摘要:

Double‐diffusion technique was used to investigate myxomycete relationships within the order Physarales. Extracts of plasmodia of 22 slime mold isolates were reacted with five antisera produced to Plasmodia ofDidymium nigripes, Physarella oblonga, Physarum polycephalum, Physarum gyrosumandFuligo septica.Two isolates ofFuligo septicatested alike. Four isolates ofPhysarum pusillumdid not test alike, and no valid conclusion of the relationship of this species was possible. These isolates showed strong serological affinity: (1)Physarum gyrosum, Physarella oblonga, two isolates ofFuligo septica, and possibly two isolates ofPhysarum pusillum, andPhysarum tenerum; (2)Physarum polycephalumandPhysarum flavicomum; (3)Fuligo septicaand many of the species tested; (4)Didymium nigripesand at least one isolate ofDidymium iridis.In most cases serologial relationships among species tested did not coincide with current taxonomy based on morphology of fructification.

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1967.tb10753.x

出版商:Wiley    

年代:1967

数据来源: WILEY

摘要:

Three new taxa are described:Dolyella hawaiiensisvar.clavatavar. nov.,Cottoniella triseriatasp. nov., andTaenioma dotyisp. nov. A modified characterization of the genusCottoniellais given, and certain critical distinctions between the species are presented.Taenioma dotyiis distinctive in the increased width of the determinate branches resulting from division of the flanking cells.

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1967.tb10754.x

出版商:Wiley    

年代:1967

数据来源: WILEY

摘要:

Spherosomes in plant tissue culture cells from normal sunflower stems and sunflower crown gall tumors reacted similarly to several nonfluorescent and fluorescent lipid dyes. Sudan IV and black B were good selective spherosome stains. The lipid fluorochromes, Nile blue and 3, 4‐benzpyrene were excellent selective spherosome stains and visualized the smallest particles more readily than did Sudan IV. Spherosomes could not be seen in tissues stained with Sudan IV or 3,4‐benzpyrene after ether‐alcohol extraction. Acid phosphatase was detected on the spherosomes in both normal and tumor tissues using the lead sulfide precipitation and the post‐incubation coupling procedures.

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1967.tb10755.x

出版商:Wiley    

年代:1967

数据来源: WILEY

摘要:

Chronic gamma irradiation of an oak‐pine forest on Long Island reduced populations of corticolous and terrestrial lichens in approximate proportion to the rate of irradiation. The decline in species diversity was approximately linearly related to logarithmic increases in daily radiation exposure. While a daily exposure of 2700 R/day was estimated to have reduced diversity to 50% in the first year, a linear extrapolation of diversity, coefficient of community and similarity curves to zero suggested that certain lichens would survive 3 years' exposure at daily rates of 5,000–10,000 R, possibly more. There was an apparent threshold at 300 R/day for radiation effects on the composition of lichen communities; changes in relative density occurred at lower exposures. The crustose forms were more resistant than foliose or fruticose forms, an observation which parallels previous observations that the most radio‐resistant higher plants tend to be of short, stature.

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1967.tb10756.x

出版商:Wiley    

年代:1967

数据来源: WILEY

摘要:

Salivary secretions injected into the cortex or outer phloem byAdelges piceae(balsam woolly aphid) feeding onAbies grandisinduce the production of wood that is in some respects similar to compression wood. Cambial activity was analyzed by examination of serial tangential sections through an annual ring in the xylem produced before infestation occurred and compared with similar sections from a ring produced after infestation. Growth after infestation was characterized by increased periclinal and anticlinal divisions of fusiform initials, increased production of new ray initials from fusiform initials and from anticlinal divisions of existing ray initials, and decline of numerous fusiform initials and termination of many tiers by maturation. This results in increased frequency of ray fusion and separation by decline or intrusion of adjacent fusiform initials. There was a marked increase in size and number of rays and number of parenchyma strands both of which also distinguish aphid‐affected wood from compression wood with which it frequently has been compared.

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1967.tb10757.x

出版商:Wiley    

年代:1967

数据来源: WILEY

摘要:

The flowers ofLimnocharis flava(L.) Buch. are borne in an indeterminate umbel and each consists of three sepals, three yellow petals, and about 18 carpels surrounded by numerous stamens and staminodia. The androecium is centrifugally developed, and the last‐formed members are staminodial; it is supplied by branching vascular systems. Carpels arise almost simultaneously, and a prominent residual floral apex remains. The carpels are partially conduplicately closed and are also primitive in possessing laminar placentation and in lacking differentiation of a style. The gynoecium is essentially apocarpous, but there are slight fusions of adjacent carpels near their ventral margins where they are attached to the receptacle. It is suggested that theLimnocharisflower is the most primitive in the family.

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1967.tb10758.x

出版商:Wiley    

年代:1967

数据来源: WILEY

摘要:

Chromosome counts of dividing nuclei of the myxomycetePerichaena vermicularisindicate a number of 25 ± 2 in the amoebae and 50 ± 4 in the Plasmodia, confirming earlier reports that amoebae are haploid and plasmodia diploid. Chromosome numbers obtained from nuclei during sporangial development indicate a fluctuation in the location of meiosis influenced by environmental conditions. The implications of these observations are discussed in reference to past conflicting evidence of the location of meiosis.

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1967.tb10759.x

出版商:Wiley    

年代:1967

数据来源: WILEY

摘要:

Leaf and tumor extracts of the genetically tumor‐conditioned amphiploidNicotiana glaucaXN. langsdorffii, as well as leaf extracts from the parent species and a nontumorous mutant of the amphiploid, were separated on acrylamide gel columns by the method of disc electrophoresis. Gels were stained for general proteins with amido black and specifically for esterases, peroxidases and leucine amino peptidase. The results show characteristic protein and enzyme patterns for leaves of each of the parental species and the amphiploid hybrids. The amphiploids show some bands which are comparable to bands of either one or both of the parental species, while other bands do not have their equivalents in the parental species. Leaf tissue of the tumorous and nontumorous amphiploids were found to differ by a few protein bands, at least two for esterases and at least one for peroxidases. Extracts from tumor tissue show very different patterns from those of the leaves of the same genotype.

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1967.tb10760.x

出版商:Wiley    

年代:1967

数据来源: WILEY

摘要:

Flowering and stem‐lengthening responses of the long‐day plantHyoscyamus nigerL. were followed under various photo‐ and dark‐period combinations. Phytochrome action was identified by its photoreversibility, spectral region of response, and requisite levels of irradiance. Flowering control was also affected by another photoreaction having an action maximum at 710–720 nm. This reaction, while observable over appropriate short periods, is best displayed by protracted irradiation. The effectiveness of this reaction has a half‐life of the order of 1–4 min. Responses to it can be observed over an intensity range of more than 100‐fold. The two photoreactions interplay in flowering control depending on light quality during photoperiods. The interplay is a prominent factor affecting the adequacy of fluorescent and incandescent‐filament radiation in plant growth experiments.

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1967.tb10761.x

出版商:Wiley    

年代:1967

数据来源: WILEY

摘要:

Outer cells from the root cap ofCattleyaorchids are characterized by their secretory activity. They are arranged in layers intercalated with layers of secretory product and form a protective mantle over the root tip. The ultrastructure of these cells is similar to those of terrestrial roots (for exampleZea mays) in that they are characterized by copious quantities of endoplasmic reticulum and numerous dense‐staining prevacuolar bodies. In contrast, most root cap cells of water hyacinth and duckweed are highly vacuolate with no dense‐staining prevacuolar bodies. The endoplasmic reticulum is sparse and dictyosomes are small and without secretory activity.

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1967.tb10762.x

出版商:Wiley    

年代:1967

数据来源: WILEY