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.

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

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 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).

scholarly journals The effect of temperature on pollen germination and pollen tube growth of pear cultivars

2016 ◽  
Vol 61 (4) ◽  
pp. 333-341 ◽  
Author(s):  
Aleksandar Radovic ◽  
Dragan Nikolic ◽  
Dragan Milatovic ◽  
Dejan Djurovic
Keyword(s):  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Pollen Germination ◽  
Tube Growth ◽  
Effect Of Temperature ◽  
Tube Length ◽  
In Vitro Pollen Germination ◽  
Different Temperatures ◽  
Pollen Tube Length

The effect of three different temperatures (8, 16 and 24?C) on pollen germination and length of pollen tube in vitro was investigated in four pear cultivars (?Butirra Precoce Morettini?, ?Williams?, ?Conference? and ?Abate Fetel?). The temperature showed a significant effect on in vitro pollen germination. The highest pollen germination was determined at a temperature of 24?C (53.25%), somewhat lower at 16?C (44.72%) and the lowest at 8?C (23.16%). The temperature effect was significantly more pronounced on the length of pollen tube. Pollen tube length was about three times higher at the temperatures of 16 and 24?C compared to 8?C. The temperature of 8?C was not sufficient for pollen germination and pollen tube growth in pear cultivars. However, temperatures of 16 and 24?C were optimal for pollen germination and pollen tube growth.

scholarly journals Hyperoside promotes pollen tube growth by regulating the depolymerization effect of actin-depolymerizing factor 1 on microfilaments in okra

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Biying Dong ◽  
Qing Yang ◽  
Zhihua Song ◽  
Lili Niu ◽  
Hongyan Cao ◽  
...  
Keyword(s):  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Pollen Germination ◽  
Pollen Tubes ◽  
Tube Growth ◽  
Actin Depolymerizing Factor ◽  
Specific Mechanism ◽  
Promoting Effect ◽  
New Research

AbstractMature pollen germinates rapidly on the stigma, extending its pollen tube to deliver sperm cells to the ovule for fertilization. The success of this process is an important factor that limits output. The flavonoid content increased significantly during pollen germination and pollen tube growth, which suggests it may play an important role in these processes. However, the specific mechanism of this involvement has been little researched. Our previous research found that hyperoside can prolong the flowering period of Abelmoschus esculentus (okra), but its specific mechanism is still unclear. Therefore, in this study, we focused on the effect of hyperoside in regulating the actin-depolymerizing factor (ADF), which further affects the germination and growth of pollen. We found that hyperoside can prolong the effective pollination period of okra by 2–3-fold and promote the growth of pollen tubes in the style. Then, we used Nicotiana benthamiana cells as a research system and found that hyperoside accelerates the depolymerization of intercellular microfilaments. Hyperoside can promote pollen germination and pollen tube elongation in vitro. Moreover, AeADF1 was identified out of all AeADF genes as being highly expressed in pollen tubes in response to hyperoside. In addition, hyperoside promoted AeADF1-mediated microfilament dissipation according to microfilament severing experiments in vitro. In the pollen tube, the gene expression of AeADF1 was reduced to 1/5 by oligonucleotide transfection. The decrease in the expression level of AeADF1 partially reduced the promoting effect of hyperoside on pollen germination and pollen tube growth. This research provides new research directions for flavonoids in reproductive development.

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.

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 Pollen Viability and Vigor in Hybrid Southern Highbush Blueberries (Vaccinium corymbosum L. ×spp.)

HortScience ◽  
1992 ◽  
Vol 27 (5) ◽  
pp. 425-427 ◽  
Author(s):  
Gregory A. Lang ◽  
E. James Parrie
Keyword(s):  
Pollen Tube ◽  
Growth Rates ◽  
Pollen Tube Growth ◽  
Pollen Viability ◽  
Pollen Tubes ◽  
Vaccinium Corymbosum ◽  
Tube Growth ◽  
Multiple Pollen ◽  
Southern Highbush

Pollen from six southern highbush blueberry cultivars derived from Vaccinium corymbosum L. and one or more other species (V. darrowi Camp, V. ashei Reade, and V. angustifolium Aiton) was incubated on nutrient agar to determine tetrad viability, pollen tube growth rates, and incidence of multiple pollen tube germinations. `Avonblue' pollen had a significantly lower tetrad germination percentage than `Georgiagem', `Flordablue', `Sharpblue', `Gulfcoast', or `O'Neal', all of which had >90% viable tetrads. The in vitro growth rate of `O'Neal' pollen tubes was significantly higher than the growth rates of `Sharpblue' and `Georgiagem pollen tubes. Of those tetrads that were viable, more than two pollen tubes germinated from 83% and 91% of the `Gulfcoast' and `Sharpblue' tetrads, respectively, while only 11% of the `Flordablue' tetrads produced more than two pollen tubes. The total number of pollen tubes germinated per 100 tetrads ranged from 157 (`Flordablue') to 324 (`Sharpblue'), resulting in actual pollen grain viabilities ranging from 39% to 81%. Genetic differences in pollen vigor, as indicated by pollen viability, pollen tube growth rates, and multiple pollen tube germinations, may influence blueberry growers' success in optimizing the beneficial effects of cross-pollination on fruit development.

scholarly journals Pollen Tube Growth in Carya and Temporal Influence of Pollen Deposition on Fertilization Success in Pecan

1992 ◽  
Vol 117 (2) ◽  
pp. 328-331 ◽  
Author(s):  
Robert D. Marquard
Keyword(s):  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Pollen Tubes ◽  
Fertilization Success ◽  
Tube Growth ◽  
In Vivo Studies ◽  
Pollen Deposition ◽  
Cape Fear

In vivo pollen tube growth of pecan [Carya illinoinensis (Wangenh.) K. Koch] was estimated to be ≈ 150 μm·hour-1 from 3 to 8 hours postpollination. Pollen tubes averaged 47, 194, 405, and 946 μm after 2, 3, 4, and 8 hours postpollination, respectively. Pollen tube growth was strongly influenced by temperature, and in vitro studies demonstrated pollen germination and tube growth were optimal at 27C for `Cape Fear' pecan. In in vivo studies, tubes of cross-pollen did not grow significantly faster than tubes of self-pollen. Pollen tubes of water hickory [C. aquatica (Michx. f.) Nutt.] grew significantly faster than those of C. illinoinensis. Bitternut [C. cordiformis (Wangenh.) K. Koch] and mockernut hickory (C. tomentosa Nutt.) pollen tubes grew significantly slower on pecan stigmas than did pecan pollen. Pollen arriving first on the stigma has a decided advantage for fertilization success of pecan. The fertilization success rate of pecan pollen arriving 24 hours after first pollen arrival was <3%.

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