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

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.

1967 ◽  
Vol 45 (6) ◽  
pp. 839-845 ◽  
Author(s):  
P. L. Pfahler

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.


1971 ◽  
Vol 49 (1) ◽  
pp. 55-57 ◽  
Author(s):  
P. L. Pfahler

Pollen grains from the near-isogenic inbreds, Oh 43 Rf1Rf1, Oh 43 rf1rf1, 106 Rf1Rf1, and 106 rf1rf1 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). At certain combinations of Ca and B, significant differences between the Rf1Rf1 and rf1rf1 genotypes were obtained for germination percentage, rupturing percentage, and pollen tube length. However, the effect of the Rf1 and rf1 alleles was not consistent in magnitude for both inbreds. Apparently, the Rf1 and rf1 alleles can alter certain in vitro germination characteristics but genetic background is also involved.


Genetika ◽  
2017 ◽  
Vol 49 (3) ◽  
pp. 791-800
Author(s):  
Milica Fotiric-Aksic ◽  
Radosav Cerovic ◽  
Vera Rakonjac ◽  
Ivana Bakic ◽  
Slavica Colic ◽  
...  

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).


2016 ◽  
Vol 65 (2) ◽  
pp. 11-16 ◽  
Author(s):  
Ni Zhan ◽  
Liejian Huang

Abstract We investigated the effects of Ca2+ on in vitro pollen germination of Acacia auriculiformis, Acacia mangium, and Acacia crassicarpa under different concentrations of Ca2+ (50 mg.L−1, 100 mg.L−1, 150 mg.L−1, 200 mg.L−1, 250 mg.L−1, 300 mg.L−1, 350 mg.L−1 and 400 mg.L−1) in the present study. Our results revealed that Ca2+ could stimulate the pollen germination percentage and the pollen tube growth of A. auficuliformis and A. crassicarpa under a certain concentration. In vitro pollen germination of A. mangium did not require exogenous Ca2+. With high Ca2+ concentration, the pollen germination of A. auriculiformis, A. mangium, and A. crassicarpa were obviously inhibited. With the rise of Ca2+ concentration, the percentage of pollen germination, the pollen tube length, the pollen tube growth, and the number of pollen tube were increased. However, the pollen germination percentage decreased with high Ca2+ concentration.


2016 ◽  
Vol 61 (4) ◽  
pp. 333-341 ◽  
Author(s):  
Aleksandar Radovic ◽  
Dragan Nikolic ◽  
Dragan Milatovic ◽  
Dejan Djurovic

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.


1990 ◽  
Vol 38 (4) ◽  
pp. 383 ◽  
Author(s):  
PL Gore ◽  
BM Potts ◽  
PW Volker ◽  
J Megalos

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.


2017 ◽  
Vol 54 (5) ◽  
pp. 731-743 ◽  
Author(s):  
C. S. RANASINGHE ◽  
M. D. P. KUMARATHUNGE ◽  
K. G. S. KIRIWANDENIYA

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.


1986 ◽  
Vol 64 (11) ◽  
pp. 2602-2607 ◽  
Author(s):  
J. M. Anderson ◽  
S. C. H. Barrett

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.


1980 ◽  
Vol 58 (5) ◽  
pp. 557-561 ◽  
Author(s):  
P. L. Pfahler ◽  
H. F. Linskens ◽  
M. Wilcox

Because of their structure and active metabolic state, pollen grains are vulnerable to any agent in the in vitro germination medium. Surfactants are used in biological systems to reduce surface tension but are also known to produce subtle biochemical effects. This study investigated the effect of three nonionic surfactants on the germination characteristics of pollen grains from three pollen source genotypes. Pollen grains from three single cross hybrids (Wf9 × H55, K64 × K55, Ky228 × Ky226) were cultured on an artificial medium (15% sucrose, 0.6% bacto-agar, 0.03% calcium nitrate, 0.01% boric acid) supplemented with all possible combinations of three concentrations (10, 100, 1000 ppm, v/v) of the following surfactants: (i) Tween 80 (polyoxyethylene sorbitan monooleate); (ii) X-114 (alkyl phenoxypolyethoxy ethanol); and (iii) commercial sticker spreader (alkyl olefin aromatic polymers). A control containing no supplement was included. Over all genotypes, increasing concentrations of Tween 80 had the least effect on the germination characteristics measured (germination and ruptured percent, pollen tube length at 1, 2, and 3 h after inoculation) and X-114 had the greatest effect with no germination found above 10 ppm. For most of the germination characteristics, highly significant pollen source genotype X concentration interactions were found for each surfactant. The direction and magnitude of the surfactant effects depended on the surfactant, its concentration, the germination characteristic involved, and the pollen source genotype.


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