Reproductive isolation between two closely related species of the Queensland fruit fly Dracus tryoni (Frogg) and D. neohumeralis Hardy (Diptera : Tephritidae) II. Genetic variation in humeral callus pattern in each species as compared with laboratory-bred hybrids

1967 ◽  
Vol 15 (3) ◽  
pp. 515 ◽  
Author(s):  
H Wolda
Keyword(s):  
Entire Range ◽  
Fruit Fly ◽  
The Other ◽  
F1 Hybrids ◽  
Selection Experiment ◽  
Closely Related Species ◽  
Bright Yellow ◽  
Greenish Yellow ◽  
In The Wild ◽  
Range Of Variation

The variation in humeral callus pattern in Dacus tryoni is genetic. The more brown there is in the parents, the more there is in the offspring. The possible range of variation in D. tryoni obtained in a selection experiment is from an almost entirely yellow humeral callus to a completely brown one. The variation in Dacus neohumeralis is also genetic. The range of variation seen in D. neohumeralis in a selection experiment is from an entirely brown humeral callus to a very large yellow area. The possible range of variation extends probably to much more yellow. The actual colour forms obtained were different in the two species. For a given length of the yellow area in D. neohumeralis flies this yellow area is narrower, further away from the posterior margin of the humeral callus, further away from the posterodorsal margin and closer to the frontal margin, than it is in D. tryoni. In D. neohumeralis the yellow is dirty greenish yellow while in D. tryoni it is bright yellow. The range of variation in F1 hybrids between the two species is different again. The darker F1 flies closely resemble D. neohumeralis, in fact most F1 flies from these experiments were of this type. The more yellow F1 flies are very like D. tryoni and the ones intermediate between these two are unlike any D. tryoni or D. neohumeralis seen. The range of variation in F2 hybrids is much greater than in either species. In fact it covers the whole range of both species. Over the entire range of variation one finds some flies that look like variants of D. tryoni, some that look like variants of D. neohumeralis, and again some others that look different. At the darker end of the scale, variants resembling D. neohumeralis predominate while it is variants resembling D. tryoni that are most the frequent on the other end of the scale. The flies obtained from the wild could all easily be classified as either D. tryoni or D. neohumeralis variants. It is concluded that the occurrence of intermediates is no evidence for hybridization between the two species taking place in the field. The evidence available from the literature in favour of the hypothesis that the two species do hybridize is discussed and it is shown that this evidence can also easily be explained under the hypothesis that they are completely isolated reproductively. Selection in D. tryoni in the wild apparently favours flies with some dorsal brown and acts against both extremes, an entirely yellow humeral callus on one hand and more brown on the humeral callus on the other. Selection in D. neohumeralis in the wild apparently favours flies with a mottled brown humeral callus and acts against both plain brown and yellow areas. The nature of the selective factors bringing this about is still unknown.

Reproductive isolation between two closely related species of the Queensland fruit fly Dracus tryoni (Frogg) and D. neohumeralis Hardy (Diptera : Tephritidae) I. Variation in humeral callus pattern and the occurrence of intermediate colour forms in the wild

1967 ◽  
Vol 15 (3) ◽  
pp. 501 ◽  
Author(s):  
H Wolda
Keyword(s):  
Reproductive Isolation ◽  
Related Species ◽  
Fruit Fly ◽  
Abundant Species ◽  
Colour Pattern ◽  
Wild Populations ◽  
Closely Related Species ◽  
Similar Variation ◽  
In The Wild

A number of samples from wild populations of the Queensland fruit fly, Dacus tryoni and D. neohumeralis, were studied. There is a considerable variation in the colour pattern on the humeral callus. This variation is continuous so that any criterion for distinguishing between "intermediates" and "good species" is purely arbitrary. It was found in areas where D. neohumeralis does not occur as well as in localities where it is very abundant. By whatever criterion one defines intermediates, there appears to be no relation between the frequency of such forms and the presence or absence of D. neohumeralis or with the relative proportions of the two species in the population. However, flies with only a very small yellow area on an otherwise brown humeral callus were found only in Cairns where D. neohumeralis is usually the most abundant species. A similar variation in humeral callus pattern was found in other related species, such as D. kraussi and D. halfordiae. It is concluded that the intermediate colour forms may not be hybrids between D. tryoni and D. neohumeralis but variants of D. tryoni and, possibly the darker forms from Cairns, of D. neohumeralis.

Expression of amphicarpy in Vigna lanceolata morphotypes and their hybrids and implications for cultivar development

2016 ◽  
Vol 67 (9) ◽  
pp. 978 ◽  
Author(s):  
R. J. Lawn ◽  
L. M. Bielig
Keyword(s):  
Leaf Litter ◽  
Environmental Stresses ◽  
The Other ◽  
F1 Hybrids ◽  
Herbaceous Legumes ◽  
Similar Expression ◽  
Reproductive Structures ◽  
Cultivar Development ◽  
Heavy Grazing ◽  
In The Wild

Amphicarpy is an adaptation that enhances persistence under various environmental stresses, including heavy grazing, through the production of both aerial and underground seeds on the same plant. The trait occurs in several Australian endemic tropical herbaceous legumes, including Vigna lanceolata. The objective of the current research was to compare aerial and underground reproductive structures in six amphicarpic morphotypes of V. lanceolata (four perennials and two annuals), and in hybrids among these morphotypes and also with a seventh, non-amphicarpic perennial morphotype. The aim was to establish how easily the trait might be manipulated in a breeding program to develop improved amphicarpic cultivars, for ley and forage purposes. In the four amphicarpic perennials, the underground fruiting structures formed on leafless underground stems or rhizomes, and in all four, amphicarpy was habitual, i.e. individual plants routinely developed both aerial and underground fruiting structures. In the two annuals, the underground fruiting structures developed on specialised axillary geotropic stems that arose along the prostrate aerial stems and penetrated the soil or leaf litter. One of the annuals exhibited habitual amphicarpy, whereas the other was opportunistic, in that the underground fruiting structures developed only where aerial stems became covered with soil or leaf litter. F1 hybrids between the two annual morphotypes exhibited habitual amphicarpy, indicating dominance of habitual over opportunistic amphicarpy. F1 hybrids between the four perennial amphicarpic morphotypes were all amphicarpic, reflecting the similar expression of the trait in these forms. By contrast, when these four were crossed with the non-amphicarpic perennial, none of the viable F1 hybrids exhibited amphicarpy, suggesting dominance for non-expression. Many of the perennial F1 hybrids were self-sterile, but in the hybrids that were at least partially fertile, many more geocarpic than aerial seeds were produced, raising the possibility that in the wild, amphicarpy may facilitate the persistence of chance natural outcrosses that might otherwise not survive. The results suggested that it would be feasible to develop amphicarpic annual and amphicarpic perennial cultivars for, respectively, ley and forage purposes.

LABORATORY REARING OF THE WESTERN CHERRY FRUIT FLY, RHAGOLETIS INDIFFERENS (DIPTERA: TEPHRITIDAE): OVIPOSITION AND LARVAL DIETS

1977 ◽  
Vol 109 (9) ◽  
pp. 1227-1234 ◽  
Author(s):  
M. T. AliNiazee ◽  
R. D. Brown
Keyword(s):  
Wheat Germ ◽  
Artificial Diet ◽  
Choline Chloride ◽  
Fruit Fly ◽  
The Other ◽  
Larval Diet ◽  
Tropical Fruit ◽  
Laboratory Rearing ◽  
Greenish Yellow ◽  
Rhagoletis Indifferens

AbstractIn a laboratory study, larvae of the western cherry fruit fly, Rhagoletis indifferens Curran, were successfully reared on an artificial diet consisting of wood pulp, agar, wheat germ, Brewer’s yeast, sugar, salt, choline chloride, ascorbic, citric and propionic acids, cholesterol, methyl para-hydroxybenzoate (MPH), and water. Ten other diets consisting of various ingredients obtained variable results. A premixed tropical fruit fly diet (prepared by Nutritional Biochemicals, Cleveland, Ohio) was not suitable for rearing the cherry maggots. Formaldehyde was not satisfactory as a mold inhibitor.The eggs were obtained on artificial cherries made up of a soft ceresin wax. No oviposition occurred on the other materials tested (candle wax, a regular ceresin wax, beeswax, and silicone). Significantly (5% level) more eggs were deposited on wax cherries of orange, green, and greenish-yellow colors than black, red, white and blue. A laboratory rearing method employing orange colored wax cherries and an artificial larval diet was established for culturing the western cherry fruit flies.

scholarly journals Premating barriers in young sympatric snail species

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Arina L. Maltseva ◽  
Marina A. Varfolomeeva ◽  
Arseniy A. Lobov ◽  
Polina O. Tikanova ◽  
Egor A. Repkin ◽  
...  
Keyword(s):  
Gene Flow ◽  
Snail Species ◽  
Sympatric Populations ◽  
Gastropod Species ◽  
Shell Size ◽  
Closely Related Species ◽  
Partial Canonical Correspondence Analysis ◽  
In The Wild ◽  
Isolation Index

AbstractSympatric coexistence of recently diverged species raises the question of barriers restricting the gene flow between them. Reproductive isolation may be implemented at several levels, and the weakening of some, e.g. premating, barriers may require the strengthening of the others, e.g. postcopulatory ones. We analysed mating patterns and shell size of mates in recently diverged closely related species of the subgenus Littorina Neritrema (Littorinidae, Caenogastropoda) in order to assess the role of premating reproductive barriers between them. We compared mating frequencies observed in the wild with those expected based on relative densities using partial canonical correspondence analysis. We introduced the fidelity index (FI) to estimate the relative accuracy of mating with conspecific females and precopulatory isolation index (IPC) to characterize the strength of premating barriers. The species under study, with the exception of L. arcana, clearly demonstrated preferential mating with conspecifics. According to FI and IPC, L. fabalis and L. compressa appeared reliably isolated from their closest relatives within Neritrema. Individuals of these two species tend to be smaller than those of the others, highlighting the importance of shell size changes in gastropod species divergence. L. arcana males were often found in pairs with L. saxatilis females, and no interspecific size differences were revealed in this sibling species pair. We discuss the lack of discriminative mate choice in the sympatric populations of L. arcana and L. saxatilis, and possible additional mechanisms restricting gene flow between them.

Pimpinella ibradiensis (Apiaceae), an unusual new species from Turkey

Phytotaxa ◽  
2015 ◽  
Vol 217 (2) ◽  
pp. 164 ◽  
Author(s):  
İlker Çinbilgel ◽  
özkan Eren ◽  
Hayri Duman ◽  
Mustafa Gökceoğlu
Keyword(s):  
New Species ◽  
Geographical Distribution ◽  
Related Species ◽  
Conservation Status ◽  
Identification Key ◽  
The Other ◽  
Site Conditions ◽  
Closely Related Species

Pimpinella ibradiensis, an unusual new species found in the Toka Yayla (İbradı, Antalya) in southern Anatolia, is described and illustrated. Site conditions, synecology and conservation status of P. ibradiensis are considered. In light of the comparison with the other closely related four species, namely P. nephrophylla, P. flabellifolia, P. sintenisii and P. paucidentata, its similarity within the genus are discussed. P. ibradiensis is easly distinguished from its relatives by its white petals, presence of bracts and bracteoles, larger fruits (4–5.5 × 1–2 mm), and having serrulate basal leaves with 60–95 strongly cartilaginous teeth along margins. The geographical distribution of P. ibradiensis and closely related species are mapped and the identification key of those species is updated.

The Ecology of the Western Swamp Tortoise Pseudemydura Umbrina (Testudines: Chelidae).

1981 ◽  
Vol 8 (1) ◽  
pp. 203 ◽  
Author(s):  
AA Burbidge
Keyword(s):  
Water Temperature ◽  
Aquatic Organisms ◽  
The Other ◽  
Restricted Range ◽  
Monotypic Genus ◽  
Insect Larvae ◽  
Relict Species ◽  
Desiccation Rate ◽  
In The Wild ◽  
Growth Activity

Western swamp tortoise (Pseudemydura umbrina) was rediscovered in Western Australia in 1954. It is a relict species of a monotypic genus, of very restricted range and specialized habitat. Population was estimated to be 13 to 45 and decreasing at 1 of its 2 native reserves and to be 10 to 45 and static at the other reserve. It does not use permanent water, but lives and feeds in ephemeral winter swamps and spends the other 6 to 9 months of the year in refuges in leaf litter, under fallen branches or in holes in the ground, in contact with the soil. The tortoise is carnivorous and in the wild takes only live aquatic organisms. Captive adults will not take meat until they have starved for many months. Stomach of 1 female (Edward, pers. commun.) had aquatic crustaceans, chiefly Eulimnadia sp., with insects and insect larvae, mainly Coleoptera and Diptera. Study of faeces confirmed that observation had shown that small tadpoles and an aquatic earthworm (Eodrilus cornigravei) were eaten also. Reproduction, growth, activity relative to body and water temperature, and desiccation rate, were noted. One adult female tortoise was eaten by a fox. Foxes and bandicoots (Isoodon obesulus) eat eggs of other tortoises and would eat those of P. umbrina. Hatchlings may be eaten by large wading birds such as straw-necked ibis (Threskiornis spinicollis) and white-faced heron (Notophoyx novaehollandiae).

scholarly journals Analysis of variance of partial diallel tables

2000 ◽  
Vol 23 (1) ◽  
pp. 229-234 ◽  
Author(s):  
José Marcelo Soriano Viana ◽  
Cosme Damião Cruz ◽  
Antonio Américo Cardoso ◽  
Adair José Regazzi
Keyword(s):  
Genetic Variability ◽  
Common Bean ◽  
Statistical Tests ◽  
Diallel Analysis ◽  
The Other ◽  
F1 Hybrids ◽  
Dominance Testing ◽  
The Common ◽  
The Mean ◽  
Partial Diallel

The theory of variance analysis of partial diallel tables, following Hayman's proposal of 1954, is presented. As several statistical tests yield similar inferences, the present analysis mainly proposes to assess genetic variability in two groups of parents and to study specific, varietal and mean heteroses. Testing the nullity of specific heteroses equals testing absence of dominance. Testing equality of varietal heteroses of the parents of a group is equivalent to testing the hypothesis that in the other group allelic genes have the same frequency. Rejection of the hypothesis that the mean heterosis is null indicates dominance. The information obtained complements that provided by diallel analysis involving parents and their F1 hybrids or F2 generations. An example with the common bean is included.

Locomotion is not influenced by denticle number in larvae of the fruit fly Drosophila melanogaster

2005 ◽  
Vol 83 (2) ◽  
pp. 368-371 ◽  
Author(s):  
Mark J Fitzpatrick ◽  
Evelyn Szewczyk
Keyword(s):  
Drosophila Melanogaster ◽  
Related Species ◽  
Natural Variation ◽  
Fruit Fly ◽  
Fruit Flies ◽  
Negative Effects ◽  
Closely Related Species ◽  
Locomotory Performance ◽  
Locomotion Speed

Denticles are small projections on the underside of larval fruit flies that are used to grip the substrate while crawling. Previous studies have shown that (i) there is natural variation in denticle number and pattern between Drosophila melanogaster (Meigen, 1830) and several closely related species and (ii) mutations affecting denticle morphology have negative effects on locomotory performance. We hypothesized that there would be a correlation between denticle number and locomotory performance within populations of D. melanogaster. Despite finding considerable variation in denticle number, we found no correlation between denticle number and three measurements of larval locomotion: speed, acceleration, and absolute turning rate.

scholarly journals Repeated evolution of asymmetric genitalia and right-sided mating behavior in theDrosophila nannopteraspecies group

2019 ◽  
Author(s):  
Andrea Acurio ◽  
Flor T. Rhebergen ◽  
Sarah Paulus ◽  
Virginie Courtier-Orgogozo ◽  
Michael Lang
Keyword(s):  
Related Species ◽  
Current Data ◽  
The Other ◽  
Genital Morphology ◽  
Closely Related Species ◽  
Outgroup Species ◽  
Repeated Evolution ◽  
Drosophila Pachea ◽  
Species Specific ◽  
Group Species

AbstractBackgroundMale genitals have repeatedly evolved left-right asymmetries, and the causes of such evolution remain unclear. TheDrosophila nannopteragroup contains four species, among which three exhibit left-right asymmetries of distinct genital organs. In the most studied species,Drosophila pachea, males display asymmetric genital lobes and they mate right-sided on top of the female. Copulation position of the other species is unknown.ResultsTo assess whether the evolution of genital asymmetry could be linked to the evolution of one-sided mating, we examined phallus morphology and copulation position inD. pacheaand closely related species. The phallus was found to be symmetric in all investigated species exceptD. pachea, which display an asymmetric phallus with a right-sided gonopore, andD. acanthoptera, which harbor an asymmetrically bent phallus. In all examined species, males were found to position themselves symmetrically on top of the female, except inD. pacheaandD. nannoptera, where males mated right-sided, in distinctive, species-specific positions. In addition, the copulation duration was found to be increased innannopteragroup species compared to closely related outgroup species.ConclusionOur study shows that gains, and possibly losses, of asymmetry in genital morphology and mating position have evolved repeatedly in thenannopteragroup. Current data does not allow us to conclude whether genital asymmetry has evolved in response to changes in mating position, or vice versa.

scholarly journals The effect of cadmium contained in fertilizers on the cadmium content of vegetables

1979 ◽  
Vol 51 (1) ◽  
pp. 158-162 ◽  
Author(s):  
Antti Jaakkola ◽  
Johan Korkman ◽  
Tuomo Juvankoski
Keyword(s):  
Dry Matter ◽  
Fine Sand ◽  
The Other ◽  
Raw Material ◽  
Cadmium Content ◽  
Rye Grass ◽  
Wide Range ◽  
Npk Fertilizer ◽  
Clear Increase ◽  
Range Of Variation

The aim of the study was to find out to what extent the cadmium contained in fertilizer influences the cadmium content of vegetables. For this purpose, highly cadmium-bearing batches of fertilizer were prepared from selected quantities of raw material with an exceptionally high cadmium content. To one such batch of fertilizer, an extra amount of cadmium was added at the mixing stage. In a two-year field experiment carried out in soil consisting of clayey fine sand and begun in 1977, 1000 kg/ha of NPK fertilizer with a cadmium content of either 57 or 81 mg/kg brought about a clear increase in the cadmium content of radish tops. The cadmium content of radish roots, spinach and lettuce appeared likewise to rise, but the differences registered were not, owing to the unevenness of the field, significant. The cadmium content of the dry matter of rye grass was lower than that of the other experimental plants, and it appeared to rise less with an increase in the cadmium content of the fertilizer. Owing to the wide range of variation, the cadmium uptake of the experimental plants could not be determined reliably, The spinach, however, appeared to have taken up the largest amount of cadmium, and the rye grass the least amount. The increase in the cadmium content of the spinach harvested in 1978 corresponded to 1.5‰ of the cadmium introduced into the ground during the two-year period through application of the fertilizer with the highest content of the metallic element.

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