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GENETIC DIVERSITY OF Beauveria bassiana (BALSAMO) VUILLEMIN IN CHILE REVEALED BY A NUCLEAR GENE SEGMENT SEQUENCING. Luis Devotto 1* , Stephen A. Rehner 2 , M. Méndez 3 and A. France 4 . 1 Escuela de Graduados, Facultad de Ciencias Agrarias, Universidad Austral de Chile, Valdivia, Chile. 2 USDA, Agricultural Research Service, Insect Biocontrol Laboratory, BARC-West, Beltsville, MD, USA. 3 Instituto de Nutrición y Tecnología de los Alimentos, Universidad de Chile, Santiago, Chile, Av. El Líbano 5524, Santiago, Chile. 4 Departamento de Producción Vegetal, Centro Regional de Investigación Quilamapu, Instituto de Investigaciones Agropecuarias (INIA), Chile. Avda. Vicente Méndez 515, Chillán, Chile. * Current address: Departamento de Producción Vegetal, Centro Regional de Investigación Quilamapu, Instituto de Investigaciones Agropecuarias (INIA), Chile. ldevotto@inia.cl Summary. The genetic structure of seven Chilean putative populations of the entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin was investigated by sequencing a ca. 1400 bp nuclear gene fragment named B locus. Ninety seven B. bassiana sensu lato isolates were included, which have been previously collected accross the country, most of them from soil using the Galleria mellonella baiting method. Phylogenetic and demographic approaches were adopted in a sequential fashion to analyze the resulting data set. The 97 isolates were collapsed to 20 haplotypes. Neighbour-joining and maximum parsimony trees revealed 9 well supported clades. Only one clade included isolates collected in the same locality and they corresponded to Eastern Island isolates. The remaining clades gathered isolates from very different geographical origin, including isolates thousands of kilometers apart. Seven populations were defined a priori based on ecological and climatic conditions. The AMOVA analysis revealed a significant but limited support for the proposed structure. One isolate, coded QU-B931, is a good potential candidate for biological pest control. This isolate was distinguishable from the rest of the 17
sample, showing the potential use of this nuclear fragment for strain fingerprinting. A eleven sub-sample, representing the major clades, was additionally analized by sequencing the elongation factor 1 alpha (EF1-α) gene. The resulting EF1-α topology mostly agreed with the B locus topology and allowed to analyze the genetic diversity of the fungus in Chile under current phylogenetic hypotheses for the B. bassiana complex, which suggest the existence of cryptic species into what is morphologically defined as B. bassiana. Keywords: entomopathogenic fungus; biological control; population structure; elongation factor 1 alpha. Introduction. The haploid filamentous fungus Beauveria bassiana (Balsamo) Vuillemin (Ascomycota: Hypocreales) is a common soil inhabiting organism, consuming organic matter (saprophytic stage) and/or infecting arthropods (parasitic stage). Its pathogenic properties have been long recognized and have attracted much effort to use this fungus as a biological control agent against many agricultural, medical and veterinary important pests. Several biological control programmes based on this fungus have successed in recent years, but in other cases more erratic results have been obtained. Some of these failures could have been explained and overcome if a better understanding of life traits, ecological interactions and phylogenetic constraints were available. The efforts directed to understand the above mentioned issues are limited by the lack of enough reliable phenotypic characters to discriminate among species into the genus and among strains into the species. The genus Beauveria harbours several species defined mostly by the conidia morphology, while strain identity at infra-species level is even more unclear if morphology is the only criteria. The species and strain identity is an integral part of any environmental risk and efficacy assessment structure. In consequence, biochemical and molecular tools have been used to fingerprint strains of particular interest. The mitochondrial DNA has been the preferred target of infra-species studies because of its faster evolution rate, but recently the nuclear DNA has arose as another valid alternative. Nuclear genes are suitable for intraspecific studies as they serve as nonlinked genetic markers, converse to mitochondrial genes which 18
Page 1 and 2: UNIVERSIDAD AUSTRAL DE CHILE FACULT
Page 3 and 4: DIVERSIDAD Y CONTROL BIOLÓGICO DE
Page 5 and 6: ÍNDICE DE CONTENIDOS INTRODUCCIÓN
Page 7 and 8: 4.- CAPÍTULO CUARTO: ANÁLISIS DE
Page 9 and 10: CAPÍTULO I. INDICE DE CUADROS Tabl
Page 11 and 12: CAPÍTULO I. ÍNDICE DE FIGURAS Fig
Page 13 and 14: Figure 5. Rarefaction curves for th
Page 15 and 16: ABSTRACT About 10% of Southern Chil
Page 17 and 18: Sin embargo, a pesar de esta percep
Page 19 and 20: preeminencia de esta idea ha sido e
Page 21 and 22: niveles tróficos completos o grand
Page 23 and 24: Se ha propuesto diversos enfoques p
Page 25 and 26: El control de esta especie se reali
Page 27 and 28: con la consiguiente pérdida o dism
Page 29 and 30: 4. Numerosos estudios se concentran
Page 31: 1.- CAPÍTULO PRIMERO: DIVERSIDAD G
Page 35 and 36: and put it in a phylogeographical p
Page 37 and 38: centrifugation and supernatant was
Page 39 and 40: (Schneider and Excoffier, 1999; Alt
Page 41 and 42: All the putative populations showed
Page 43 and 44: strongly influenced by insect host
Page 45 and 46: supported a geographical sub-divisi
Page 47 and 48: Neuveglise C, Brygoo Y, Vercrambe B
Page 49 and 50: Table 1. Environmental data for the
Page 51 and 52: B907 Poike 27º 06' 109º 21' Easte
Page 53 and 54: B606 Lago Icalma 38º 50' 71º 20'
Page 55 and 56: Figure 1. NJ tree of the B fragment
Page 57 and 58: Figure 2. Haplotype tree inferred f
Page 59 and 60: Figure 4. Mismatch distributions of
Page 61 and 62: Figure 5. Haplotype diversity in th
Page 63 and 64: Table 6. Analyses of molecular vari
Page 65 and 66: Table 8. Pairwise differentiation e
Page 67 and 68: CONSERVATION BIOLOGICAL CONTROL OF
Page 69 and 70: Introduction. In last decades, mode
Page 71 and 72: a dose of 10 12 spores per ha was s
Page 73 and 74: aerea were very low at 1 and 30 day
Page 75 and 76: explanation than no toxicity of the
Page 77 and 78: fields that are sprayed with pestic
Page 79 and 80: affected species, when present, whe
Page 81 and 82: Kiss, B., Samu, F., 2000. Evaluatio
Page 83 and 84:
Wilby, A., Villareal, S., Lan, L.,
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ARANEAE Gnaphosidae 253 54 % Lycosi
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Activity density (individuals per p
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NON-TARGET EFFECTS OF Dalaca pallen
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same percentage of mortality on lar
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Treatments were applied on 15 Octob
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(Departamento de Producción y Sani
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Predators. Data set I. The principa
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predators extracted from soil cores
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particularly carabids. Most of the
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the consistent results allow us to
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Kenmore, P.E., Cariño, F., Perez,
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Traugott, M., Strasser, H. and Prie
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Table 2. Significance of treatment
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Figure 1. Persistence of B. bassian
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Figure 3. Principal response curve
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Figure 5. Principal response curve
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RESPONSE OF GRASSLAND SOIL ARTHROPO
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Introduction. Declining diversity h
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Fungus. Beauveria bassiana strain Q
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Data collection. The abundance and
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N is the total number of individual
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catches), while dominant species re
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knowledge of South Chile grassland
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Dennis, P., 2003. Sensitivity of up
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invertebrates. In: IFOAM 2000 The W
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Figure 2. Estimated numbers Beauver
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Figure 4. Effects of B. bassiana an
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Figure 6. Rarefaction curves for th
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genética coincide con la zona de m
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Crosonychus viridis, Trechisibus an
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depredadores de lepidópteros, en l
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Respuesta a nivel de grupos funcion
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La conservación de los herbívoros
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Se ha propuesto que esta hipotétic
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En esta línea de razonamiento, las
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suceda en sistemas simples con poco
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BIBLIOGRAFIA Alarcón R. 1997. Resp
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isolated from the European cockchaf
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Hardin MR, Benrey, M Coll, WO Lamp,
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Lockwood JA, 1993. Environmental is
Page 165 and 166:
Pimentel D, C Glenister, S Fast y D
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Swift MJ, J Vandermeer, PS Ramakris
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Zelada SH, 1998. Rol de la franja d
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Anexo 1. Índices de severidad de l
Page 173 and 174:
Anexo 3. Capturas provenientes de l
Page 175 and 176:
Page 177:
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