Micropropagation of socotran fig, <Emphasis Type="Italic">Dorstenia gigas</Emphasis> schweinf. Ex Balf. F. —A threatened species,endemic to the island of Socotra,Yemen

Summary As an alternative to seed propagation, and efficient micropropagation system based on axillary shoot formation and subsequent rooting was developed for the threatened and medicinal plant species Dorstenia gigas (Moraceae). Three different basal media were tested. For the best basal medium, a modified WPM medium, different concentrations of the carbohydrates sucrose, glucose, fructose and maltose were tested. The total number of shoots was not markedly affected. For all carbohydrates but maltose, however, there was a reduction in the number of normal, healthy shoots for carbohydrate concentrations greater than 14.6 mM for the disaccharides and 27.8 mM for the monosaccharides (i.e., approximately 5 gl⁻¹). Using 14.6 mM (5 gl⁻¹) sucrose it has been possible to produce vigorous and true-to-type plants with a multiplication factor of approximately 2.6 per 6 wk.     

Some contributions of I.E. Purkyn? to the visual physiology

In the research of binocular vision J. E. Purkyn? pointed out the role of retinal corresponding areas. He observed binocular interaction of pressure phosphenes elicited in them and the fusion of images projected on the corresponding foveal areas even in eyes with artificial divergency. For the first time he proposed the examination of visual fields (perimetry) in several planes and he also introduced the colour perimetry. Purkyn? analyzed profoundly the different functions of direct (foveal) and indirect (peripheral) vision. In indirect vision he anticipated the modern concept of the useful field of view. Of fundamental importance was Purkyn?'s research of the strategy and different types of ocular movements. In analysis of motion perception, he evolved the hypothesis of "general sense of space" which is very close to modern feed-back conception of "corollary discharge".     

Description of Oerskovia gen. n. to Harbor ?rskov's Motile Nocardia

The genus Oerskovia is proposed to harbor actinomycetes forming an extensively branched substrate mycelium which usually breaks up into motile elements. Cell wall preparations contain major amounts of lysine and galactose. Aspartic acid is often present in major amounts. Aerial mycelium is not formed. Gram reaction and catalase production are positive. The type species is Oerskovia turbata comb. n.     

Fijian Business—a Bone of Contention. Was it One of the Factors Leading to the Political Crisis of 2000?

In this paper I seek to cast light on a particular aspect of the background for the political crisis in Fiji in 2000. Before and during this crisis politicians and media kept hammering on the theme of Fijians' inferior position in the economic life of the country. The public argument in Fiji further emphasised the success of the Indians and that this in turn further marginalised the Fijians. It was frequently asserted that the Fijians needed affirmative action in order to get on in the modern business world and that the new Prime Minister Mahendra Chaudhry was favouring the Indians. The theme of this article is that the rhetoric used prior to and during the crisis was a reiteration of a longstanding discourse in Fiji. Similar arguments were used in the 1970s and 1980s, particularly as a means of legitimating the coup in 1987, and during the regime of Rabuka in the 1990s. My primary concern here is not to document the success or failure of Fijians in modern business enterprises, but rather to make clear how the dichotomy of business‐vanua comprises a variety of concerns and doubts related to modernisation, urbanisation, ethnicity, belonging, values and choices. By constantly discussing and exposing the interface between business and vanua, money and land, people seek to make sense of complex urban situations. The ongoing debate may be looked upon as a ‘work of coherence’ in Hannerz’ terms, and as such is a debate on modernity.     

Physiological Mechanisms of <Emphasis Type="Italic">Solanum tuberosum</Emphasis> L. Plants’ Tolerance to Chloride Salinity

The mechanisms of potato (Solanum tuberosum L.) plants’ tolerance to chloride salinity were investigated in cv. Lugovskoi regionalized in Russia. Regenerated plants were produced in vitro from apical meristem and grown on half-strength Murashige and Skoog medium (0.5 MS) using a hydroponic unit in controlled-climate conditions. At the age of six weeks, the plants were exposed to salt stress (50–150 mM NaCl, 7 days). Plant response to salt stress was estimated by growth parameters (fresh and dry biomass of the aboveground and underground parts of plants, linear dimensions of shoot and root, area of leaf surface, and number of stolons) and physiological characteristics (level of photosynthetic pigments, accumulation of sodium, potassium, and calcium ions in the aboveground and underground parts of plants, content of proline, activity of antioxidant enzymes, plant tissue hydration, osmotic potential, and POL). It was found that, in response to salinity, the plants of potato, cv. Lugovskoi, showed a considerable inhibition of growth processes, reduction in chlorophyll a content, and suppression of stolon formation, which points to a rather low salinity tolerance of the cultivar. At the same time, under weak or moderate salt stress, the plants preserved water homeostasis owing to effective osmoregulation, actively accumulated proline that acted as a stress protector, and showed hardly any signs of oxidative stress. It was assumed that low salt tolerance of this cultivar depends on the inability of its root system to retain sodium ions and ensure selective ion transport to the aboveground part of the plant and on inefficiency of the system of sodium ions’ removal from the cytoplasm of leaf cells and their compartmentalization in the central vacuole with the purpose of reducing their toxic effect. The obtained results may be useful for working out a technique of improving salt tolerance of this cultivar by the methods of molecular genetics.     

Bi‐parental vs. cooperative breeding in a passerine: fitness‐maximizing strategies of males in response to risk of extra‐pair paternity?

In socially monogamous species, males that risk cuckoldry more than others might gain inclusive fitness by yielding paternity to relatives. We tested this prediction in the Tibetan ground tit Pseudopodoces humilis , an unusual facultative cooperative breeder wherein most helpers (87% males) join a mated pair shortly before clutch completion. Extra-pair paternity among bi-parental broods occurred less often (26% of broods, 9% of young) compared with cooperative broods (68%, 25%). In the former, most extra-pair sires (88%) were pair breeders unrelated to the cuckolded males, whereas in the latter, sires (87%) were mainly helpers related to the dominant males. Brood productivity did not differ between the bi-parental and cooperative breeders, but helpers' partitioning over group paternity reduced the realized reproductive success of helped males. After taking inclusive fitness into account, however, there was no difference in success of dominant males between the two social systems. One possible explanation for the differences in the rates of cuckoldry in the two systems was body size, because pair-bond males in bi-parental situations were significantly larger than those in cooperative ones. We propose two alternative strategies for males to maximize fitness: breed as a pair if large to avoid cuckoldry from helpers, or breed cooperatively if small but compromise some paternity to relatives. Our results provide an unusual route to the incidence of cooperative groups, based on constraints imposed by low competitive ability of breeding males rather than some external ecological or demographic factors.