Ecogeographical variation in the Pleurotus eryngii complex in Israel

The geographical distribution and ecological habitats of the Pleurotus eryn gii complex in Israel are described from a study of 60 genotypes from 10 po pulations. Both MEA and PDA media were suitable for growth of all genotypes at all temperatures tested (4-37 degreesC). There was a high correlation b etween a coefficient of growth and the mean colony diameter growth rate. Al l genotypes reached the maximum growth at 27 degrees. Growth rate at 30 deg rees was greater than at 19 degrees. We found highly significant (p < 0.000 1) variability among growth rates of Israeli genotypes, indicating ecogeogr aphical differences among populations. The growth rate of 12 European genot ypes from the Ukraine and Slovakia was higher than most of the Israeli geno types when grown at 27<degrees> (non-stress conditions), but israeli genoty pes tolerated 37 degrees (stress conditions) better, and recovered faster t han European populations when returned to 27 degrees. We conclude that Isra eli genotypes are better adapted to hot and dry climates than European geno types. Based on multiple regression analyses, strong correlations were foun d between relative humidity and rainfall parameters, but not temperature, o f the locations from which Israeli isolates were collected, and their growt h rates. This indicates that, paradoxically, relative humidity and rainfall have a stronger effect than temperature on the adaptability of this comple x to different environments.