Number Of Anthers Research Articles

Pollen Production in Relation to Ecological Class of Some Hydrophytes and Marsh Plants

The knowledge of quantitative production and method of dispersal give some idea about the frequency of presence of particular plant pollen grains in the atmosphere or hydrosphere. Pollen production in terms of number per anther along with the particular anther number per flower, anther length, pollen grain size, mode of anther dehiscence was determined for 51 angiospermous hydrophytes and marsh species occurring in Tripura, India. Pollen production is species specific. The level of pollen production directly related to the anther size and anther number per flower. However, no such correlation could be drawn between pollen production and size of pollen grains. Most of the hydrophytic taxa of the present investigation are anemophilous. The anemophilous taxa are characterized by high pollen production. However no correlation could be drawn from the present study between the high pollen production and mode of anther dehiscence as in all the studied taxa they show only one kind of anther dehiscence.

Amphicarpy in Trifolium argentinense: morphological characterisation, seed production, reproductive behaviour and life strategy

Trifolium argentinense Speg. is an amphicarpic species that occurs naturally in native pastures of Rio Grande do Sul, southern Brazil. Amphicarpy is a rare mode of reproduction in which aerial and subterranean seeds are produced by the same individual. In the present paper, we compare morphology, anther number, pollen viability, seed production and mode of reproduction of T. argentinense flowers, and comment on the life strategy of the species. Plants grown from aerial seeds and from the regrowth of storage roots of aerial plants had longer stolons and a larger plant diameter than did those grown from subterranean plants. Plants grown from seeds were also taller than plants grown from storage roots. More resources were allocated to subterranean reproduction in plants of subterranean origin than in those of aerial origin. Aerial flowers produced more seeds, presented more anthers and produced more pollen grains than did the subterranean ones. T. argentinense is a versatile species, self- and cross-pollinated, consistent with the values of high polymorphism information content. T. argentinense adopts the ‘pessimistic strategy’ (early allocation of energy to large subterranean propagules), common in amphicarpic species when growing in disturbed habitats, such as the native pastures of Rio Grande do Sul, where intense grazing and trampling, as well as long seasonal dry spells, may periodically destroy the aerial plants, thus assuring survival by germination of subterranean seeds and regrowth of storage roots.

Study of individual plant responsiveness in anther cultures of selected pepper (Capsicum spp.) genotypes

Abstract One of the key factors determining the effectiveness of pepper anther cultures is donor plant genotype. The stock material for androgenic embryos inductions is usually made up of hybrid forms, since the higher the degree of heterozygosity, the greater the chances of producing regenerates with unique genotypes. The aim of the presented research was to evaluate individual plant reaction in anther cultures for the C. annuum hybrid (‘ATZ1’ × ‘TG’)F2, interspecific hybrid (C. frutescens × C. chinense)F2 and androgenic DH line AT6. The effectiveness of androgenesis was determined individually for each plant as the percentage of the embryos produced compared to the total number of anthers cultured. In the hybrid (‘ATZ1’ × ‘TG’)F2, anthers of 19 out of 20 plants evaluated produced embryos at a rate of 0.5 to 16.5%. Anthers of the AT6 DH line formed embryos considerably less frequently. A positive reaction was recorded for 13 out of 20 plants and the effectiveness of androgenesis did not exceed 3% for this genotype. The lowest androgenic response was recorded for the hybrid (C. frutescens × C. chinense)F2, where embryo development was observed in only five out of 19 plants and the effectiveness of androgenesis did not exceed 2%. The ploidy level of the regenerates was defined cytometrically. The analysis revealed the presence of haploid and diploid plants among the regenerates of all the genotypes evaluated.

The estimation of Adonis vernalis populations in chosen patches of Lublin Upland

The number of <i>Adonis vernalis</i> populations, their size and abundance in xerothermic communities of the Lublin Upland have decreased significantly in the last 40-50 years, which indicates that there is a real risk of species extinction in the studied area. The paper is an attempt to indicate the possible factors which influence the decrease of <i>Adonis vernalis</i> populations. Detailed studies were carried out in six sites differing habitat conditions, land use and the size of <i>Adonis vernalis</i> populations. Observations were made of the abundance of blooming and the number of anthers per flower. The ability for reproduction was estimated indirectly by the mass of pollen delivered and its biological value. The populations of <i>Adonis vernalis</i> differ in number of anthers per flower (94.4 - 131.5, on average), the mass of pollen delivered (0.83 mg - 3.18 mg per 100 anthers, on average), the biological value of pollen and the size of pollen grains. Generally, stronger populations were characterized by better quality and a higher quantity of pollen. Potential energy of pollen in flowers from Pliszczyn and Łabunie was 69-72%, compared to 36%-47% in the remaining populations. Grass burning did not cause a reduction of potential biological value of <i>Adonis vernalis</i> pollen. Xerothermic swards in Pliszczyn and Kąty regularly burnt developed strong, most abundant populations of <i>Adonis vernalis</i> with favorable pollen. The development of the shrub layer, if it is out of control, stands in the way of satisfactory reproduction of halophilous <i>Adonis vernalis</i>.

Flowering, nectar secretion, pollen shed and insect foraging on Aquilegia vulgaris L. (Ranunculaceae)

This study on blooming biology, nectar secretion, pollen production and insect visitation of <i>Aquilegia vulgaris</i> L. was carried out in 2009 and 2011 in Lublin. The peak of flower opening during the day was between 5.00 and 7.00 (GMT +2). The flowers are protandrous with the female phase beginning approx. on the 3rd day of anthesis. The dynamics of nectar secretion and pollen shed from anthers (progressing from the central part of the androecium outwards) support the reproductive system. The amount of nectar accumulated in the spurs increased from the bud stage and was the highest in the phase with approx. ¾ of dehisced anthers, usually on the 3<sup>rd</sup> day of flower life. Then, towards the end of anthesis, the amount of secreted and accumulated nectar decreased. The number of anthers developed per flower varied from 41 to 61 (mean = 49.1). The mass of pollen per 100 anthers averaged 6.7 mg. Pollen production per flower (mean = 3.28 mg) slightly varied between years and was mainly correlated with the number of developed anthers. Estimated pollen yield was 1.69 g per m<sup>2</sup> and sugar yield 1.22 g per m<sup>2</sup>. Species from the genus <i>Bombus</i> were the main flower visitors, with <i>B. terrestris</i> being the most frequent forager.

The biology of flowering of winter aconite (Eranthis hyemalis (L.) Salisb.)

<i>Eranthis hyemalis</i> belongs to the Ranunculaceae family whose representatives enrich early spring pollen flow and nectar for pollinating insects. Flowering biology and morphological characteristics flowers of winter aconite were studied. The forage value was estimated as the rate of nectar production. Observations were carried out between 2008 and 2011 in the Botanical Garden of the Maria Curie-Skłodowska University located in the Lublin area. In the conditions of Lublin, flowering of winter aconite plants started at the beginning of February and lasted until the end of March. The seasonal bloom dynamics was strongly affected by maximum temperatures, which intensified flower blooming, and snowfalls which hampered this process. During the day, flowers opened between 8.00 am and 3.00 pm, but the highest intensity was between 10.00 am and 12.00 am. The process of pollen release, with the average number of 29 stamens shedding pollen in the flowers, lasted from 2 to 3 days. During the day the largest number of anthers opened at noon hours, between 11.00 am and 1.00 pm, though a certain rise in this number was also observed in the morning hours between 8.00 and 9.00 am. <i>Eranthis hyemalis</i> flowers develop funnel-shaped nectaries, on average 3-6 per flower. The determined amount of nectar per flower was 1.23 mg, while the concentration of sugars in it averaged 72.11%. The weight of nectar sugar per flower was 0.88 mg.

Comparison of Pollen Production and Quality Characteristics of Cultivated and Wild Almond Species

There are several wild almond species in Turkey included Amygdalus orientalis (Mill.), Amygdalus turcomanica (Lincz.), Amygdalus fenzliana (Fritsch) Lipsky, Amygdalus trichamygdalus (Hand.-Mazz.) Woronow, Amygdalus arabica (Olivier), and Amygdalus webbii (Spach). These species offer a great value for the almond improvement; we studied the pollen viability, germination ratio and pollen yield for seven genotypes of A. orientalis, seven genotypes of A. turcomanica all growing under natural conditions in Southeastern Anatolia (Gaziantep and Sanliurfa provinces, Turkey). Almond cultivars ( Prunus dulcis [Mill.] D.A. Webb) obtained from Pozanti Agricultural Experimental Station, Cukurova University, were also used in the experiment. The pollen viabilities of various almond genotypes were determined by 2,3,5-triphenyltetrazolium chloride (TTC) and fluorescein diacetate (FDA) tests. At the end, pollen germination ratios were established according to Petri dishes method in vitro conditions (1% agar + 0, 10, 15 and 20% sucrose) while pollen yield was estimated with hemacytometric methods. The results indicated that pollen viability ratios were close to each other in both methods for the genotypes A. orientalis and A. turcomanica. Pollen germination ratios were found to be dependent on the sucrose content as well as on the genotypes used. The pollen of almond cultivars showed similar germination ratios in all of the sucrose concentrations while those pollens of A. orientalis and A. turcomanica genotypes displayed higher germination ratios in 10% sucrose. The number of anthers in one flower was higher in cultivars whereas the number of pollen grains was lower in other almond species. While the number of pollen grains in one flower was relatively high in A. orientalis genotypes, pollen quality was high in all the three species under research. The results suggested that these two species, namely A. orientalis and A. turcomanica could be employed for future almond breeding programs.

Embryogenic callus induction and regeneration in anther culture of noug (Guizotia abyssinica (L.F) Cass.)

Two released noug varieties, Shambu and Fogera, were used for this experiment. Initially, two experiments were conducted to identify the appropriate morphological stage of capitula (buds) for harvesting maximum number of responsive anthers and to study the optimum cold pretreatment duration for callus induction from the anthers. Three culture media, MS, B 5 and NN, were employed for callus induction. MS medium, with nine different combinations of KN and IAA, was used for shoot regeneration study. Three different concentrations of IBA and growth regulator-free MS medium were used for the rooting experiment. The results showed that capitula, fully or slightly covered by sepal having whitish-green or greenish-yellow anthers, were the optimum stages of harvesting capitula; callus was efficiently induced when the capitula were pre-treated at 4 ° C for 24 hours. The types of calli induced significantly (P≤0.05) varied among the three media. Embryogenic calli were mainly produced in NN and B 5 media, while varying in texture and colour. High percentage of embryogenic calli (80%) was induced on NN medium from the variety Shambu, followed by b 5 medium showing 40% inductions for both varieties. Among nine different KN and IAA combinations, 2 mg/l KN combined with 1 mg/l IAA, was the most efficient for shoot regeneration. It was also found that 0.5 mg/l IBA was optimum for root induction. In the growth room as well as in the glasshouse, the survival rate of regenerants was generally better for the variety Shambu than for Fogera.

Phylogenetic Relationships ofAllomaieta,Alloneuron,Cyphostyla, andWurdastom(Melastomataceae) and the Resurrection of the Tribe Cyphostyleae

In the Melastomataceae, flowers with superior ovaries usually develop into capsular fruits, while flowers with inferior or partially inferior ovaries develop into berries. The phylogenetic position and affinities of four enigmatic genera with inferior ovaries and capsular fruits, Allomaieta, Alloneuron, Cyphostyla, and Wurdastom, were investigated using three plastid loci (rbcL, ndhF, and rpl16) and morphological characters. These four genera have been placed at times in their own tribe, the Cyphostyleae, but they have also been placed in the Miconieae, and whether they form a group at all has also been the subject of debate. We find that these four genera form a well-supported group that can be diagnosed by the unique character combination of haplostemonous flowers (same number of anthers and petals), inferior ovaries, and capsular fruits. Most members of the tribe also have a calyptrate calyx, but the mode of dehiscing of the calyx varies across species. This character combination and the phylogenetic position of this clade within the family warrant the recognition of the tribe Cyphostyleae. The previously proposed synonymy of Cyphostyla under Allomaieta is maintained, and a key to the genera in the tribe and a list of all species, with nomenclatural and taxonomic information, are provided. Lectotypifications for two species are also included.

Quantitative trait loci analysis of morphological traits in Citrus

The objectives of this study were to understand the genetic basis of morphological variation observed in the genus Citrus and its relatives and to identify genomic regions associated with certain morphological traits using genetic linkage mapping and quantitative trait loci (QTLs) analysis with random amplified polymorphic DNA (RAPD) markers. First, a genetic linkage map was constructed with RAPD markers obtained by screening 98 progeny plants from a {Citrus grandis × [C. paradisi × Poncirus trifoliata]} × {[(C. paradisi × P. trifoliata) × C. reticulata] × [(C. paradisi × Poncirus trifoliata) × C. sinensis]} intergeneric cross. The map contains 69 RAPD markers distributed into nine linkage groups. Then, 17 different morphological traits, including six tree and two leaf characters of 98 progeny plants and six floral and three fruit characters of about half of the same progeny plants were evaluated for 2 years and statistically analyzed for variation. Statistical analysis of individual traits indicated that trunk diameter and growth, tree height, canopy width, tree vigor and growth, leaf length and width, petal and anther numbers, petal length and width, length of pistil and style, fruit length and diameter, and fruit segment number showed normal or close to normal distribution, suggesting that these traits may be inherited quantitatively. Quantitative data from the morphological traits were analyzed to detect markers and putative QTLs associated with these traits using interval mapping method. QTL analysis revealed 18 putative QTLs of LOD > 3.0 associated with 13 of the morphological traits analyzed. The putative QTLs were distributed in several different linkage groups, and QTLs associated with similar traits were mostly mapped to the same LG or similar locations in the linkage group, indicating that the same genomic region is involved in the inheritance of some of the morphological traits.

Floral color variation and associations with fitness‐related traits inMalva moschata(Malvaceae)

AbstractGenetic polymorphisms for floral color are interesting phenomena to study because they are likely to be maintained by opposing selective forces. Pollinator preferences may exert direct selection on floral color; however, floral color might also be the indirect target of selection through genetic associations with other traits under selection.Malva moschata(Malvaceae) is a North American species that produces either red or white flowers. In the present study, we present reflectance spectrophotometry data that characterize the nature of floral color variation in this species and show that honey bees and bumble bees should be able to distinguish between the morphs through differential sensitivity at the green (long‐wavelength) photoreceptor. Second, we use a series of phenotypic measures to investigate whether the color morphs differ with respect to other floral traits, vegetative traits or female reproductive success, and use a series of correlation analyses to infer the relative independence of color from these other traits. We found that red‐flowered morphs produced more anthers per flower and had greater leaf area, and that white‐flowered morphs had greater percentage fruit set; however, there were no reproductive success differences between the morphs. The relationship between flower size and anther number was the only correlation that differed between the morphs. Finally, a series of pollinator‐choice experiments showed that bumble bees strongly prefer red morphs in terms of visit frequency and duration, but honey bees have no preference. Taken together, our results suggest that color is rather independent of other phenotypic traits, and that honey bee abundance is likely to play a role in maintaining color variation in this system.

An amended description of Rafflesia leonardi and a revised key to Philippine Rafflesia (Rafflesiaceae)

The taxonomic identity of Rafflesia banaoana from Kalinga Province in northern Luzon (Philippines) and its affinity with R. leonardi of the adjacent Cagayan Province are discussed. Both taxa share a unique combination of morphological characters pertaining to the color and shape of the perigone lobes, their warts, the diaphragm aperture, the size and number of disk processes, and anther number. The only notable difference between R. banaoana and R. leonardi is flower size and characters correlated with size. Because Rafflesia species show large intraspecific variation in flower size, and because R. banaoana and R. leonardi share a number of other morphological features, we conclude that these two taxa are conspecific. The name R. banaoana should therefore be considered a synonym of the earlier name R. leonardi. Here, we present an amended description of R. leonardi. An updated key to all ten known species of Philippine Rafflesia is also provided.

QTL involved in the partial restoration of male fertility of C-type cytoplasmic male sterility in maize

Partial restoration of male fertility limits the use of C-type cytoplasmic male sterility (C-CMS) for the production of hybrid seeds in maize. Nevertheless, the genetic basis of the trait is still unknown. Therefore, the aim to this study was to identify genomic regions that govern partial restoration by means of a QTL analysis carried out in an F(2) population (n=180). This population was derived from the Corn Belt inbred lines B37C and K55. F(2)BC(1) progenies were phenotyped at three locations in Switzerland. Male fertility was rated according to the quality and number of anthers as well as the anthesis-silking interval. A weak effect of environment on the expression of partial restoration was reflected by high heritabilities of all fertility-related traits. Partial restoration was inherited like an oligogenic trait. Three major QTL regions were found consistently across environments in the chromosomal bins 2.09, 3.06 and 7.03. Therefore, a marker-assisted counter-selection of partial restoration is promising. Minor QTL regions were found on chromosomes 3, 4, 5, 6 and 8. A combination of partial restorer alleles at different QTL can lead to full restoration of fertility. The maternal parent was clearly involved in the partial restoration, because the restorer alleles at QTL in bins 2.09, 6.04 and 7.03 originated from B37. The three major QTL regions collocated with other restorer genes of maize, a phenomenon, which seems to be typical for restorer genes. Therefore, a study of the clusters of restorer genes in maize could lead to a better understanding of their evolution and function. In this respect, the long arm of chromosome 2 is particularly interesting, because it harbors restorer genes for the three major CMS systems (C, T and S) of maize.

Número de anteras por flor, grãos de pólen por antera e capacidade germinativa do pólen de diferentes cultivares de macieiras

O objetivo deste trabalho foi avaliar o número de anteras por flor, grãos de pólen por antera e capacidade germinativa do pólen de diferentes cultivares de macieiras. O trabalho foi executado no Laboratório de Fisiologia do Desenvolvimento e Genética Vegetal da Universidade Federal de Santa Catarina, e as coletas a campo foram realizadas na Epagri/Estação Experimental de Caçador-SC, em outubro de 2005. Foram utilizadas as seguintes cultivares comerciais de macieira desenvolvidas no Brasil: Primícia, Princesa, Fred Hough, Catarina, Baronesa, Lisgala, Suprema, Condessa, Daiane, Duquesa, Imperatriz e Joaquina. As cultivares de macieira Condessa, Princesa, Eva, Duquesa, Imperatriz, Gala, Fred Hough, Daiane, Baronesa e Suprema produzem pólen em quantidade suficiente e com boa capacidade germinativa. A cv. Condessa, embora apresente alta capacidade germinativa de pólen, produz menos anteras e grãos de pólen por antera que as demais. A cv. Princesa é a que apresenta o melhor perfil como polinizadora, por conjugar número de anteras/flor, número de grãos de pólen/antera e capacidade germinativa do pólen mais satisfatórios.

Floral ontogeny of Knema and Horsfieldia (Myristicaceae): evidence for a complex androecial evolution

The floral ontogeny of two species of Knema and one of Horsfieldia was examined and described using scanning electron microscopy. The perianth is trimerous with three tepals arising in succession. Pistillate flowers have a rounded floral apex with a convex top. The single carpel primordium is initiated along the margin of the bud and develops a plicate shape with an apical bilobed stigma. In staminate flowers, the floral apex is broadly hemispherical with a somewhat three-sided shape. Several anther primordia are initiated almost simultaneously around the margin of the floral apex. In Horsfieldia, stamens extend laterally in antetepalous groups, whereas, in Knema, anthers form two whorls. The alternitepalous stamens were found to be different from the antetepalous stamens, which are pressed within a limited space. The anther primordia remain adnate to the receptacle and grow longitudinally, producing a pair of microsporangia. The central area of the floral apex persists as an undifferentiated residuum without any trace of a gynoecium. Myristicaceous anthers are basically homologous, although the number of anthers, pollen sacs and shape of the androecium are variable. The evolution of the androecium is discussed in the family, with opposing possibilities for reductions and increases in anther number in Myristicaceae. © 2010 The Linnean Society of London, Botanical Journal of the Linnean Society, 2010, 164, 42–52.

Styloceras connatum (Buxaceae), una Nueva Especie de Bolivia

A new species of the genus Styloceras Kunth ex A. Juss. (Buxaceae) was collected in the cloud forests of Madidi National Park and Pilon Lajas Biosphere Reserve and Communal Lands in the Bolivian Andes. We describe and illustrate S. connatum Torrez & P. Jorg., a taxon that has morphological similarities with S. penninervium A. H. Gentry & Aymard, but can be distinguished by the consistency of the leaves, numbers of anthers, flower color, and the characteristics of the fruit. A key to the species of Styloceras is provided.

Sex-allocation plasticity in hermaphrodites of sexually dimorphic Fragaria virginiana (Rosaceae)

Sex-allocation plasticity is thought to play an important role in the evolution of separate sexes in plants. Accordingly, much attention has been paid to environmentally induced variation in fruit and seed production in sexually dimorphic species, but we know little about whether this variation arises as a direct response to environmental variation or is instead an indirect consequence of changes in plant size. In this study, we characterize sex-allocation plasticity across a resource gradient for several reproductive traits in hermaphrodites of gyno(sub)dioecious Fragaria virginiana Duch. We find significant plasticity, on average, for flower number, proportion fruit set, ovule number, proportion seed set, and runner number in response to resource variation. Plasticity of most traits examined tended to be at least partially independent of variation in plant size, suggesting that it is not simply an indirect consequence of plant allometry. Moreover, we find genetic variation for plasticity of key reproductive traits. Comparisons of relative plasticities among traits reveal that F. virginiana hermaphrodites are more likely to adjust female investment via changes in fruit and seed set than ovule number, and most likely to adjust male investment via flower number rather than anther number or pollen per anther, although there is genotypic variation for plasticity in pollen per anther. Evidence of within-population variation can logically be extended to suggest that variation in hermaphrodite sex-expression seen among natural populations of F. virginiana may be due, at least in part, to sex-allocation plasticity.

Effects of ozone fumigation on cotton ( Gossypium hirsutum L .) morphology, anatomy, physiology, yield and qualitative characteristics of fibers

This experiment was conducted to study the effect of high ozone concentrations on two cotton ( Gossypium hirsutum L.) cultivars. Two cotton cultivars (Romanos and Allegria) were exposed to control (CF < 4 ppb O 3) and 100 ppb O 3. Plant exposure to ozone began eight days after emergence and was interrupted one day before removing the leaves, to calculate the leaf area. Plants were exposed to ozone 7 h/day, in closed and controlled-environment chambers, during their illumination with artificial visible light. In comparison to control plants, plants exposed to O 3 showed chlorotic and necrotic patches on their leaves, increased stomatal or epidermal cell density and yellowness of cotton fibers. Elevated ozone concentration did not have a significant effect on stomatal width, total leaf thickness and thickness of histological components of leaves. Exposure to ozone concentration reduced non-glandular hair density of main leaf veins, plant height, mainstem internode length, chlorophyll content, net photosynthetic rate, stomatal conductance and length and area of bracts and petals. Elevated ozone treatment reduced the maximum length of staminal tube, anther number, pollen grain germination, leaf area, leaf dry weight, boll number, raw cotton weight, total branch length, dry weight of the mainstem–branches–bracts–carpophylls and of root dry weight. Furthermore, exposure to O 3 reduced the seed weight, the lint weight, the yield, the ratio of lint weight to seed weight, the fiber strength, the micronaire, the maturity index and the fiber uniformity index values. This study shows that the exposure to high ozone concentrations mainly affected the rate of photosynthesis, raw cotton weight and strength of cotton fibers.

Pollen production, flowering and insect visits on Euphorbia cyparissias L. and Euphorbia virgultosa Klok

SummaryThis study investigated the morphological features, flower biology, pollen output and insects which foraged on Euphorbia cyparissias L. and Euphorbia virgultosa Klok. The observations were made between 2002 and 2006 on ruderal plots in Lublin, south eastern Poland. Both species formed inflorescences of the pseudantium type, known as cyathia. The number of inflorescences was 117.06 per shoot for E. cyparissias and 84.72 for E. virgultosa. The opening of spathe in the successive cyathia occurred almost simultaneously in both species, as early as at 6.00 h with the peak between 7.00 and 8.00 h. All cyathia of E. cyparissias are hermaphroditic. In the case of E. virgultosa, the bisexual cyathia on the shoots accounted for 58.3%. Hermaphroditic cyathia are protogynous. Dichogamy in Euphorbia virgultosa is strengthened through the occurrence of exclusively male flowers in part of the cyathia. The mean number of anthers per cyathium in E cyparissias and E. virgultosa, was 17.22 and 14.22, respectively. The small stamens of E. cyparissias yielded a mean of 0.38 mg of pollen per 100 anthers while the larger stamens of E. virgultosa yielded 0.51mg per 100 anthers. The weight of pollen per plant averaged 2.64 mg in E. virgultosa and 3.68 mg in E. cyparissias. Several hymenopteran species (Apis mellifera L. and solitary bees) visit E. cyparissias flowers. Additionally, Bombus spp. forages on E. virgultosa. Among the pollinators of both plants taxa, Diptera were present. Over the five-year period of observation, the density of species studied per square unit varied, but the plants renew each year. The associations with E. cyparissiasand E. virgultosa are not subjected to rapid succession. Hence, the studied species should be considered as an important component of the food chain for Apoidea and Diptera.

Inheritance of potential for in vitro androgenesis in spring barley

Inheritance of the ability to produce androgenic structures and regenerate plants in an in vitro anther culture with doubled-haploid spring barley lines derived from F1 reciprocal hybrids from crosses of cultivars with contrast (high × low), high (high × high), and low (low × low) growth capacity is studied. A general trend towards transgressive segregation in terms of the indices, “number of anthers with new growths” and “rate of regeneration of plants,” was found. The data attest to a major role of nonallelic interaction of genes in genetic control of in vitro androgenesis and their variance distribution in the parent forms of the hybrids.