Pollen Analysis of Carrots

Why the Analysis of Carrot Pollen Quality is without Alternative

The analysis of carrot pollen quality improves breeding and seed production processes of this crop and enables data-driven decisions based on well-founded information. Amphasys enables fast, easy, and accurate measurements of pollen quality to:

  • Select those lines with high pollen viability and low number of aberrant cells
  • Select those lines with high amount of viable pollen cells
  • Know the impact of abiotic stress for crop placement

Ensuring high pollen viability and a substantial pollen quantity is crucial for achieving a robust seed set, making it an indispensable factor in cost-effective seed production. The early identification and understanding of effective pollinator lines during the breeding process not only streamline efforts in breeding but also result in time and resource savings in subsequent production research and seed production.

As a biennial crop, carrot breeding and seed production are lengthy processes and gains in efficiency have a significant impact on the result. Knowing the properties of carrot lines with respect to reproduction can help to save a lot of effort and resources and to improve the yield.

Our specific “Carrot Chip” facilitates automated data analysis of pollen viability and quantity. It delivers instantaneous results, offering a time and resource-efficient solution for routine quality control and systematic pollen screening.

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Amphasys provides support and consultancy for the optimization of your pollen analyses for breeding and production processes. Whether it be the measurement of individual pollen samples or a large pollen screening project at your greenhouses or fields: ask for a non-binding offer.

Characterization of Pollen Quality in Carrot Breeding and Seed Production

Viable pollen in a sufficient amount is a basic requirement for successful plant reproduction. However, carrot lines show significant variation in viability and quantity among the different varieties. Amphasys’ technology offers a fast, reliable, and cost-efficient solution for line characterization – even with automated data analysis.

Identification of the best pollinator lines: Systematic line screening

As breeding is about reproduction, pollen quality plays a crucial role. The screening of a large number of different carrot lines revealed great variation in terms of pollen quality. The good pollinator lines reach viability values of 50% to 70%, the lines under investigation (see figure below) on average rather 20% or below. The low viability and high values for aberrant cells shows the heat sensitivity of these carrot lines and can be assigned to a heat wave in the days prior to the measurements.

Figure 1: Percentage of viable and aberrant pollen cells of different carrot lines

In parallel to the line dependent viability, a strong variation of the fraction of aberrant cells depending on the line can be observed. The share of aberrant cells ranges from 15% to approx. 50% and exceeds in most cases the values of viable cells. The tolerance of the lines to abiotic stress, especially heat stress, should be investigated. 

All these results confirm the importance of proper line selection during carrot breeding by means of pollen quality analysis to prevent delayed breeding processes and subsequent issues in seed production.

Identification of abiotic stress

The existence of aberrant cells can be an indication of abiotic stress. Aberrant cells are dead pollen cells that have been aborted during maturation and have morphological differences. Especially higher concentrations of aberrant cells give notice on the impact of abiotic stress prior to flowering.

If a high concentration of aberrant cells is observed, like in the example in the figure 1 above, further investigation should be done to detect the cause of this behavior. The eligibility of these lines should be reconsidered for the further breeding process.

Improvement of Carrot Seed Production

Characterization of the pollinator lines to avoid poor seed set

Knowing the impact factors for crop placement, determining the optimum female to male ratio, having the right pollen storage protocol in place – these are important success factors for hybrid seed production. For carrot seed production this is especially relevant given that the preconditions are already poor: relatively low pollen viability, high share of aberrant cells, and high variability between lines. In addition, the quantification of the pollen cells show that the amount of cells per umbellet can vary significantly between lines.

Figure 2: Number of pollen cells per umbellet of different carrot lines and corresponding viability

If low viability comes along with low amount of pollen cells, reproduction of this line becomes a great challenge. The analysis of the carrot lines for the amount of produced pollen shows, how uneven the properties are distributed: some lines with high viability produce only low amounts of pollen (lines 2 and 3) whereas the lines with low viability show high pollen production (lines 9 and 11).

The analysis of pollen quality as early as possible is an indispensable prerequisite. To prevent issues in breeding and seed production, pollen quality is a mandatory parameter in all steps.

Pollen quality information for efficient crop placement

Viability, number of aberrant pollen cells, and quantity of pollen formed can be indicators for line sensitivity to abiotic stress. Different lines may behave differently under certain conditions. The comparison of these parameters of the same lines under different environmental conditions can disclose the eligibility of certain lines for certain conditions. Placing the right lines in the right conditions ensures a high seed set and profit. 

Sampling and sample preparation

For the determination of pollen viability and pollen quantity, the carrot umbels should be well defined and round, and not show brownish flowers already. Ideally, all flowers of an umbel are open, and the pollen is visible at the anthers. 

Carrot umbels with individual umbellets in an ideal stage for pollen analysis.

The best time for flower or anther collection is about lunchtime or early afternoon.

For sample preparation, the best results are obtained collecting two umbellets (critical lines with low viability or low pollen number 3 to 5 umbellets) in one tube and shaking the pollen out of the anthers by moving the tube over a rack before adding the AmphaFluid buffer (“dry rack method”). Sample preparation instructions are provided on the Ampha P20 instrument using the “Carrot Chip”.

Equilibration time in the buffer is 2 minutes for fresh pollen and 5 minutes for stored pollen. Pollen is stable in the buffer for more than one hour without loss of viability. If stored carrot pollen is used, a prior rehydration step is recommended to obtain the best results.

Further information regarding sample preparation you can find here: Amphasys – Pollen Analysis Instructions

Amphasys Pollen Analyzers

Amphasys Pollen Analyzers provide pollen quality metrics which enable you to improve your plant breeding and seed production processes:

The Ampha Z40 is a high-end laboratory device. It offers full flexibility for all pollen quality related research tasks and predefined templates for routine quality control.

The Ampha P20 is a mobile high-tech instrument for greenhouses and fields. With its easy handling and automated data analysis you get immediate results on site.

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