Varietal Distinctions Research Articles

Wild Buckwheat, Eriogonum inflatum (Polygonaceae): An Enigmatic Plant

The characteristics of the upper first internode of flowering stems of Eriogonum infla- tur have been regarded as indicators of varietal differences within the species: var. inflatum, with inflations; var. deflatum, without inflations. Inflations also have been claimed to be caused by galling insects. Studies on three populations in central and northwestern Arizona indicate that each individual passes through a stage without inflated stems before producing inflated stems, indicating that these varietal distinctions are invalid. Also, inflations developed without insect attack, and a population in northwestern Arizona has large inflations in the total absence of insect attack. Eriogonum inflatum Torr. et Frem., wild buckwheat or desert trumpet, is a common component of the native flora in many areas of the arid southwestern United States and northern Mexico. Occurring in the Mohave and Sonoran deserts and adjacent uplands, mostley below 1,200 m elevation, the scapose perennial has a basal rosette of leaves and branched flowering stems up to 1 m tall, with striking inflations found in the upper portion of the lowermost internode of many plants, and often in the second and third internodes of larger plants. There is some doubt about the validity of the varieties E. inflatum var. inflatum and deflatum Johnst. (Stokes, 1936; Stone and Mason, 1979), although a recent monograph treats them as biological realities (Reveal, 1976). While the literature generally has regarded the inflated stems as an intrinsic character of the species, Stone and Mason (1979) have argued that these stems are induced by insect attack and should be regarded as insect galls (caused by pyralid moth or mordellid beetle larvae). This study was initiated to attempt to understand the nature of inflations, partly because the arguments made by Stone and Mason (1979) were not com- pletely convincing: (1) In one population they reported that 97% of inflated stems showed insect damage(p. 78), but the question of why 3% should have inflated stems but no insect damage was not addressed. (2) The authors noted that in greenhouse studies neither seedlings nor transpanted stock developed inflations and concluded that in the absence of insects these did not develop (p. 79). The alternatve hypothesis that conditions in the greenhouse were not sufficiently favorable for development of inflated stems was not considered. (3) the authors observed that larger inflations usually contained larvae whereas smaller inflations were damaged but without larvae, concluding that the longer a larva was present the larger the inflation would become (p. 80). However, the alternative hypothesis was not evaluated that larvae select preformed inflations and remain in them according to the amount of food present. (4) The authors also argued that inflations on internodes above those attacked were induced by the larvae in the lower internode (p. 80-81). This would be a most unusual effect of a galling insect without an apparent adaptive value to the insect. (5) Stokes (1936) had suggested that the inflations failed to develop in extremely dry conditions, but this possibility was not examined by Stone and Mason (1979).

Determination of varieties and cultivars in peruvian coca: Determinacion de variedades y cultivares en Erythroxylon L.)

Due to the various geographical and ecological sites in which the cultivated coca species ( Erythroxylon coca Lam. and E. novogranatense Morris Herion.) are found, some specimens do not correspond to the usual specific descriptions. Field observations, morphological and anatomical studies and chemical composition of the cultivated species allow us to recognize varietal distinctions in the Peruvian cocas. In accordance with the International Code of Botanical Nomenclature of Cultivated Plants, the Peruvian cocas must be considered as cultivars instead of botanical varieties.

Varietal identification of single seeds of barley by analysis of hordein polypeptides

AbstractMethods for the extraction and separation of hordein fractions from single or half‐seeds of barley have been evaluated. Sodium dodecylsulphate‐polyacrylamide gel electrophoresis at pH 8.9 gave rapid and reproducible separations of reduced and alkylated hordein, and this system was used to analyse hordein fractions from 88 barley varieties. On the basis of this character the varieties can be divided into 29 groups, each containing between one and 25 varieties. The largest group can be further divided into four subgroups on the basis of minor hordein polypeptide differences revealed by a second electrophoretic system, urea polyacrylamide gel electrophoresis at pH 4.6. Of the samples of the varieties studied, all except five contained seed homogeneous with respect to hordein polypeptide pattern. It is concluded that analysis of hordein polypeptide patterns from single seeds is of great potential value, both for the commercial identification of grain samples and as an aid to existing techniques for the establishment of varietal distinctness.

Cheilanthes kuhnii var. brandtii and the Composition of Its Farina

Cheilanthes kuhnii Milde var. brandtii (Fr. & Sav.) Tagawa is a fern endemic to central Honshu in Japan. This fern is morphologically characterized as follows. The fragile stipes are 8-20 cm long, castaneous, and bear broadly lanceolate, pale brown scales on the lower parts. The laminae are narrowly ovate, tripinnatifid, 15-30 cm long, and 6-13 cm wide. They are summer-green, thinly herbaceous, and more or less farinose beneath. The indusia are continuous in fully soriferous leaves, but sometimes are interrupted in less soriferous ones. According to Ching (1941), this fern belongs toAleuritopteris sect. Dalhousiae, characterized by not or thinly farinose laminae and relatively thin texture. He regarded it as being identical with C. kuhnii Milde var. kuhnii of Korea, Amur, Manchuria, and North China. But typical C. kuhnii of the mainland of Asia has lanceolate and rather deeply dissected laminae. The Japanese plants seem to be more appropriately treated as a variety of C. kuhnii. Cheilanthes kuhnii var. brandtii is usually not rare in the habitats where it grows, but its geographical range is limited to the limestone areas of central Honshu. It is usually found in rather open, dry, and more or less disturbed places, such as on roadside rocks or stone walls near villages, but rarely is found on moist and shaded rocks deep in the mountains. The density of the white farina on the lower surface of the lamina is strongly influenced by the habitat. The plants in open and dry places bear a considerable amount of farina, whereas those in moist and shaded places are hardly farinose. Makino (1917) described var. efarinosa having non-farinose laminae, but it seems to be only an extreme form not worthy of varietal distinction.

Transplantation of seagrasses, with special emphasis on eelgrass, Zostera marina L.

A background, listing the history of transplanting seagrasses is given. There is a need for seagrass field planting methods owing to the extremely high productivity of seagrasses and the perturbations they are subjected to. I have planted vegetative stocks and seeds of Zostera marina L. (eelgrass) across tidal zones, across latitudinal zones (from Alaska into Puget Sound), and into water deeper than indigenous growth. Data from these plantings indicate: (1) varietal distinctions based on leaf dimensions are invalid; (2) the possibility of local physiological race distinction in eelgrass; (3) the depth limit of eelgrass is due to a lack of suitable light deeper than a certain minimum depth; and (4) eelgrass seedlings require a higher light intensity than is present deeper than a certain minimum depth. Thus, transplanting experiments yield much more data concerning seagrass biology than just planting method information.

Characterization and classification of mycorrhizae of Douglas fir. I. Pseudotsuga menziesii + Poria terrestris (blue- and orange-staining strains)

Two newly discovered ectotrophic mycorrhizae of Douglas fir (Pseudotsuga menziesii (Mirb.) Franco), each formed by a distinct strain of Poria terrestris (DC. ex Fries) Sacc., are described. Each is named according to tree and fungus species, including strain of the latter as denoted by characteristic staining of respective sporocarps: Pseudotsuga menziesii + Poria terrestris (blue-staining) and P. menziesii + P. terrestris (orange-staining). Macro- and micro-scopic descriptions of the natural mycorrhizae, of surrounding mycelia and rhizomorphs, and of nutrient agar cultures of each fungal strain of P. terrestris are given. The two described strains of Poria terrestris are proposed for at least varietal distinction on the basis of their mycorrhizal and cultural differences.

VARIETAL AND ENVIRONMENTAL EFFECTS ON RAPESEED: I. ISOTHIOCYANATE AND THIOOXAZOLIDONE CONTENT

The isothiocyanate and thiooxazolidone content was determined on seven rapeseed varieties grown at seven locations across Western Canada. The isothiocyanate content varied significantly for varieties but not for stations whereas the thiooxazolidone content differed significantly for both varieties and stations. The Argentine-type could easily be distinguished from the Polish-type as the thiooxazolidone content was approximately three times greater in the former. No such varietal distinction was found for the isothiocyanate content.

Studies of vinegar bacteria

AbstractAn account is given of vinegar‐producing bacteria isolated by one of the authors (R. M. N.) in the Department of Agriculture, Nairobi, and also of acetic acid bacteria isolated from English malt vinegar acetifiers. The cultures selected in East Africa consisted mainly of strains of Acetobacter acetigenum, A. xylinum and A. acetosum: two of the organisms have been accorded varietal distinction under the respective names A. acetosum var. nairobiense and A. xylinum var. africanum. Of 10 pure cultures isolated from English acetifiers, 4 organisms which formed surface pellicles were provisionally identified as A. kützingianum (2 strains), A. xylinum (1 strain) and A. pasteurianum (1 strain), while 6 non‐pellicle‐formers were considered to be strains of A. acetosum and A. ascendens.

Investigations on the Varietal Distinctions of Crop Plants in the Resistance to the Toxic Action of Potassium Chlorate and their Physiological Signification

Investigations on the Varietal Distinctions of Crop Plants in the Resistance to the Toxic Action of Potassium Chlorate and their Physiological Signification

Insects of Arctic Canada

THE insects of various orders—as well as a few spiders, mites, and centipedes—collected by members of the recent Canadian Arctic Expedition (1913–18) have been recorded and described in vol. iii. of the Report (Ottawa, 1919–20). The lists contain much information of value to. students of zoological geography. Among the Lepidoptera (described by Arthur Gibson) it is interesting to see varieties of such well-known British butterflies as Pieris napi, Papilio machaon, and Vctnessa antiopa. Most of the Coleoptera (by J. M. Swaine, H. C. Fall, C. W. Leng, and J. D. Sherman) belong to species already known in North America, and the same remark applies to the bees described by F. W. L. Sladen, who points out that buryible-bees are “particularly well adapted to Arctic conditions,” and records the capture of five nearly full-fed Bombus larwe on Melville Island (75° N. lat.) on June 21, 1916. The sawflies, described by A. G. MacGillivray, are mostly new species, and, as might have been expected, willow feeders. Among the Diptera (by C. P. Alexander, H. G. Dyar, and J. R. Malloch) there are some interesting details of larvae as well as descriptions and records of flies, which are relatively numerous in species. The occurrence of larvæ of Oedemagena tarandi—the warblefly of the European Reindeer—in Barren-ground Caribou at Bernard Harbour is noteworthy. Mosquitoes of a couple of species of the genus Ædes were observed (and felt) in swarms. As regards wingless parasites, Prof. G. H. F. Nuttall records that headlice (Pediculus caitis) from the Copper Eskimo of Coronation Gulf show no varietal distinction from members of the species found elsewhere. Dr. J. W. Folsom enumerates a dozen species cf springtails (Collembola); two only of these are new, but his figures of structural details, drawn carefully from Arctic specimens of common and widespread northern forms, will be welcome to students of this order.