bassiana. Experimental work with these and other similar isolates will be needed to substantiate this hypothesis. A generally accepted notion that insect hosts are related to certain genotypes of entomopathogenic fungi has been tested in several occasions in the past for B. bassiana and B. brongniartii. However, only a few cases supported a host – fungal
genotype specificity. For instance, associations have been reported between B. brongniartii and Melolontha melolontha, M. hippocastani or Hoplochelus marginalis [17, 52]. A common B. bassiana genotype was detected in isolates from Ostrinia nubilalis [10] and from CYC202 Alphitobius diaperinus [53]. More often, B. bassiana isolates collected from the same insect species were found to be genetically dissimilar [54, 55] or showed cross-infectivity [56]. Similarly, fungal isolates derived from different insect species, families or orders clustered together
[57]. Our results from the concatenated mt and nuclear gene datasets come to an agreement with the latter view, since molecular variability showed no general correlation between strains and host and/or geographic origin. This indicates that B. bassiana is a generalized insect pathogen, and is in agreement which its world-wide distribution, the vast variety of hosts from which it has been isolated and its entomopathogenic and/or endophytic characteristics [1, 58]. It is only in rare occasions that a particular genotype, like Clade A sub-group 1 isolates (Fig. 6; Table 1), may PS341 be associated with a particular host (Ostrinia nubilalis). In the case of B. TCL brongniartii and under the light of previous analyses of larger fungal populations [17, 52], the association between fungal genotypes and a particular host seem to be stricter. Table 1 Data from the phylogenetic analyses ITS1-5.8S-ITS2 atp6-rns nad3-atp9 Concatenated Total characters 640 687 496 1823 Constant
characters 258 222 155 642 Variable characters 117 122 109 382 Informative characters 265 343 232 799 Tree length 1106 1085 750 2918 Consistency Index (CI) 0.56 0.68 0.71 0.64 Homoplasy Index (HI) 0.44 0.37 0.29 0.36 Retention Index (RI) 0.86 0.87 0.87 0.83 Rescaled Consistency Index (RC) 0.48 0.59 0.62 0.53 Parsimonious trees 2700 7700 7700 4100 Data obtained from the phylogenetic analyses of the nuclear ITS1-5.8S-ITS2 and the two mitochondrial intergenic regions atp6-rns and nad3-atp9 for all isolates examined in this study. An increasing number of Selleckchem Elafibranor studies point towards a broad correlation of fungal isolates with their place of origin and/or habitats [e.g., [18, 21, 30, 59, 60]]. Obviously, the factors that can influence B. bassiana population structures are many and can include: climate conditions, the range of temperatures in which the various isolates can grow in nature, humidity levels, UV exposure, habitat, cropping system and soil properties [18, 27, 59, 61].