scholarly journals Overcoming Pre-Fertilization Barriers in Intertribal Crosses between Anemone coronaria L. and Ranunculus asiaticus L.

Horticulturae ◽  
2021 ◽  
Vol 7 (12) ◽  
pp. 529
Author(s):  
Emmy Dhooghe ◽  
Dirk Reheul ◽  
Marie-Christine Van Labeke
Keyword(s):  
Pollen Tube ◽  
Seed Set ◽  
Sperm Nucleus ◽  
Tube Length ◽  
Egg Cell ◽  
Dichlorophenoxyacetic Acid ◽  
Style Length ◽  
Ranunculus Asiaticus ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Pollen Tube Length

Hybridization in flowering plants depends, in the first place, on the delivery of pollen to a receptive stigma and the subsequent growth of pollen tubes through the style to the ovary, where the sperm nucleus of the pollen grain can ultimately fertilize the egg cell. However, reproductive failure is often observed in distant crosses and is caused by pre- and/or post-zygotic barriers. In this study, the reproductive pre-fertilization barriers of intertribal crosses between Anemone coronaria L. and Ranunculus asiaticus L., both belonging to the Ranunculaceae, were investigated. Despite the incongruity of intertribal crosses between A. coronaria and R. asiaticus having been of low intensity at the stigmatic level, interstylar obstructions of the pollen tube growth occurred, which confirmed the presence of pre-fertilization barriers. We show that these barriers could be partially bypassed by combining pollination with a stigma treatment. More specifically, a significantly higher ratio of the pollen tube length to the total style length and a better seed set were observed when the stigma was treated with the auxin 2,4-dichlorophenoxyacetic acid (2,4-D, 1 mg.mL−1) together with the cytokinin kinetin (KIN, 0.5 mg.mL−1) 24 h after pollination, irrespective of the cross direction. More specifically, the stigma treatments with any form of auxin (combined or not combined with cytokinin) resulted in a full seed set, assuming an apomictic fruit set, because no pollination was needed to obtain these seeds.

Differences in Style Length and In vitro Germinated Pollen Tube Length and Other Reproductive Structures of Tetraploid and Diploid Cottons

2000 ◽  
Vol 3 (9) ◽  
pp. 1372-1374
Author(s):  
Mohammed Jurial Baloch . ◽  
Abdul Rahim Lakho . ◽  
Hidayatullah Bhutto . ◽  
Mohammad Hussain Arain .
Keyword(s):  
Pollen Tube ◽  
Tube Length ◽  
Style Length ◽  
Reproductive Structures ◽  
Germinated Pollen ◽  
Pollen Tube Length

Unilateral Cross-Incompatibility in Eucalyptus: the Case of Hybridisation Between E. globulus and E. nitens

1990 ◽  
Vol 38 (4) ◽  
pp. 383 ◽  
Author(s):  
PL Gore ◽  
BM Potts ◽  
PW Volker ◽  
J Megalos
Keyword(s):  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Pollen Tubes ◽  
Full Length ◽  
Tube Length ◽  
Style Length ◽  
Similar Difference ◽  
Structural Barrier ◽  
Pollen Tube Length

The growth of E. globulus and E. nitens pollen tubes in styles of E. globulus was examined in order to elucidate the site of the unilateral barrier to hybridisation. Pollen tubes of E. nitens failed to grow the full length of the larger E. globulus style. E. globulus pollen tubes grew an average of 1.4 mm per day for the first 4 days, compared with 0.8 mm per day for pollen tubes of E. nitens. From days 4 to 14, the growth of E. nitens pollen tubes slowed to an average of 0.2 mm per day and virtually no growth occurred after day 14. In contrast, E. globulus pollen tubes grew through the style and into the ovary between days 5 and 14. By day 28, at about the time of style abscission, E. nitens tubes had grown only 6 mm, well short of the full length of the E. globulus style (9-10 mm). A similar difference in growth was obtained in vitro where E. nitens pollen tubes were significantly shorter than those of E. globulus. A comparison also including E. ovata, E. urnigera and E. gunnii indicated a significant correlation between style length and in vitro pollen tube length. It is argued that the unilateral cross-incompatibility between E. globulus and E. nitens is due to a structural barrier arising from an inherent limit to pollen tube growth which is associated with pistil size.

GENOTYPIC DIFFERENCES IN CARDINAL TEMPERATURES FOR IN VITRO POLLEN GERMINATION AND POLLEN TUBE GROWTH OF COCONUT HYBRIDS

2017 ◽  
Vol 54 (5) ◽  
pp. 731-743 ◽  
Author(s):  
C. S. RANASINGHE ◽  
M. D. P. KUMARATHUNGE ◽  
K. G. S. KIRIWANDENIYA
Keyword(s):  
High Temperature ◽  
Sri Lanka ◽  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Pollen Germination ◽  
Fruit Set ◽  
Tube Growth ◽  
Tube Length ◽  
Cardinal Temperatures ◽  
Pollen Tube Length

SUMMARYSuccessful fruit set in coconut depends on several reproductive processes including pollen germination and pollen tube growth. High temperature (˃33 °C) during flowering reduces fruit set in coconut. Therefore, identification and development of coconut varieties or hybrids with high reproductive heat tolerance will benefit the coconut industry in view of the climate changes. This experiment was conducted to quantify the response of pollen germination and pollen tube growth of seven coconut hybrids to increasing temperature from 16 to 38 °C. A Principal Component Analysis (PCA) was carried out to classify coconut hybrids on the basis of their temperature tolerances to pollen germination. Pollen germination and pollen tube length of the hybrids ranged from 56 to 78% and 242 to 772 µm, respectively. A modified bilinear model best described the response to temperature of pollen germination and pollen tube length. Cardinal temperatures (Tmin, Topt and Tmax) of pollen germination and pollen tube length varied among the seven hybrids. PCA identified Tmax for pollen germination and Topt for pollen tube length as the most important parameters in describing varietal tolerance to high temperature. PCA also identified SLGD × Sri Lanka Tall and Sri Lanka Brown Dwarf × Sri Lanka Tall as the most tolerant hybrids to high temperature stress and Sri Lanka Tall × Sri Lanka Tall and Sri Lanka Green Dwarf × San Ramon as less tolerant ones based on cardinal temperatures for pollen germination and pollen tube length. Tmax for pollen germination of the most tolerant and less tolerant hybrids were 41.9 and 39.5 °C, respectively. Topt for pollen tube length in the most tolerant and less tolerant hybrids were 29.5 and 26.0 °C, respectively.

scholarly journals Effects of storage temperature and duration on pollen grain viability and pollen-tube elongation in Chinese chinqapin (Castanea henryi Skan)

2020 ◽  
Vol 49 (2) ◽  
pp. 297-304
Author(s):  
Huan Xiong ◽  
Deyi Yuan ◽  
Zhi-Yu Deng ◽  
Genhua Niu ◽  
Feng Zou
Keyword(s):  
Pollen Tube ◽  
Room Temperature ◽  
Storage Temperature ◽  
Southern China ◽  
Germination Rate ◽  
Pollen Viability ◽  
Pollen Grain ◽  
Tube Length ◽  
Storage Duration ◽  
Pollen Tube Length

Chinese chinquapin [Castanea henryi (Skan) Rehder & E.H. Wilson] is used as a food and timber crop in southern China. Most chinquapin cultivars are self-incompatible and bloom at different times; consequently, artificial pollination is used to ensure fruit set and nut yield. Effective pollen storage that enables producers and breeders to use stored pollen for cross-pollination at a later date is important. In this study, the cultivar Changmangzi was used to estimate the viability and pollen tube length of pollen stored at room temperature, and at 4, −20, and −80°C using in vitro germination tests. It was observed that pollen grain germination significantly decreased at all four storage temperatures. Pollen viability was 14.4% after only 24 days of storage at room temperature. The germination rate was 13.3% after 90 days of storage at 4°C, and 14.5% after 180 days at −20°C. The initial germination rate of pollen stored at −80°C was 56.3% at the beginning of the test and decreased to 15.4% after 240 days. Pollen-tube length decreased with increased storage duration; mean pollen-tube lengths ranged from 109.44 to 257.51 μm. Based on these results, it is suggested that a storage temperature of −80°C for Changmangzi pollen is good.

Effect of nickel on pollen germination and pollen tube length in Arabis alpina (Brassicaceae)

2016 ◽  
Vol 64 (4) ◽  
pp. 302 ◽  
Author(s):  
Dolja Pavlova
Keyword(s):  
Pollen Tube ◽  
Pollen Germination ◽  
Pollen Grains ◽  
Tube Length ◽  
Serpentine Soils ◽  
Nutritional Medium ◽  
Arabis Alpina ◽  
Pollen Tube Elongation ◽  
Germinated Pollen ◽  
Pollen Tube Length

In this work we studied and compared the toxic effect of nickel (Ni) on pollen germination and pollen tube length in Arabis alpina L. collected from serpentine and non-serpentine populations distributed in the Rila mountains, Bulgaria. Pollen grains were treated with prepared standard solutions of 100, 300, 500, and 700 μM Ni as NiCl2 in distilled water. A nutritional medium was also used to assess pollen germination. Nickel inhibited pollen germination and pollen tube elongation in both serpentine and non-serpentine plants. The percentage of germinated pollen in serpentine plants treated with Ni was higher than in non-serpentine plants but there was no difference in pollen tube elongation between groups. However, pollen tubes showed abnormalities such as coiling and swelling of the tip, or burst, and varied considerably among the samples. A complete break of pollen tube elongation is due to such abnormalities. Also, decreased pollen fertility in both populations was found. The plants from serpentines were less sensitive to (i.e. more tolerant of) elevated Ni concentrations commonly found in serpentine soils.

Pollen tube growth in tristylous Pontederia cordata (Pontederiaceae)

1986 ◽  
Vol 64 (11) ◽  
pp. 2602-2607 ◽  
Author(s):  
J. M. Anderson ◽  
S. C. H. Barrett
Keyword(s):  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Pollen Tubes ◽  
Tube Growth ◽  
Pollen Size ◽  
Tube Length ◽  
Pontederia Cordata ◽  
Incompatible Pollen ◽  
Hand Pollination ◽  
Pollen Tube Length

Pollen tube growth rates in legitimate cross- and self-pollinations were compared by controlled hand pollination in two varieties of Pontederia cordata L. (Pontederiaceae). In each pollen–stigma combination pollen germinated readily on stigmas and pollen tubes penetrated stigmatic tissue. Pollen tube length in styles was positively correlated with pollen size. In most pollinations legitimate pollen tubes grew more rapidly in styles than self pollen tubes. This difference was statistically significant in most comparisons. Inhibition of incompatible pollen tubes was either in the style or ovary. It is suggested that the mechanisms of incompatibility may differ among the floral morphs and depend on the particular pollen size involved in pollinations. The observed differences in pollen tube growth of legitimate cross- and self-pollinations in P. cordata suggest that the species is primarily outbreeding.

In vitro germination and pollen tube growth of maize (Zea mays) pollen. II. Pollen source, calcium, and boron interactions

1968 ◽  
Vol 46 (3) ◽  
pp. 235-240 ◽  
Author(s):  
P. L. Pfahler
Keyword(s):  
Zea Mays ◽  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Calcium Nitrate ◽  
Pollen Grains ◽  
Germination Percentage ◽  
Tube Growth ◽  
Tube Length ◽  
Pollen Tube Length

Pollen grains from six single cross hybrids (Wf9 × H55, Wf9 × H50, H49 × H55, H49 × H50, Ky49 × Ky27, and K64 × K55) of Zea mays L. were cultured on an artificial medium containing 15% sucrose and 0.6% bacto-agar supplemented with all possible combinations of two levels (0.00 and 0.03%) of calcium nitrate (Ca) and two levels (0.00 and 0.01%) of boric acid (B). The effect of Ca and B on germination percentage was found to be dependent on the genetic source of the pollen. At the 0.00% levels of Ca and B, the germination percentage of the hybrids ranged from 26.6% for Ky49 × Ky27 to 58.1% for K64 × K55. With either Ky49 × Ky27 or K64 × K55 pollen, the addition of Ca and B to the medium resulted in a lower germination percentage whereas the addition of Ca and B increased the germination percentage of the other hybrids. The addition of B in the absence of Ca sharply reduced the germination percentage in all hybrids while in the presence of Ca, the effect of B varied with the hybrid involved. For pollen tube length, highly significant interactions between hybrids and levels of Ca and B were found. However, maximum pollen tube lengths were obtained for all hybrids with both Ca and B in the medium. The addition of B in the absence of Ca reduced the pollen tube length of all hybrids whereas the addition of B in the presence of Ca increased pollen tube length. In general, the addition of both Ca and B increased the rate of pollen tube growth especially in the period 2 to 3 hours after inoculation.

scholarly journals Longevity and germination of Juniperus communis L. pollen after storage

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Andrej Kormuťák ◽  
Peter Bolecek ◽  
Martin Galgóci ◽  
Dušan Gömöry
Keyword(s):  
Pollen Tube ◽  
Pollen Viability ◽  
Germination Percentage ◽  
Tube Length ◽  
In Vitro Germination ◽  
Short Term ◽  
Term Storage ◽  
Pollen Tube Length ◽  
Common Juniper

AbstractPollen storage belongs among the most important activities associated with pollen handling. It overcomes the differences in pollen shedding and ovule receptivity during controlled pollination experiments. It is especially important for species like common juniper (Juniperus communis L.) with an extremely low quality of seeds due to pollination failure. Additionally, it is a substantial part of germplasm preservation programmes in pollen banks. In the present paper, the effect of short-term storage of pollen was studied using pollen samples from five shrubs in an in vitro germination test. Two temperature regimes were tested. The pollen viability of freshly collected pollen varied considerably between individual shrubs, exhibiting 67.3–88.6% germination rate and 248.0–367.3 µm of pollen tubes. Storage at + 4 °C for four months was accompanied by a profound decline in pollen viability. The germination percentage was reduced to 49.2–75.2% and the pollen tube length to 32.5–69.0%, depending on individual shrubs. The corresponding decline in pollen viability characteristics during storage at − 20 °C was only negligible in two of the tested shrubs. In the remaining three shrub samples, an increase in germination percentage was observed. Pollen tube growth responded more sensitively to freezing, but, on average, the decrease in length was lower than that at + 4 °C. The rate of reduction in pollen tube length varied between 11.5 and 45.4%. Cytological events accompanying in vitro germination of freezer-stored pollen exhibited some delay in releasing the exine from pollen grains during the early stages of germination as compared with freshly collected pollen. In conclusion, short-term storage of the common juniper pollen in a freezer is better for the preservation of its viability than storage at + 4 °C.

IN VITRO GERMINATION AND POLLEN TUBE GROWTH OF MAIZE (ZEA MAYS L.) POLLEN.: I. CALCIUM AND BORON EFFECTS

1967 ◽  
Vol 45 (6) ◽  
pp. 839-845 ◽  
Author(s):  
P. L. Pfahler
Keyword(s):  
Pollen Tube ◽  
Boric Acid ◽  
Calcium Nitrate ◽  
Pollen Grains ◽  
Germination Percentage ◽  
Tube Length ◽  
Artificial Medium ◽  
Bacto Agar ◽  
Pollen Tube Length

Pollen grains from the single cross hybrid Wf9 × H55 were cultured on an artificial medium containing 15% sucrose and 0.6% bacto-agar supplemented with all possible combinations of three concentrations (0.00, 0.03, and 0.06%) of calcium nitrate and three concentrations (0.00, 0.01, and 0.02%) of boric acid. The combination containing 0.03% calcium nitrate and 0.01% boric acid produced the highest germination (47.9%) and the longest tube length (405 μ). The addition of either calcium nitrate or boric acid alone decreased the germination percentage and pollen tube length. The percentage of grains producing more than one pollen tube was reduced by the addition of calcium nitrate or boric acid singly or in combination. The significance of these results in relation to pollen physiology was discussed.

scholarly journals Vitality and in vitro pollen germination of different ‘Oblacinska’ sour cherry clones

Genetika ◽  
2017 ◽  
Vol 49 (3) ◽  
pp. 791-800
Author(s):  
Milica Fotiric-Aksic ◽  
Radosav Cerovic ◽  
Vera Rakonjac ◽  
Ivana Bakic ◽  
Slavica Colic ◽  
...  
Keyword(s):  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Pollen Germination ◽  
Fruit Set ◽  
Sour Cherry ◽  
Tube Growth ◽  
Tube Length ◽  
In Vitro Pollen Germination ◽  
Pollen Tube Length

Vitality of pollen, in vitro pollen germination and pollen tube growth (pollen tube length and pollen tube growth rate) were investigated in Oblacinska sour cherry in order to determine the differences between clones which have divergent yielding potential. For this purpose two ?Oblacinska? sour cherry clones with high fruit set and high yields (II/2, III/9) and two with low fruit set and low-yielding (XI/3 and XIII/1) were used in this study. Pollen germination was done on artificial medium containing 14% sucrose and 0.3% agar-agar at room temperature (23?C). Pollen tube growth was stopped with a drop of 40% formaldehyde, 1, 3, 6, 12 and 24 h after contact with the medium. The maximum percentage of germination ranged from 13.01% (clone II/2, after 1 h) to 54.19% (clone III/9, after 24 h). Pollen tube length varied from 64.84 ?m (clone XIII/1, after 1 h) to >1,100 ?m (clones II/2 and III/9, after 24 h). Pollen growth rate was quite high (up to 1.71 ?m min-1) after 6 h of germination, but rather decreasing until 24 h of germination (0.56-0.83 ?m min-1). The dynamics of in vitro pollen tubes growth among the clones were quite different, especially after 12 h and 24 h of germination. Clones that are singled out as fruitful (II/2 and III/9) gave much better results regarding pollen germination and pollen tube growth in comparison to clones which were characterized by low fruit set and yields (XI/3 and XIII/1).

Sign in / Sign up

Export Citation Format

Share Document