Pollen grain number and viability contribute to variation in effective ovule number among oilseed rape genotypes

Abstract While no significant differences in initial ovule number were found among oilseed rape genotypes, there was a large variation in effective ovule number (EON), which determines the final seeds per silique (SPS), a critical component of yield. In this study, we selected 18 oilseed rape genotypes with contrasting nitrogen utilization efficiency (NUtE) to unravel the main factors responsible for different EON and determine the critical period of EON formation under both a field and a pot experiments from 2016-2018. The high NUtE genotypes displayed significantly higher NUtE by 14.3%, along with greater yield per plant (29.4%) and SPS (21.1%) than the low NUtE genotypes. The greater productivity of the high NUtE genotypes was associated with 44.1% higher pollen grain number, 23.5% greater pollen viability, and 39.3% lower ovule abortion rate, compared to the low NUtE genotypes. In addition, the heart stage was the critical ovule development period for delineating the variability of EON among contrasting NUtE oilseed rape genotypes, when the high NUtE genotypes displayed higher silique net photosynthetic rate, surface area, biomass, and RNA expression levels. Taken together, this study indicated the pollen grain number, pollen viability and ovule abortion rate contributed to the final variation in EON and the heart stage was the critical period of determining the EON differences among contrasting NUtE genotypes. Increasing pollen grain number and pollen viability, and decreasing ovule abortion rate before heart stage should be the prerequisite for breeders to improve yield and NUtE of oilseed rape genotypes.

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Relationships between pollen histochemistry, pollen grain number, ovule number and pollinators in Phyllanthaceae

Biodiversity Science ◽

10.1360/biodiv.070162 ◽

2007 ◽

Vol 15 (6) ◽

pp. 645 ◽

Cited By ~ 3

Author(s):

Li Yongquan

Keyword(s):

Pollen Grain ◽

Grain Number ◽

Ovule Number

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Addition of rye chromosome 4R to wheat increases anther length and pollen grain number

Theoretical and Applied Genetics ◽

10.1007/s00122-015-2482-4 ◽

2015 ◽

Vol 128 (5) ◽

pp. 953-964 ◽

Cited By ~ 18

Author(s):

Vy Nguyen ◽

Delphine Fleury ◽

Andy Timmins ◽

Hamid Laga ◽

Matthew Hayden ◽

...

Keyword(s):

Pollen Grain ◽

Grain Number ◽

Anther Length

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The effects of soil sodicity on emergence, growth, development and yield of oilseed rape (Brassica napus)

The Journal of Agricultural Science ◽

10.1017/s002185960007310x ◽

1996 ◽

Vol 126 (2) ◽

pp. 169-173 ◽

Cited By ~ 5

Author(s):

F. H. Gutiérrez Boem ◽

R. S. Lavado

Keyword(s):

Oilseed Rape ◽

Sandy Loam ◽

Total Yield ◽

Main Stem ◽

Growth And Yield ◽

Exchangeable Sodium ◽

Grain Number ◽

Soil Crusting ◽

Growth Development ◽

Pod Number

SUMMARYThe effects of exchangeable sodium on emergence, growth, development and yield composition of oilseed rape were investigated at Buenos Aires, Argentina in 1992. A pot experiment was performed using five exchangeable sodium levels, expressed as Sodium Adsorption Ratio (SAR: 12, 20, 27, 34 and 44). Soil with nine different exchangeable sodium contents (SAR from 0·5 to 50) and seven different particle size distributions (from sandy loam to clay) were used in a parallel trial to study the effect of soil crusting on oilseed rape emergence. Soil crusts were made using a rainfall simulator after seeds were sown. Both experiments showed that the direct effect of sodium on emergence occurred with SAR values higher than those which caused clay dispersion (SAR > 20). Oilseed rape seedlings could penetrate crusts having a resistance of < 230 kPa. At SAR values > 20, main stem growth and yield decreased significantly (P < 0·05). These reductions were counterbalanced by an increase in the number of secondary stems. At SAR levels > 34, stem number, grain number per pod on the main stem, as well as pod number on both main stem and secondary stems, were reduced, leading to a marked reduction in total yield. The most important agronomic effect of soil sodium on oilseed rape would be at emergence stage, due to soil crusting.

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Pollen number and vigor contribute to effective ovule numbers among contrasting nitrogen utilization efficiency oilseed rapes genotypes before heart stage

10.21203/rs.3.rs-18413/v1 ◽

2020 ◽

Author(s):

Xiao Guo ◽

Yuyu Xie ◽

Yunyou Nan ◽

Xiaoming Wu ◽

Biyun Chen ◽

...

Keyword(s):

Oilseed Rape ◽

Critical Period ◽

Abortion Rate ◽

Utilization Efficiency ◽

Ovule Abortion ◽

Nitrogen Utilization Efficiency ◽

Ovule Number ◽

Pollen Number ◽

Main Factors ◽

Pollen Vigor

Abstract Background: While no significant differences in initial ovule number were found among oilseed rape genotypes, there was a large variation in effective ovule number (EON), which determines the final seeds per silique (SPS), a critical component of yield. Up to date, on study has been focused on unraveling the pre-flowering main factors to restrict EON and identifying the critical period of EON formation among contrasting nitrogen utilization efficiency (NUtE) oilseed rape genotypes.Results: In this study, we selected 18 oilseed rape genotypes with different NUtE to identify the main factors that contribute to EON, and determine if genotypes differed in the critical period of EON formation under both field and pot experiments from 2016-2018. Our results showed the high NUtE genotypes also showed 14.3% higher NUtE, accompanied with 29.4% higher yield per plant and 21.1% higher SPS. The greater productivity of the high NUtE oilseed rape genotypes was associated with 44.1% greater pollen number, 23.5% higher pollen vigor, and 39.3% lower ovule abortion rate, compared to the low NUtE genotypes. In addition, at the heart stage, the high NUtE genotypes displayed higher silique net photosynthetic rate, surface area, biomass, and RNA expression levels, compared to the low NUtE ones. Taken together, this study indicated the pollen number, pollen vigor and ovule abortion rate contributed to the final EON of diverse oilseed rape genotypes; the critical period of determining EON among contrasting NUtE genotypes was at the heart stage.Conclusion: Increasing pollen number and vigor, and decreasing ovule abortion rate before the heart stage should be the prerequisite for breeders to improve yield and NUtE of oilseed rape genotypes.

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Radiation and nitrogen use at the leaf and canopy level by wheat and oilseed rape during the critical period for grain number definition.

Functional Plant Biology ◽

10.1071/pp00019 ◽

2000 ◽

Vol 27 (10) ◽

pp. 899 ◽

Cited By ~ 2

Author(s):

M. Fernanda Dreccer ◽

Ad H. C. M. Schapendonk ◽

Marcel van Oijen ◽

C. Sander Pot ◽

Rudy Rabbinge

Keyword(s):

Vertical Distribution ◽

Oilseed Rape ◽

Critical Period ◽

Plant Density ◽

Canopy Photosynthesis ◽

Leaf Photosynthesis ◽

Grain Number ◽

N Supply ◽

Leaf N Content ◽

Leaf N

During the critical period for grain number definition, the amount of biomass produced per unit absorbed radiation is more sensitive to nitrogen (N) supply in oilseed rape than in wheat, and reaches a higher value at high N. This response was investigated by combining experimental and modelling work. Oilseed rape and wheat were grown at three levels of N supply, combined with two levels of plant density at high N supply. Canopy photosynthesis and daytime radiation use efficiency (RUEA) were calculated with a model based on observed N-dependent leaf photosynthesis and observed canopy vertical distribution of light and leaf N. In oilseed rape, RUEA was higher than in wheat and, in contrast to wheat, the sensitivity to canopy leaf N content increased from the start to the end of the critical period. These results were partly explained by the higher leaf photosynthesis in oilseed rape vs wheat. In addition, oilseed rape leaves were increasingly shaded by the inflorescence. Thus, RUEA increased because more leaves were operating at non-saturating light levels. In both species, the vertical distribution of leaf N was close to that optimising canopy photosynthesis. The results are discussed in relation to possibilities for improvement of N productivity in these crops.

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Contribution of pollen to atmospheric ice nuclei concentrations

Atmospheric Chemistry and Physics ◽

10.5194/acp-14-5433-2014 ◽

2014 ◽

Vol 14 (11) ◽

pp. 5433-5449 ◽

Cited By ~ 52

Author(s):

J. D. Hader ◽

T. P. Wright ◽

M. D. Petters

Keyword(s):

North Carolina ◽

Fold Increase ◽

Pollen Grain ◽

Background Concentrations ◽

Grain Number ◽

Wetting And Drying ◽

Ice Nuclei ◽

Southeastern Us ◽

Maximum Value ◽

Pollen Types

Abstract. Recent studies have suggested that the ice-nucleating ability of some types of pollen is derived from non-proteinaceous macromolecules. These macromolecules may become dispersed by the rupturing of the pollen grain during wetting and drying cycles in the atmosphere. If true, this mechanism might prove to be a significant source of ice nuclei (IN) concentrations when pollen is present. Here we test this hypothesis by measuring ambient IN concentrations from the beginning to the end of the 2013 pollen season in Raleigh, North Carolina, USA. Air samples were collected using a swirling aerosol collector twice per week and the solutions were analysed for ice nuclei activity using a droplet freezing assay. Rainwater samples were collected at times when pollen grain number concentrations were near their maximum value and analysed with the drop-freezing assay to compare the potentially enhanced IN concentrations measured near the ground with IN concentrations found aloft. Ambient ice nuclei spectra, defined as the number of ice nuclei per volume of air as a function of temperature, are inferred from the aerosol collector solutions. No general trend was observed between ambient pollen grain counts and observed IN concentrations, suggesting that ice nuclei multiplication via pollen grain rupturing and subsequent release of macromolecules was not prevalent for the pollen types and meteorological conditions typically encountered in the southeastern US. A serendipitously sampled collection after a downpour provided evidence for a rain-induced IN burst with an observed IN concentration of approximately 30 per litre, a 30-fold increase over background concentrations at −20 °C. The onset temperature of freezing for these particles was approximately −12 °C, suggesting that the ice-nucleating particles were biological in origin.

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