국화는 국내외적으로 주요 화훼작물이지만 국화 흰녹병은 안정적 생산에 큰 걸림돌이 되고 있다. 현재까지 국화 흰녹병 방제는 농약살포를 통한 화학적 방제와 다습한 재배환경을 개선하는 재배적 방제에 의존하고 있지만, 살균제 저항성을 갖는 새로운 병원균 출현으로 농약 살포를 통한 병 방제에는 한계가 있어 병 저항성 품종 개발이 절실하다. 흰녹병은 순활물기생균인 Puccinia horiana에 의해 발생하는 곰팡이 병으로 이로 인한 경제적 손실이 크지만, 다른 주요 작물병과 비교하여 상대적으로 연구가 미흡하다. 특히 병원균의 전파 경로와 병원성의 다양성(pathogenic diversity), 병원균 침입기작 및 기주식물과의 상호작용에 대한 전반적인 지식 부족으로 효과적 농약 살포 기준 설정과 병저항성 품종개발에 어려움이 있다. 따라서 본 논문에서는 이러한 과제를 해결하는데 기초자료를 제공하고자 각 연구분야별로 현재까지 발표된 연구결과를 정리하고 앞으로 요구되는 연구과제에 대하여 모색하여 보았다. 특히 효과적 약제처리 기준 설정과 병저항성 품종 개발의 출발점이 되는 흰녹병균의 생활사와 생태, 병원균 DNA 정보를 이용한 조기진단, 병원균의 병원형 등에 관해 현재까지의 연구결과들을 정리하였다. 앞으로 흰녹병균의 식물체 침입 기작에 관한 종합적 이해의 폭을 넓히고, 병원균 침입 시 식물체내에서 발병과 병저항성 유도 요인에 대한 분자 수준에서 연구가 진행된다면 흰녹병균 저항성 품종 육성 시기를 앞당길 수 있으리라 사료된다.

Rhizopogon roseolus (Corda) Th. M. Fr. (=R. rubescens Tul. & Tul.), known as “shoro” in Japan, is a hypogeous basidiomycete that is an important ectomycorrhizal symbiont of the Pinaceae. Rhizopogon roseolus produced a fruiting body with a basic globose to subglobose shape. Basidiospores were encompassed in a glebal chamber in the fruiting body. However, little is known about basidiosporogenesis and nuclear behavior after karyogamy. We treated R. roseolus glebar chambers with Gimsa acid and observed their hymenium microscopically to characterize nuclear behavior and basidiosporogenesis. Our observations revealed the following five characteristics: ⅰ) meiosis and postmeiotic mitosis took place in the basidium; ⅱ) meiosis occurred in the center of the basidium; ⅲ) the sterigma appeared when the first meiotic division occurred; ⅳ) the center of the basidium constricted slightly when the second meiotic division occurred; ⅴ) after postmeiotic mitosis, asynchronous nuclear migration from the basidium to the basidiospores took place, producing eight uninucleate basidiospores. However, unusual nuclear behavior was frequently observed, indicating that regulations of the timing and the way of nucleus entering to the spores were not exact in R. roseolus.

Apexes of basidia in Rhodophyllus muraii var. albus are divided into four sections or depressed in the center. A spore is formed by inflation of the apex of the sterigma. The apex of the sterigma is swollen and changed from a papilla through a peinsform and a club into a globeform. Six spots of globose spore are regularly or irregularly depressed with hilum axes. Finally the spores come cuboid.

Apexes of basidia in Rhodophyllus(synonyum of Entoloma) muraii var. albus are divided into four sections or depressed in the center. A spore is formed by inflation of the apex of the sterigma. The apex of the sterigma is swollen and changed from a papilla through a penisform and a club into a globeform. Six spots of globose spore are regularly or irregularly depressed with hilum axes. Finally the spores are cuboid. Basidia of Entoloma squamiferrum are developed from hymenium layer of crator-shaped parabasidium. Apex of basidium is flat or depressed in the center. Although four sterigmata are developed, only two sterigmata are symmetrically swollen to two spores in certain basidia. It means that two sterigmata among four sterigmata are infertile. The apex of the sterigma is swollen into a paillaform, and then turned into a penisform. It is swollen from a clubform into a globeform. Six spots of the surfaces of globose spore are deperssed with hilum axes. Finally the spore is cuboid, and then it is released from hilum. Four sterigmata of papillaform of E. violaceobrunneum are developed from cartor-shaped basidium. The apex of sterigma is swollen to a small globeform. And then it is swollen to a clubform. The clubform is again swollen to a ellipticalform, and then more than six spots of spore surfaces are ramomly depressed with hium axes. When the depression of surface of a elliptical spore is over, it is the multi-angular spore of the heterometrical-form.

Four sterigmata of papillaform E. violaceobrunneum are developed from crator-shaped basidium. The apex of sterigma is swollen to a small globeform. And then it is swollen to a clubform. The clubform is again swollen to a ellipticalform, and then more than six spots of spore surfaces are ramdomly depressed with hilum axes. When the depression of surface of a elliptical spore is over, the spore is a heterodiametrical spore of multi-angular.

Basidia of Entoloma squamiferrum are developed from hymenium layer of cartor-shaped parabasidium. Apex of basidium is flat or depressed in the center. Although four sterigmata are developed, only two sterigmata are symmetrically swollen to two spores im certain basidia. It means that two sterigmata among four sterigmata are imfertil. A spore is formed by inflation of the apex of the sterigma. The apex of the sterigma is swollen into a paillaform and then turned into a penisform. It is swollen from a clubform into a globefrom. Six spots of the surfaces of globose spore are depressed with hilum axes. Finally the spore is cuboid, and then it is released from hilum.