Basidiomycetes - Basidiomycetes
|
A general term for fungi that reproduce sexually, producing basidiophores at the base of the basidiospores. Many produce fruiting bodies (mushrooms) large enough to be seen with the naked eye, but a few are molds. [Hironori Terakawa] Biology and NutritionIn the natural world, basidiomycetes play a major role in breaking down fallen leaves and wood and reducing them to inorganic matter. Some also form mycorrhizae in symbiosis with the roots of many plants, supporting their life. They also continue to live by parasitizing plants and mushrooms, or by saprophytic habit in animal droppings and soil. [Hironori Terakawa] Organization and ReproductionThe vegetative body of basidiomycetes is a mycelium that lives buried in a substrate. Mycelium is formed as follows. First, the hyphae that arise from the basidiospores are elongated cells containing a single haploid nucleus, and are arranged in a row. These hyphae grow at the tip and repeatedly branch from the sides of the hyphae, and the hyphae of the branches grow in the same way. This is the mycelium (haploid mycelium). When the tip of the hyphae of one haploid mycelium comes into contact with the side of another compatible haploid mycelium, the cell walls at the contact point melt and the cytoplasm connects (the first stage of conjugation). Next, the nucleus migrates and pairs with the partner nucleus, and a heterhyphae containing two nuclei in the cells is formed as a branch of the heterhyphae. This hyphae undergoes simultaneous nuclear division (conjugated nuclear division) with the two nuclei aligned side by side, and grows while maintaining the state of each cell containing two haploid nuclei, and eventually branches to become heterhyphae. During conjugated nuclear division, small bulges (clamps) are formed on the sides of the hyphae at the septum (clamp formation), however, some hyphae are unable to form clamps. The grown heterephtal mycelium forms fruiting bodies in response to environmental stimuli such as temperature changes, and in certain parts of the fruiting bodies, such as in mushrooms with a cap, the two nuclei fuse to form a single diploid nucleus in the terminal cells of the hyphae (basidiophores of the hyphae) that line the surface of the folds under the cap (the second stage of conjugation). This diploid nucleus immediately undergoes meiosis to become four haploid nuclei. Eventually, the tips of the four pedicels that appear at the end of the basidium swell to form basidiospores, each of which contains a single nucleus. Mature basidiospores generally have a mechanism that allows them to be repelled from the pedicels. In addition to directly forming fruiting bodies, the mycelium can also produce hyphal bundles or sclerotia, which can then give rise to fruiting bodies. Basidiospores are true spores that are produced through meiosis, but some basidiomycetes produce vegetative spores on the mycelium through the division of the mycelium. In species such as Auricularia, budding from basidiospores can also be seen. [Hironori Terakawa] ClassificationBasidiomycetes are divided into three classes: Protobasidiomycetes, Heterobasidiomycetes, and Eubasidiomycetes. Protobasidiomycetes do not produce fruiting bodies, but rather their hyphal cells become resting spores (teliospores), whose germ tubes generally become in-line four-lobed basidiom. Heterobasidiomycetes produce in-line four-lobed or parallel four-lobed basidiom on the fruiting body. Eubasidiomycetes generally produce one-lobed basidiom on the fruiting body, and are divided into the subclasses Protobasidiomycetes, Capsidiomycetes, and Gastromycetes. (1) Protobasidiomycetes [1] Sphaerothecales They parasitize plants of the Gramineae family and cause smut, and their teliospores are also called teliospores. Some species do not produce basidiospores. [2] Udiniformes They cause rust in plants, and have a complex life cycle, with vegetative spores including teliospores, rust spores, and uredospores in addition to teliospores. Some species do not produce basidiospores. (2) Heterobasidiomycetes [1] Auriculares Many of them are saprophytic on rotting wood. Except for the Mompackin family, the fruiting body is agaric, and the basidium has four parallel chambers on its surface. [2] Tremolophores The fruiting body is agaric, and they are saprophytic on rotting wood, and the basidium has four parallel chambers. They come in a variety of colors other than white. (3) Eubobasidiomycetes [Hironori Terakawa] Protozoan Capsulcota[1] Bacillariales: Generally parasitizes plants of the Theaceae family, and the affected parts turn into galls with numerous cylindrical, single-chambered basidiophores on the surface. [2] Turraniales: Produces downward-facing fruiting bodies on rotting wood, some of which are agaric. The single-chambered basidiophores have four or two swollen episacs. [3] Auriculariales: Produces agar or waxy fruiting bodies on rotting wood, and the basidiophores are Y-shaped and single-chambered. They are not necessarily red in color. [Hironori Terakawa] Capsularia[4] Polyporaceae: Many species are saprophytic on wood, but some species form mycorrhizae. In general, the fruiting bodies spread over the host, or are umbrella-shaped, sessile or stalked, with well-developed mycelial tissue. The fruiting layer covers the surface with downward projections, pores, and folds, and the basidium is a club-shaped or cylindrical chamber. [5] Agaricales: Some species decompose fallen leaves and dead wood, while others form mycorrhizae. The fruiting bodies are generally erect, and many have a stalk attached to a umbrella with folds or pores. The Agaricales are divided into the suborders Agaricales, Agaricales, Agaricales, and Agaricales. The suborders of the Atractylodes and Chanterelles are often lumped together with the aforementioned Polyporaceales and Polyporaceales and are also called the Aphylloparales, but given the pattern of fruiting body development, it is better not to group them together. [Hironori Terakawa] Gastromycetes[6] Pseudobasidiophores and others The Pseudobasidiophores order includes the groundnut, and the Pseudobasidiophores order includes the red porphyra. Others include the Pseudobasidiophores, the Polytrichumales, the Porphyrales, and the Pectinidales. These fruiting bodies are initially spherical and occur underground, above ground, or on rotting wood, with a basic body (gleba) that produces many one-chambered basidiophores inside. Some are endofructose, with the outer wall remaining closed even after the spores have matured, but generally they are fruiting, with the outer wall not opening until they mature. [Hironori Terakawa] [Reference] | |©Junzo Fujishima "> Main types of mushrooms (Basidiomycota) (1) [… ©Junzo Fujishima "> Main types of mushrooms (Basidiomycota) (2) [… ©Junzo Fujishima "> Main types of mushrooms (Basidiomycota) (3) [… ©Junzo Fujishima "> Main types of mushrooms (Basidiomycota) (4) [… ©Junzo Fujishima "> Main types of mushrooms (Basidiomycota) (5) [… ©Junzo Fujishima "> Major types of mushrooms (Basidiomycota) (6) [… ©Junzo Fujishima "> Main types of mushrooms (Basidiomycota) (7) [… Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend |
|
有性生殖を経て担子器を生じ、その先に担子胞子を外生する菌類の総称。多くのものは肉眼的大きさの子実体（キノコ）をつくるが、少数のものはカビである。 ［寺川博典］ 生態と栄養担子菌類は、自然界のなかで、落ち葉や木を分解して無機物に還元する際の主役である。また、なかには、多くの植物類の根と共生して菌根をつくり、植物類の生活を支えているものもある。さらに、植物体やキノコに寄生、あるいは動物類の糞(ふん)や土壌などに腐生して、その生活を続ける。 ［寺川博典］ 体制と生殖担子菌類の栄養体は基物内に潜って生活する菌糸体である。菌糸体は次のようにして形成される。まず、担子胞子から生じた菌糸は単相の一核を含む細長い細胞であり、一列に並んでいる。この菌糸は先端成長を行うとともに、菌糸側面から枝分れを繰り返し、枝の菌糸も同様の成長を行う。これが菌糸体（単相菌糸体）である。一つの単相菌糸体の菌糸の先端が、和合性のある他の単相菌糸の側面に接すると、接触部の細胞壁が溶けて細胞質が連絡する（接合の第一段階）。次に核が移行して相手核と対(つい)になり、単相菌糸の枝として細胞に二核を含む重相菌糸を生ずる。この菌糸は、二核が並んだままで同時に核分裂（共役核分裂）を行い、各細胞に単相の二核を含む状態を維持したまま成長し、やがて分岐して重相菌糸体となる。共役核分裂に伴って、隔壁の位置で菌糸側面に小さい膨らみ（クランプ）をつくる（かすがい形成）が、なかにはクランプのできないものもある。 成長した重相菌糸体は、温度変化などの環境の刺激によって子実体を形成し、その特定の部分、たとえば傘のあるキノコでは傘の裏のひだの表面に並んだ菌糸末端細胞（子実層の担子器）内で、二核が癒合し、一つの複相核ができる（接合の第二段階）。この複相核はすぐに減数分裂を行って四つの単相核となる。やがて担子器の先に生じた四つの小柄(しょうへい)の先が膨らんで担子胞子ができるが、このとき、それぞれに一つの核が入る。成熟した担子胞子は、一般に小柄からはじき飛ばされるような仕組みをもっている。 重相菌糸体は、直接に子実体を形成するほかに、菌糸束または菌核をつくり、これらから子実体を生ずることもある。また、担子胞子は減数分裂を経て生ずる真正胞子であるが、担子菌類のなかには、菌糸体上に体の分裂によってできる栄養胞子を生ずるものもある。キクラゲなどの仲間では担子胞子からの出芽もみられる。 ［寺川博典］ 分類担子菌類は、原生担子菌綱、異型担子菌綱、真正担子菌綱の三つに分類される。原生担子菌綱は子実体をつくらないで菌糸細胞が休眠胞子（冬胞子）になり、その発芽管は一般に直列四室の担子器となる。異型担子菌綱は子実体上に直列四室または並列四室の担子器を生ずる。真正担子菌綱は一般に子実体上に一室担子器を生じ、原生帽菌亜綱、帽菌亜綱、腹菌亜綱に分けられる。 （1）原生担子菌綱〔1〕クロボキン目 イネ科植物などに寄生して黒穂(くろほ)病をおこし、冬胞子は黒穂胞子ともいわれる。担子胞子が知られていないものもある。〔2〕サビキン目 植物類にさび病をおこし、生活環は複雑で、栄養胞子としては、冬胞子のほかに、さび胞子、夏胞子がみられる。担子胞子が知られていないものもある。 （2）異型担子菌綱〔1〕キクラゲ目 朽ち木などに腐生するものが多い。モンパキンの仲間以外は子実体が寒天質で、その表層に直列四室の担子器を生ずる。〔2〕シロキクラゲ目 子実体は寒天質で朽ち木などに腐生し、担子器は並列四室である。色は白以外にさまざまなものがある。 （3）真正担子菌綱 原生帽菌亜綱〔1〕モチビョウキン目 一般にツバキ科植物に寄生し、侵された部分は菌こぶとなって表面に円柱状の一室担子器を多数生ずる。〔2〕ツラズネラ目 朽ち木などに下向きの子実体を生じ、寒天質のものもある。一室担子器には膨らんだ上嚢(じょうのう)が四つまたは二つある。〔3〕アカキクラゲ目 朽ち木などに寒天質か蝋(ろう)質の子実体を生じ、担子器はY字形の一室である。色は赤とは限らない。 ［寺川博典］ 帽菌亜綱〔4〕サルノコシカケ目 木などに腐生するものが多いが、菌根をつくるものもある。一般に子実体は宿主上に広がるか、あるいは無柄か有柄の傘形で、菌糸組織が発達している。子実層は、下向きの突起、管孔、ひだの表面を覆い、担子器は棍棒(こんぼう)形か円柱形の一室である。〔5〕ハラタケ目（マツタケ目） 落ち葉や枯れ木を分解するものや、菌根をつくるものなどがある。子実体は一般に直立し、多くはひだか管孔のある傘に柄がついている。ハラタケ目は、ホウキタケ亜目、アンズタケ亜目、アミタケ亜目、ハラタケ亜目に分けられる。ホウキタケ亜目とアンズタケ亜目のものは、前記のモチビョウキン目、サルノコシカケ目といっしょにして、ヒダナシタケ目ともいわれるが、子実体発達様式からみて、一括しないほうが望ましい。 ［寺川博典］ 腹菌亜綱〔6〕ニセショウロ目その他 ニセショウロ目にはツチグリ、ケシボウズタケ目にはクチベニタケなどが含まれる。そのほか、ショウロ目、チャダイゴケ目、ホコリタケ目、スッポンタケ目などがある。これらの子実体は、初めは球状で、地中、地上、朽ち木などに生じ、内部に一室担子器を多数生ずる基本体（グレバ）がある。胞子の成熟後も外壁が閉じたままの内実性のものもあるが、一般には、成熟するまでは外壁が開かない被実性である。 ［寺川博典］ [参照項目] | |©藤島淳三"> キノコのおもな種類（担子菌類）(1)〔… ©藤島淳三"> キノコのおもな種類（担子菌類）(2)〔… ©藤島淳三"> キノコのおもな種類（担子菌類）(3)〔… ©藤島淳三"> キノコのおもな種類（担子菌類）(4)〔… ©藤島淳三"> キノコのおもな種類（担子菌類）(5)〔… ©藤島淳三"> キノコのおもな種類（担子菌類）(6)〔… ©藤島淳三"> キノコのおもな種類（担子菌類）(7)〔… 出典 小学館 日本大百科全書(ニッポニカ)日本大百科全書(ニッポニカ)について 情報 | 凡例 |
<<: Men's Society - Danshikessha
Recommend
Heel - Heel (English spelling)
It is also called the "hip" or "hip...
Dewey Decimal Classification
…Japan Book Code Classification [Yasuhiro Ono]. …...
Orange Meat
Yellow-brown discoloration frequently occurs in ca...
Achaearanea angulithorax
A spider of the Theridiidae family. It is named af...
Azolla japonica (English spelling) Azollajaponica
…[Masahiro Kato]. . . *Some of the terminology th...
Trichomonas vaginalis
…[Kawaguchi Hiroaki]. … *Some of the terminology ...
Gaius Valerius Catullus
A Roman poet from the late Republic. Born in Vero...
Brachytarsina amboinensis (English name) Brachytarsinaamboinensis
…Like spider flies, they pupate in a cocooning ma...
Kami Ezochi
…Although a certain number of Ainu lived in the J...
Juvenile detention center - Shounenin
These are facilities that house juveniles (genera...
Araburukami - Araburukami
Also written as 'jashin', 'bōshin'...
Carrot - Carrot
…In the early period, men wore tight-fitting bere...
Cardiac skeleton
...It closes during diastole to prevent blood fro...
Strange Tales of the Peony Lantern - Kaidan Botan Douro
Commonly known as "The Peony Lantern." (...
Sierra Nevada [mountain range] (English spelling)
A mountain range in eastern California, in the wes...