摘要:

The apparent rate of photosynthesis in the lowbush blueberry was measured, at four periods of the day, on leaf disks in Warburg flasks and with the use of Pardee's CO2buffers. Significant differences were found in rates of O2evolution at the four different periods. Oxygen evolution was greatest in the early morning when reducing sugars and starch levels were lowest. By early afternoon when starch and reducing sugar levels were much greater in the leaf disks the rate was the lowest.Leaf disks infected withExobasidium vacciniihad a lower rate of apparent photosynthesis than normal leaves of the same clone. Disks cut from normal leaves ofVaccinium angustifoliumhad a higher rate of apparent photosynthesis than those of a variegated mutant. The leaves of the mutant were significantly smaller and seedlings of the mutant type grew more slowly than normal ones of the same cross. For these reasons lowbush blueberry plants of the mutant type or having the red-leaf disease are at a distinct disadvantage in nature.

ISSN:0008-4026    

DOI:10.1139/b66-064

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

Ipomoea pentaphyllaJacq. is a twining, hirsute annual. After infection byAlbugo ipomoeae-panduranae(Schw.) Swingle, two types of galls develop on the stem—bud and cerebriform. The bud gall originates from an infected bud while the cerebriform gall arises from the internode. The two types are distinct from each other in their morphology, anatomy, rate of development, and morphogenesis. The bud gall is of the organoid type while the cerebriform gall is of the histioid type. Tissues of the bud gall grown under in vitro conditions give rise to a structure like the cerebriform gall. The very distinct morphology of the two types has been interpreted on the basis of the possible organizing influence of the shoot apical meristem.

ISSN:0008-4026    

DOI:10.1139/b66-065

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

Photosynthesis in14CO2was observed in 12 algal species from six rhodophycean orders. Rates of CO2uptake ranged from 0.5 to 4.0 mg h−1 × g−1on a fresh weight basis. Excretion of new photosynthate was not important in macrophytes whereas 4.4% of the14C fixed byPorphyridiumsp. was excreted in 2 hours.Members of the Ceramiales could be distinguished by their relatively large accumulation of14C in the alcohol-insoluble fraction.In most species, alanine, glutamic and aspartic acids, serine, and glycine were the most radioactive soluble amino acids. The chief soluble radioactive carbohydrate was floridoside except in the Ceramiales, in which it was low or absent.Batrachospermum, which contained14C-trehalose, also lacked floridoside.14C-Mannitol was recorded in nine species and14C-glucose in two others. Several unknown substances were detected on chromatograms.

ISSN:0008-4026    

DOI:10.1139/b66-066

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

Phenolase (o-diphenol: O2oxidoreductase, E.C. 1.10.3.1) is reported for the first time in a green alga. This enzyme isolated fromMonostroma fuscum(Postels and Ruprecht) Wittrock resembles the enzyme from higher plants in most of its characteristics, including its substrate specificities, the influence of inhibitors, and its relatively low oxygen affinity. The in vivo role of the enzyme is discussed in relation to its intracellular localization and its oxygen affinity.

ISSN:0008-4026    

DOI:10.1139/b66-067

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

A new combination,Nothophacidium phyllophilum, is proposed forNothophacidium abietinellum(Dearn.) Reid & Cain. This fungus is a secondary invader of needles of balsam fir (Abies balsamea(L.) Mill.) infected byHypodermellaspp.Pezisella minutaDearn., occurring on needles of hard pines, is similar to, if not identical with,N. phyllophilum.

ISSN:0008-4026    

DOI:10.1139/b66-068

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

Apical growth of the leader and lateral branches, as well as radial increment at the top and bottom of the trunk, were studied in two black spruce trees during 1960–63. The study complemented that of the developmental anatomy of shoot tips from adjacent trees during the period 1955–62. Time of initiation of apical growth varied from the third week of May in 1960, 1962, and 1963 to early June in 1961. The termination period of apical growth extended from early July in the lower branches, until about 2 weeks later in the upper branches and leader. Radial increment in the trunk started at about the same time as bud swelling and continued into August. A temporary mid-summer cessation of radial increment occurred at the top of the tree in two consecutive years. The response to artificially induced short and long days from May to August in 12-year-old saplings indicated that initiation of apical growth is not affected by photoperiod. Short days were associated with a reduction in apical extension, needle length, and growth period.Reproductive buds could be recognized by early August, but the formation of ovuliferous scales or pollen sacs did not occur until several weeks later. The male cones differentiated about 1 week before the female ones. The consistent production of flower buds in black spruce compared to the sporadic formation in white spruce is partly attributed to the difference in time of initiation of apical growth. In black spruce the development of buds occurs about 2 weeks later, usually during a warmer part of the summer when conditions are considered more conducive to reproductive growth.

ISSN:0008-4026    

DOI:10.1139/b66-069

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

The specific separation ofCirsium hilliiandC. pumilumhas long been questioned. Their morphology, cytology, and distribution are discussed and it is concluded that two subspecies be recognized:C. pumilum(Nutt.) Spreng. ssp.pumilumand ssp.hillii(Canby) Moore & Frankton. The chromosome number of each subspecies is 2n = 30. Hybrids with the somatic chromosome numbers 31, 32 between ssp.pumilum(2n = 30) andC. horridulumMichx. (2n = 34) have been found in Massachusetts. It is suggested that introgression ofC. horriduluminto ssp.pumilummay be increasing variability of the latter.

ISSN:0008-4026    

DOI:10.1139/b66-070

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

Nine ascomycetes and two fungi imperfecti were found associated with cankers on branch swellings caused by western hemlock dwarf mistletoe,Arceuthobium campylopodumEngelm. formatsugensisGill, in an investigation in the coastal forest of British Columbia. One ascomycete is described asDurandiella tsugaesp. nov. The following fungi are discussed:Lachnellula agassizii(Berk, and Curt.) Dennis,Caliciopsis pseudotsugaeFitzp.,Capnodium spongiosumBarr,Durandiella tsugaeBaranyay sp. nov.,Helotiumsp.,Lophium mytilinum(Pers.) Fries,Mytilidion tortile(Schw.) Ell. & Ev. non Sacc,Retinocyclus abietis(Crouan) Groves & Wells,Biatorella resinae(Fr.) Mudd.,Epicoccum nigrumLink, andTruncatella truncata(Lév.) Steyaert.

ISSN:0008-4026    

DOI:10.1139/b66-071

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

3-Hydroxytyramine (dopamine; 3, 4-dihydroxyphenylethylamine) is reported for the first time as an algal constituent. It was isolated and crystallized in approximately 0.3% of the fresh weight of the green alga,Monostroma fuscum. The identity was established by the comparison of its physical and chemical properties with those of an authentic specimen. 3-Hydroxytyramine is the principal phenol and the natural substrate for phenolase in this organism.

ISSN:0008-4026    

DOI:10.1139/b66-072

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

A new genus of the Pottiaceae,Crumia, is proposed to accommodateMerceya latifoliaKindb. This species is shown not to be closely related toMerceya, but probably has greater affinity toTortulaandDesmatodon. Both sporophyte and gametophyte are described and illustrations show detailed structure and distribution.

ISSN:0008-4026    

DOI:10.1139/b66-073

出版商:NRC Research Press    

年代:1966

数据来源: NRC