PHWVZ Doubled Haploid Maize Line for Transgene Introgression

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The existing maize transformation technology using the Hi-II line is hindered by its hybrid nature, making it difficult to achieve a uniform, homozygous background for transgene development, and it lacks the quality genetics present in elite inbreds, requiring labor-intensive backcrossing to remove deleterious genomes.

Innovation Solution

Development of a novel double haploid maize line, PHWVZ, which is homozygous and has elite genotype characteristics, maintaining high transformability and culturability, allowing for efficient introgression of transgenes into an elite background through backcross conversion and transformation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If Hi-II maize line is used for transformation, then transformability and culturability are improved, but homozygosity and elite genotype quality deteriorate

Engineering Contradiction:
ImprovetransformabilityVSAvoidhomozygosity
Core Design Contradiction:
Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The patent applies preliminary action by creating doubled haploid lines before transformation. The Hi-II line is crossed with elite inbred lines, and doubled haploid progeny are generated and screened for homozygosity and transformation capability. This preliminary creation of homozygous lines with elite genetics before the transformation process resolves the contradiction by ensuring both transformability and homozygosity are achieved in the same line.

Inventive Principle:
Principle #10Preliminary action

2Ease of manufacture

If Hi-II maize line is used for transformation, then transformability is improved, but elite genotype quality deteriorates, requiring labor-intensive backcrossing

Engineering Contradiction:
ImprovetransformabilityVSAvoidbackcrossing time
Core Design Contradiction:
Ease of manufactureVSLoss of time

Solution Approach 1:

The patent performs preliminary action by pre-crossing Hi-II with elite inbred lines and selecting doubled haploid progeny that already possess elite genotype characteristics. This eliminates or significantly reduces the need for subsequent labor-intensive backcrossing to remove deleterious Hi-II genome, thereby saving time while maintaining transformability.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent extracts the desirable elite genotype characteristics from elite inbred lines and combines them with the transformability of Hi-II through controlled crossing and doubled haploid selection. This extraction and combination approach removes the need for extensive backcrossing to eliminate unwanted Hi-II traits.

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of manufacture

If non-homozygous plants are used for transgene development, then transformability is maintained, but determination of transgene effects becomes difficult

Engineering Contradiction:
ImprovetransformabilityVSAvoidtransgene effect determination
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent applies local quality by ensuring that the genetic background is uniformly homozygous while allowing the transgene to be the variable element. The doubled haploid lines provide a homogeneous genetic background, which enhances the precision of measuring transgene effects by eliminating genetic variability as a confounding factor.

Inventive Principle:
Principle #3Local quality

Data Source

PatentUS8030560B2Highly transformable elite doubled haploid line PHWVZ
Publication Date: 2011.10.04 PIONEER HI BREED INTERNATIONAL INC

AI summary

A novel double haploid maize line designated PHWVZ and seed, plants and plant parts thereof. Methods for producing a maize plant that comprise crossing double haploid maize line PHWVZ with another maize plant. Methods for producing a maize plant containing in its genetic material one or more traits introgressed into PHWVZ through backcross conversion and/or transformation, and to the maize seed, plant and plant part produced thereby. Hybrid maize seed, plant or plant part produced by crossing the double haploid line PHWVZ or a trait conversion of PHWVZ with another maize line. Inbred maize lines derived from double haploid maize line PHWVZ, methods for producing other inbred maize lines derived from double haploid maize line PHWVZ and the inbred maize lines and their parts derived by the use of those method.