Sunflower Double-Haploid Breeding Through Pollen-Free Gynogenesis

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Solution Overview

Problem

Existing haploidization techniques for sunflowers are cumbersome, complex, and yield unsatisfactory results, lacking efficiency and reliability in producing defect-free haploid plants.

Innovation Solution

A method involving castration of sunflower flowers by removing male organs to induce immature haploid embryos in unfertilized ovaries, followed by embryo rescue and optional chromosome doubling, without the need for pollination or pollen treatment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If androgenesis or gynogenesis techniques are used to obtain haploids in sunflower, then haploid plants can be produced, but the process becomes cumbersome and complex with unsatisfactory results

Engineering Contradiction:
Improveyield of viable haploid plantsVSAvoidcomplexity of haploidization process
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts and eliminates the unnecessary pollination step from the haploidization process. By removing the male organs (anthers) before pollen emission and preventing any pollen contact with the flower, the method directly induces haploid embryo formation in the ovary without requiring pollen treatment, irradiation, or complex pollination procedures, thereby simplifying the process while maintaining reliability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The method segments the haploidization process into distinct chronological phases: (1) castration before pollen emission, (2) isolation period without pollen contact, (3) harvesting at specific developmental stage, and (4) in vitro culture. This segmentation allows precise control over embryo development and simplifies each individual step, reducing overall process complexity

Inventive Principle:
Principle #1Segmentation

2Loss of time

If traditional haploidization methods are used, then haploid plants can be obtained, but the varietal selection cycle takes 7 to 8 generations

Engineering Contradiction:
Improveduration of varietal selection cycleVSAvoidspeed of obtaining pure lines
Core Design Contradiction:
Loss of timeVSProductivity

Solution Approach 1:

The method performs preliminary chromosome doubling action by inducing embryo formation directly from the ovary in a haploid state, then subsequently doubling the chromosomes to create immediately fertile doubled haploid plants. This preliminary action eliminates the need for 7-8 generations of successive self-fertilization, reducing the selection cycle from years to a single growing season

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention changes the chromosomal parameter from haploid (n) to doubled haploid (2n) through controlled chromosome doubling after embryo rescue. This parameter change creates fertile plants that can immediately be used for varietal selection, dramatically increasing productivity by eliminating multiple generational cycles required in traditional methods

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If pollination with functional or non-functional pollen is used to induce haploid development, then embryos can be formed, but the process requires complex pollen treatment and contact procedures

Engineering Contradiction:
Improveease of haploid inductionVSAvoidcomplexity of pollination procedures
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

Instead of using pollen to induce haploid development as in traditional methods, the invention inverts the approach by using pollen absence (castration) as the inducing agent. By removing male organs and preventing pollen contact, the method triggers automatic haploid embryo formation in the ovary, eliminating the need for complex pollen collection, treatment, and application procedures

Inventive Principle:
Principle #13The other way round (Inversion)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This method simplifies the process, achieves high yields of viable haploid and doubled haploid sunflower plants, reducing the need for complex manipulations and shortening the varietal selection cycle by 3 to 5 years.

Implementation Method 1

By doubling the number of chromosomes in these cells, the normal diploid state (2n) is restored. Since both copies of each gene are identical, homozygous diploid plants are obtained for each locus.

Methodology Applied
Scientific EffectChromosome doubling:

Implementation Method 2

Colchicine blocks cell divisions, that is to say it stops mitosis at the metaphase phase by blocking the microtubule spindle.

Methodology Applied
Scientific EffectMitosis blocking:

Data Source

PatentEP4072273B1Double-haploid method for sunflower plants
Publication Date: 2025.08.27 RAGT 2N

AI summary

The invention relates to a double-haploid method for sunflower plants by in situ gynogenesis characterized in that no pollen is used. The invention is based solely on castration that makes it possible to obtain an immature haploid embryo in the ovary on the plant, followed by embryo rescue.