency (>90%) of hybrids with glossy and trichome traits, emphasizing the need to transfer these traits into both parents for better expression in the F₁ hybrids. The expression pattern of trichome density, leaf glossiness and leaf sheath pigmentation in the F₁ hybrids and their parents suggested that the interactions between cytoplasmic and nuclear genes possibly control the expression of traits associated with resistance to sorghum shoot fly in the F₁ hybrids.     

A little-leaf disease of Eucalyptus in Kerala,India*

A little-leaf disease of Eucalyptus tereticornis, E. grandis and E. globulus characterized by stunting of plants and considerable reduction in size of leaves and internodes, was recorded during survey of nurseries and plantations in Kerala State. The survey indicated that though the little leaf disease was widespread, its incidence was quite low. Transmission of the symptoms by sap and graft techniques was unsuccessful. However, positive fluorescence and staining of phloem tissues by Dienes' stain indicates that this disease may be caused by mycoplasmalike organisms (MLO).     

Pharmacokinetics and Dosage Regimen of Ceftriaxone in Buffalo Calves

The pharmacokinetics and dosage regimen of ceftriaxone were investigated in buffalo calves (n = 6) following a single intravenous administration of ceftriaxone (10 mg/kg). The elimination rate constant was 0.18 +/- 0.01 h(-1) and the elimination half-life was 3.79 +/- 0.09 h. The apparent volume of distribution (Vd(area)) was 1.40 +/- 0.01 L/kg and the total plasma clearance was 0.26 +/- 0.01 L/(kg h). Approximately 43% of total administered dose of ceftriaxone was excreted in urine within 8 h. To maintain a minimum therapeutic concentration of 1 microg/ml, a satisfactory intravenous dosage regimen of ceftriaxone in buffalo calves is 13 mg/kg repeated at 12 h intervals.     

Depression of lymphocyte responses to phytohaemagglutinin in lambs experimentally infected with bovine respiratory syncytial virus.

Eight lambs were experimentally infected with bovine respiratory syncytial virus (BRSV) and the responses of their peripheral blood lymphocytes to the mitogen phytohaemagglutinin and BRSV antigen compared with that of control lambs injected with tissue culture fluid. The lymphocyte transformation responses to phytohaemagglutinin were significantly reduced five and 10 days after experimental infection with BRSV (P less than 0.05). It appears that these reductions were associated with CD4+ lymphocytes because CD4-enriched lymphocytes obtained five days after infection had more significantly reduced responses to phytohaemagglutinin than those obtained from the same group before infection and from the control group five days after inoculation (P less than 0.01). There were no significant lymphocyte transformation responses to BRSV antigen in both groups of lambs up to 21 days after inoculation (P greater than 0.05).     

A Protective Effect of Vitamin E and Selenium in Ameliorating the Immunotoxicity of Malathion in Chicks

A study was conducted to determine whether a combination of vitamin E and selenium was able to counteract the immunosuppressive effects of chronic toxicity of malathion in chicks. The chicks were divided into three groups. The first group received malathion 10 mg/kg body weight; the second group received the same dose of malathion but was supplemented with vitamin E and selenium for 60 days; and the third group served as the control. The concentration of total immunoglobulins and circulatory immune complexes decreased following the administration of malathion, whereas the supplementation of the diet with vitamin E and selenium partially counteracted this effect. The histopathological changes in the bursa of Fabricius due to malathion were consistent with these findings. Supplementation with vitamin E and selenium partially ameliorated the degenerative changes in the bursa of Fabricius. Sodhi, S., Sharma, A. and Brar, R.S., 2006. A protective effect of vitamin E and selenium in ameliorating the immunotoxicity of malathion in chicks. Veterinary Research Communications, 30(8), 935–942     

Acceptability,growth performance and nutritional status of chickens fed cassava leaf meal (CLM)–based diets

Tropical Animal Health and Production - This study evaluated the effect of feeding cassava leaf meal–based diets on feeding behavioural patterns, growth performance parameters and nutritional...