scholarly journals REPRODUCTIVE BIOLOGY OF TWO EDIBLE HONEYSUCKLES [Lonicera edulis Turcz. ex Freyn., Lonicera kamtchatica (Sevast.) Pojark.] IN THE CONDITIONS OF SOUTHWESTERN SLOVAKIA

2020 ◽  
Vol 19 (3) ◽  
pp. 63-72
Author(s):  
Ľuba Ďurišová ◽  
Tünde Juríková ◽  
Pavol Jr Eliáš ◽  
Jiří Mlček
Keyword(s):  
Female Gametophyte ◽  
Pollen Grains ◽  
Reproductive Organs ◽  
Climatic Conditions ◽  
Pollen Grain ◽  
Flower Initiation ◽  
Winter Dormancy ◽  
Normal Appearance ◽  
Male And Female ◽  
Female Gametophyte Development

The formation and development of reproductive organs and fruits was examined for two edible honeysuckle species Lonicera edulis Turcz. ex. Freyn. and Lonicera kamtchatica (Sevast.) Pojark. ‘Gerda’ using cytological and embryological methods. We found out that the flower initiation has began during June in the conditions of southwestern Slovakia. Male and female archespores were differentiated before entering winter dormancy. In most cases we have observed normally developed tetrads, normal appearance of microspores, two-celled polen grains and mature pollen grain. In both species a sufficient amount of normally developed pollen grains was observed. Disturbances during female gametophyte development occurred occasionally, most mature ovules contained 7 cells female gametophyte. Our research pointed to fact that the species are protogynous. Flowering usually takes place in the first half of April. The fruits were mature in the second half of May. We have found that 10 to 11 fully developed seeds have evolved in the fruits of both representatives of Lonicera on average. The above results show the suitability of L. edulis and L. kamtchatica cultivation in SW Slovakia with a relatively low risk of fruit loss due to climatic conditions.

scholarly journals Prunus necrotic ringspot virus Early Invasion and Its Effects on Apricot Pollen Grain Performance

2007 ◽  
Vol 97 (8) ◽  
pp. 892-899 ◽  
Author(s):  
Khalid Amari ◽  
Lorenzo Burgos ◽  
Vicente Pallas ◽  
María Amelia Sanchez-Pina
Keyword(s):  
Developmental Stages ◽  
Generative Cell ◽  
Pollen Grains ◽  
Growth Zone ◽  
Pollen Tubes ◽  
Climatic Conditions ◽  
Pollen Grain ◽  
Ringspot Virus ◽  
Prunus Necrotic Ringspot Virus

The route of infection and the pattern of distribution of Prunus necrotic ringspot virus (PNRSV) in apricot pollen were studied. PNRSV was detected both within and on the surface of infected pollen grains. The virus invaded pollen during its early developmental stages, being detected in pollen mother cells. It was distributed uniformly within the cytoplasm of uni- and bicellular pollen grains and infected the generative cell. In mature pollen grains, characterized by their triangular shape, the virus was located mainly at the apertures, suggesting that PNRSV distribution follows the same pattern as the cellular components required for pollen tube germination and cell wall tube synthesis. PNRSV also was localized inside pollen tubes, especially in the growth zone. In vitro experiments demonstrated that infection with PNRSV decreases the germination percentage of pollen grains by more than half and delays the growth of pollen tubes by ≈24 h. However, although PNRSV infection affected apricot pollen grain performance during germination, the presence of the virus did not completely prevent fertilization, because the infected apricot pollen tubes, once germinated, were able to reach the apricot embryo sacs, which, in the climatic conditions of southeastern Spain, mature later than in other climates. Thus, infected pollen still could play an important role in the vertical transmission of PNRSV in apricot.

scholarly journals Identification and evaluation of the novel genes for transcript normalization during female gametophyte development in sugarcane

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12298
Author(s):  
Maokai Yan ◽  
Xingyue Jin ◽  
Yanhui Liu ◽  
Huihuang Chen ◽  
Tao Ye ◽  
...  
Keyword(s):  
Gene Expression ◽  
Sexual Reproduction ◽  
Reference Genes ◽  
Female Gametophyte ◽  
Developmental Stages ◽  
Reproductive Organs ◽  
The Novel ◽  
Biofuel Feedstock ◽  
Gametophyte Development ◽  
Female Gametophyte Development

Background Sugarcane (Saccharum spontaneum L.), the major sugar and biofuel feedstock crop, is cultivated mainly by vegetative propagation worldwide due to the infertility of female reproductive organs resulting in the reduction of quality and output of sugar. Deciphering the gene expression profile during ovule development will improve our understanding of the complications underlying sexual reproduction in sugarcane. Optimal reference genes are essential for elucidating the expression pattern of a given gene by quantitative real-time PCR (qRT-PCR). Method In this study, based on transcriptome data obtained from sugarcane ovule, eighteen candidate reference genes were identified, cloned, and their expression levels were evaluated across five developmental stages ovule (AC, MMC, Meiosis, Mitosis, and Mature). Results Our results indicated that FAB2 and MOR1 were the most stably expressed genes during sugarcane female gametophyte development. Moreover, two genes, cell cycle-related genes REC8 and CDK, were selected, and their feasibility was validated. This study provides important insights into the female gametophyte development of sugarcane and reports novel reference genes for gene expression research on sugarcane sexual reproduction.

Sexual reproduction of Larix occidentalis

1979 ◽  
Vol 57 (23) ◽  
pp. 2673-2690 ◽  
Author(s):  
John N. Owens ◽  
Marje Molder
Keyword(s):  
Female Gametophyte ◽  
Pollen Grains ◽  
Larix Occidentalis ◽  
Embryo Abortion ◽  
Meristematic Tissue ◽  
Micropylar Canal ◽  
Empty Seed ◽  
Mother Cells ◽  
Pollen Cone ◽  
Female Gametophyte Development

Pollen-cone and seed-cone buds broke dormancy about 2 weeks before vegetative buds on the same tree. Pollen mother cells, which had over-wintered at pachytene or the diffuse stage of meiosis, resumed meiosis and tetrads of microspores were formed by mid-March. Wingless five-celled mature pollen developed by mid-to late April when pollination occurred.When development resumed after dormancy a ring of meristematic tissue formed the integument around the nucellus. The integument tip developed a short abaxial tip and a large adaxial lobe on which developed numerous long stigmatic hairs. A slit-like micropyle remained between the two lips. Several pollen grains usually adhered to the stigmatic hairs and then the two lips grew into the micropyle, engulfing the pollen. No pollination drop was observed. Within the micropylar canal, pollen greatly elongated then formed a pollen tube when the elongated pollen contacted the nucellus.Megaspore mother cells underwent meiosis at the time of pollination. Female gametophyte development, which was the same as in most other members of the Pinaceae, was completed in early June and two to five archegonia were formed. Fertilization occurred in early June, 6 to 8 weeks after pollination. A 16-celled proembryo developed. Simple polyembryony was common but cleavage polyembryony was not observed. Embryo development was similar to other members of the Pinaceae. Embryos and seeds were mature by mid-August.Normal appearing but inviable seed is common in L. occidentalis because the ovule is fully enlarged and the seed coat well developed at fertilization. Inviable seed commonly resulted from the absence of pollination, inviable pollen, lack of fertilization, later ovule abortion, or embryo abortion, primarily during early embryonic stages. Flat empty seed also occurred and resulted from abortion of the megaspore mother cell or early female gametophyte.

scholarly journals Floral herbivory does not reduce pollination-mediated fitness in shelter rewarding Royal Irises

2017 ◽  
Author(s):  
Mahua Ghara ◽  
Christina Ewerhardy ◽  
Gil Yardeni ◽  
Mor Matzliach ◽  
Yuval Sapir
Keyword(s):  
Fruit Set ◽  
Seed Set ◽  
Pollen Grains ◽  
Reproductive Organs ◽  
Pollen Grain ◽  
Lower Number ◽  
Pollen Deposition ◽  
Pollination Services ◽  
Pollinator Visitation ◽  
Direct Damage

ABSTRACTFlorivory, the damage to flowers by herbivores can affect fitness both directly and indirectly. Flowers consumed by florivores may fail to produce fruit or produce lower seed set because of direct damage to reproductive organs. In addition, eaten flowers are less attractive to pollinators because of reduced or modified advertisement, which reduces pollination services. While observational data are abundant, experimental evidence is scarce and results are contrasting. We tested experimentally the effect of florivory on both pollinator visitation and reproductive success in three species of the Royal Irises, which have large flowers that are attractive to pollinators, and potentially also for florivores. We hypothesized that florivory will reduce pollen deposition due to reduced attractiveness to pollinators, while fruit set and seed set will depend on the extent of florivory. We performed artificial florivory in two experiments over two years. In the first experiment, each of the three floral units of a single Iris flower was subject to either low or high artificial florivory, or left un-touched as control. We counted the number of pollen grains deposited on each of the three stigmas as a measure of pollinator visitation. In the second experiment, three flowers of the same plant received low, high, or no artificial florivory and were further recorded for fruit and seed production. In 2016, high artificial florivory revealed lower number of pollen grains on stigmas of Iris atropurpurea, but in 2017 there was no difference. Similarly, number of pollen grains in high artificial was lower than low florivory in 2017 in I. petrana. No significant effect of florivory was found on pollen grain deposition, fruit set or seed set. The results remained consistent across species and across years. The results undermine the assumption that flower herbivory is necessarily antagonistic interaction and suggests that florivores may not be strong selection agents on floral reproductive biology in the Oncocyclus irises.

Cytological and histological studies on male and female gametophyte of endangered species Amygdalus nana in Slovakia

Biologia ◽  
2011 ◽  
Vol 66 (5) ◽  
Author(s):  
Renáta Chudíková ◽  
Ľuba Ďurišová ◽  
Tibor Baranec ◽  
Ivan Ikrényi
Keyword(s):  
Fruit Set ◽  
Abiotic Factors ◽  
Reproductive Potential ◽  
Pollen Grains ◽  
Reproductive Organs ◽  
Great Variability ◽  
Ornamental Plant ◽  
Natural Habitats ◽  
Male And Female ◽  
Female Reproductive Organs

AbstractAmygdalus nana L. (Dwarf Russian Almond) a well-known ornamental plant is endangered in its natural habitats on the territory of Slovakia. Using methods of cytology and embryology, the stages of reproductive cycle of the species were clarified. Especially the development of the male and female reproductive organs, processes of the fertilization and formation of the embryo were studied. The reduction of reproductive potential was caused by synergic influence of negative biotic and abiotic factors. Despite the presence of degenerated, misshapen pollen grains and a great variability in shape and size, a sufficient amount of normally developed viable pollen grains originated within the species Amygdalus nana. We did not observe serious disturbances during megasporogenesis and megagametogenesis, the reduction in fruit set was caused by the degeneration of ovules after unsuccessful pollination (unfavourable conditions during the flowering period) and after unsuccessful seed development, caused mainly by damages of reproductive organs by pests.

scholarly journals Flower stages, germination and viability of pollen grains of Annona squamosa L. in tropical conditions

2021 ◽  
Vol 43 ◽  
pp. e51013
Author(s):  
Digelma Camila Barros Araújo ◽  
Pollyana Cardoso Chagas ◽  
Edvan Alves Chagas ◽  
Elias Ariel Moura ◽  
Railin Rodrigues de Oliveira ◽  
...  
Keyword(s):  
Pollen Grains ◽  
Floral Biology ◽  
Storage Conditions ◽  
Germination Percentage ◽  
Climatic Conditions ◽  
Pollen Grain ◽  
Ambient Conditions ◽  
Climate Conditions ◽  
Tropical Conditions ◽  
Germinated Pollen

The success in the application of artificial pollination techniques, aspects of floral biology should receive special attention, especially regarding the viability studies of pollen grains. In this sense, two experiments were carried out, aiming to determine the floral stages: floral opening (anthesis), female, male and senescence stages of A. squamosa L flowers under tropical climate conditions, and to evaluate the germination and viability of pollen grains submitted to different storage conditions. In the first experiment, observations and data collection began when flowers were still closed. Readings were taken every two hours for 46 hours until all the flowers reached the senescence stage. For the second, the experimental design was completely randomized, in a 2 x 7 factorial scheme, with 2 storage conditions (environment at 27 ± 2°C and refrigerated at 5 ± 2°C) and 7 pollen grain conditioning times (0, 4, 8, 12, 16, 20 and 24 hours), with 4 repetitions for the analysis of pollen grain germination and 3 repetitions for the analysis of pollen grain viability, and each repetition consisted of one blade. The variables evaluated were percentage of viable and non-viable pollen grains and percentage of germinated and non-germinated pollen grains. For tropical climatic conditions, the flower anthesis (female stage) of the sugar-apple begins at 00:00 h, extending until 12:00h on the same day. The flowers of the tree reach a functionally staminate stage (male stage) from 6 a.m. the next day. Pollen grains stored at room conditions (27 ± 2°C) remain viable for up to 24 hours after collection, showing that storage in a cold environment at low temperatures (5 ± 2°C) is not necessary. Seed pollen grains have a germination percentage of 51.25% when stored under ambient conditions (27 ± 2°C) for up to 4 hours after collection.

scholarly journals Microsporogenesis, Megasporogensis and Male and Female Gametophyte Development in Feijoa sellowiana (Myrtaceae)

2016 ◽  
Vol 18 (03) ◽  
pp. 637-642 ◽  
Author(s):  
Feng Zou ◽  
Sheng-Lin Chen ◽  
De-Yi Yuan ◽  
Ri-Qing Zhang ◽  
Lin Zhang ◽  
...  
Keyword(s):  
Female Gametophyte ◽  
Male And Female ◽  
Gametophyte Development ◽  
Female Gametophyte Development
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