摘要:

Certain aspects of the nutrition of five genera in Leptomitales, an order of aquatic fungi, were investigated. Asparagine was an adequate nitrogen source for all of the fungi tested. Ammonium sulfate could replace asparagine as the nitrogen source inMindeniella. No single carbon source would support growth in all of the Leptomitales.ApodachlyaandLeptomituswere capable of hydrolyzing proteins and metabolizing amino acids, especially glutamate, proline, leucine, and alanine.Apodachlya, Araiospora, andSapromycesutilized acetate, succinate, pyruvate andd(–) lactate.Leptomitus, Apodachlya, andAraiosporautilizedl(+) lactate and succinate. OnlyApodachlyametabolized malate. Three sugars, i.e., glucose, fructose, and sucrose, were excellent carbon sources forMindeniellaandSapromyces. Both of these fungi were capable of growth and fermentation under anaerobic conditions. Utilization of these sugars was more restricted inApodachlya, Leptomitus, andAraiospora. Each of the five genera is quite distinct physiologically. The order Leptomitales contains a spectrum of related organisms ranging from strongly fermentative to obligately aerobic.Apodachlya, Leptomitus, andAraiosporaare obligately aerobic, whileSapromycesis facultatively fermentative.Mindeniellais strongly fermentative even when grown in media with aeration.

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1968.tb07461.x

出版商:Wiley    

年代:1968

数据来源: WILEY

摘要:

Several developmental stages of primary roots of 13 species ofLinumwere studied. The basic pattern of root apex organization in three species consisted of a single tier of cortical initials. Ten species had a basic pattern of two tiers of cortical initials. Variations, manifested by either an increase or a decrease in the tiers of cortical initials, were observed in some roots in those species that had a basic pattern of two tiers of cortical initials. Although these variations were interpreted as being ontogenetic, there was no total reorganization of the root apex. There was anatomical and cytological evidence that a quiescent center is established inLinumroots.

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1968.tb07462.x

出版商:Wiley    

年代:1968

数据来源: WILEY

摘要:

The septal pores in uredial mycelium ofPuccinia graminisandP. reconditalack the septal swelling and septal pore cap (dolipore‐parenthosome configuration) typically associated with the pores of previously investigated Homobasidiomycetidae and the Tremellales among the Heterobasidiomycetidae. The pores in young hyphae of these two species ofPucciniaare characterized by the presence of a cytoplasmic matrix which apparently occludes the pore and acts as a plug, thus preventing the migration of organelles from cell to cell. Large vesicles are typically present at the periphery of the pore matrix and the matrix may be very incompletely bounded by a membrane. Nuclei and other cytoplasmic structures migrate from cell to cell through an opening in the septum lateral to the pore. The available evidence indicates that this peripheral gap in the septum results from a breakdown of a portion of an initially complete septum rather than from incomplete septum formation. In addition to the centripetally formed septa, the hyphae ofP. graminisandP. reconditaare further compartmentalized by shallow infoldings of the lateral wall and limited unilateral septum formation. There is apparent free passage of cellular material between adjacent compartments.

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1968.tb07463.x

出版商:Wiley    

年代:1968

数据来源: WILEY

摘要:

A reinvestigation of the female gametophyte ofArceuthobium douglasiishowed that the development conforms to theAlliumtype (bisporic), and the report of tetrasporic development is erroneous.

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1968.tb07464.x

出版商:Wiley    

年代:1968

数据来源: WILEY

摘要:

During the spring of 1966 and 1967, operation of the pollination mechanism ofPedicularis canadensisL. flowers by nectar‐ and pollen‐foraging bumblebee (BombusLatr.) queens was observed in an Iowa relict prairie and was recorded by high‐speed cinematography. The stigma and style were found to sweep the forager's pronotum crevice as head and tongue were introduced into the 12‐mm corolla tube. Pollen deposited in the crevice was not removed as the forager's middle leg only groomed pollen laterally deposited on head and scutum. Thirty corbicular pollen loads from 417 foragers collected on nine prairie plant species included pollen fromPedicularis canadensis, Aquilegia canadensisL.,Dodecatheon meadiaL., and two unidentified plants not found in the prairie. The pollination mechanism was considered closely adapted morphologically and phenologically to bumblebee queens of eight species found foraging onPedicularis.

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1968.tb07465.x

出版商:Wiley    

年代:1968

数据来源: WILEY

摘要:

Nuclear DNA was measured cytophotometrically in sections and isolated nuclei of the developing embryo ofVanda. The data were interpreted in terms of developmental stage and spatial relationships of the nuclei within the embryo. An equal amount of DNA was found in all meristematic nuclei regardless of the developmental stage of the embryo and was taken as the 2C value. Most of the nuclei in the parenchymatous region fell into the discrete DNA classes, 2C, 4C, and 8C. A significant number, however, had DNA contents above 8C but could not be grouped into classes based on a whole‐number multiple of 2C. Nuclear size was found to vary in direct proportion to DNA content through 8C. Above 8C, correlation between nuclear size and DNA content was poor. The amount of DNA in the nuclei of the parenchymatous region was shown to increase in direct proportion to the distance of the nucleus from the meristem. The average amount of DNA in parenchymal nuclei above 8C was found to increase with the developmental stage of the embryo. Mechanisms which might account for the observed changes in DNA per nucleus are discussed.

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1968.tb07466.x

出版商:Wiley    

年代:1968

数据来源: WILEY

摘要:

In an attempt to define a medium and to investigate the effects of glycine, floral buds ofAquilegiawere grown in culture on coconut milk and defined media containing either White's minerals or a new mineral formula, with and without glycine. Development obtained on the best defined medium was 66 to 76% of that achieved on the equivalent coconut‐milk medium. The inability of buds to achieve development equal to that on the coconut‐milk medium may be partially explained by the existence of a barrier to carpel formation and development. The effect of glycine on floral buds grown on a defined medium was dependent not only upon the minerals used but also on the stage of development of the bud. With White's minerals, glycine inhibited the development of buds in early and intermediate stages but was slightly promotive with buds in later stages. With the new minerals, glycine was slightly promotive with early and intermediate stages of development but was inhibitory with later stages. Further work is necessary before development on a defined medium will equal or exceed development on the coconut‐milk medium.

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1968.tb07467.x

出版商:Wiley    

年代:1968

数据来源: WILEY

摘要:

Clarkia gracilis(2n= 28) is an allotetraploid which combines genomes from two subsections of sectionPrimigenia. Natural populations consist of plants homozygous for a single chromosome arrangement, which may differ from the arrangements in other populations by one or more reciprocal translocations. One arrangement, the “standard,” was widespread. Cytological observations on plants derived from crosses between populations ofC. gracilis, and on triploid plants derived from crosses withC. amoenasubsp.huntiana, one of the parents of the tetraploid, were used to determine the end arrangements present. Ten arrangements were identified, and it was found that the standardamoenasubgenome ofC. gracilisis identical in end arrangement to the previously defined standard arrangement of the diploidC. amoena. Hence a race ofC. amoenawith this arrangement was involved in the hybridization which gave rise toC. gracilis. Evidence was found that other arrangements ofC. amoenahave probably been introduced intoC. gracilisby subsequent introgressive hybridization. Cytological differences, coupled with differences in morphology, ecology, and distribution indicate thatC. gracilisshould be subdivided into four subspecies instead of the three presently recognized.

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1968.tb07468.x

出版商:Wiley    

年代:1968

数据来源: WILEY

摘要:

Azolla montanais a new species from the late Cretaceous; it has a megaspore apparatus with a single large and conspicuous columella which resembles the floats of the megaspore apparatus of many extant species. The columella differs from true floats in being pilose, like the perispore of the megaspore body. The 10–20 small true floats are appressed to the columella, and are difficult to distinguish from it. It is suggested that the floats were derived, phyletically, by segmentation of the columella; the columella represents the primitive “float” of the megaspore apparatus.

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1968.tb07469.x

出版商:Wiley    

年代:1968

数据来源: WILEY

摘要:

Study of living hyphae ofFusarium oxysporumSchlect.,Fomes annosus(Fries) Cooke,Ceratocystis fagacearum(Bretz) Hunt,Basidiobolus ranarumEidam, andMycotypha microsporaFenner with phase contrast revealed that these fungi have spherosomes similar to those in vascular plants. The spherosomes are conspicuous in the hyphal tip, suggesting some function other than fat synthesis. It may be that the Woronin bodies reported by other workers are spherosomes. Mitochondria in these fungi are highly pleomorphic and exhibit saltatory movement. They often interact with nuclei in a manner suggesting close membrane contact.

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1968.tb07470.x

出版商:Wiley    

年代:1968

数据来源: WILEY