Almond pollination studies: pollen production and viability, flower emergence and cross-pollination tests

During 1978-80, flower emergence was recorded on 12 almond cultivars (Prunus dulcis) at Angle Vale, South Australia. Early flowering cultivars showed a larger annual variation in flowering period (2-3 weeks) than late flowering cultivars (0-2 weeks). In the same period, pollen production ranged from 30 to 122 mg per 100 flowers and in vitro pollen germination ranged from 76.1 to 99.0%. Pollen production and in vitro germination differed significantly between cultivars. Hand-pollination of Nonpareil with pollen from each of eight other cultivars resulted in significantly higher nut set than with open-pollinated or self-pollinated flowers. In contrast to Nonpareil, hand-pollination of Chellaston with pollen from five other cultivars resulted in significantly higher nut set compared with self-pollinated Chellaston but not compared with open-pollinated Chellaston. The potential increase in almond yield due to improved pollination is discussed.

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Foliar Application of Boron to Almond Trees Affects Pollen Quality

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.125.2.265 ◽

2000 ◽

Vol 125 (2) ◽

pp. 265-270 ◽

Cited By ~ 29

Author(s):

A.M.S. Nyomora ◽

P.H. Brown ◽

K. Pinney ◽

V.S. Polito

Keyword(s):

Pollen Germination ◽

Foliar Application ◽

Culture Media ◽

Pollen Viability ◽

Prunus Dulcis ◽

Pollen Tubes ◽

Tube Growth ◽

Mature Trees

The effect of boron (B) on in vivo and in vitro development of almond [Prunus dulcis (Mill.) D.A. Webb (syn. P. amygdalus Batsch)] pollen and pollen tubes and the resultant effect on fruit set was studied in mature trees. The cultivars Mono (pistil donor) and Butte (pollinizer) in an orchard with low soil B in Fresno, California were sprayed with B at 0, 0.8, 1.7, or 2.5 kg·ha-1 during Fall 1993. Pollen viability as indicated by the fluorescein diacetate method (FDA) was >85% and was not affected by field-applied B, however, in vivo pollen germination and tube growth were enhanced by foliar-applied B. More effect of applied B on in vivo growth appeared as pollen tubes progressed toward the ovary. For in vitro germination, foliar-applied B reduced bursting of tubes, and addition of B to the culture media significantly increased pollen germination and pollen tube growth.

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Effect of high temperature on the reproductive development of chickpea genotypes under controlled environments

Functional Plant Biology ◽

10.1071/fp12033 ◽

2012 ◽

Vol 39 (12) ◽

pp. 1009 ◽

Cited By ~ 72

Author(s):

Viola Devasirvatham ◽

Pooran M. Gaur ◽

Nalini Mallikarjuna ◽

Raju N. Tokachichu ◽

Richard M. Trethowan ◽

...

Keyword(s):

Heat Stress ◽

High Temperature ◽

Pollen Germination ◽

Pollen Viability ◽

Pollen Grains ◽

High Temperature Stress ◽

Pollen Production ◽

Seed Number ◽

Controlled Environments

High temperature during the reproductive stage in chickpea (Cicer arietinum L.) is a major cause of yield loss. The objective of this research was to determine whether that variation can be explained by differences in anther and pollen development under heat stress: the effect of high temperature during the pre- and post-anthesis periods on pollen viability, pollen germination in a medium, pollen germination on the stigma, pollen tube growth and pod set in a heat-tolerant (ICCV 92944) and a heat-sensitive (ICC 5912) genotype was studied. The plants were evaluated under heat stress and non-heat stress conditions in controlled environments. High temperature stress (29/16°C to 40/25°C) was gradually applied at flowering to study pollen viability and stigma receptivity including flower production, pod set and seed number. This was compared with a non-stress treatment (27/16°C). The high temperatures reduced pod set by reducing pollen viability and pollen production per flower. The ICCV 92944 pollen was viable at 35/20°C (41% fertile) and at 40/25°C (13% fertile), whereas ICC 5912 pollen was completely sterile at 35/20°C with no in vitro germination and no germination on the stigma. However, the stigma of ICC 5912 remained receptive at 35/20°C and non-stressed pollen (27/16°C) germinated on it during reciprocal crossing. These data indicate that pollen grains were more sensitive to high temperature than the stigma in chickpea. High temperature also reduced pollen production per flower, % pollen germination, pod set and seed number.

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Effects of Sucrose, Boric Acid, pH, and Incubation Time on in Vitro Germination of Pollen and Tube Growth of Chinese fir (Cunnighamial lanceolata L.)

Forests ◽

10.3390/f10020102 ◽

2019 ◽

Vol 10 (2) ◽

pp. 102 ◽

Cited By ~ 3

Author(s):

Seif Fragallah ◽

Sizu Lin ◽

Nuo Li ◽

Elly Ligate ◽

Yu Chen

Keyword(s):

Boric Acid ◽

Pollen Germination ◽

Tree Breeding ◽

Chinese Fir ◽

Tube Growth ◽

In Vitro Germination ◽

Acid Ph ◽

Novel Approach ◽

The Media

In vitro pollen germination provides a novel approach and strategy to accelerate genetic improvement of tree breeding. Studies about pollen germination and tube growth of Chinese fir are limited. Therefore, this study aimed to investigate the effects of sucrose, boric acid, pH, and time of incubation on pollen germination and tube growth. Pollen from 9 clones were selected. In vitro germination was performed in basic media as control, and in different concentrations of sucrose (0, 10 and 15%), boric acid (0.01, 0.1 and 0.2%), and pH levels (4.5, 5 and 7). Pollen germination rates and tube growth were recorded periodically at 1, 12, 24, and 48 h. The results showed that sucrose imposes significant effects on pollen germination and tube growth. The effects are most obvious at concentration of 15%. Boric acid significantly promoted germination and tube growth. The promotion was most notable in lower concentration of 0.01%. The media adjusted to pH 7.0 boosted the germination and pollen tube growth. The optimum time of incubation was 24 and 48 h for pollen germination and tube growth, respectively. Sucrose, pH, and time of incubation were positively correlated, whereas boric acid negatively correlated with pollen germination and tube growth. This study provided experimental evidences for selecting viable pollens for Chinese fir breeding.

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Pollen Germination of Rhizoma Peanut cv. Florigraze1

Peanut Science ◽

10.3146/i0095-3679-19-2-11 ◽

1992 ◽

Vol 19 (2) ◽

pp. 105-107 ◽

Cited By ~ 7

Author(s):

W. L. Niles ◽

K. H. Quesenberry

Keyword(s):

Seed Production ◽

Pollen Germination ◽

Sucrose Concentration ◽

Growing Season ◽

In Vitro Germination ◽

Arachis Glabrata ◽

Pollen Germinability ◽

Poor Seed ◽

Dry Conditions

Abstract Assessing pollen germination is fundamental to investigating infertility in plants. A potential cause of poor seed production in Florigraze (Arachis glabrata Benth.), rhizomatous peanut, was investigated by incubating pollen on in vitro germination media. The optimum sucrose and boron concentrations for pollen germination was delineated in a series of factorial experiments. Pollen germinability was assessed four times during the growing season. Flowers were collected at 2 h intervals spanning 30 h of development from bud to wilted flower. The optimum sucrose concentration was 100 g kg-1 but there were no differences in germination for B concentrations between 50 and 1,000 mg kg-1. Up to 78% pollen germination was obtained in a solution consisting of 100 g kg-1 sucrose, 100 mg kg-1 H3BO3, 250 mg kg-1 Ca(NO3)2·4H2O, 200 mg kg-1 MgSO4·7H2O and 100 mg kg-1 KNO3 in deionized water. Repeatable estimates of germinability were obtained in incubations of less than 30 min at 35 C. Florigraze pollen collected from developing buds as early as 2200 h the night before anthesis germinated in vitro. Peak germination extended from 2400 h to 1200 h the morning of anthesis. Under cool, dry conditions, the pollen collected 2 d after anthesis remained germinable. These results suggested poor pollen germinability was not the basis of low seed production in rhizomatous peanut. Pollen with high in vitro germination can dependably be collected from Florigraze flowers throughout the growing season during the first 6 h following anthesis, usually between sunrise to noon.

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Viability and in Vitro Germination of Johnsongrass (Sorghum Halepense) Pollen

Weed Technology ◽

10.1614/wt-05-171.1 ◽

2007 ◽

Vol 21 (1) ◽

pp. 23-29 ◽

Cited By ~ 4

Author(s):

Ian C. Burke ◽

John W. Wilcut ◽

Nina S. Allen

Keyword(s):

Suspension Culture ◽

Boric Acid ◽

Pollen Germination ◽

Pollen Viability ◽

Calcium Nitrate ◽

Medium Composition ◽

In Vitro Tests ◽

In Vitro Germination ◽

Agar Culture

A high proportion of viable pollen grains must germinate to study the physiology of pollen growth to reduce the confounding effects of environmental influences on pollen germination. The objectives of this study were to evaluate the nuclear state and develop a suitable medium and culture method for in vitro germination of johnsongrass pollen. Johnsongrass pollen was trinucleate, and in vitro tests for pollen viability using Alexander's stain and a fluorochromatic reaction method (FCR) indicated johnsongrass pollen was viable (92.6 to 98.4%). A factorial treatment arrangement of four concentrations of sucrose, two concentrations of boric acid, and two concentrations of calcium nitrate were used to determine the optimum pollen-germination medium composition in suspension culture, agar culture, and cellophane membrane culture. Germination was highest in a suspension culture with a medium containing 0.3 M sucrose, 2.4 mM boric acid, and 3 mM calcium nitrate. Pollen germination using this medium was 78.9% when anthers were harvested just before anthesis.

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Technique for In Vitro Pollen Germination and Short-term Pollen Storage in Caladium

HortScience ◽

10.21273/hortsci.39.2.365 ◽

2004 ◽

Vol 39 (2) ◽

pp. 365-367 ◽

Cited By ~ 7

Author(s):

Zhanao Deng ◽

Brent K. Harbaugh

Keyword(s):

Pollen Germination ◽

Large Scale ◽

Pollen Viability ◽

Storage Conditions ◽

In Vitro Germination ◽

Short Term ◽

Pollen Storage ◽

Breeding Programs ◽

Sucrose Level

The sporadic nature of inflorescence production and flower protogyny in caladium (Caladium ×hortulanum Birdsey) makes it desirable to store pollen and to rapidly assess its viability for cross-pollinations in breeding programs. This study was conducted to develop a procedure to determine caladium pollen viability and to use that procedure to evaluate the effect of short-term storage conditions on pollen viability. The sucrose level in the culture medium was found to have a significant impact on the in vitro germination of caladium pollen; a concentration of 6.8% was determined to be optimal for pollen germination. Caladium pollen lost viability within 1 day under room (24 °C) or freezing (-20 °C) temperatures, but could be stored at 4 °C for 2 to 4 days. Pollen stored at 4 °C produced successful pollinations. Data obtained from large-scale greenhouse pollinations supported use of this in vitro germination assay as a convenient way to evaluate caladium pollen viability (and fertility).

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Optimization of In Vitro Pecan Pollen Germination

HortScience ◽

10.21273/hortsci.46.4.571 ◽

2011 ◽

Vol 46 (4) ◽

pp. 571-576 ◽

Cited By ~ 9

Author(s):

Patrick J. Conner

Keyword(s):

Polyethylene Glycol ◽

Pollen Germination ◽

Pollen Grains ◽

Solid Support ◽

Carya Illinoinensis ◽

Testing System ◽

In Vitro Germination ◽

Ethanesulfonic Acid ◽

Made In

Storage of pollen from 1 year to the next is often needed to enable desired crosses to be made in a pecan [Carya illinoinensis (Wangenh.) K. Koch] breeding program. Stored pollen is usually tested for viability through the use of in vitro germination tests. An in vitro germination testing system was developed for this purpose using cellophane booklets to provide a solid support for the pollen grains. Optimized germination media contained 5% sucrose, 20% polyethylene glycol 8000, 0.05% Ca(NO3)2, 0.025% H3BO3, and 10 mm 2-(N-morpholino)ethanesulfonic acid pH 6.0. Pollen should be rehydrated for 2 to 4 h in a humidified chamber before germination testing. A germination time of 4 to 24 h produces similar final germination percentages. Testing of pollen samples stored at –80 °C indicates that pecan pollen can be stored for at least 8 years without a decrease in viability. Chemical names used: polyethylene glycol (PEG); 2-(N-morpholino)ethanesulfonic acid (MES).

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In vitro germination and viability of pea pollen grains after application of organic nano-fertilizers

Pesticidi i fitomedicina ◽

10.2298/pif1701061g ◽

2017 ◽

Vol 32 (1) ◽

pp. 61-65 ◽

Cited By ~ 1

Author(s):

Natalia Georgieva ◽

Ivelina Nikolova ◽

Valentin Kosev ◽

Yordanka Naydenova

Keyword(s):

Pollen Tube ◽

Pollen Germination ◽

Culture Media ◽

Pollen Viability ◽

Pollen Grains ◽

Pollen Grain ◽

In Vitro Germination ◽

Pisum Sativum L ◽

Pollen Tube Elongation

The objective of this study was to evaluate the influence of two organic nanofertilizers, Lithovit and Nagro, on in vitro germination, pollen tube elongation and pollen grain viability of Pisum sativum L cv. Pleven 4. The effect of their application was high and exceeded data for the untreated control (44.2 and 47.23 % regarding pollen germination and pollen tube elongation, respectively), as well as the effect of the control organic algal fertilizer Biofa (17.5 and 27.9 %, respectively). Pollen grains were inoculated in four culture media. A medium containing 15% sucrose and 1% agar had the most stimulating impact on pea pollen grains. Pollen viability, evaluated by staining with 1% carmine, was within limits of 74.72-87.97%. The highest viability of pollen grains was demonstrated after the application of Nagro organic nano-fertlizer.

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In vitro pollen germination and pollen viability in passion fruit (Passiflora spp.)

Revista Brasileira de Fruticultura ◽

10.1590/s0100-29452013000400023 ◽

2013 ◽

Vol 35 (4) ◽

pp. 1116-1126 ◽

Cited By ~ 7

Author(s):

Taliane Leila Soares ◽

Onildo Nunes de Jesus ◽

Janay Almeida dos Santos-Serejo ◽

Eder Jorge de Oliveira

Keyword(s):

Pollen Germination ◽

Culture Medium ◽

Pollen Viability ◽

Pollen Grains ◽

In Vitro Germination ◽

Triphenyltetrazolium Chloride ◽

Histochemical Analysis ◽

High Viability ◽

Three Stages

The use of Passiflora species for ornamental purposes has been recently developed, but little is known about pollen viability and the potential for crossing different species. The objective of this study was to evaluate the pollen viability of six Passiflora species collected from different physiological stages of development through in vitro germination and histochemical analysis using dyes. The pollen was collected in three stages (pre-anthesis, anthesis and post-anthesis). Three compositions of culture medium were used to evaluate the in vitro germination, and two dyes (2,3,5-triphenyltetrazolium chloride, or TTC, and Lugol's solution) were used for the histochemical analysis. The culture medium containing 0.03% Ca(NO3) 4H2O, 0.02% of Mg(SO4 ).7H2O, 0.01% of KNO3, 0,01% of H3BO3, 15% sucrose, and 0.8% agar, pH 7.0, showed a higher percentage of pollen grains germinated. Anthesis is the best time to collect pollen because it promotes high viability and germination. The Lugol's solution and TTC dye overestimated the viability of pollen, as all accessions showed high viability indices when compared with the results obtained in vitro.

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