Identification of antibiotic and antixenotic resistance to Helicoverpa armigera (Lepidoptera: Noctuidae) in chickpea

Five short-medium duration desi (small seeded) and 5 medium-long duration kabuli (large seeded) chickpea, Cicer arietinum L., genotypes were screened in the laboratory for antibiosis to Helicoverpa armigera Hübner. Larvae were reared on either chickpea leaves or on pods containing green seeds. Significant variation among the desi genotypes was found for pupal weight and larval survival. Pupae resulting from larvae reared on either pods or leaves of 'ICCV 7' weighed substantially less than those for larvae reared on the susceptible controls, 'Annigeri' and ICC 3137. Pupae of larvae reared on leaves of ICC 506 weighed substantially less than those reared on ICC 3137. There was no variation in the measured parameters for larvae reared on the kabuli chickpea genotypes. In general, pupae of larvae reared on chickpea pods were heavier and developed more quickly than those reared on chickpea leaves. Seven (3 short-medium desi, 2 long duration desi, and 2 long duration kabuli) genotypes were screened in the field for ovipositional antixenosis to H. armigera. Fewer eggs were recorded on ICC 506 than the susceptible controls in both years of the study. These observations were corroborated in laboratory studies of H. armigera oviposition behavior. There was no evidence for resistance to H. armigera in any of the long duration genotypes and it is concluded that long duration genotypes do not express the same level of resistance to H. armigera outside the agroecological zone in which they are normally cultivated

Comparison of the efficacy of chemical control and Helicoverpa NPV for the management of Helicoverpa armigera (Hübner) on resistant and susceptible chickpea

The influence of host-plant resistance on the efficacy of NPV and quinalphos as mortality factors in Helicoverpa armigera Hübner populations on chickpea was examined in the field in 1993 and 1994. The effects of chickpea genotype and NPV or quinalphos were not independent. In 1994 quinalphos had a greater effect on the density of large H. armigera larvae on susceptible genotypes than on the resistant genotype (ICC 506). In 1993, NPV had greater effect on the density of large larvae on susceptible genotypes than on ICC 506. In 1993, the yields of NPV-treated susceptible genotypes were significantly greater than those in the quinalphos treatment or control. In 1994, the yields of susceptible genotypes treated with NPV or quinalphos were similar and significantly greater than those in the control. Yields of ICC 506 were similar in the treatments and control. Further studies are required to determine the factors influencing the compatibility of host-plant resistance with quinalphos or NPV; and to examine the potential for increasing the efficacy of these mortality factors when they are used in conjunction with Helicoverpa resistant chickpea

Cardiovascular-renal axis disorders in the domestic dog and cat: a veterinary consensus statement

OBJECTIVES There is a growing understanding of the complexity of interplay between renal and cardiovascular systems in both health and disease. The medical profession has adopted the term "cardiorenal syndrome" (CRS) to describe the pathophysiological relationship between the kidney and heart in disease. CRS has yet to be formally defined and described by the veterinary profession and its existence and importance in dogs and cats warrant investigation. The CRS Consensus Group, comprising nine veterinary cardiologists and seven nephrologists from Europe and North America, sought to achieve consensus around the definition, pathophysiology, diagnosis and management of dogs and cats with "cardiovascular-renal disorders" (CvRD). To this end, the Delphi formal methodology for defining/building consensus and defining guidelines was utilised. METHODS Following a literature review, 13 candidate statements regarding CvRD in dogs and cats were tested for consensus, using a modified Delphi method. As a new area of interest, well-designed studies, specific to CRS/CvRD, are lacking, particularly in dogs and cats. Hence, while scientific justification of all the recommendations was sought and used when available, recommendations were largely reliant on theory, expert opinion, small clinical studies and extrapolation from data derived from other species. RESULTS Of the 13 statements, 11 achieved consensus and 2 did not. The modified Delphi approach worked well to achieve consensus in an objective manner and to develop initial guidelines for CvRD. DISCUSSION The resultant manuscript describes consensus statements for the definition, classification, diagnosis and management strategies for veterinary patients with CvRD, with an emphasis on the pathological interplay between the two organ systems. By formulating consensus statements regarding CvRD in veterinary medicine, the authors hope to stimulate interest in and advancement of the understanding and management of CvRD in dogs and cats. The use of a formalised method for consensus and guideline development should be considered for other topics in veterinary medicine

Cephalic salt gland evolution in Mesozoic pelagic crocodylomorphs

Secondarily marine tetrapod lineages have independently evolved osmoregulatory adaptations for life in salt water but inferring physiological changes in extinct marine tetrapods is difficult. The Mesozoic crocodylomorph clade Thalattosuchia is unique in having both direct evidence from natural endocasts and several proposed osteological correlates for salt exocrine glands. Here, we investigate salt gland evolution in thalattosuchians by creating endocranial reconstructions from CT scans of eight taxa (one basal thalattosuchian, one teleosauroid, two basal metriorhynchoids and four metriorhynchids) and four outgroups (three extant crocodylians and the basal crocodyliform Protosuchus) to identify salt gland osteological correlates. All metriorhynchoids show dorsolateral nasal cavity expansions corresponding to the location of nasal salt glands in natural casts, but smaller expansions in teleosauroids correspond more with the cartilaginous nasal capsule. The different sizes of these expansions suggest the following evolutionary sequence: (1) plesiomorphically small glands present in semi-aquatic teleosauroids draining through the nasal vestibule; (2) moderately sized glands in the basalmost metriorhynchoid Pelagosaurus; and (3) hypertrophied glands in the clade comprising Eoneustes and metriorhynchids, with a pre-orbital fenestra providing a novel exit for salt drainage. The large gland size inferred from basal metriorhynchoids indicates advanced osmoregulation occurred while metriorhynchoids were semi-aquatic. This pattern does not precisely fit into current models of physiological evolution in marine tetrapods and suggests a unique sequence of changes as thalattosuchians transitioned from land to sea.Fil: Cowgill, T.. University of Edinburgh; Reino UnidoFil: Young, M.. University of Edinburgh; Reino UnidoFil: Schwab, J.. University of Edinburgh; Reino UnidoFil: Walsh, S.. National Museum Of Scotland; Reino UnidoFil: Witmer, Lawrence. Ohio University; Estados UnidosFil: Herrera, Laura Yanina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Dollman, K.. University of the Witwatersrand; SudáfricaFil: Turner, A. H.. State University of New York. Stony Brook University; Estados UnidosFil: Brusatte, S.. University of Edinburgh; Reino Unid

Mechanism of Resistance to Helicoverpa armigera (Lepidoptera: Noctuidae) in Chickpea: Role of Oxalic Acid m Leaf Exudate as an Antibiotic Factor

Mechanisms of resistance to Helicoverpa armigera Hübner in chickpea, Cicer arietinum L., were investigated. Inhibition of larval growth occurred in a feeding test using the leaves of chickpea genotypes, which had previously been identified as having resistance to H. armigera. A feeding test using unwashed and washed leaves revealed that the substance responsible for the growth inhibition was water soluble and present on the surface of the leaves. Acid components of the leaf exudate were analyzed by high-performance liquid chromatography. Oxalic acid and malic acid were detected as major components in all 4 genotypes that were analyzed. Genotypes resistant to H. armigera accumulated more oxalic acid on the leaves than susceptible genotypes. Oxalic acid showed significant growth inhibition on H. armigera larvae when included in a semi-artificial diet. The accumulation of oxalic acid is considered to be one of the mechanisms of H. arnigera resistance in chickpea. Inhibition of larval growth by oxalic acid was not caused by antifeedant effects but was more likely attributable to antibiosis. Malic acid had no effect on larval growth

Roles of oxalic and malic acids in chickpea trichome exudate in host-plant resistance to helicoverpa armigera

Effects of malic acid and oxalic acid on oviposition of Helicoverpa armigera were investigated in a laboratory cage choice experiment. Malic acid stimulated oviposition at a concentration of 0.6 μmol/cm2 but inhibited it at 3.4 μmol/cm2. Oxalic acid showed neither stimulation nor inhibition of oviposition at 0.25–1.7 μmol/cm2. Correlations between the amount of these acids in trichome exudate on leaf and pod surface and H. armigera populations and pod damage were investigated in a field experiment using 14 chickpea genotypes. Malic acid on the leaves stimulated oviposition during the vegetative and flowering stages, when its concentration was 0.1–0.7 μmol/cm2. Later, during the podding stage there was no significant correlation between either egg density or pod damage and malic acid levels. However, there was a significant negative correlation between pod damage and oxalic acid levels. Oxalic acid, which had been reported to have an antibiotic effect on H. armigera larvae, has an important role in resistance to this pest in chickpea. The length of the podding period was also a factor influencing the extent of pod damage; a longer podding period resulted in prolonged exposure to H. armigera attack and more pod damag