DefinitionsAlternatively fixed alleles:Which one is the alternatively fixed allele?Dominant vs. co-dominant markersLimitations of co-dominant markersGenotypeSlide 7Slide 8Slide 9Slide 10In the case of microbes it will probably be something likeSummary of third lessonSlide 13Slide 14Fungi… again!ASCOMYCETESAscus is the sack in which the spores are containedAsci can be placed on a disk (apothecium), many apothecia can be together in a fruitbodySlide 19Asci can be carried inside a flask (perithecium)Slide 21BASIDIOMYCETESToadstools and huitacochle are both basidiomycetesBasidium means “club”, it carries the basidiospores (dispersion propagules) nakedSlide 25Slide 26Slide 27OomycetesSlide 29Slide 30Fungi do not photosynthesizeDISEASE!!host-pathogen-environmentSlide 34Slide 35Slide 36Slide 37Slide 38Slide 39Slide 40Presence of free waterSome pathogen roles in natural plant communitiesHuman activities affecting disease incidence in forestsSlide 44Effects of fire exclusionDefinitions•Alternatively fixed alleles•Dominant vs. co-dominant markers•GenotypeAlternatively fixed alleles:•Two flower species (species 1 and species 2) can have one of two features:–Long (L) or short (s) leaves–Red ( R) or white (w) flowers•Ten individuals from species 1 have the following traits:–LR; LR ;LR ;LR; LR; LR ;LR; sR; sR; sR•Ten individuals from species 2 have the following traits:–sw; sw ;sw ;sw; sw; sw ;sw; Lw; Lw; LwWhich one is the alternatively fixed allele?•Both alleles will differentiate the groups (frequencies are significantly different)•Only one will be diagnostic because alternatively fixed•It is the color of the flower: all flowers in species 1 are R, all flowers in species 2 are w (“all” implies your sampling size is adequate!!)Dominant vs. co-dominant markers•Flowers are red or white or yellow, DNA sequence is agg, agt, agc; DNA fragment is 10, 12 0r 14 bp long (CO-DOMINANT, we know what alternative alleles are)•Flowers are red or non-red, DNA is agg or not, size is 10bp or not. We only see the dominant allele and we express it in binary code 1(present), 0(absent)Limitations of co-dominant markers•Not all non-red flowers are the same, but we assume they are (non red flowers can be orange or yellow)•If at one locus we have a dominant A allele and a recessive a allele, using a codominant marker we would say AA=Aa but not aa. We know in reality AA and Aa are quite different.Genotype•A unique individual as defined by an array of genetic markers. (the more markers you have the less mistaken identity you will have. blonde•Blonde•Blue-eyed•Blonde•Blue-eyed•Hairy•Blonde•Blue-eyed•Hairy•6 feet tall•Blonde•Blue-eyed•Hairy•6 feet tall•Missing two molarsIn the case of microbes it will probably be something like•Genotype A= 01010101•Genotype B= 00110101•Genotype C= 00010101Summary of third lesson•DNA polymorphisms can be diagnostic–Mutations/Sex/Barriers to mating•Plant Diseases can be biotic (interaction between host and causal agent ), or abiotic•Many organisms can cause plant diseases, but fungi are the No.1 cause•Diversity of fungi, but all have ideal structure for plant infection:–hypha/cord/rhizomorph/infection peg/appressorium–Sexual vs. asexual reproduction: can do bothFungi… again!•ASCOASCOMYCETES•BASIDIOBASIDIOMYCETES•OOMYCETES (fungus-like, water molds)ASCOASCOMYCETES•Yeasts (fermentation, human mycoses)Yeasts (fermentation, human mycoses)•Truffles, morelsTruffles, morels•Penicillia (penicillin), Fusaria (potent toxins, damping off of seedlings), moldsAscus is the sack in which the spores are containedAsci can be placed on a disk (apothecium), many apothecia can be together in a fruitbodyMorel fruitbodyAsci can be carried inside a flask (perithecium)NectriaPloidy is mostlynBASIDIOBASIDIOMYCETES•Mushrooms. mycorrhizal Mushrooms. mycorrhizal •Wood decay organismsWood decay organisms•Rusts, Smuts•Yeasts and damping offToadstools and huitacochle are both basidiomycetesBasidium means “club”, it carries the basidiospores (dispersion propagules) nakedMost of their life, they aren+n (dikaryons), some rareones are diploidOomycetes•Belong to the kingdom Stramenopila, used to be called Chromista•Phytophthora, Pythium, SaprolegniaH20Hyphae, sporangia, and zoospores of Hyphae, sporangia, and zoospores of P. ramorumP. ramorumMost of their lifecyclethey are 2nHave cellulose in cellwallNot fungi!!, but looklike them because of convergent evolutionFungi do not photosynthesize•Biotrophic: mycorrhyzae, rusts•Endophites: clavicipetaceae, •Necrotrophic; most pathogens•Saprobes: primary (involved in litter decomposition)DISEASE!!•Symptoms vs. signs; e.g. chlorosis vs. fruit-body•The disease trianglehost-pathogen-environment•Susceptibility of individuals or of portions of individuals•Genetic variability•Basic compatibility (susceptibility) between host and pathogen•Ability to withstand physiological alterationsGenetic resistance in host Genetic resistance in host Length of lesion (mm)Proportion of stem girdled (%)Nicasio\ 42.5a0.71aChina Camp 40.5a0.74aSan Diego 27.8b0.41bOjai 25.0b0.47bInterior live oak (Maricopa)14.1b0.33bCankers byCankers by P. ramorum P. ramorum at 3 monthsat 3 monthsfrom time of inoculation on two coastfrom time of inoculation on two coastlive oakslive oakshost-pathogen-environment•Basic compatibility with host (virulence)•Ability to maintain diversity: sex vs. no sex•Size of genetic pool•Agressiveness (pathogenicity) towards hosts•Ability to survive without hostChlamydospores of Chlamydospores of P. ramorumP. ramorumPr75 Qa MontereyPr75 Qa Monterey Pr87 Am MarinPr87 Am Marin Pr86b Am MarinPr86b Am Marin Pr86a Am MarinPr86a Am Marin Pr84 Soil MarinPr84 Soil Marin Pr82 Vo MarinPr82 Vo Marin Pr80 Vo MarinPr80 Vo Marin Pr72 Rh AlamedaPr72 Rh Alameda Pr65 Qp Santa CruzPr65 Qp Santa Cruz Pr58 Vo MarinPr58 Vo Marin Pr50 Qa SonomaPr50 Qa Sonoma Pr201b Rh Santa CruzPr201b Rh Santa Cruz Pr201a Rh Santa CruzPr201a Rh Santa Cruz Pr47b Qa SonomaPr47b Qa Sonoma Pr47a Qa SonomaPr47a Qa Sonoma Pr35 Qa SonomaPr35 Qa Sonoma Pr28 Ld SonomaPr28 Ld Sonoma Pr24 Qa SonomaPr24 Qa Sonoma Pr22 Qa SonomaPr22 Qa Sonoma Pr20 Qa SonomaPr20 Qa Sonoma Pr19 Qa NapaPr19 Qa Napa Pr16 Qa Santa CruzPr16 Qa Santa Cruz Pr13 Qa Santa CruzPr13 Qa Santa Cruz Pr11b Qa MontereyPr11b Qa Monterey Pr11a Qa MontereyPr11a Qa Monterey Pr10 Ld MontereyPr10 Ld