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Accueil du site → Doctorat → Israel → Morphological, ecological and genetic characterization of the Pleurotus eryngii species-complex in Israel

Haïfa University (2000)

Morphological, ecological and genetic characterization of the Pleurotus eryngii species-complex in Israel

Lewinsohn, Dalia

Titre : Morphological, ecological and genetic characterization of the Pleurotus eryngii species-complex in Israel

Auteur : Lewinsohn, Dalia

Etablissement de soutenance : Haïfa University

Grade : Doctor of Philosophy (PhD) 2000

Résumé partiel
Species of the genus Pleurotus are important mushrooms because of their ease of cultivation, their nutritional value and medicinal properties. Among the species ofthis genus the economic importance of Pleurotus eryngii is well supported by scientific evidence. This study was conducted with the objective ofcharacterizing the ecogeographical variation ofPleurotus eryngii species­complex in Israeli populations, fromitsmorphological,ecologicalandgenetic perspectives. The morphology characterization ofPleurotus eryngii species­complex (Pleurotaceae, higher Basidiomycetes) has been conducted by studying thirteen wild populations of this species that were collected in various ecogeographical regions during an extensive survey on the occurrence ofthis complex in Israel. The populations sampled from the Golan Heights in northern Israel extending to the south steppic area ofLahav, in the northern Negev. This study defined the exact geographical distribution ofthis complex in Israel. Previous studies describedP. eryngiivar.ferulae in Israel in close association only with Ferula communis. In the present study I found one population ofP. eryngii growing in close association with Ferulatingitana in the Satafarea(JudeanMountains, Israel). The taxonomic study ofthis peculiar collection belongingtoP. eryngii species complex and the collection from Sataf is described as a new variety P. eryngii var. tingitanus. A comparative morphological analysis and mating experiments were conductedand microscopic features are described. Themyceliumgrowthrates ofisolates thatwereassociated withFerula communis were higheratfer 7 and 12 days ofincubation, than of isolates that were associated with Ferula tingitana. The new variety, P. ayngii var. tingitanus is closelyrelated to P. eryngiivar.ferulae, but it differs from the latte DROUGHT andTHESIS rin spore size, mycelial characteristics, habitus ofbasidomata(or associatedhostplant) and ecology. In order to study the ecogeographical distribution and habitats of Pleurotus eryngii complex in Israel, I examined sixty genotypes from ten populations. Both MEA and PDA media were suitable for growth of all genotypes at all temperatures tested (4O37OC). There was a high correlation between the coefficient of growth, and the mean colony diameter growth rate. All genotypes reached the maximum growth at 27OC. Growth rate at 30oC was greater than at 19OC. I found highly significant (p< 0.0001) variability among growth rates of Israeli genotypes, indicating ecogeographical differences among populations. The growth rate of 12 European genotypes from the Ukraine and Slovakia was higher than most of the Israeli genotypes when grown at 27OC (non stress conditions), but Israeli genotypes tolerated better stress conditions )37OC), and recovered faster than the European genotypes when returned to 27OC. Thus, the Israeli genotypes are better adapted tohotand dryclimates than the European genotypes. Based on multiple regression analyses, strong correlations were found between humidity and rainfall parameters, but not temperature, ofthe locations from which Israeli isolates were collected, and their growth rates. This indicates that, humidity and rainfall have a stronger effectthan temperature on the adaptability ofthis complextodifferentenvironments.


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