Restriction Fragment Length Polymorphisms in the Mushrooms Agaricus brunnescens and Agaricus bitorquis

[This corrects the article on p. 817 in vol. 53.].     

Restriction Fragment Length Polymorphisms in the Mushrooms Agaricus brunnescens and Agaricus bitorquis

Two Agaricus species, A. brunnescens (a commercial mushroom) and A. bitorquis (a wild, edible species), were examined for restriction fragment length polymorphisms. EcoRI-digested nuclear DNA from isolates of both species were cloned in plasmid vector pUC18. Ten random recombinant clones were used in Southern DNA-DNA hybridizations to probe EcoRI-digested DNA from 11 A. brunnescens isolates (7 commercial, 2 wild type, and 2 homokaryotic) and 7 A. bitorquis isolates. Most cloned fragments were polymorphic in both species. There were fewer different genotypes than expected, however, in the sample of commercial A. brunnescens strains. DNA from homokaryotic strains showed fewer bands in most hybridizations than DNA from heterokaryotic strains. All A. bitorquis isolates could be distinguished from each other as well as from every A. brunnescens strain. Putative homokaryons were detected by the loss of polymorphic bands among protoplast regenerates from one commercial strain and two strains collected in the wild.     

Restriction fragment length polymorphisms in the mushrooms Agaricus brunnescens and Agaricus bitorquis

Two Agaricus species, A. brunnescens (a commercial mushroom) and A. bitorquis (a wild, edible species), were examined for restriction fragment length polymorphisms. EcoRI-digested nuclear DNA from isolates of both species were cloned in plasmid vector pUC18. Ten random recombinant clones were used in Southern DNA-DNA hybridizations to probe EcoRI-digested DNA from 11 A. brunnescens isolates (7 commercial, 2 wild type, and 2 homokaryotic) and 7 A. bitorquis isolates. Most cloned fragments were polymorphic in both species. There were fewer different genotypes than expected, however, in the sample of commercial A. brunnescens strains. DNA from homokaryotic strains showed fewer bands in most hybridizations than DNA from heterokaryotic strains. All A. bitorquis isolates could be distinguished from each other as well as from every A. brunnescens strain. Putative homokaryons were detected by the loss of polymorphic bands among protoplast regenerates from one commercial strain and two strains collected in the wild.     

双孢蘑菇子实体营养成分分析

测定了双孢蘑菇子实体中氨基酸、矿质元素、多糖、粗蛋白、粗脂肪、灰分、粗纤维、核苷酸、维生素C和SOD等含量。结果表明,粗蛋白含量为37．86％,在测定的18种氨基酸中含有17种氨基酸,8种必须氨基酸含量占氨基酸总量的42．30％;必需氨基酸与非必需氨基酸比值（E／N）为0．73。还含有丰富的多糖、纤维素、超氧化物歧化酶（SOD）和核苷酸类物质。     

Confirmation of crosses between lines of Agaricus brunnescens by isozyme analysis

In this paper are presented the results of isozyme analysis which confirmed intraspecific crosses between putative homokaryotic lines of Agaricus brunnescens. Putative homokaryotic lines were recognized by electrophoresis of single-spore-derived cultures and used as breeding stock. These breeding stock lines were grown together in dual culture on agar and selections were made from the interaction zone. These selections were then transferred to make spawn. Alternatively, spawns from each of two selected lines were mixed together and inoculated directly into compost. Intraspecific crosses were confirmed by the presence of heteromeric isozymes. Many of these newly developed lines were characterized by unique isozymic phenotypes reflecting unique genotypic classes.     

Host-parasite relationships of Agaricus brunnescens and a number of mycoparasitic hyphomycetes

Host-parasite relationships of Agaricus brunnescens Peck and twelve mycoparasitic hyphomycetes belonging to the genera Arnoldiomyces, Cladobotryum, Hypomyces (anamorphic state of), Mycogone, Sepedonium, Sibirina and Verticillium were studied in paired cultures. Four distinct growth reactions were recognized reflecting the relative abilities of the hyphomycetes to affect the host.     

Investigation of Mitochondrial Transmission in Selected Matings between Homokaryons from Commercial and Wild-Collected Isolates of Agaricus bisporus (= Agaricus brunnescens)

Ten heterokaryons of Agaricus bisporus (= Agaricus brunnescens) were shown to carry four different mitochondrial (mt) genotypes by analysis of mt restriction fragment length polymorphisms (RFLPs). Fifteen homokaryons derived from these strains were used to investigate mt inheritance in A. bisporus. One hundred eighty-nine pairings were performed in 25 different combinations. Pairings in 15 different combinations produced heterokaryons on the basis of nuclear RFLP analyses and/or fruiting trials. The mt genotype of each new intraspecies hybrid was examined by using mt RFLPs as genetic markers. Our results suggest the following. (i) Recombination between the mt genomes was not a common event. (ii) From most individual pairings, all heterokaryons carried the same mt genotype. (iii) Heterokaryons carrying either of the two possible mt genotypes were observed in certain crosses after modification of the pairing procedure. A biparental transmission pattern was demonstrated for some crosses, but there appears to be a preference for one of the mt genotypes to predominate in any specific pairing.     

Effect of an Extract from Saprozoic Nematode-Infested Compost on the Mycelial Growth of Agaricus brunnescens

Extracts from compost infested with Caenorhabditis elegans suppressed mycelial growth of Agaricus brunnescens. An extract from uninfested compost also inhibited mycelial growth but to a lesser degree. The critical role of compost bacteria and/or other compost micro-organisms is implicated by these results.     

Crosses among Homokaryons from Commercial and Wild-Collected Strains of the Mushroom Agaricus brunnescens (= A. bisporus)

A new technique for the production of hybrid strains of the cultivated mushroom Agaricus brunnescens is described. Homokaryons were recovered from regenerated protoplasts obtained from several heterokaryotic strains. A total of 16 novel hybrids were produced in 63 attempted crosses between paired homokaryons. Recovery of both homokaryons and hybrids was verified by analysis of restriction fragment length polymorphisms. Three of four hybrids fruited in small-scale tests, further confirming that the isolates were true hybrids. Colony morphology alone was found to be a poor indicator of hybrid status. In two instances, three homokaryons crossed successfully in all combinations, suggesting that there are at least three alleles at the putative mating-type locus. Crosses between homokaryons from commercial and wild-collected isolates indicated that these strains belong to the same biological species.     

桦木科2个植物名称后选模式的指定

指定了桦木科(Betulaceae)的九龙桦(Betula jiulungensis Hu ex P.C.Li)和天台鹅耳枥(Carpinus tien-taiensis W.C.Cheng)这2个植物名称的后选模式.该2个植物名称发表时,同时指定两号标本为模式,而没指定主模式.     

Periplast structure of the cryptomonad flagellateHemiselmis brunnescens

Summary The periplast ofHemiselmis brunnescens Butcher is a complex cell covering comprised of the plasma membrane (PM) sandwiched between a surface periplast component (SPC) and an inner periplast component (IPC). The SPC is revealed by deep-etching, and consists of hexagonal plates composed of tripartite subunits that appear to self-assemble into a crystalline layer with a hexagonal symmetry. Small scales (termed fibrillar scales) accumulate on the crystalline plates during cell growth, eventually forming a carpet that itself may appear crystalline when fully formed. Heptagonal rosette scales are occasionally observed on the surface as well. The position of the crystalline plates is precisely mirrored by both the E and P fracture faces of the PM. The plate proper is underlain by membrane with a high concentration of intramembrane particles (IMPs) while the bands of membrane underlying the plate borders lack IMPs. Access of subunits and fibrillar scales to the cell surface following initial plate formation appears to be at the plate boundaries. This study suggests that cryptomonad flagellates may provide model systems for studying the self-assembly of cell surface components, and for relating membrane structure to function, as evidence suggests a major role for the PM in mediating periplast assembly and development.     

蔷薇科五个植物学名后选模式的指定

由于蔷薇科中有5个植物名称的模式为复份标本,没指定主模式。根据《国际植物命名法规》规则8.1、8.3、9.9、9.14和37.2,辅则9A.2和9A.3,以及前言第8段的精神,对这些名称作出后选模式指定。     

皱叶黄杨的异名平卧皱叶黄杨后选模式的指定

林祁(1999)曾对黄杨科Buxaceac黄杨属Buxus Linn．的皱叶黄杨B．rugulosa Hatusima作过考订,将平卧皱叶黄杨B．microphylla Siebold ＆ Zuccarini var．prostrata W．W．Smith归并入皱叶黄杨B．rugulosa Hatusima中,并注意到平卧皱叶黄杨的模式标本还是合模式状态,没指定出后选模式。由于当时没查阅到相关的重要标本而不便处理,现查阅到平卧皱叶黄杨的合模式标本,经研究后对它作出后选模式指定。     

Lectotypification of the red alga Ceramium secundatum Lyngbye

Ceramium secundatum is typified by a cystocarp-bearing specimen from the Faroes in Lyngbye's herbarium (C). This specimen resembles that illustrated by Lyngbye (1819, Tab. 37 A). The type locality was revisited in 1992 and C. secundatum and other Ceramium spp. were collected.     

Lectotypification of two Musa sections (Musaceae)

The present work is part of a continuing study to revise the old names in Musa and aims to clarify the taxonomy in the sections Rhodoclamys and Callimusa. Lectotypes are designated here for Musa sect. Callimusa and M. sect. Rhodochlamys . These sections were first erected without the indication of a type species.     

多裂紫菊(菊科-菊苣族)后选模式的指定

指定了多裂紫菊Prenanthes henryi Dunn (=Notoseris henryi (Dunn) Shih)的后选模式。     

Lectotypification of Cacao guianensis Aublet (Sterculiaceae)

Hitherto “suppressed,”Cacao guianensis, based on a mixture of elements that can be referred to three currently recognized species (i.e.,Theobroma cacao, T. subincanum, andT. velutinum), is lectotypified by Aublet's illustrations of its flowers. This makesC. guianensis a taxonomic synonym ofT. cacao and encourages nomenclatural stability by permitting the continued use ofT. subincanum andT. velutinum.     

Lectotypification of Chorizanthe watsonii (Polygonaceae: Eriogonoideae)

Chorizanthe watsonii Torr. & Gray is lectotypified onTorrey 435 (NY) collected in the Humboldt Mountains of Nevada in 1865. A fragment of the lectotype is at GH.