Search results for "Pollen tube"
showing 10 items of 11 documents
Agronomic treatments to avoid seed presence in ‘Nadorcott’ mandarin I. Effect on in vivo pollen tube growth
2022
Abstract Fresh market demands high quality fruit and, therefore, citrus growers and researchers are constantly looking for solutions to avoid seed presence. Current horticultural techniques have low effectiveness or high cost. The objective of this study is to evaluate the inhibition effect of seven products on the in vivo pollen tube growth in Nadorcott mandarin, which is a high-value seedy variety. To achieve this main objective, three inorganic fertilizers (ammonium nitrate, potassium nitrate, sulfur), and four saccharides (saccharose, methyl cellulose, callose, chitosan) were applied to Nadorcott stigmas 24 h before and after hand pollination. Pollen tubes were counted 1, 3, and 5 days …
Effect of temperature on pollen germination for several Rosaceae species: influence of freezing conservation time on germination patterns
2019
[EN] Between February 2018 and April 2018, flowers were collected from eight Rosaceae species. Flowers were kept in a freezer at -20 degrees C for three freezing times (Treatment 1, two months; Treatment 2, four months; Treatment 3, six months). After extracting pollen, in vitro germination was induced in a culture medium and incubated at six different temperatures for 72 h. The percentage of pollen germination, average pollen tube length and maximum pollen tube length were measured. Pollen germination was maximum for all species between 15 degrees C and 30 degrees C. Cydonia oblonga, Malus sylvestris, Prunus avium, Prunus domestica, Prunus dulcis, Prunus persica and Pyrus communis obtained…
Pollen‐tube growth rate and seed‐siring success among Betula pendula clones
1999
The aim of this study was to investigate whether genetically different pollen donors (Betula pendula clones) differed in pollen-tube growth rate across 11 maternal plants and in vitro, and whether the differences between the donors were consistent across the recipients. To compare the seed-siring success of competing pollen donors, a two-donor hand-pollination experiment with six donors and six recipients was conducted. The experiments were performed at a plastic-house seed orchard. The donors showed significant variation in pollen-tube growth rate on all the 11 recipients. The rankings of the pollen donors were statistically consistent across different maternal plants. A significant positi…
Flowering and fruiting phenology and breeding system ofCistus albidusL.
1995
Summary The flowering and fruiting phenology and breeding system of Cistus albidus L. are studied. Four phases are established for the development of the flower, which remains open for a period of less than 14hrs, although this time—span can be further reduced if environmental conditions are unfavourable. Only 65.6 % flowers develop ripe fruits, the greatest losses occurring in the change from flower to unripe fruit. H is a xenogamous species with a PAD ratio of 5.426 ±816. Experimentally, fruits may be formed by autogamy through manual pollination, although this does not occur spontaneously. There is recognition by the plant of its own pollen tube, which reduced the production of fruits by…
Floral and Vegetative Morphogenesis in California Poppy (Eschscholzia californicaCham.)
2005
For studies of the evolution of development in angiosperms, early‐diverging eudicot taxa are of particular interest for comparisons with established core eudicot model plants, such as Arabidopsis. Here we provide a detailed description of shoot and floral development of the basal eudicot California poppy (Eschscholzia californica). Rosette formation in the vegetative phase is accompanied by increased leaf complexity and shoot apex size. The flowering phase is characterized by internode elongation, formation of dissected cauline leaves, terminal flowers, and basipetal inflorescence branching. For developing flowers and fruits, we have defined 14 stages according to important landmark events,…
Do pollen donors with fastest-growing pollen tubes sire the best offspring in an anemophilous tree,Betula pendula(Betulaceae)?
2001
The relationship between pollen and progeny performance has been a subject of many studies but the evidence for pollen-tube growth rate as an indicator of progeny fitness is equivocal. We used an anemophilous tree, Betula pendula, to examine the relationship between pollen-tube growth rate and seed and seedling performance. We crossed nine maternal plants with pollen from six pollen donors in a clonal B. pendula seed orchard, measured the pollen-tube growth rates for every cross, and analyzed the performance of the resulting seeds and seedlings. The only significant positive correlation was found between pollen-tube growth rate and seed mass when we controlled for seed number per infloresce…
Effects of temperature and pollination site on pollen performance in Betula pendula Roth – evidence for genotype-environment interactions
2000
We studied whether the differences between genetically different pollen donors (Betula pendula Roth clones) with respect to pollen-tube growth rate were consistent under different thermal conditions during pollen germination in vivo and in vitro. We conducted a single-donor hand-pollination experiment with same pollen donors and recipients in a plastic house seed orchard and at an outdoor clone collection. The prevailing daily mean temperature during pollen germination was 13°C higher in the plastic house than outdoors. The pollen-tube growth rate of each pollen donor was additionally determined in vitro on agar medium at five temperatures (10°, 15°, 22°, 30° and 35°C). A significant intera…
Preliminary Results on the Effect of Magnetic Fields on Anther Culture and Pollen Germination of Citrus clementina Hort. ex Tan.
2003
Exposure to electromagnetic fields seems to modify the biological behaviour of seeds, roots, pollen grains and buds of several plants. This procedure has been also suggested as a tool to improve the utilization of plant species (Firetto et al., 2000, 2001, Petruszewski S., 1996). Since the first haploid embryogenic calli production and plantlet regeneration by anther culture of C. clementina Hort. ex Tan. 'Nules' was reported (Germany et al., 1994), several studies have been carried out to improve both the frequency of microspore embryogenesis and the percentage of plantlet regeneration. To enlarge the number of respondent genotypes and to improve the induction rate (the frequency of pollen…
The breeding system of Fumana ericifolia: first evidence of autogamy in woody Cistaceae
2001
Fumana ericifolia belongs to the family Cistaceae, in which all perennial species previously studied have been reported to be self-incompatible and xenogamous. Here we show that F. ericifolia is self-compatible and autogamous. Its flowers last only four to eight hours and produce a small amount of pollen and ovules. Self-pollination depends on changes in the relative position of the stigma and the anthers, triggered by the abscission of the petals; this in turn causes closing of the sepals, which push the anthers onto the stigma. Pollen remains highly viable and germinable, and the stigma keeps its receptivity several hours after the loss of the petals. Hand pollination treatments revealed …
Breeding system and conservation strategy of the extremely endangered Cistus carthaginensis Pau (Cistaceae) of Spain
2001
Cistus carthaginensis is one of the most endangered plants in Europe: at present there exist only a few individuals in Murcia and one in Valencia (SE and E Spain). To design an adequate conservation strategy able to avoid the extinction of this species, various aspects of its reproductive biology were studied. The extreme rarity of C. carthaginensis is not related to problems of development and/or fertility of pollen or ovules produced by the few existing specimens. Meiosis in the pollen mother cells is always regular and chromosome segregation is completely equilibrated in the male gametes. Pollen and ovule production is high and similar to that reported for other related species of Cistus…