擔子菌類的“性”

Sexuality in the Basidiomycetes

我們所生活的世界是經常在變動的。為了要生存在這個世界上，一個'種'必須具有許多變異。這種生物界的變動過程被稱為生物的進化，而這種變化通常藉'性'的手段以達成。性'是將遺傳物質，也就是兩個個體的遺傳潛力結合在一起的一種方法。有些生物的'性' 過程受心理上及文化的影響，同時也因構造上及生理上的不同而趨複雜，但在多菌類中，尤其是擔子茵沒有這些複雜的因素，所以可用來研究一些有關'性'方面的生物學問題。所謂'性'包括三個步驟：第一是兩交配個體間細胞質的結合，由於細胞質的結合而將兩種不同的細胞核共存於同一細胞質中；第二是細胞核的結合；第三是減數分裂，在此分裂過程中，染色體的數目由雙套而減為單套。

The essential events in the sexual process are described briefly and related to the places where they occur in the life cycle of Basidiomycetes. The early history is presented of studies of life cycles and sexuality in the Basidiomycetes up te through the discovery of the hemi-compatible reactions by Papazian and by Fulton in 1959. This led to the more recent investigations on heterokaryosis, the structure of the mating type loci, nuclear migration, and hyphal fusions. The conflicting conclusions of different investigators concerning a relationship between mating type and frequency of hyphal fusions is discussed, and the evidence that a diffusible substance is responsible for increased frequency of hyphal fusions is presented. The studies dealing with fruiting which involved a genetic approach are emphasized. It is suggested that future developments in the study of fungi involving gentic techniques will be made in both fundamental and applied research. On the basic or fundamental side we can expect an understanding of incompatibility at the molecular level, and more complete knowledge of the developmental processes, including the control of enzyme systems during development and the mode of operation of repression-depression mechanisms from spore to hypha to the complex organization of a fruiting body. The study of fine structure will lead eventually to knowledge of the roles of various organelles. In applied research we can expect genetic techniques to be used increasingly for the imprpvement of strains used in fermentation processes for the improvement of strains used for production of mushrooms on a commercial scale. These techniques will also be important in making possible the commercial cultivation of species of economic potential which have not been so cultivated as yet. In both the basic and applied areas, research of the higher fungi, and especially the Basidiomycetes, has a bright future and the exchange of ideas between researchers in both these areas should hasten the achievement of the goals sought.