摘要:

A deficiency of biotin forHypomyces chlorinusTul. does not change the nature of major components of walls but alters their proportions. The mean percentage of neutral sugars decreased from 48.97% for the biotin-rich walls to 40.98% for the biotin-deficient walls. The molar proportions for glucose, galactose, and mannose are respectively 10:5.5:9 and 10:3:8; glucosamine, incorporated in the form ofN-acetylglucosamine in chitin, increased from 19.17% to 26.75%. Variations of proteins and lipids are not significant. The results indicate occurrence of a peptide–polysaccharide complex and a glucan having essentially a β configuration. All walls treated by β-D-glucosidase have fibrillar structure. This structure disappears when the walls are treated with chitinase.

ISSN:0008-4026    

DOI:10.1139/b77-032

出版商:NRC Research Press    

年代:1977

数据来源: NRC

摘要:

This study was done to compare events of conidiogenesis with previous studies done on the closely related generaDoratomycesandScopulariopsis. Formation of the first conidium by aT. spiralisannellide was not observed. Conidial initials blew out through the annellide apex, increased in size, and were eventually delimited by centripetally developing septa. Each conidial-delimiting septum subsequently split; the distal layer formed part of the conidial base, and the proximal layer became a portion of the wall of the next conidial initial. A circumscissile rupture of the wall layer continuous between conidium and annellide produced the characteristic annellations and conidial basal frills. Annellations onT. spiraliswere more conspicuous than on the two species ofDoratomycesand the two species ofScopulariopsispreviously studied with electron microscopy. Differences in nuclear behavior and other differences and similarities among the five species were discussed. The term holoblastic to describe conidiogenesis in annellides was questioned.

ISSN:0008-4026    

DOI:10.1139/b77-033

出版商:NRC Research Press    

年代:1977

数据来源: NRC

摘要:

Two hyphomycetes,Beejasamuha samalagen. et sp. nov. andSutravarana samalagen. et sp. nov., isolated from goat and rabbit dung samples, respectively, are described from India. The taxonomy of these two fungi is discussed.

ISSN:0008-4026    

DOI:10.1139/b77-034

出版商:NRC Research Press    

年代:1977

数据来源: NRC

摘要:

Fifteen isolates ofPyrenophora tritici-repentiswere used to determine the effects of substrate, temperature, and photoperiod on growth and conidiation. Conidiation was achieved with seven isolates when either 15% V-8 juice agar (1.5 g/l CaCO3and 15 g/l agar) or autoclaved leaves of wheat or wheatgrass (Agropyron dasystachyum(Hook.) Scribn.) were used as substrates. However, V-8 juice agar provided the most consistent and abundant conidiation. Conidiophore production was observed over a temperature range of 10 to 31 °C while conidia were produced from 10 to 25 °C. Optimal conidiation on 15% V-8 juice agar occurred at about 21 °C. Twenty-five different photoperiods were tested and conidiophores were formed with all regimens containing alight period. Conidia were produced with 1 to 21 h of light (4790 lx) per day with an optimum at 12 ± 1 h at 21 °C on 15% V-8 juice agar.

ISSN:0008-4026    

DOI:10.1139/b77-035

出版商:NRC Research Press    

年代:1977

数据来源: NRC

摘要:

Inheritance of virulence ofUstilago triticion four cultivars of wheat was studied, using a cross between races T 1 and T 2. Two recessive genes for virulence were identified:Utv1conditioned virulence on the cultivars Renfrew and Florence × Aurore;Utv2conditioned virulence on Kota and Little Club.

ISSN:0008-4026    

DOI:10.1139/b77-036

出版商:NRC Research Press    

年代:1977

数据来源: NRC

摘要:

The upper side of the leaves ofBegonia hispidaSchott. var.cuculliferaIrmsch. Bears appendages that may be classified as hair-like and leaf-like appendages. In addition, trichomes occur. Externally, the two classes of epiphyllous appendages and the trichomes are continuous. Anatomically, a discontinuity exists between the trichomes and the most hair-like appendages. The former lack vascular tissue and other tissues such as chlorenchyma, a hypodermis, and typical epidermis. The hair-like appendages, the leaf-like appendages, and the intermediates between them share the following common element of construction: they terminate in an attenuation at whose base a hump is situated. A vascular bundle supplies this hump and ends in two hydathodes. The smallest hair-like appendages consist only of one attenuation-hump element. In the leaf-like appendages the tip as well as each tooth ends in an attenuation-hump element. The same applies to the main leaves, i.e. the teeth of the main leaves are built in a similar fashion. The anatomy of the epiphyllous appendages, especially the leaf-like appendages, is strikingly similar to that of the main leaf. The leaf-like appendages as well as the main leaves have an upper epidermis with a large-celled hypodermis, palisade and spongy tissue, a lower hypodermis, and epidermis with stomata.

ISSN:0008-4026    

DOI:10.1139/b77-037

出版商:NRC Research Press    

年代:1977

数据来源: NRC

摘要:

Two hundred and fourteen specimens ofVacciniumsubgen.Cyanococcnswere collected from 40 sites in northeastern North America for taxonomic studies. Data collected using various techniques indicate thatV. borealeHall & Aalders should be recognized as a species. Three characters, viz. dimension, pubescence, and leaf margin, separateV. borealefromV. angustifoliumandV. myrtilloides. Although the three species are sympatric, only a few natural hybrids betweenV. borealeandV. myrtilloideshave been found among the collected material. Crossing trials betweenV. borealeandV. pallidumsuggest that the two are probable ancestors ofV. angustifolium.

ISSN:0008-4026    

DOI:10.1139/b77-038

出版商:NRC Research Press    

年代:1977

数据来源: NRC

摘要:

The relationship betweenSclerotinia sclerotiorum, causal agent of wilt or basal stem rot of sunflower (Helianthus annuusL.), and its hyperparasiteConiothyrium minitanswas investigated in a sunflower field naturally infested with the two organisms. Sclerotia ofS. sclerotiorumwere collected biweekly from roots and basal stems of wilted plants and analyzed for infection by the hyperparasite. The results showed thatC. minitansparasitized and killed the sclerotia produced on the root surface. This hyperparasite continued to parasitize the pathogen inside the root and upwards into the base of the stem, thus infecting the sclerotia produced at these sites. By the end of the growing season, 59%, 76%, and 29% of sclerotia on the root surface, inside the root, and inside the stem, respectively, had been killed by the hyperparasite, while 4%, 9%, and 68% of the sclerotia at these locations were healthy. Death of the rest of the sclerotia was due to organisms other thanC. minitans. The data also indicate thatC. minitansis more effective in parasitizing sclerotia produced on or inside the root than those produced in the basal stem.

ISSN:0008-4026    

DOI:10.1139/b77-039

出版商:NRC Research Press    

年代:1977

数据来源: NRC

摘要:

Impatienscrosses were made between Plant Introduction (P.I.) 349629 (2n = 16) and cultivar Tangerine (2n = 8), producing a hybrid (2n = 12) that seemed sterile. A large number of pollinations of the hybrid with 'Tangerine' pollen, however, produced only three progeny with 2nnumbers of 8, 9, and 12. The backcross with hybrid pollen on P.I. 349629 produced five progeny, all of which were 2n = 20. None of these backcross progeny has shown fertility at present. Backcrosses involving the hybrids between 32 chromosome P.I. accessions and 'Tangerine' have been unproductive. Eleven of the hybrids (2n = 24) between P.I. 349629 and several of the 32-chromosome P.I. accessions occasionally produced viable pollen. When used on a 'Tange-glow' female, which is a 24-chromosome amphidiploid, numerous progeny resulted, some of which proved to be fertile in subsequent crosses.

ISSN:0008-4026    

DOI:10.1139/b77-040

出版商:NRC Research Press    

年代:1977

数据来源: NRC

摘要:

Descriptions and illustrations ofNeolecta irregularisandN. vitellinefrom Canada are given. Amyloid ascus walls are reported for both species and conidia fromN. vitelline. TheNeolectaceaefam. nov. is created forNeolectaand is tentatively placed in the Lecanorales.

ISSN:0008-4026    

DOI:10.1139/b77-041

出版商:NRC Research Press    

年代:1977

数据来源: NRC