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A leishmaniose visceral (LV) está entre as mais importantes doenças transmitidas por vetores que ocorrem no Brasil, principalmente devido ao seu caráter zoonótico. Atualmente, está presente em quase todo o território brasileiro, e seu controle é um desafio tanto para médicos veterinários como para agentes de saúde pública. O agente etiológico da doença é a Leishmania infantum (syn chagasi), e o principal vetor no Brasil é a Lutzomyia longipalpis. De todos os animais identificados como reservatórios da LV, o cão é considerado o reservatório doméstico mais importante. Apesar da doença já ter sido identificada em gatos, o papel epidemiológico desta espécie animal ainda é incerto. O presente artigo apresenta uma breve revisão sobre a situação epidemiológica da doença, a sua forma de transmissão, os aspectos clínicos nos cães e gatos, bem como possíveis fatores de risco associados à ocorrência da doença no Brasil.

The identification and location of sources of genetic resistance to plant diseases are important contributions to the development of resistant varieties. The combination of different sources and types of resistance in the same genotype should assist in the development of durably resistant varieties. Using a doubled haploid (DH), mapping population of barley, we mapped a qualitative resistance gene ( Rpsx) to barley stripe rust in the accession CI10587 (PI 243183) to the long arm of chromosome 1(7H). We combined the Rpsx gene, through a series of crosses, with three mapped and validated barley stripe rust resistance QTL alleles located on chromosomes 4(4H) (QTL4), 5(1H) (QTL5), and 7(5H) (QTL7). Three different barley DH populations were developed from these crosses, two combining Rpsx with QTL4 and QTL7, and the third combining Rpsx with QTL5. Disease severity testing in four environments and QTL mapping analyses confirmed the effects and locations of Rpsx, QTL4, and QTL5, thereby validating the original estimates of QTL location and effect. QTL alleles on chromosomes 4(4H) and 5(1H) were effective in decreasing disease severity in the absence of the resistance allele at Rpsx. Quantitative resistance effects were mainly additive, although magnitude interactions were detected. Our results indicate that combining qualitative and quantitative resistance in the same genotype is feasible. However, the durability of such resistance pyramids will require challenge from virulent isolates, which currently are not reported in North America.

Our results demonstrated that the presence of other infectious agents may lead to cross-reactivity on leishmaniasis serological tests.

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Laboratory, greenhouse, and field studies with Euschistus heros (F.) and Nezara viridula (L.) (Heteroptera: Pentatomidae) in northern Paraná, Brazil, demonstrated greater survival and longevity with E. heros than N. viridula when fed the weed Acanthospermum hispidum DC. (Compositae). E. heros was better adapted to A. hispidum than N. viridula but neither species reproduced on this plant. Stink bugs moved from soybean to A. hispidum mainly during mid‐March to mid‐April when soybean plants matured. The infestation reached 60 and 100% with a maximum of ca. 3 and 10 stink bugs/plant in 1988 and 1989, respectively. Surprisingly, E. heros and N. viridula, which are normally seed‐feeders, strongly preferred the high moisture stems of A. hispidum. Both species demonstrated similar feeding frequencies. These results suggest that in northern Paraná, the common weed A. hispidum functions as a temporary host providing water and nutrients to those two pentatomid pests of soybean. Finally, both species do not seem to recognize A. hispidum as an unsuitable or perhaps toxic plant.