scholarly journals Flowering and nectar and pollen flow in Geranium sanguineum L., Geraniaceae

2012 ◽  
Vol 59 (1) ◽  
pp. 165-175 ◽  
Author(s):  
Marzena Masierowska
Keyword(s):  
Honey Bees ◽  
Pollen Grains ◽  
Pollen Production ◽  
Flowering Period ◽  
Flower Buds ◽  
Total Sugars ◽  
Flower Nectar ◽  
Modified Stomata ◽  
Floral Nectaries ◽  
The Mean

This 3-year study examined the seasonal and daily dynamics of blooming, as well as the nectar and pollen production in <i>Geranium sanguineum</i> L. Moreover, the type and localization of floral nectaries were observed using LM and SEM, and measurements of pollen grains were performed. The visitation of insects on flowers was monitored, too. <i>Geranium sanguineum</i> bloomed from the beginning of May until the middle of July with the peak occurring between the second and the fifth week of flowering period. Most of the flower buds opened on plants in the afternoon hours. Flowers are protandrous. In a flower, nectar is secreted by five phanarothetic-discoid nectaries and it flows through modified stomata. It was found that one gland is bigger than the others. Ten flowers produced 30.58 mg of highly concentrated nectar, on average. The mean mass of total sugars secreted in nectar per 10 flowers was 7.94 mg. Pollen mass per 10 flowers was 23.14 mg, on average. Tricolpate, spherical pollen grains can be classified as very big size (sporae permagne). Flowers of <i>G. sanguineum</i> were visited mainly by honey bees, bumble bees and flies. Insects collected mainly nectar.

scholarly journals Studies on the Structure of Flowers and Inflorescences of Cornelian Cherry (Cornus mas L.)

2012 ◽  
Vol 40 (2) ◽  
pp. 53 ◽  
Author(s):  
Cevriye MERT
Keyword(s):  
Pollen Grains ◽  
Flower Morphology ◽  
Flower Number ◽  
Flower Buds ◽  
Cornelian Cherry ◽  
Cornus Mas ◽  
Conducting Tissue ◽  
Stereo Microscope ◽  
The Mean ◽  
Scanning Electron

This study reports on the arrangement of flower buds and structure of floral organs of cornelian cherry (Cornus mas L.) cultivars local to Turkey. The local cultivars were investigated under stereo microscope, light microscope, and scanning electron microscope (SEM). The results indicate that each node has two oppositely positioned buds on 1-year-old shoot. Inflorescences resembled the umbel structure that enclosed four (two sets of oppositely oriented) bud scales. The mean flower number varied between 16.3 and 19.9 per cluster among the cultivars. The flowers resembled the hermaphrodite type and one flower was found to have four rudimentary sepals, four petals, four stamens, and one pistil. The stamens were noted to be arranged around the base of the ovary. Each normal anther was observed to have two pollen-producing theca, and each theca was found to have two locules. The number of pollen grains per anther varied between 1380 and 4240 among the genotypes. The pistil was noted to have a deeply hollowed papillate stigmatic surface, and the central part of the style had conducting tissue. The ovarium part of the pistil was found to be surrounded by the nectary tissue, inferior type, and had two atropous ovules. The fruit resembled single-seeded, stone fruit type. This study is the first detailed study on the flower morphology and inflorescences of the cornelian cherry cultivars in Turkey.

Clonal variation in pollen-related characteristics of Douglas-fir

1982 ◽  
Vol 12 (2) ◽  
pp. 403-408 ◽  
Author(s):  
W. T. Adams
Keyword(s):  
Genetic Variation ◽  
Pollen Grains ◽  
Seed Orchard ◽  
Douglas Fir ◽  
Clonal Variation ◽  
Pollen Production ◽  
The Mean ◽  
Pollen Cone ◽  
Grain Diameter

The mean number of pollen grains produced per pollen cone (P) ranged from 37 310 to 62 960 ([Formula: see text], SE = 1584) among eight seed-orchard clones of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) and correlated significantly (r = 0.87, p < 0.05) with the mean number of microsporophylls per cone but not significantly with pollen cone length. The number of pollen grains per milligram (G) also differed among clones (range 2323–3112; [Formula: see text], SE = 32) and correlated significantly and negatively (r = −0.86) with grain diameter. Although this study provides evidence for genetic variation in both P and G, the differences were relatively small. Adjusting pollen-cone counts for P would add little, if any, precision to estimates of pollen production in seed-orchard clones. If balanced clonal representation in pollen mixes is desired, equal weights of pollen would probably suffice for most breeding applications.

scholarly journals Flowering of siberian peashrub (Caragana arborescens Lam.) and its forage value to pollinating insects

2014 ◽  
Vol 67 (3) ◽  
pp. 13-20 ◽  
Author(s):  
Ernest Stawiarz ◽  
Anna Wróblewska
Keyword(s):  
Pollen Grains ◽  
Growing Season ◽  
Average Weight ◽  
Pollen Production ◽  
Flowering Period ◽  
Caragana Arborescens ◽  
Pollinating Insects ◽  
Nectar Sugar ◽  
Single Flower ◽  
Forage Value

<p class="abstracttekst">Under the conditions of Lublin (central-eastern Poland), observations were conducted on the flowering of <em>Caragana arborescens </em>shrubs for two growth seasons as well as nectar and pollen production by the flowers of this species was investigated.</p><p class="abstracttekst">The flowering period of <em>Caragana arborescens </em>began at the turn of April and May and lasted for 24 days, while for a single flower it was 6.30 ± 0.79 days. The average weight of nectar, sugars and pollen produced by 10 Siberian peashrub flowers was, respectively: 46.70 ± 8.39 mg, 22.79 ± 6.10 mg, and 4.45 ± 0.34 mg. The nectar sugar concentration amounted 49.60 ± 10.08%. Pollen grains reached average dimensions of 21.94 ± 0.76 µm x 21.52 ± 0.71 µm. During a growing season, one <em>Caragana arborescens</em> shrub can provide on average 101.8 g of nectar, 49.7 g of sugars, and 9.7 g of pollen.</p>

scholarly journals Anther and Pollen Morphology and Anatomy in Walnut (Juglans regia L.)

HortScience ◽  
2010 ◽  
Vol 45 (5) ◽  
pp. 757-760 ◽  
Author(s):  
Cevriye Mert
Keyword(s):  
Electron Microscopy ◽  
Pollen Morphology ◽  
Juglans Regia ◽  
Staminate Flower ◽  
Pollen Grains ◽  
Pollen Grain ◽  
Pollen Production ◽  
Transmission Electron ◽  
Pollen Surface ◽  
The Mean

The morphology and ultrastructure of anthers and pollen grains were described for eight walnut (Juglans regia L.) cultivars (Şebin, Bilecik, Kaman I, Kaplan 86, Yalova 3, Pedro, Hartley, and Franquette) using light microscopy and scanning and transmission electron microscopy. Anther and pollen dimensions and pollen production capabilities were also determined. The mean number of stamens per staminate flower (14.90 to 20.03) and mean anther dimensions (1412.5 to 2553.5 μm in length and 849.0 to 1145.5 μm in width) differed significantly among the cultivars. The number of pollen grains per anther also varied significantly and ranged from 4720 to 9840 among the cultivars. The pollen grains of walnut plants are spherical in shape (nearly circular) and pantocolporate (with many colporate apertures on the exine). The pollen surface is microechinate with spiniferous projections. The germination pores are circular and nonbordered. Pollen grain length varied from 33.35 to 37.50 μm in the examined cultivars. The ultrastructure of the pollen walls was similar between walnut cultivars. The exine was comprised of nexine and sexine, which was thicker than the underlying nexine. The sexine appeared as a strong tectum that was traversed by thin channels and decorated with spinulose processes. The thicknesses of the various layers of the pollen wall were as follows: intine: 82.1 to 200 nm; exine: 793.1 to 1161.1 nm; and total wall: 954.4 to 1327.8 nm.

scholarly journals Pollen productivity and morphology of pollen grains in two cultivars of honeyberry (Lonicera kamtschatica (Sevast.) Pojark.)

2012 ◽  
Vol 60 (1) ◽  
pp. 73-77 ◽  
Author(s):  
Małgorzata Bożek
Keyword(s):  
Honey Bees ◽  
Pollen Viability ◽  
Pollen Grains ◽  
Pollen Production ◽  
Pollen Productivity

In the years 2004-2006, investigations on the abundance of pollen production in two cultivars of <i>Lonicera kamtschatica</i> (Sevast.) Pojark. - Atut and Duet, were conducted at the Felin Experimental Farm of the Agricultural University in Lublin. Moreover, the viability of pollen grains was estimated and measurements of their size were taken. Ten flowers of both studied cultivars supplied 11.42 mg of pollen and the average pollen productivity per 1 ha of a several-years-old plantation was 30.04 kg. The pollen of the observed plants was eagerly collected by honey bees. Pollen grains of both cultivars are suboblate. Considering their size, they can be described as large ones (P=47.55 µm, E=60.37 µm). Pollen viability for both cultivars is high, about 95%.

scholarly journals Reproductive Traits of Hermaphroditic Muscadine Cultivars

HortScience ◽  
2016 ◽  
Vol 51 (3) ◽  
pp. 255-261 ◽  
Author(s):  
Luiz A. Biasi ◽  
Patrick J. Conner
Keyword(s):  
Pollen Germination ◽  
Pollen Viability ◽  
Calcium Nitrate ◽  
Pollen Grains ◽  
Reproductive Traits ◽  
Pollen Grain ◽  
Flowering Period ◽  
Flower Buds ◽  
Vitis Rotundifolia ◽  
Ethanesulfonic Acid

Native muscadines (Vitis rotundifolia Michx.) are dioecious, but muscadine vineyards are usually planted with a mixture of female plants and hermaphroditic pollenizers. Hermaphroditic cultivars are derived from either of two separate sources original hermaphroditic plants, H1 or H2. Nine hermaphroditic and two female cultivars were studied to determine their potential as pollenizers. Inflorescences of each cultivar were collected in the field to evaluate the number of anthers per flower, the number of pollen grains per anther, and pollen viability and germination in the main and secondary flowering periods. The number of flower clusters per shoot ranged from one to four with most producing two or three flower clusters per shoot. The number of anthers per flower varied by cultivar and cluster position, but in general was between six and eight anthers per flower. ‘Noble’ showed the highest pollen grains production per anther and per flower, reaching 5777 and 39,860, respectively, in the first cluster and ‘Carlos’ produced the least amount of pollen. All cultivars that had secondary flowering showed lower pollen production per anther and per flower as compared with the main flowering period. Optimal muscadine pollen germination media contained 50 mg·L−1 boric acid, 145 mg·L−1 calcium nitrate, 188 g·L−1 sucrose, 10 g·L−1 agar, and 10 mm 2-(N-morpholino)ethanesulfonic acid (MES) pH 6.0. The pollen grain viability of hermaphroditic and female cultivars was high, but pollen grain germination was low in hermaphroditic cultivars and absent in female cultivars. H1-derived cultivars produced more flower buds per cluster and higher germination rates than H2-derived cultivars, indicating they may be better pollenizers. Chemical names used: 2-(N-morpholino)ethanesulfonic acid (MES).

INFLUENCE OF CLIPPING HEIGHT ON THE NEUTRAL CARBOHYDRATE LEVELS OF ROOT EXUDATES OF ALFALFA PLANTS GROWN UNDER GNOTOBIOTIC CONDITIONS

1972 ◽  
Vol 52 (4) ◽  
pp. 643-649 ◽  
Author(s):  
R. A. HAMLEN ◽  
F. L. LUKEZIC ◽  
J. R. BLOOM
Keyword(s):  
Root Exudates ◽  
Dry Weight ◽  
Root Tissue ◽  
Minor Components ◽  
Flower Buds ◽  
Total Sugars ◽  
Spectral Techniques ◽  
Mass Spectral ◽  
Mature Leaves ◽  
Carbohydrate Levels

Influence of clipping height on neutral carbohydrate levels in root exudates of alfalfa grown gnotobiotically was investigated by gas-chromatographic and mass-spectral techniques. Exudates were obtained from plants that were lightly clipped (removal of flower buds), intermediately clipped (15 cm), and severely clipped (removal of all but four mature leaves). Glucose, inositol, sucrose, and four unidentified (U) components were detected. Fluctuations in the level of sugars were observed in exudates from two sampling periods. Glucose and U1 were most concentrated under light clipping. Levels of inositol and sucrose were maximum under intermediate clipping. Amounts of U3 were greatest from severely clipped plants, whereas levels of U5 remained constant at all cuttings. Concentration of U4 was lowest under severe clipping. U2, present in exudates from seedling plants, was not detected. Quantities of sugars released per gram of dry weight of root tissue were greater under severe clipping. U1 was the major component, with glucose, inositol, and sucrose minor components of the total sugars.

POLLEN PRODUCTION AND DISSEMINATING PROPERTIES OF TRITICALE RELATIVE TO WHEAT

1972 ◽  
Vol 52 (4) ◽  
pp. 569-574 ◽  
Author(s):  
K. C. YEUNG ◽  
E. N. LARTER
Keyword(s):  
Seed Set ◽  
Marker Gene ◽  
Pollen Grains ◽  
Triticum Aestivum L ◽  
Hybrid Seed Production ◽  
Pollen Production ◽  
Hexaploid Triticale ◽  
Anther Length ◽  
Anther Extrusion ◽  
Wide Range

A study of the pollen production properties of three hexaploid triticale strains (Triticale hexaploide Lart.) showed that their anther length was significantly greater than that of wheat anthers (Triticum aestivum L. em Thell.) and the estimated number of pollen grains per anther ranged from 15,000 to 21,000. In comparison, a total of 8000 grains per anther was estimated for wheat, cult Manitou. Eighty-nine percent anther extrusion occurred in triticale cult Rosner, while Manitou averaged 70% anther extrusion. The period of anthesis of triticale varied according to strain but generally was of longer duration than in Manitou and thereby promoted outcrossing. Using a triticale strain carrying a dominant marker gene, 50% seed-set was obtained at a distance of 12 m leeward of the pollen source; however, a small percentage was still obtained at a distance of 30 m. It would appear from the limited number of triticales used in this study that a wide range of variability exists within this species in its pollen production and disseminating properties. With appropriate selection pressures, strains with an outbreeding habit could be developed for the purpose of hybrid seed production.

scholarly journals Thermoregulation in colonies of africanized and hybrids with Caucasian, Italian and Carniolan Apis mellifera honey bees

1999 ◽  
Vol 42 (4) ◽  
Author(s):  
Vagner de Alencar Arnaut de Toledo ◽  
Regina Helena Nogueira-Couto
Keyword(s):  
Apis Mellifera ◽  
Honey Bees ◽  
Maximum Temperature ◽  
Tropical Region ◽  
Internal Temperature ◽  
Africanized Honey Bees ◽  
Significant Difference ◽  
The Mean ◽  
One Year ◽  
Brood Nest

This experiment was carried out to study the internal temperature regulation of a colony of Africanized honey bees (AFR), compared with hybrid Caucasian (CAU), Italian (ITA), and Carniolan (CAR) bees, during the period of one year and different size hives located in a sub-tropical region. The instant internal temperature, 33.7 ± 1.5° C for the AFR, 33.5 ± 1.4° C for the CAU, 33.7 ± 1.5° C for the ITA and 33.8 ± 1.4° C for the CAR, did not show any significant difference (P>0.05). The maximum temperature (36.1 ± 2.3° C) was statistically different (P<0.05) from the minimum (27.6 ± 5.3° C). There was no difference (P>0.05) in the mean internal temperature, between the nucleus (31.7 ± 6.3° C) and the brood nest (32.1 ± 5.3° C) measured between two and four o'clock in the afternoon.

scholarly journals ATBS1-INTERACTING FACTOR 2 Negatively Modulates Pollen Production and Seed Formation in Arabidopsis

2021 ◽  
Vol 12 ◽  
Author(s):  
Yoon Kim ◽  
Sun-Ho Kim ◽  
Dong-Min Shin ◽  
Soo-Hwan Kim
Keyword(s):  
Pollen Grains ◽  
Starch Accumulation ◽  
Bhlh Transcription Factor ◽  
Pollen Production ◽  
Sucrose Transport ◽  
Seed Formation ◽  
Helix Loop Helix ◽  
Knockout Mutants ◽  
Auxin Signalling ◽  
Genes Encoding

ATBS1-INTERACTING FACTOR 2 (AIF2) is a non-DNA-binding basic-helix-loop-helix (bHLH) transcription factor. Here, we demonstrate that AIF2 negatively modulates brassinosteroid (BR)-induced, BRASSINAZOLE RESISTANT 1 (BZR1)-mediated pollen and seed formation. AIF2-overexpressing Arabidopsis plants (AIF2ox) showed defective pollen grains and seed production while two AIF2 knockout mutants, aif2-1 and aif2-1/aif4-1, displayed opposite phenotypes. Genes encoding BZR1-regulated positive factors of seed size determination (SHB1, IKU1, MINI3) were suppressed in AIF2ox and genes for negative factors (AP2 and ARF2) were enhanced. Surprisingly, BZR1-regulated pollen genes such as SPL, MS1, and TDF1 were aberrantly up-regulated in AIF2ox plants. This stage-independent abnormal expression may lead to a retarded and defective progression of microsporogenesis, producing abnormal tetrad microspores and pollen grains with less-effective pollen tube germination. Auxin plays important roles in proper development of flower and seeds: genes for auxin biosynthesis such as TCPs and YUCCAs as well as for positive auxin signalling such as ARFs were suppressed in AIF2ox flowers. Moreover, lipid biosynthesis- and sucrose transport-related genes were repressed, resulting in impaired starch accumulation. Contrarily, sucrose and BR repressed ectopic accumulation of AIF2, thereby increasing silique length and the number of seeds. Taken together, we propose that AIF2 is negatively involved in pollen development and seed formation, and that sucrose- and BR-induced repression of AIF2 positively promotes pollen production and seed formation in Arabidopsis.

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