Maize Fusarium Resistance via Molecular Marker Selection

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Solution Overview

Problem

Current methods for selecting maize plants resistant to Fusarium ear mold are time-consuming and unreliable, particularly due to environmental sensitivity and the need for phenotypic selection, which complicates the incorporation of genetic resistance in breeding programs.

Innovation Solution

The use of molecular markers associated with Fusarium ear mold resistance allows for early identification and selection of maize plants with enhanced resistance, utilizing specific marker alleles and loci linked to resistance traits on chromosomes 1 and 6, enabling rapid breeding for resistant hybrids.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If phenotypic selection is used to introgress resistance, then resistance can be identified, but the process is time consuming and difficult

Engineering Contradiction:

Improveresistance identification reliabilityVSAvoidselection time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent replaces phenotypic selection (mechanical/physical observation of disease symptoms) with molecular marker-based genotypic selection. Specific molecular markers (e.g., SSR markers, SNP markers) are used to detect resistance alleles directly at the DNA level, eliminating the need to grow plants to maturity and observe phenotypic expressions of resistance. This substitution enables early selection at the seedling or even seed stage, dramatically reducing the time required for resistance introgression while maintaining reliable identification through validated marker-trait associations.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If phenotypic selection is used, then resistance can be assessed, but selection based solely on phenotype is unreliable due to environmental sensitivity

Engineering Contradiction:

Improveresistance selection reliabilityVSAvoidenvironmental sensitivity

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent substitutes phenotypic assessment with molecular marker-based genotypic assessment. Resistance is determined by detecting the presence of specific resistance alleles through DNA analysis rather than by observing phenotypic symptoms that are influenced by environmental conditions. This approach eliminates environmental sensitivity as a source of selection error, as molecular markers provide stable, heritable indicators of resistance that are independent of external factors such as temperature, humidity, or pathogen pressure during the selection period.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If plants are grown to maturity for resistance classification, then accurate resistance level determination is achieved, but the process becomes costly and time consuming

Engineering Contradiction:

Improveresistance level classification accuracyVSAvoidbreeding efficiency

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The patent implements preliminary action by performing resistance assessment at early developmental stages (seedling or seed stage) using molecular markers, rather than waiting for plants to reach maturity. The molecular markers are validated to accurately predict resistance levels that would be expressed at maturity, allowing breeders to make selection decisions early in the breeding cycle. This preliminary genotypic screening maintains measurement precision for resistance classification while dramatically improving breeding productivity by enabling multiple generations to be advanced in parallel and reducing the duration of each selection cycle.

Inventive Principle:

Principle #10Preliminary action

4Reliability

If specialized disease screening sites are used, then resistance screening can be performed, but operational costs increase

Engineering Contradiction:

Improveresistance screening accuracyVSAvoidbreeding program cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces the need for specialized disease screening sites with routine molecular biology laboratories equipped for DNA extraction and marker analysis. Instead of requiring controlled infection facilities, pathogen inoculation equipment, and expert phytopathological assessment capabilities, the screening process is transferred to standard molecular genetics workflows. This substitution maintains reliable resistance identification through validated marker-trait associations while significantly reducing operational costs by eliminating the need for specialized infrastructure and reducing the requirement for highly trained personnel.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS9551041B2Genetic loci associated with fusarium ear mold resistance in maize

Publication Date: 2017.01.24 CORTEVA AGRISCIENCE LLC

AI summary

The invention relates to methods and compositions for identifying and selecting maize plants with enhanced resistance to Fusarium ear mold. Maize plants generated by the methods of the invention are also a feature of the invention.