Genetic Diversity and Fumonisin Analyses of Fusarium species in the Philippines

Transcription

1 Genetic Diversity and Fumonisin Analyses of Fusarium species in the Philippines ASIAHORC Symposium July 18-20, 2009 Nagoya, Japan Christian Joseph R. CUMAGUN Crop Protection Cluster College of Agriculture University of the Philippines Los Baños

2 Fusarium (Gibberella) A notorious pathogen Can incite diseases in plants, humans and animals Many plants at least one Fusariumassociated disease (81 of the 101 economically important plants) Produce secondary metabolites

3 Ear rot of maize (Fusarium verticillioides)

4 Bakanae disease of rice (Fusarium fujikuroi) Fusarium head blight of wheat (Fusarium graminearum)

5 Crown rot of banana (Fusarium verticillioides)

6 Fusarium wilt of bottle gourd (F. oxysporum f.sp. lagenariae)

7 Fusarium wilt of bitter gourd (F. oxysporum fsp. momordicae)

8 Plant Disease 81(12): Bakanae disease on the rise: A cause for concern Gergon, E & Angeles, AT. Poster presented at the 37 th Anniversary & Annual Scientific Conference of PMCP. May 2-5,2006. Davao City

9 POPULATION GENETICS : What do we know about it? Fisher s Fundamental Theorem of Natural Selection: Mean fitness of population always increases Rate of increase in fitness is proportional to additive genetic variance for genes that affect fitness More genetically diverse pathogen populations have greater evolutionary potential Pathogenic traits affect fitness

10 Genetic Structure of Pathogen Populations The amount and distribution of genetic diversity within and among populations varies INCREASE Recombination Gene flow Mutation DECREASE Selection Random drift Genetic structure is a result of all evolutionary processes that have affected a population (species) through time and space

11 Variation of agressiveness and cultural characters Front cover of Vol 53 of Plant Pathology : Cumagun et al. (2004)

12 Cumagun et al., 2009 VCG diversity = isolates grouped into 19 VCGs

13 High diversity at small spatial scale VCG1 IsoIate T3 VCG2 VCG3 Isolate IM3 Isolate IB3 Cumagun et al., 2009

14 Source: Cumagun et al., 2009 High diversity at small spatial scale VCG1 IsoIate T3 MATA-1 ( + ) VCG2 VCG3 Isolate IM3 Isolate IB3 MATA-2 ( - ) other mating population

15 Effective population number for F. verticillioides Effective population number (Ne) Mating N fs :N h Mating Male/hermaphrodite Reference type type polymorphism (N ef ) Sexual reproduction of in the (N e(mt) ) Philippines does not occur frequently 27:23 35: Cumagun et al :47 62: Chulze et al :23 10: Danielsen et al :17 39: Mansuetus et al : : Leslie and Klein 1996 Source; Cumagun (2008). Journal of Applied Genetics

16 Vegetative Compatibility Grouping nit1 nit 3 Nit M 2-4 VCGs in F. oxysporum in bitter gourd 2-3 VCGs in F. oxysporum in bottle gourd Medium compatibility Strong compatibility Source: Cumagun et al. (2008) Journal of Plant Protection Research

17 F. oxysporum in Batangas and Bulacan Host Batangas Bulacan No compatibility was detected between upo and ampalaya isolates Ampalaya Upo Cross infection was observed normally in young plants Tomato 10 0 No association between pathogenicity and VCG Total Source: Cumagun et al. (2008) Journal of Plant Protection Research

18 Worldwide Collection: AFLP dendrogram of F. graminearum lineage 7 Source: Cumagun et al The Philippine Agricultural Scientist

19 Worldwide Collection: AFLP dendrogram of F. graminearum lineage 7 Source: Cumagun et al The Philippine Agricultural Scientist Large variation No specialization

20 . and Fumonisin Detection using PCR Assay 1000 bp 1000 bp 800 bp 750 bp 500 bp 400 bp

21 Cluster analysis of Fusarium verticillioides and F. fujikuroi 27.9% 48.1% 29.3% 9.1% 53.3% 44.7% 72.1% 36.6% 59.6% 84.9% 25.7% 28.0% 43.7% 34.3% 39.4 % 78.3% 100.0% 58.9% 99.0% 96.9% 46.7% 78.7% 68.7% 78.4% 61.0% 57.6% 97.1% 99.6% Identification F. fujikuroi ND F. proliferatum F. fujikuroi F. proliferatum ND ND ND ND F. fujikuroi ND ND ND F. fujikuroi ND F. fujikuroi F. fujikuroi F. proliferatum ND F. fujikuroi ND ND F. subglutinans F. subglutinans Origin Tester Strain Tester Strain Tester Strain Tester Strain Tester Strain Tester Strain

22 What is the cause of the non production of fumonisin by strains isolated from banana? Excision Hypothesis: 44 kb of the FGC has been excised from banana Maize from Philippine banana have the FGC while those in Central America do not have! Banana Source: Van Hove et al. (2006)

23 Low association between aggressiveness and fumonisin production of Fumonisin B1 production (ug/g) r = Aggressiveness (%) Source: Cumagun et al. (2007) Source: Cumagun et al. (2007) Asian Conference on Plant Pathology

24 No association between aggressiveness and fumonisin production of F. fujikuroi 250 Fumonisin prodn (ug/g) 200 Aggressiveness Fumonisins prodn Aggressiveness (mm) A-NE 13A-NE 19A-NE La1-NE LB4-NE Isolates Source: Cumagun et al. (2008) unpublished results 0

25 Fumonisin production of and F. fujikuroi isolates in the Philippines Source Host No of isolates Mean fumonisin production (µg/g) FB1 FB2 FB3 maize maize N. Ecija rice Source: Cumagun et al. (2007) Asian Conference on Plant Pathology

26 Genotypic variation among populations of three Fusarium species for aggressiveness and mycotoxin production Fusarium species F. verticillioides Host No of Genotypic Range isolates Aggressiveness Mycotoxin production maize cm µg/g F. fujikuroi rice mm F. graminearum F. oxysporum ampalaya upo µg/g wheat % mg/ kg Reference Alviar, 2006, Cumagun et al., 2006 Cumagun et al., 2007 Aguilar, 2007 Cumagun et al., 2007 Cumagun and Miedaner Aguirre, 2007

27 Conclusions VCG is not correlated with aggressiveness Large variation and no specialization for F. graminearum, and F. fujikuroi. High variation in aggressiveness in, F. fujikuroi and F. graminearum. Sexual reproduction in is less frequent. from Asia and Africa have the FUM gene cluster while Central America do not. Mating population A is prevalent in Philippine corn. Philippine F. fujikuroi isolates are low fumonsin producers. isolates from Northern Luzon are high fumonisin producers compared to Southern Luzon. No to low association between aggressiveness and fumonisin production in both rice and maize isolates of

28 Acknowledgements