GENETIC VARIATION IN THE PONDEROSAE OF THE SOUTHWEST

Ninety-five seedling populations of southwestern ponderosa pine (Pinus ponderosa var. scopulorum) along with single populations of Pinus engelmannii and Pinus arizonica were compared in four environmentally disparate common gardens. Differentiation among ponderosa pine populations was detected for a diverse assortment of variables that included patterns of shoot elongation, measures of growth potential, winter and spring freezing damage, and leaf characteristics. Multiple regression models accounted for as much as 85% of the variance among populations and described complex clines that were dominated by elevational and latitudinal effects. Although P. ponderosa, P. arizonica, and P. engelmannii were readily differentiated, the performance of progenies from one population suggested introgression primarily involving P. ponderosa and P. arizonica but also implicating P. engelmannii.     

METAMORPHOSIS IN THE ARACEAE

In the Araceae, as in many other monocotyledons, the stem undergoes gradual thickening as successive internodes are produced. Along with this primary thickening of the stem, successive foliage leaves will be larger and often more complex. In many species, in addition to these and other gradual changes, there are abrupt changes, metamorphoses, that occur under certain conditions. Some metamorphoses are the result of endogenous cycling (e.g., Syngonium, Rhektophyllum, Philodendron linnaei), some are a response to changes in conditions in the environment, usually the gain or loss of contact with a substrate (e.g., Syngonium, Monstera, Rhodospatha, Philodendron section Pteromischum), and some occur when the plant reaches a certain level of maturity (e.g., Monstera). Some of these latter changes are associated with a transition from monopodial to sympodial growth (e.g., Philodendron, Anthurium). Metamorphosis enhances the developmental plasticity of the Araceae in two distinct ways: it allows for a more complex relationship between size and shape in the development to maturity, and it allows shoots to engage in dispersal activities and developmental holding patterns when conditions are not suitable for development to the adult form and reproduction.     

ENROL IN THE SOCIETY

Earlé, R. A. 1981. Factors governing avian breeding in Acacia savanna, Pietermaritzburg, Part 2: Intrinsic factors. Ostrich 52:74-83.

The most important factor governing avian breeding in Acacia savanna is the body condition (protein reserve) of the bird. Breeding can take place only if the female has a large enough protein reserve to form eggs. The protein reserve is dependent on an adequate food supply which is once again dependent on climatic factors. Both the protein reserve and body weight of several species were found to be at their lowest towards the end of the breeding season. Moult and breeding were found to be largely separated in time. In most species examined testis activity was at its lowest between April and June and highest from September to January. Colius striatus showed a less seasonal pattern of testis activity while Nectarinia talatala showed very early testis activity and had fully active testes in May.     

NUTRITIONAL COMPARISONS IN THE LEPTOMITALES

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 in Mindeniella. No single carbon source would support growth in all of the Leptomitales. Apodachlya and Leptomitus were capable of hydrolyzing proteins and metabolizing amino acids, especially glutamate, proline, leucine, and alanine. Apodachlya, Araiospora, and Sapromyces utilized acetate, succinate, pyruvate and d (–) lactate. Leptomitus, Apodachlya, and Araiospora utilized l(+) lactate and succinate. Only Apodachlya metabolized malate. Three sugars, i.e., glucose, fructose, and sucrose, were excellent carbon sources for Mindeniella and Sapromyces. Both of these fungi were capable of growth and fermentation under anaerobic conditions. Utilization of these sugars was more restricted in Apodachlya, Leptomitus, and Araiospora. 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, and Araiospora are obligately aerobic, while Sapromyces is facultatively fermentative. Mindeniella is strongly fermentative even when grown in media with aeration.     

STUDIES IN THE GENETICS AND CYTOLOGY OF TWO SPECIES IN THE GENUS ASTER AND THEIR POLYMORPHY IN NATURE

The following genetical and cytological studies were made in conjunction with investigations in relative growth and morphogenesis (Delisle, 1938) in two species of Aster, A. novae-angliae L., A. multiflorus Ait.² and their hybrid. Certain aspects of this work appear significant when considered in relation to the polymorphy of these species and possibly have a bearing on the recognized polymorphy in the genus. A. novae-angliae is tall, hairy, stout, and relatively unbranched in the young stages, becoming corymbed only at the summit later. It has numerous large, soft, minutely pubescent, lanceolate, acute, entire leaves which are provided with marked auriculations at the base. The bracts of the involucre are loose, erect, nearly equal, glandular-viscid and linear; the heads are characteristically solitary on individual branchlets; the rays of the type species are violet-purple and those of the forms roseus (Desf.) Britton and geneseensis. House are rose and white, respectively. This species flowers from August to October, with the bulk of the plants blooming in September.     

HABITAT PREFERENCE IN THE BOMBINA HYBRID ZONE IN CROATIA

This paper demonstrates the effect of habitat heterogeneity and a habitat preference on the genetic structure of a hybrid zone between the toads Bombina bombina and B. variegata (Anura: Discoglossidae); 1613 toads from 85 sites across a transect near Pe??enica, Croatia, were scored for five unlinked diagnostic allozyme markers. These were found to be largely concordant. Aside from minor systematic deviations, there was little variance in allele frequency among loci within sites. Yet the allele frequencies did not follow a smooth cline, but formed a mosaic in the center, such that neighboring sites could differ markedly in their enzyme score. A detailed ecological survey revealed a correlation between this pattern and habitat. In keeping with the typical breeding sites of the parental taxa, B. bombina-like hybrids were found more often in ponds, whereas B. variegata-like hybrids were more common in puddles. In addition, there was significant heterozygote deficit (F_IS) and strong linkage disequilibrium (R), both of which were stronger on the B. bombina side of the transect, and stronger in puddles than ponds. Mark-recapture data showed: (1) that the animals disperse beyond the scale of the habitat pattern; (2) frequent turn-over of individuals within sites; and (3) nonrandom movement between two sites of different habitat type. We conclude that an active habitat preference must contribute to the observed association between marker alleles and habitat. As a consequence, there is incomplete mixing of the two gene pools, which could explain the high level of F_IS and R. The asymmetry in these parameters may reflect asymmetry in the preference or in the distribution of habitats across the zone. We discuss the implications of habitat preference for the dynamics of hybrid zones.     

THE DISTRIBUTION AND TAXONOMIC SIGNIFICANCE OF LIGNIN IN THE LEMNACEAE

Lignification characteristics of 14 species of Lemnaceae were studied by the alkaline oxidation technique in an attempt to resolve conflicting reports of the presence of lignin and to provide chemotaxonomic data for supplementing previous systematic treatments. Four species of Spirodela, eight of Lemna, Wolffiella oblonga, and Wolffia microscopica were clonally subcultured, homogenized, exhaustively extracted and the insoluble residue oxidized in alkaline cupric hydroxide. Barley (Hordeum vulgare), Elodea densa and Spirogyra sp. were examined to validate the technique. The benzaldehydes were extracted, separated by thin-layer chromatography, and quantitated spectrophotometrically. Recovery of syringaldehyde, vanillin, and to a lesser extent p-hydroxybenzaldehyde, was accepted as evidence that these plants are lignified. The highest yields of syringaldehyde and vanillin were recovered from S. intermedia, the largest member of the Lemnaceae. Lesser amounts were obtained from S. polyrhiza and S. oligorhiza. Spirodela biperforata yielded no syringaldehyde which substantiates its distinctiveness from the morphologically similar S. polyrhiza. All Lemna species are nerved, yet vanillin (but not syringaldehyde) was recovered only from L. trinervis, L. perpusilla, L. minor, and L. minima. The species L. trisulca, L. gibba, L. obscura, and L. valdiviano yielded only p-hydroxybenzaldehyde. Thus the presence of nerves is not evidence for lignification within the genus Lemna, and the relationships suggested by their gross morphology are not supported by their lignin chemistry. Wolffiella is non-lignified by these criteria. Wolffia microscopica is the smallest flowernig plant and it has no nerves; vanillin was unexpectedly recovered and microscopic examination showed highly lignified anther walls.     

THE CELL CYCLE TIME IN THE RAT JEJUNAL MUCOSA

The regional variation of the duration of cell cycle parameters was studied by constructing fraction of labelled mitoses curves at several levels in the jejunal crypt column of male Wistar rats. Prolonged T_c and T_s values were apparent only in the bottom eight cell positions, and these differences were shown to be significant compared with the remaining cell positions by analysing the data by the method of Gilbert (1972). Above cell position 8 the proliferating crypt cells showed effectively the same phase durations. For the whole crypt column T_c was 11.32 ± 0.14 (SE) and T_s 6.49 ± 0.10. Although variation in phase durations was confined to the basal portion of the crypt, the results essentially confirm the findings of Cairnie, Lamerton & Steel (1965a), and may be interpreted in terms of the slow cut-off model. The demonstration of prolonged T_c values in basal cell positions confirms the presence of a longer cycling subpopulation of cells at the bottom of the crypt.     

CHROMOSOME MORPHOLOGY IN THE GENUS SAMBUCUS

Two basic chromosome karyotypes were found in the genus Sambucus. Chromosome numbers were observed to be 2n = 38 for S. callicarpa, S. cerulea, S. glauca, S. kamtschatica, S. melanocarpa, S. mexicana, S. miquelli, S. sibirica, and S. sieboldiana and 2n = 36 for S. simpsonii and S. williamsii. Measurements of 18 karyotypes are presented. The major differences between the two basic chromosome karyotypes can be explained as the result of a mis-division of a metacentric chromosome giving rise to two telocentric chromosomes, thus reducing the number of metacentrics from five to four and increasing the chromosome number from 2n = 36 to 2n = 38. Observed chromosome aberrations and aneuploidy may result from unstable telocentric chromosomes.     

CRASSULACEAN ACID METABOLISM IN THE GESNERIACEAE

The occurrence of the Crassulacean acid metabolism (CAM) was studied in four epiphytic species of the Gesneriaceae: two neotropical species, Codonanthe crassifolia and Columnea linearis, and two paleotropical species, Aeschynanthus pulcher and Saintpaulia ionantha. Gas exchange parameters, enzymology, and leaf anatomy, including mesophyll succulence and relative percent of the mesophyll volume occupied by airspace, were studied for each species. Codonanthe crassifolia was the only species to show nocturnal CO₂ uptake and a diurnal organic acid fluctuation. According to these results, Codonanthe crassifolia shows CAM-cycling under well-watered conditions and when subjected to drought, it switches to CAM-idling. Other characteristics, such as leaf anatomy, mesophyll succulence, and PEP carboxylase and NADP malic enzyme activity, indicate attributes of the CAM pathway. All other species tested showed C₃ photosynthesis. The most C₃-like species is Columnea linearis, according to the criteria tested in this investigation. The other two species show mesophyll succulence and relative percent of the leaf volume occupied by airspace within the CAM range, but no other characters of the CAM pathway. The leaf structure of certain genera of the Gesneriaceae and of the genus Peperomia in the Piperaceae are similar, both having an upper succulent, multiple epidermis, a medium palisade of one or a few cell layers, and a lower, succulent spongy parenchyma not too unlike CAM photosynthetic tissue. We report ecophysiological similarities between these two distantly related families. Thus, the occurrence of CAM-cycling may be more common among epiphytic species than is currently known.     

THE MORPHOLOGY OF THE EXINE IN NIGELLA (RANUNCULACEAE)

The pollen morphology of eight species of Nigella (Ranunculaceae) was examined by scanning and transmission electron microscopy. The exomorphology of all species was identical: 3-colpate, spinulose, and punctate, but thin sections revealed two structural patterns. The ektexine structure of Nigella integrifolia, consisting of thickened foot layer, columellae, and thin tectum, is typical for the family as well as the order Ranunculales in general. In contrast, the remaining seven species, N. arvensis, N. damascena, N. elata, N. hispanica, N. sativa, N. segetalis, and N. stellaris, have an ektexine with an additional unit, a horizontal layer with shorter columellae, placed between the foot layer and tectum. Of all genera examined in the Ranunculaceae, only Nigella had this unusual stratification. This difference in the exine structure would add support to the treatment of N. integrifolia as a monotypic genus, Komaroffia integrifolia (Regel) Lemos Pereira.     

子囊菌亚门石耳科属级分类及拉诺属地位的研究

关于子囊菌亚门石耳科的属级分类问题地衣学家持有不同的观点。这些观点使属级分类出现了单属系统,二属系统,三属系统以及四属系统与五属系统。现在新二属系统,即石耳属一疱脐衣属系统已被越来越多的地衣学家和子囊菌学家所接受。但是,因为由Dodge (1968)描述的单种属拉诺属(Llanoa)的模式种与早已为人熟知的网脊石耳很相似,而近年来,这一单种属又被一些作者所接受、因此、我们不得不对该属模式种所依据的原始材料进行必要的复查。复查结果表明,拉诺属的模式种卖为网脊石耳的异名。因此,拉诺属也就成为石耳属的异名。此外,基于石耳科中三十五种地衣和五十二项特征的聚类分析结果也支持新的二属系统。     

THE MYCORRHIZAE OF PIONEER SPECIES IN DISTURBED ECOSYSTEMS IN WESTERN PENNSYLVANIA

Study plots with ten types of disturbances were established in a Solidago-Aster community in western Pennsylvania. One year after disturbance, 93% of all species had vesicular-arbuscular mycorrhizae (VAM) and accounted for 92% of all plant cover. After 3 yr, 96% of the species had VAM and 96% canopy coverage. An adjacent 10-yr Solidago-Aster community had 100% VAM species. The VAM annuals, Ambrosia artemisiifolia and Setaria glauca, were major first year dominants while VAM perennials, Agropyron repens, Solidago canadensis, and Aster ericoides, dominated at 3 yr. The mean percent mycorrhizae of all dominants at 1 yr was 39% and 34% at 3 yr. Four disturbed sites had 100% VAM colonization after 1 yr and six sites after 3 yr. Severe physical disturbances (topsoil removed and topsoil-subsoil removed) resulted in complete colonization by VAM species and mean mycorrhizal infections of more than 75%. The plowed-disked-prometone and plowed-disked-vapam disturbances resulted in low levels of mycorrhizae after 3 yr. The plowed-disked-atrazine plot showed an initial severe decrease in percentage of mycorrhizae, but doubled its infection rate by 3 yr. Three non-mycorrhizal species (Chenopodium album, Rumex acetosella, and Polygonuspersicaria) were observed during the 3-yr period. C. album was the major dominant after 1 yr in the plowed-disked-fertilized site and R. acetosella a dominant in the plowed-disked-prometone plot.     

UNUSUAL PHENOMENA IN THE LIFE HISTORIES OF FLORIDEAE IN CULTURE1

Several Florideae grown in natural seawater media under defined laboratory conditions have interesting and unusual life histories. Antithamnion occidentale males of one generation produced tetraspores that gave rise to nonsporangiate males. The functional females of A. pygmaeum developed spermatangia and tetrasporangia; the tetraspores formed new females. Antithamnion defectum tetrasporophytes of one generation bore spermatangia in addition to tetrasporangia; the tetraspores gave rise to typical gametophytes. Tetraspores from successive generations of Callitham-nion sp. developed into tetrasporophytes and males but no females were produced. Functional female gametophytes of Platythamnion sp. bore abortive tetrasporangia. Field-collected plants of two species of Fauchea produced tetraspores that yielded additional sporangiate plants: those of F. pygmaea being bispo-rangiate and tetrasporangiate, and those of F. lacini-ata being strictly tetrasporangiate. Male plants of Pleonosporium vancouverianum from a running seawater table bore spermatangia and polysporangia when collected. The same plants in unialgal culture produced only spermatangia.     

SEASONAL VARIATION IN SEXUAL SELECTION IN THE MOTTLED SCULPIN

Seasonal variation in sexual and natural selection in male mottled sculpins (Cottus bairdi) can be evaluated by calculating selection differentials, which measure the magnitude of phenotypic change resulting from selection, and by calculating indices of the opportunity for selection, which indicate the potential for phenotypic selection in a given interval. Selection differentials are high at the beginning of the breeding season and decline throughout the breeding season. The magnitude and direction of selection differentials depend on when spawning occurs and are independent of the size or age of the females that spawn. Annual selection differentials due to differences in mating success (female choice) are nearly constant between years. Annual selection differentials associated with hatching success are variable. Opportunities for selection (I = fitness variance/[mean fitness]²) show clear seasonal patterns. They are highest at the beginning and at the end of the spawning season. However, this variation is dependent on the mean used to calculate I, and hence variation in I values does not indicate a significant change in the variance of male fitness.     

GENETIC STRUCTURE AND EVOLUTION OF SPECIES IN THE MANGROVE GENUS AVICENNIA (AVICENNIACEAE) IN THE INDO-WEST PACIFIC

Allozyme variation in species of the mangrove genus Avicennia was screened in 25 populations collected from 22 locations in the Indo-West Pacific and eastern North America using 11 loci. Several fixed gene differences supported the specific status of Avicennia alba, A. integra, A. marina, and A. rumphiana from the Indo-West Pacific, and A. germinans from the Atlantic-East Pacific. The three varieties of A. marina, var. marina, var. eucalyptifolia, and van australasica, had higher genetic similarities (Nei's I) and no fixed gene differences, confirming their conspecific status. Strong genetic structuring was observed in A. marina, with sharp changes in gene frequencies at the geographical margins of varietal distributions. The occurrence of alleles found otherwise in only one variety, in only immediately adjacent populations of another variety, provided evidence of introgession between varieties. The varieties appear to have diverged recently in the Pleistocene and are apparently not of ancient Cretaceous origin, as suggested earlier. Despite evidence of high degrees of outcrossing, gene flow among populations was relatively low (N_em < 1–2), except where populations were geographically continuous, questioning assumptions that these widespread mangrove species achieve high levels of long-distance dispersal.     

BIOGEOGRAPHICAL AND TOPOGRAPHICAL VARIATION IN THE PREY OF THE BLACK EAGLE IN THE CAPE PROVINCE,SOUTH AFRICA

Boshoff, A.F., Palmer, N.G., Avery, G., Davies, R.A.G. & Jarvis, M.J.F. 1991. Biogeoraphical and toporaphical variation in the prey of the Black Eagle in the Cape Province, South Africa. Ostrich 62: 58–72.

Prey remains collected at or near Black Eagle Aquilu verreauxii nest sites in the Cape Province, South Africa, were analysed according to frequency of occurrence of prey scies in the samples. A total of 5748 prey individuals, collected from 73 sites, was analysed according to tree biome groups and four nest site types. The Rock Hyrax Procuvia capensis is the dominant prey species, but the eagles' diet sctrum vanestypes. The according to its availability. Indices of species richness and diversity of the prey are inverser correlated with the proportion of the prey contributed by P. capenis, which in turn is determined by topography and vegetation. Biome has a greater influence on the indices than has nest site type. The age structure of the P. capensis prey remains closely reflects the juvenile: sub- adult: adult ratios in the biomes and at the nest site tpes. hfedium-sized (aprox. 1–4,5 kg) pre is usually taken. Juvenile domestic small-stock (lambs ani goat kids) comprised onb 3,4% of the over, total.     

中国团黑粉菌属和团散黑粉菌属

本文报道我国团黑粉菌属10种,团散黑粉菌属22种。其中新组合8种,即:水蔗草团散黑粉[Sporisorium apludae (H. Sydow & Sydow) L. Guo]、营大孢团散黑粉[Sporisorium benguetensis (Zundel) L. Guo]、细柄草团散黑粉[Sporisorium capillipedii (Ling) L. Guo]、营小孢团散黑粉[Sporisorium exsertum (McAlp.) L. Guo]、芒粒团散黑粉[Sporisorium miscanthi (Yen) L. Guo]、黄茅粒团散黑粉[Sporisorium moniliferum (Ell. & Ev.) L. Guo]、光高粱团散黑粉[Sporisorium taianum (Syd.) L. Guo]和鸭嘴草团散黑粉[Sporisorium tanglinensis (Tracy&Earle) L. Guo]。     

SPECIES LIMITS IN THE LONG-BILLED PIPITS OF THE SOUTHERN AFROTROPICS

Clancey, P. A. 1985. Species limits in the long-billed pipits of the southern Afrotropics. Ostrich 56:157-169.

It has long been appreciated by systematists that the present polytypic species of Longbilled Pipit Anthus similis of the Afrotropics is composite, the populations inhabiting deciduous Miombo (Brachystegia) woodland south of the equator being specifically distinct from those of drier, more open and often mountainous terrain, to the south and northeast. Resolution of the complex requires the recognition of three species: the Longbilled Pipit Anthus similis Jerdon, the Wood Pipit A. nyassae Neumann and Jackson's Pipit A. latistriatus Jackson in which a new subspecies is proposed. The African Richard's Pipit A. cinna-momeus Rüppell is marginally involved. The current complicated mosaic of sympatric polytypic species of the Miombo woodlands biome extending from western Zaïre and Angola, to southern Tanzania, Moçambique and Zimbabwe results from a situation in which specifically discrete descendants of a primary colonization are sympatric with populations of a lineage resulting from a second colonization. The ancestral stocks are considered to be of Eurasian origin. They have become modified in Africa since the Pleistocene by the interaction of climatic and vegetational oscillations, dieback, subspeciation and adaptive convergence. The Mountain Pipit A. hoeschi of the southeastern highland massif of Africa is seen as a remotely detached isolate stemming from the same ancestral stock as the contemporary Jackson's Pipit A. latistriatus. A revised systematic arrangement of the taxa involved in this enquiry is proposed.     

GLYCOSYLATION PATTERN IN THE APPENDIX TESTIS IN CHILDREN WITH CRYPTORCHIDISM

In humans, at about week 6, sex cords develop within the forming testes. Testes normally descend to the scrotum; cryptorchidism occurs when one or two testes do not descend to scrotum and in some case are accompanied by the appendix testis. The appendix testis is a small sessile or polypoid structure located at the antero superior pole of the testis, adjacent to the head of the epididymis. Glycans can be involved in development of the appendix testis and cryptorchidism. In this work, lectin histochemistry was used to evaluate glycans expression in appendix testis in children with cryptorchidism. Our results showed that lectin from Lens culinaris, Ulex europaeus I., Canavalia ensiformis, Artocarpus integrifolia, Glycine max, and Griffonia simplicifolia recognizes epithelial and estromal cells. Not interaction was observed with lectin from Amaranthus leucocarpus, while lectin from Dolichus biflorus lectin only recognizes epithelial cells. Our results suggest that O-glycans linked in some glycoproteins represent important elements in appendix testis development.