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 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 High Temperatures during Flowering Reduce Fruit Set in Rabbiteye Blueberry

2019 ◽  
Vol 144 (5) ◽  
pp. 339-351
Author(s):  
Qin Yang ◽  
Er Liu ◽  
Yan Fu ◽  
Fuqiang Yuan ◽  
Tingting Zhang ◽  
...  
Keyword(s):  
High Temperature ◽  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Pollen Germination ◽  
Fruit Set ◽  
Tube Growth ◽  
Important Indicator ◽  
High Temperature Range ◽  
Temperature Range ◽  
Fruit Setting

After nearly a decade of development, the scale of blueberry (Vaccinium sp.) cultivation has increased, particularly in south China; however, this region is becoming increasingly challenged by temperature changes during the flowering phenophase. Understanding the effects of temperature on pollen germination and pollen tube growth in blueberry is thus important. Using the rabbiteye blueberry (V. ashei) ‘Brightwell’, different temperature treatments were carried out during open pollination and cross-pollination with the pollen from rabbiteye blueberry ‘Gardenblue’ in field, greenhouse, and controlled temperature experiments over two consecutive years. The differences in pollen germination, pollen tube dynamics, and ovule viability following different treatments were analyzed, and the critical temperatures were calculated using quadratic and modified bilinear equations to quantify the developmental responses to temperature. The results showed that the fruit set of the artificially pollinated plants inside the greenhouse was significantly higher than that outside the greenhouse. Furthermore, pollen germination and pollen tube growth gradually accelerated under the appropriate high-temperature range, resulting in reduced pollen tube travel time to the ovule. However, the percentage of the style traversed by the pollen tube did not increase at temperatures greater than 30 °C, and a high-temperature range could accelerate ovule degeneration. Therefore, impairment of pollen tube growth in the upper half of the style following pollen germination and ovule degeneration constituted important factors leading to reduced fruit setting under short periods of high temperature during the flowering phenophase in rabbiteye blueberry. This work advances our understanding of the effect of temperature on pollen germination, pollen tube growth, ovule longevity, and fruit setting in rabbiteye blueberry, and provides a foundation for continued cultivation and breeding enhancement. The findings propose that the tolerance of rabbiteye blueberry to a certain high-temperature range in the flowering phenophase should inform breeding strategies for temperature resistance and that temperature range is also an important indicator of suitable environments for cultivation to mitigate potential temperature stress.

scholarly journals Effects of Temperature and the Combination of Liquid Lime Sulfur and Fish Oil on Pollen Germination, Pollen Tube Growth, and Fruit Set in Apples

HortScience ◽  
2009 ◽  
Vol 44 (5) ◽  
pp. 1277-1283 ◽  
Author(s):  
Keith Yoder ◽  
Rongcai Yuan ◽  
Leon Combs ◽  
Ross Byers ◽  
Jim McFerson ◽  
...  
Keyword(s):  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Pollen Germination ◽  
Fruit Set ◽  
Pollen Tubes ◽  
Tube Growth ◽  
Pollen Tube Growth Rate ◽  
Golden Delicious ◽  
Effects Of Temperature ◽  
Increasing Temperature

Effects of temperature and the combination of liquid lime sulfur (LLS) and fish oil (FO) applied during bloom on pollen germination and pollen tube growth in flowers and fruit set were examined in apples (Malus ×domestica Borkh.). Percent germination of pollen of ‘Manchurian’ crabapples and ‘Golden Delicious’ apple flowers on the stigmatic surface of ‘Golden Delicious’ pistils increased with increasing temperature from 13 to 29 °C in the first 24 and 48 h after pollination, respectively, but not thereafter. Pollen tube growth rate in the style increased quadratically with increasing temperature from 13 to 29 °C. ‘Manchurian’ was a more effective pollenizer of ‘Golden Delicious’ than was ‘Golden Delicious’ pollen. For example, at 24 or 29 °C, some ‘Manchurian’ pollen tubes grew to the base of ‘Golden Delicious’ styles by 24 h after pollination. On the other hand, no ‘Golden Delicious’ pollen tube grew to the base of a ‘Golden Delicious’ style regardless of temperature and time. Pollen tube growth rate in the style increased with increasing day/night temperature from 7/0 to 24/7 °C. The time required for pollen tubes to grow to the base of styles decreased with increasing day/night temperature from 13/2 to 24/7 °C. Only ≈36 h was required for pollen tubes to grow to the base of style at 24/7 °C, whereas pollen tubes grew very slowly and no pollen tubes grew to the base of style at 7/0 °C regardless of pollen source. LLS + FO, applied 4 or 24 h after pollination, inhibited pollen germination, pollen tube growth in the style, fertilization, and fruit set, but it had no effect when applied 48 h after pollination. These results suggest that LLS + FO applied at this bloom stage causes flower or fruit abscission most likely by inhibiting pollen germination, pollen tube growth in the style, and fertilization.

scholarly journals Pollen Tube Growth and Fruit Set in Apple

HortScience ◽  
2017 ◽  
Vol 52 (8) ◽  
pp. 1054-1059 ◽  
Author(s):  
Khalil R. Jahed ◽  
Peter M. Hirst
Keyword(s):  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Pollen Germination ◽  
Fruit Set ◽  
Pollen Tubes ◽  
Tube Growth ◽  
Physiological Basis ◽  
Golden Delicious ◽  
Malus Floribunda ◽  
Seed Crops

Pollination is an essential prerequisite for the production of many fruit and seed crops, including apple. In apple, successful fertilization requires pollen transfer to the stigma, pollen germination, and successful pollen tube growth resulting in fruit set. Precise selection of the most effective pollinizers for commercial orchards is not possible however, until these processes are more fully understood. The present study was undertaken to compare pollinizers in terms of pollen tube growth and fruit set. On trees of ‘Honeycrisp’, ‘Fuji’, and ‘Gala’ from which bees were excluded, flowers were hand-pollinated using pollen collected from crabapple (‘Ralph Shay’ or Malus floribunda), ‘Delicious’ and ‘Golden Delicious’. Flowers were harvested at one, two, three, and four days after pollination (DAP). Pollen source had a significant influence on pollen germination on the stigmatic surface, number of pollen tubes penetrating the stigma, distance of pollen tube growth down the style, and pollen tubes reaching the base of the style. In ‘Honeycrisp’ and ‘Gala’, ‘Golden Delicious’ pollen grew the fastest, followed by ‘Delicious’ and crabapple. Neither ‘Ralph Shay’ nor Malus floribunda were effective pollinizers for ‘Honeycrisp’ and resulted in low fruit set suggesting incompatibility may be involved. However, both these crabapples were effective pollinizers for ‘Fuji’ and ‘Gala’. These results indicate that pollen source can have a tremendous impact on pollen tube growth and fruit set. The physiological basis for these effects is not clear, but implications for pollinizer selection are obvious.

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.

scholarly journals Differences in in vitro Pollen Germination and Pollen Tube Growth of Cotton Cultivars in Response to High Temperature

2005 ◽  
Vol 96 (1) ◽  
pp. 59-67 ◽  
Author(s):  
V. G. KAKANI ◽  
K. R. REDDY ◽  
S. KOTI ◽  
T. P. WALLACE ◽  
P. V. V. PRASAD ◽  
...  
Keyword(s):  
High Temperature ◽  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Pollen Germination ◽  
Tube Growth ◽  
In Vitro Pollen Germination

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 Effective Pollination Period in Almond Cultivars

HortScience ◽  
2004 ◽  
Vol 39 (1) ◽  
pp. 19-22 ◽  
Author(s):  
E. Ortega ◽  
J. Egea ◽  
F. Dicenta
Keyword(s):  
High Temperature ◽  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Fruit Set ◽  
Fruit Trees ◽  
Prunus Dulcis ◽  
Tube Growth ◽  
Stigma Receptivity ◽  
Flower Density

In almond [Prunus dulcis (Mill.) D.A. Webb], a high flower density and fruit set rate is important, because yield increases with higher fruit set ratio. Furthermore, because the ovule of some cultivars mature at anthesis, rapid pollination and pollen tube growth along the style are essential to ensure fertilization of a viable ovule. In this work, we studied the effective pollination period (EPP) of four almond cultivars of different bloom time by studying pollen tube growth and fruit set. EPP in almond was longer than in other fruit trees, and its duration was determined by stigma receptivity, which decreased with high temperature. An acceptable fruit set for all cultivars was obtained following pollination from day 0 to day 4 after emasculation.

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