scholarly journals Notes on the self-pollination in Dendrobium biflorum (Orchidales, Dendrobiinae)

2012 ◽  
Vol 81 (3) ◽  
pp. 223-228 ◽  
Author(s):  
Agnieszka K. Kowalkowska ◽  
Hanna B. Margońska
Keyword(s):  
Pollen Grains ◽  
Weather Conditions ◽  
Pollen Tubes ◽  
French Polynesia ◽  
Growth Conditions ◽  
Society Islands ◽  
Self Pollination ◽  
Two Stages ◽  
Germination Of Pollen ◽  
First Time

The conditions favouring self-pollination are determined for a species of <em>Dendrobium </em>Sw. A survey of gynostemium micro­morphology in collected flowers of <em>Dendrobium biflorum </em>revealed two stages of a unique form of autogamy: on germination of pollen tetrads, pollen tubes reached the stigmatic region without the pollen being displaced from the anther locules. This is the first time for this type of autogamy to be reported in <em>Dendrobium biflorum</em>. Pollen grains germinated directly from the locules, bypassing the stigma or falling or sliding down onto the stigmatic surface. The pollen tubes were long and reached the stylar canal. On The Society Islands, differences in exposure of the habitats to weather conditions and altitude gradients influence both composition and form of the vegetation, as well as the occurrence of pollinators. The form of autogamy described here may be the usual method of pollination found on The Society Islands (and even the whole of French Polynesia), where suitable pollinators are absent and/or growth conditions stressful.

First record of the superfamily Proctotrupoidea from French Polynesia (Hymenoptera)

2020 ◽  
Vol 125 (4) ◽  
pp. 404-406
Author(s):  
Thibault Ramage
Keyword(s):  
First Record ◽  
French Polynesia ◽  
Society Islands ◽  
First Time

A Helorid wasp, Helorus ruficornis Förster, 1856, is reported for the first time on Tahiti (Society Islands), which is also the first record of both Proctotrupoidea and family Heloridae in French Polynesia. The potential hosts of Helorus ruficornis in French Polynesia are discussed.

scholarly journals The Campsicnemus lobatus and zigzag groups in the Society Islands, French Polynesia (Diptera: Dolichopodidae)

Zootaxa ◽  
2008 ◽  
Vol 1910 (1) ◽  
pp. 27-44 ◽  
Author(s):  
NEAL L. EVENHUIS
Keyword(s):  
New Species ◽  
Endemic Species ◽  
French Polynesia ◽  
Society Islands ◽  
Species Groups ◽  
Group 5 ◽  
First Time

The genus Campsicnemus is recorded for the first time from the Society Islands in French Polynesia. Two endemic species groups are recognized: the lobatus group (5 new species) and the zigzag group (5 new species) and keys given to species within them. The following 10 new species are described and illustrated: Campsicnemus borabora Evenhuis, n. sp. (Bora Bora); C. lobatus Evenhuis, n. sp. (Moorea); C. mylloseta Evenhuis, n. sp. (Huahine); C. ogradyi Evenhuis, n. sp. (Tahiti); C. ostlinx Evenhuis, n. sp. (Raiatea); C. paralobatus Evenhuis, n. sp. (Tahiti); C. rheocrenus Evenhuis, n. sp. (Tahiti); C. tahaanus Evenhuis, n. sp. (Tahaa); C. tunoa Evenhuis, n. sp. (Moorea); and C. zigzag Evenhuis, n. sp. (Tahiti).

Metabetaeus Borradaile, 1899 revisited, with description of a new marine species from French Polynesia (Crustacea: Decapoda: Alpheidae)

Zootaxa ◽  
2010 ◽  
Vol 2552 (1) ◽  
pp. 37 ◽  
Author(s):  
ARTHUR ANKER
Keyword(s):  
Marine Species ◽  
French Polynesia ◽  
Rapa Nui ◽  
Society Islands ◽  
Christmas Island ◽  
Distribution Ranges ◽  
The Indian Ocean ◽  
First Time ◽  
Detailed Diagnosis ◽  
Alpheid Shrimp

The alpheid shrimp genus Metabetaeus was previously known from two species associated with anchialine pools and caves, M. minutus (Whitelegge, 1897) and M. lohena Banner & Banner, 1960. In the present study, a somewhat unusual, coral reef inhabiting species of Metabetaeus, M. mcphersonae n. sp., is described based on one male and three female specimens collected off Moorea, Society Islands, French Polynesia. A detailed diagnosis of Metabetaeus is provided for the first time, accommodating characters of all three species. Distribution ranges are updated for M. minutus, recorded for the first time from Sulawesi and Christmas Island in the Indian Ocean, and for M. lohena, recorded for the first time from Rapa Nui (Easter Island). A key to the species of Metabetaeus is also provided.

scholarly journals Impact of temperature and air moisture on pollen viability

2020 ◽  
Vol 183 (3) ◽  
pp. 51-57
Author(s):  
D.V. Starikova ◽  
◽  
Yu.D. Syrova ◽  
L.A. Gorlova ◽  
◽  
...  
Keyword(s):  
Nutrient Medium ◽  
Sucrose Solution ◽  
Pollen Viability ◽  
Pollen Grains ◽  
Weather Conditions ◽  
Reproductive Organs ◽  
Weather Factors ◽  
Winter Rapeseed ◽  
Germinating Pollen ◽  
Germination Of Pollen

The environments have a direct impact on formation and functioning of the generative organs in plants. Parameters characterizing viability of pollen grains are closely linked with weather conditions, especially temperature and air moisture. Very often a phase of a beginning of flowering of winter rapeseed (end of March – beginning of April) lasts in unfavourable conditions. In April 2020, we studied influence of the main weather factors (frosts, low moisture) on germination of pollen grains of the varieties Loris, Sarmat and hybrids 40059 × Jesper 16– 132 and 40008 × INRA of winter rapeseed bred in VNIIMK. Pollen viability was determined by B.A. Trankovsky’s method, accounting amount of germinating pollen grains on the artificial nutrient medium, calculating a percentage of germinating pollen grains to their total quantity. We determined optimal concentration of sucrose solution (20%) in a nutrient medium for germination of pollen of winter rapeseed varieties and hybrids. Due to our results, lowered air temperatures (from -0.5 to -1.9 оС) combined with air moisture from 39 to 86% in a period of beginning of crop flowering negatively influenced on germination of pollen grains. Viability of pollen of the varieties Loris and Sarmat was in average 47 and 37%, respectively. Pollen grains of the hybrids (F1 40059 × 52 Jesper 16-132 and F1 40008 × INRA) had less viability – 38 and 21%, respectively, this certifies higher susceptibility of tissues of the reproductive organs to low temperature and moisture.

scholarly journals Reproductive capabilities of representatives of the genus Hosta Tratt. when introduced in the forest-steppe zone of Western Siberia

2021 ◽  
pp. 58-68
Author(s):  
L. L. Sedelnikova ◽  
Keyword(s):  
Western Siberia ◽  
Reproductive Potential ◽  
Pollen Grains ◽  
Weather Conditions ◽  
Steppe Zone ◽  
Seed Morphology ◽  
Forest Steppe ◽  
Seed Productivity ◽  
High Viability ◽  
First Time

In the forest-steppe zone of Western Siberia, a comparative study of seed productivity, flowering features, fruit and seed morphology, pollen fertilization ability was conducted for the first time in representatives of the Hosta Tratt genus: H. decorata, H. sieboldiana, H. lancifolia, H. albomarginata, H. crispula, H. kikutii, H. montana, H. rectifolia, H. undulata and varieties Golden Tiara, Night before Christmas, and Stiletto. It is noted that the reproductive potential and fertility of pollen in 9 species and 3 varieties of host have intraspecific and varietal specificity and are associated with seasonal weather conditions. The results of free pollination of the host were studied. It was found that fruit formation within a single generative shoot is heterogeneous, with the exception of the species H. decorata. The coefficient of productivity of species is 16—93%, varieties 12.5—36.4%. Morphometric indicators of length of generative shoots, fruits and seeds are presented. It is shown that the fruit is a freely opening loculicidal tricuspid capsule. Seeds are linear to oval in shape. It was revealed that with high viability of pollen grains (46—82.6%) in H. albomarginata, H. rectifolia, H. sieboldiana, the productivity coefficient is 2—3.8 times lower than in H. decorata. The flowers are characterized by geitonogamy with the phenomenon of peterandre, chasmogamous pollination and flowering in acropetal direction. H. decorata has a high adaptive advantage of seed productivity. The studied species and varieties consistently pass all the phenophases of development and are characterized by vitality. The growing season from spring growth to fruiting in Novosibirsk is 98—112 days. The reproductive capabilities of the host during introduction in the forest-steppe zone of Western Siberia are realized partly due to seed reproduction and are distinguished by species and variability.

scholarly journals The effect of oleander glycosides on the germination of pollen grains and the mitosis of the generative nucleus in Tradescantia bracteata Small and Allium cepa L.

2015 ◽  
Vol 44 (3) ◽  
pp. 451-460 ◽  
Author(s):  
J. A. Tarkowska
Keyword(s):  
Allium Cepa ◽  
Water Solution ◽  
Pollen Grains ◽  
Pollen Tubes ◽  
Nerium Oleander ◽  
Generative Nucleus ◽  
Effect Of Water ◽  
Allium Cepa L ◽  
Germination Of Pollen

The effect of water solution of a mixture of glycosides from oleander (<i>Nerium oleander</i> L.) on the germination of pollen grains and on the mitosis of the generative nucleus in <i>Tradescantia bracteata</i> Small and <i>Allium cepa</i> L. has been studied. An inhibition of the germination and of the growth of pollen tubes was observed, proportionally to the concentration of glycosides. The pollen grains of <i>A. cepa</i> are more sensitive. The disturbances in mitosis lead to the formation of two or more uneven-sized doughter nuclei, or to the formation of restitution nuclei. These anomalies are more numerous in <i>T. bracteata</i>. From these results d t appears that pollen grains of <i>A. cepa</i> are characterized by a generally high physiological sensitivity and a small mitotic sensitivity, wheras for <i>T. bracteata</i> the opposite is true.

scholarly journals ОСОБЕННОСТИ РАЗВИТИЯ МУЖСКОГО ГАМЕТОФИТА СОСНЫ ОБЫКНОВЕННОЙ PINUS SILVESTRIS L. В УСЛОВИЯХ ГОРОДСКОЙ СРЕДЫ

2016 ◽  
Vol 6 (01) ◽  
pp. 390-408
Author(s):  
L.P. Khlebova ◽  
O.V. Bychkova
Keyword(s):  
Urban Environment ◽  
Male Gametophyte ◽  
Pollen Viability ◽  
Pollen Grains ◽  
Weather Conditions ◽  
Pollen Tubes ◽  
Biological Indicator ◽  
Histochemical Staining ◽  
Pinus Silvestris ◽  
Germinated Pollen

<p>The peculiarities of the development of the male gametophyte of Pinus silvestris L. in the urban environment were studied. Quality of pollen was evaluated by laboratory experiments through germination at the nutrient medium and by histochemical staining to determine the presence of redox enzymes. It was shown that pollen viability is closely linked to climatic and weather conditions during the period of microsporogenesis and mass pollination. Atmospheric pollution affected the pollen significantly. Low temperatures and high humidity in the background of the weak capacity of self-purification of the atmosphere led to a reduction of the potential pollen viability. The ability of the pollen grains to germinate was reduced, the number of abnormal pollen tubes was increased, and the proportion of cells containing active peroxidase was decreased. We revealed a close positive correlation between the frequency of germinated pollen grains and the presence of active peroxidase, as well as a negative correlation between the percentage of colored pollen and the frequency of pollen tube anomalies, which confirmed the role of peroxidase activity not only in the induction of pollen germination, but also the formation of pollen tubes.<br />A ranking of the urban territory on the strength of unfavorable environmental factors has been carried out. The reaction of male gametophyte of pine allowed us to consider it as a biological indicator of unfavorable ecological situation in the urban environment.</p>

scholarly journals Pollination and pollen germination in common juniper (Juniperus communis: Cupressaceae)

2018 ◽  
Vol 18 (4) ◽  
pp. 162-174 ◽  
Author(s):  
Mikhail Surso
Keyword(s):  
Pollen Germination ◽  
Pollen Viability ◽  
Chemical Properties ◽  
Morphological Structure ◽  
Pollen Grains ◽  
Weather Conditions ◽  
Pollen Tubes ◽  
External Agents ◽  
Amino Acids Composition

Pollination and fertilization are the most important and responsible stages in sexual reproduction of coniferous plants. The period of high concentrations of juniper pollen in overhead during pollination period is no more than 4–6 hours and within one calendar day. This dependence remains invariable from year to year, and does not depend neither from weather conditions, nor the peculiarities of the place where juniper grows. Influence of external agents on dynamics of exudation of a juniper pollination droplet is studied. The duration of exudation and volume of secretory liquid exuded by tissues of ovules during the period of prescription in the juniper depend from presence of external agents on a surface of pollination droplet, their sizes and physical and chemical properties. The pollination droplet chemical compound is studied. In sugars composition of juniper pollination droplet there are only two monosaccharides: glucose and galactose. the amino acids composition is prevailed by arginine, aspartic and glutamic acids. The results of the studies confirm complex chemical composition and multifunctionality of juniper pollination droplet. The pollination mechanism of juniper is effective and selective. The morphological structure of pollen grains of juniper predetermines the processes of pollen germination at early stages. The hydrophilic capsule, formed pollen hydration, promotes to exine rupture and shedding. This capsule remains until the fertilization. The distal tip of pollen tube remains in itduring all time of its growth. In culture in vitro development of pollen tubes of juniper proceeds non-uniformly. At definition of juniper pollen viability it is necessary to consider a stage of pollen tubes development.

scholarly journals The biological value of pollen of some blackcurrantcultivars (Ribes nigrum L.)

2012 ◽  
Vol 59 (1) ◽  
pp. 147-154 ◽  
Author(s):  
Bożena Denisow
Keyword(s):  
Significant Influence ◽  
Agar Medium ◽  
Pollen Grains ◽  
Weather Conditions ◽  
Pollen Tubes ◽  
Ribes Nigrum ◽  
Biological Value ◽  
High Viability ◽  
Germination Ability

The studies were carried out in 1994-1997. The experimental bushes were grown in Puławy. Eight cultivars were examined ('Ben Alder', 'Ben Lomond', 'Ben Nevis', 'Ben Tirran', 'Ceres', 'Ojebyn', 'Titania', 'Triton'). Pollen grains viability was estimated in acetocarmine slides, while germination ability was estimated on agar medium. All cultivars showed high viability (80-100%). Weather conditions (especially temperatures at the time of blooming) had significant influence on germination ability. In colder years, only 10-40% of pollen produced pollen tubes, while in warmer years 50-80%. The biological value of blackcurrant pollen grains can be more effectively estimated on the basis of their ability to form pollen tubes than their viability.

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