Pollen tube growth and early ovule development following self- and cross-pollination in Eucalyptus nitens

AbstractA newly released, late ripening plum cultivar Pozna Plava sets fruit poorly, although it produces high quality fruit. This study aimed to evaluate which factors in the reproductive process could be related to the lack of fruit set. In two consecutive years, establishment of a suitable polleniser and the stage of ovule development at anthesis as well as initial and final fruit set have been studied. In addition to this, the impact made by temperature fluctuations on the interaction between male gametophytes and female sporophytes was also analysed. Growth of the pollen tubes in the style and penetration into the nucellus as well as fruit set were more effective in cross-pollination than in open and self-pollination. A relative delay in ovule development was observed, and most ovules had an embryo sac with eight nuclei. Considering the results of the quantitiative parameter study of pollen tube growth in the ovary as well as the results of the stage of ovule development, a conclusion can be made that this cultivar is characterised by an extremely short effective period of pollination.

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Transcriptomic Analysis Reveals a Comprehensive Calcium- and Phytohormone-Dominated Signaling Response in Leymus chinensis Self-Incompatibility

International Journal of Molecular Sciences ◽

10.3390/ijms20092356 ◽

2019 ◽

Vol 20 (9) ◽

pp. 2356 ◽

Cited By ~ 2

Author(s):

Shuangyan Chen ◽

Junting Jia ◽

Liqin Cheng ◽

Pincang Zhao ◽

Dongmei Qi ◽

...

Keyword(s):

Pollen Tube ◽

Pollen Tube Growth ◽

Time Course ◽

Molecular Mechanisms ◽

Tube Growth ◽

Leymus Chinensis ◽

Self Incompatibility ◽

Cross Pollination ◽

Grass Family ◽

Self Pollination

Sheepgrass (Leymus chinensis (Trin.) Tzvel.) is an economically and ecologically important forage in the grass family. Self-incompatibility (SI) limits its seed production due to the low seed-setting rate after self-pollination. However, investigations into the molecular mechanisms of sheepgrass SI are lacking. Therefore, microscopic observation of pollen germination and pollen tube growth, as well as transcriptomic analyses of pistils after self- and cross-pollination, were performed. The results indicated that pollen tube growth was rapidly inhibited from 10 to 30 min after self-pollination and subsequently stopped but preceded normally after cross-pollination. Time course comparative transcriptomics revealed different transcriptome dynamics between self- and cross-pollination. A pool of SI-related signaling genes and pathways was generated, including genes related to calcium (Ca2+) signaling, protein phosphorylation, plant hormone, reactive oxygen species (ROS), nitric oxide (NO), cytoskeleton, and programmed cell death (PCD). A putative SI response molecular model in sheepgrass was presented. The model shows that SI may trigger a comprehensive calcium- and phytohormone-dominated signaling cascade and activate PCD, which may explain the rapid inhibition of self-pollen tube growth as observed by cytological analyses. These results provided new insight into the molecular mechanisms of sheepgrass (grass family) SI.

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Reciprocal intercompatibility between Byrsonima Rich. exKunth species (Malpighiaceae), in an urban ecotonal fragment of Semi-Deciduous Seasonal Forest and Cerrado

Anales de Biología ◽

10.6018/analesbio.43.20 ◽

2021 ◽

pp. 211-221

Author(s):

Frederic Mendes Hughes

Keyword(s):

Pollen Tube ◽

Pollen Tube Growth ◽

Tube Growth ◽

Self Incompatibility ◽

Prezygotic Isolation ◽

Stigmatic Surface ◽

Cross Pollination ◽

Self Pollination ◽

Isolation Mechanisms ◽

Hypothesis Evaluation

Byrsonima species present floral monomorphism and sharing visitor/pollinator guild. These traits suggest the hypothesis evaluation of reciprocal inter-incompatibility between two syntopic Byrsonima species: B. pachyphylla and B. crassifolia. Pollen tube growth with similar behavior was observed in the stigmatic surface, pistil canal, ovary and micropylar channel to both species. In addition, partial self-incompatibility in self-pollination with greater fruiting in autogamy was observed. Cross-pollination and self-pollination coexist, and reciprocal intercompatibility occurs. Prezygotic isolation mechanisms are unlikely by the absence of abnormal pollen tubes, higher fruiting production and absence of hybrids in the study site. Las especies de Byrsonima presentan monomorfismo floral y comparten gremio de visitantes/polinizadores. Estos rasgos sugieren la evaluación de hipótesis de interincompatibilidad recíproca entre dos especies sintópicas de Byrsonima: B. pachyphylla y B. crassifolia. Se observó el crecimiento del tubo polínico con comportamiento similar en la superficie estigmática, canal del pistilo, ovario y canal micropilar de ambas especies. Además, se describió la autoincompatibilidad parcial en la autopolinización con mayor fructificación en la autogamia. La polinización cruzada y la autopolinización coexisten y se produce una intercompatibilidad recíproca. Los mecanismos de aislamiento precigóticos son improbables por la ausencia de tubos polínicos anormales, producción de frutos y ausencia de híbridos en la área de estudio.

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Comparison of Self- and Cross-pollination on Pollen Tube Growth, Seed Development, and Germination in Crapemyrtle

HortScience ◽

10.21273/hortsci.41.3.575 ◽

2006 ◽

Vol 41 (3) ◽

pp. 575-578 ◽

Cited By ~ 3

Author(s):

Cecil Pounders ◽

Sandra Reed ◽

Margaret Pooler

Keyword(s):

Seed Germination ◽

Pollen Tube ◽

Seed Production ◽

Pollen Tube Growth ◽

Tube Growth ◽

Cross Pollination ◽

Landscape Plants ◽

Incompatibility System ◽

Self Fertilization ◽

Self Compatibility

Crapemyrtle (L. indica and L. indica × L. fauriei hybrids) is one of the most popular flowering landscape plants in the U.S. Although many cultivars have been developed through breeding efforts, little has been published on the reproductive biology of the genus. The objective of this study was to evaluate barriers to successful self-seed production in crapemyrtle. Self-compatibility was assessed by comparing pollen tube growth, fruit and seed production, and seed germination following controlled self- and cross-pollinations. Observations of pollen tube growth at intervals up to 24 hours after self- and cross-pollination indicated no barriers to self-fertilization acting at the stigmatic or stylar level in L. indica, L. fauriei or cultivars derived from inter-specific hybrids of these two species. Self-pollinations of `Catawba', `Whit IV', `Tonto' and `Tuscarora' had lower percent seed pod set and seed germination than did cross-pollinations of these cultivars. The number of seeds per pod was lower when `Catawba', `Whit IV' and `Tuscarora' were self-rather than cross-pollinated, but no difference between `Tonto' self- and cross-pollinations was observed. When decreased pod set is combined with much lower seed germination for self-pollinations, selfing of crapemyrtle is extremely unproductive when compared to cross-pollination. A late-acting self-incompatibility system or inbreeding depression is indicated for L. indica and inter-specific crosses with L. fauriei.

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Comparison of different classical and molecular methods for identifying self-incompatibility in two olive cultivars

Spanish Journal of Agricultural Research ◽

10.5424/sjar/2019173-14761 ◽

2019 ◽

Vol 17 (3) ◽

pp. e0804 ◽

Cited By ~ 1

Author(s):

Elham Aslmoshtaghi ◽

Ali Reza Shahsavar ◽

Majid Talebi ◽

Aziz Dazeh

Keyword(s):

Pollen Tube ◽

Molecular Analysis ◽

Pollen Tube Growth ◽

Tube Growth ◽

Research Station ◽

Self Incompatibility ◽

Controlled Pollination ◽

Cross Pollination ◽

Self Pollination ◽

Olive Cultivars

Aim of study: To determine compatibility relationships and select suitable pollinizers for two olive (Olea europaea L.) cultivars (‘Amygdalolia’ and ‘Konservalia’).Area of study: The Kazeroun Olive Research Station, Fars, Iran.Material and methods: Emasculated flowers from ‘Amygdalolia’ and ‘Konservalia’ cultivars were treated with self-pollination, open-pollination, and cross-pollination with pollen from cultivars such as ‘Dacal’, ‘Amygdalolia’,‘Konservalia’, ‘Koroniki’, and ‘Manzanilla’. Controlled pollination, pollen tube growth, and molecular analysis were employed.Main results: Controlled pollination, pollen tube growth, and molecular analysis showed that cross-pollination was beneficial for ‘Amygdalolia’ compared to self-pollination. The results showed that this cultivar is self-incompatible, and its best pollinator is the ‘Dacal’ cultivar. Experiment results indicated that ‘Konservalia’ behaves as a self-compatible cultivar. The highest fruit percentage and higher pollen tube growth rates were found in self-pollination treatments. Molecular attempts to isolate candidates for sporophytic self-incompatibility (SSI) led the researchers to analyze the expression of SRK and SLG genes.Research highlights: The results indicated an antagonist transcriptional expression pattern in the flowers of ‘Amygdalolia’, classified as a self-incompatible cultivar, and ‘Konservalia’, classified as a self-compatible cultivar, for the SRK and SLG genes.

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Stigmatic Receptivity Limits the Effective Pollination Period in `Agua de Aranjuez' Pear

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.128.4.0458 ◽

2003 ◽

Vol 128 (4) ◽

pp. 458-462 ◽

Cited By ~ 13

Author(s):

Javier Sanzol ◽

Pilar Rallo ◽

María Herrero

Keyword(s):

Pollen Tube ◽

Pollen Tube Growth ◽

Fruit Set ◽

Strong Relationship ◽

Tube Growth ◽

Limiting Factor ◽

Ovule Development ◽

Fruit Crops ◽

Reproductive Process ◽

Speed Up

Apples and pears are fruit crops particularly susceptible to cropping irregularities. A strong relationship has been observed between the effective pollination period (EPP) and the general cropping of the orchard. The EPP concept has also been proven to be a useful parameter to establish a relationship between the variation in the reproductive process and cropping behaviors. For apples and pears, a slow pollen tube growth has been shown to be the main limiting factor of the EPP in the traditional cooler temperate cultivation regions. However, while higher temperatures speed up the pollen tube growth, the expansion of these crops into warmer areas often results in failures of fruit set. Thus, with the aim to ascertain the main limiting factor responsible for fruit set failures in Mediterranean conditions we have evaluated the EPP for two consecutive years in `Agua de Aranjuez' pear, the main Spanish cultivar, by studying the stigmatic receptivity, pollen tube kinetics, and ovule development. Complete flower fertility was maintained for just 2 days after anthesis in both years. Pollen tube kinetics and ovule degeneration do not appear to limit flower receptivity. However, the stigmatic receptivity expressed as flowers with at least one receptive stigma, closely matches the duration of the EPP evaluated from fruit set experiments. This was consistent over the 2 years of experiments, in spite of the differences recorded in the EPP, suggesting that stigmatic receptivity is clearly the limiting factor of flower receptivity. This is the first report for stigmatic receptivity limiting the EPP in pears and suggests that stigmatic receptivity could be an important factor limiting pear flower receptivity and hence cropping performance under warmer conditions.

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