| Pleurotus citrinopileatus Sing, is a famous edible mushroom of Basidiomycetes in the Northeast of China which exerts an important effect on anti-exhaustion and theimprovement of human body immunity. It could be produced yearly, but the studies ongenetics and breeding of P. c/Y/7'nopileatus are still little known to the world .The sexualreproduction of edible mushrooms in Basidiomycetes is controlled by the incompatibilityfactors and for this reason the studies of the compositions of these incompatibility factors^B and their genetic characters are of great importance.In this view, the compositions of incompatibility factors, the related gene linkage map and di-mon mating mechanism of P. citrinopileatus were studied. Along with this study, the relationship between the incompatibility factors and temperature characters was discussed, and high-optimum-temperature strains were selected and cultivated. The results are as follows.The incompatibility factors of P. citrinopileatus are factor A and factor B. They are not linked and located on different chromosomes. Factor A only consists of an independent subunit while factor B consists of two continuous subunits B a and B P . Their genetic distance is 0.38cM on the chromosome map.The previous experimental data show that there are at least six chromosomes in P. citrinopileatus. Only one auxotrophic gene locus is determined in the sixth linkage group. The auxotrophic gene loci ade2.pabl,ade5,met2, and met? are located in the first linkage group of factor A, chol and adel in the second linkage group of factor B( B a and B P ),? met9,argl,hisl,ade7,his3, and metl in the third linkage group, nicl.nic2, ade4, and pdx2 inthe fourth linkage group, panl and inol in the fifth linkage group, and only ilel in the sixth linkage group. It shares the common characters with Schizophyllum commune Fr.. Coprinus cinereus ((Schaeff.)Cook). and Flammulina velutipes (Curt.:Fr.) Sing.) on the genetic map, >- namely, the auxotrophic gene loci ade and pab are located near factor A.In this research, to study the phenomenon of dikaryolization, the di-mon mating of P. citrinopileatus was divided into complete compatibility combination, semi-comp atibility combination, and mono-factor combination. The phenomenon of dikaryolizati on of monokaryon in P. citrinopileatus was further studied. In the complete compati bility combination, all of monokaryons have dikaryolization onone side, but two nuc lei of the donor nuclei in dikaryon do not migrate intomonokaryon on an equal pro bability and the pre-entrance nucleus exists. In the semi-compatibility combination, if there is pre-entrance nucleus in donor nucleus of dikaryon, dikaryolization will occ ur in monokar-yon. If not, dikaryolization will not occur or a part of mycelia has d ikaryolization. This demonstrates that the nucleus of donor nuclei has selective entra nee. In mono-factor combination, dikaryolization also occurs. It may be caused by the chromosomes exchange and recombination between the two nuclei of dikaryon. Moreover, in the test related to di-mon mating, there is a phenomenon of dedikaryol ization in the tip of colony. This indicates that di-mon mating is caused by mon-mo n mating.The optimum temperature for the growth of monokaryon in P. citrinopileatus var ies between 23.4?8.1癈 and under this condition its variation takes on a normal d istribution. The hybrids of dikaryon also take on a normal distribution in the range of 23.6~28.7癈. In the mating of having different optimum-temperature strains as p arents, if both of the parents are high-optimum-temperature strains, the frequency ofhigh-optimum-temperature hybrids is up to 61.8%. If one of the parents is high-opt imum-temperature monokaryon, half of the strains will be high-optimum-temperature hybrids. If both of the parents are mid- or low-optimum-temperature strains, the freq uency of high-optimum-temperature strains is lower than 27%. Among the compatibi liry factors, incompatibility fac...
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