Importance of incomplete lineage sorting and introgression in the origin of shared genetic variation between two closely related pines with overlapping distributions

Genetic variation shared between closely related species may be due to retention of ancestral polymorphisms because of incomplete lineage sorting (ILS) and/or introgression following secondary contact. It is challenging to distinguish ILS and introgression because they generate similar patterns of shared genetic diversity, but this is nonetheless essential for inferring accurately the history of species with overlapping distributions. To address this issue, we sequenced 33 independent intron loci across the genome of two closely related pine species (Pinus massoniana Lamb. and Pinus hwangshanensis Hisa) from Southeast China. Population structure analyses revealed that the species showed slightly more admixture in parapatric populations than in allopatric populations. Levels of interspecific differentiation were lower in parapatry than in allopatry. Approximate Bayesian computation suggested that the most likely speciation scenario explaining this pattern was a long period of isolation followed by a secondary contact. Ecological niche modeling suggested that a gradual range expansion of P. hwangshanensis during the Pleistocene climatic oscillations could have been the cause of the overlap. Our study therefore suggests that secondary introgression, rather than ILS, explains most of the shared nuclear genomic variation between these two species and demonstrates the complementarity of population genetics and ecological niche modeling in understanding gene flow history. Finally, we discuss the importance of contrasting results from markers with different dynamics of migration, namely nuclear, chloroplast and mitochondrial DNA

Bioactivity of neem oil on Alphitobius diaperinus (Coleoptera: Tenebrionidae) in stored peanut seeds

Amanda da Silva Lira: Atualmente é professora efetiva do Departamento de Estatística e Ciências Atuariais na Universidade Federal de Sergipe UFS (2011)Propôs-se, neste trabalho, avaliar a bioatividade do óleo de nim sobre Alphitobius diaperinus, em sementes armazenadas. Sementes de amendoim cultivar BRS Havana foram tratadas com óleo de nim nas concentrações de 0,0; 1,0; 2,0; 3,0 e 4,0% (volume/massa de sementes) e mantidas em bandejas durante 24 h. Cinquenta gramas de sementes foram colocados em recipientes plásticos e infestados com 20 insetos adultos de A. diaperinus. Avaliaram-se, aos 30, 60, 90 e 120 dias de armazenamento, a mortalidade, o número de descendentes (larvas, pupas e adultos) e o número de sementes perfuradas. Para análise de variância dos dados utilizou-se o teste de Friedman (p ≤ 0.05), sendo a comparação das médias realizada pelo teste de Student Newman Keuls (p ≤ 0.05). Calculou-se, também, a eficiência do produto pelo método de Henderson & Tilton (1955). Eficiência do óleo de nim sobre a mortalidade de A. diaperinus acima de 74,92% foi observada a partir dos 90 dias do armazenamento, para as concentrações de 3 e 4%; entretanto, o produto conferiu proteção às sementes de amendoim, em todas as concentrações, nos períodos estudados, visto que afetou todos os descendentes de A. diaperinus da geração F1. _________________________________________________________________________________________ ABSTRACT: This work aimed to evaluate the bioactivity of neem oil on Alphitobius diaperinus, in stored seed. Peanuts seeds, cultivar BRS Havana, were treated with neem oil at concentrations of 0.0, 1.0, 2.0, 3.0 and 4.0% (volume/weight) and kept in trays for 24 h. Fifty grams of seeds were put in plastic containers and infested with 20 adult insects of A. diaperinus. The mortality, the offspring number (larvae, pupae and adults) and the number of punched seeds were evaluated at 30, 60, 90 and 120 days of storage. For variance analysis of data, Friedman test (p £ 0.05) was used. Student Newman Keuls test (p £ 0.05) was used for comparison of means. The product efficiency was also analysed by using Henderson & Tilton (1955) method. Neem oil efficiency on the mortality of A. diaperinus above 74.92% was observed from 90 days of storing for concentrations of 3 and 4%. However, the neem oil conferred protection to peanut seeds in all concentrations and studied periods, by affecting all offspring of A. diaperinus of the F1 generation

Biological control of Alphitobius diaperinus with Steinernema rarum CUL and Heterorhabditis bacteriophora SMC and feasibility of application in rice hull

Chemical insecticides often are not efficient in reducing Alphitobius diaperinus populations in poultry farms and have induced insect resistance. Entomopathogenic nematodes (EPNs) appear as an alternative to pest biocontrol agents; however, their efficiency on rice hull litter is still unknown. The aim of this study was to evaluate the potential of Steinernema rarum (CUL isolate), Heterorhabditis bacteriophora (SMC isolate) and their symbiotic bacteria as biocontrol agents of A. diaperinus larvae and adults in rice hull litter. Mortality of insect adults and fifth- and seventh-instar larvae was determined in Petri dishes containing filter paper or rice hull. The effect of Xenorhabdus szentirmaii and Photorhabdus luminescens on L7 and adults in rice hull substrate was also evaluated. Moreover, the effectiveness of the EPNs was assessed in bags in an environment simulating the prevailing conditions in a broiler chicken farm. Under laboratory conditions, insect mortality was significantly affected by EPN species, substrate, insect stage and time after application. Mortality of L5 and L7 caused by EPNs in rice hulls reached a peak of 64 and 57.3 %, respectively, whereas symbiotic bacteria applied on rice hull showed low mortality rate at both insect stages. In the simulated poultry farm conditions, S. rarum and H. bacteriophora caused up to 40.8 and 50.4 % mortality of A. diaperinus larvae, respectively, but with adult mortality being low for both species. We conclude that infective juveniles from S. rarum CUL and H. bacteriophora SMC isolates can be used as biological control agents of A. diaperinus larvae in chicken litter containing rice hulls.Fil: del Valle, Eleodoro Eduardo. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Frizzo, Laureano Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Ciencias Veterinarias del Litoral. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias. Instituto de Ciencias Veterinarias del Litoral; ArgentinaFil: Malmierca, Melisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Ciencias Veterinarias del Litoral. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias. Instituto de Ciencias Veterinarias del Litoral; ArgentinaFil: Zbrun, María Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Ciencias Veterinarias del Litoral. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias. Instituto de Ciencias Veterinarias del Litoral; ArgentinaFil: Lax, Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Zoología Aplicada; ArgentinaFil: Doucet, Marcelo Edmundo. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Zoología Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentin