The number and distribution of incompatibility factors in natural populations of Pleurotus ostreatus and Pleurotus sapidus

Abstract

A. S. and SCHWANDT, J. W. 1991. The number and distribution of incompatibility factors in natural populations of Pleurotus ostreatus and Pleurotus sapidus. Can. J. Bot. 69 : 2187-2191.Pairings of single-spore isolates from different basidiocarps were made to examine the numbers and distributions of incompatibility factors in the tetrapolar basidiomycetes Pleurotus ostreatus and Pleurotus sapidus. These factors do not appear to be randomly distributed, with multiple basidiocarps on a single tree or log arising from a single mycelium, multiple basidiocarps on a single tree or log sharing a single common monokaryotic parent, and a tendency toward spatial clustering of factors even when multiple basidiocarps from the same tree or log are excluded from the analyses. For one 30-km2 collection area, the estimated numbers of A and B factors in the P. ostreatus population were 126 and 354, respectively, yielding an estimated outbreeding efficiency of 0.99. Estimated outbreeding efficiencies were quite high (a0.79) even in a sample taken from a very small area (0.09 mZ), illustrating the ability of the tetrapolar mating system to simultaneously prevent self mating and minimize the number of incompatible matings. ANDERSON, N. A,, FURNIER, G. R., WANG, A. S. et SCHWANDT, J. W. 1991. The number and distribution of incompatibility factors in natural populations of Pleurotus ostreatus and Pleurotus sapidus. Can. J. Bot. 69 : 2187-219 1 . Afin de dCtenniner les nombres et les distributions des facteurs dYincompatibilitCs chez deux basidiomycktes tetrapolaires,Pleurotus ostreatus et Pleurotus sapidus, les auteurs ont effectue des croisements d'isolats monosporaux provenant de different~ basidiocarpes de ces espkces. Ces facteurs ne semblent pas &tre distribuCs au hasard, considCrant que de nombreux basidiocarpes venant sur un seul arbre ou un seul tronc proviennent d'un mCme et seul mycelium, que de nombreux basidiocarpes sur un m&me arbre ou tronc ont en commun un mCme parent monokaryotique. I1 y a de plus une tendance vers un regroupement spatial des facteurs, m&me lorsque de nombreux basidiocarpes du mCme arbre ou tronc sont exclus des analyses. Sur une surface de collection couvrant 30 km2, les auteurs estiment que les nombres de facteurs A et B dans la population du P. ostreatus atteignant 126 et 354, respectivement, ce qui entraine une efficacitC de croisements externes estimCs a environ a 0,99. Les efficacitCs de croisements externes estimes Ctaient en effet passablement ClevCs (30,79), mCme dans un Cchantillon pris a partir d'une trks petite surface (0,09 m2), ce qui illustre la capacitC du systkme tCtrapolaire a empCcher simultanCment I'autofCcondation et a minimiser le nombre de croisements incompatibles.

Genetic structure of Fennoscandian populations of the threatened wood-decay fungus Fomitopsis rosea (Basidiomycota)

“…Multiple mating alleles have been observed in several basidiomycete populations (e.g. Anderson et al 1991, Kay & Vilgalys 1992. In the tetrapolar Pleurotus ostreatus a tendency towards spatial clustering of mating alleles (A and B) was observed (Anderson et al 1991).…”

The genetic structure and diversity of the A and B mating-type genes from the tropical oyster mushroom, Pleurotus djamor

“…Mushrooms in the genus Pleurotus appear to deviate slightly from this pattern. Mating-type surveys of the two species P. populinus and P. pulmonarius (first reported as P. ostreatus and P. sapidus, respectively [see Anderson et al, 1973;Vilgalys et al, 1993]), revealed consistently more B alleles than A alleles (126 A and 354 B alleles estimated for P. populinus and 30 A and 90 B alleles estimated for P. pulmonarius [Anderson et al, 1991]). An additional unique property of the Pleurotus A mating-type is that with only a single exception, there has been no demonstration of intra-A mating-type recombination in P. spondoleucus, P. ostreatus, and P. djamor (Larraya et al, 1999;Liou, 2000;Takemaru, 1961).…”

Isolation of the B incompatibility factor mutants in Pleurotus ostreatus

“…Kummer is an excellent edible mushroom widely cultivated in many countries of the world. As in most hymenomycetes, the mating system of this fungus, leading to the formation of a dikaryon that can differentiate to produce fruiting bodies, is known to be bifactorial heterothallism (tetrapolality) controlled by two unlinked multialletic factors, A and B (Terakawa 1960;Eguenio and Anderson 1968;Anderson et al 1991).…”