Hybrid Corn CH030486 Breeding via Segmentation and CMS

The patent applies preliminary action by developing and selecting homozygous inbred plants before creating the hybrid cross. The inbred line P1 was developed through multiple generations of self-pollination and selection to achieve uniformity and stability, ensuring that the starting materials for the cross are genetically uniform. This preliminary development of stable inbred lines before the cross-pollination event ensures that the resulting hybrid population, while diverse in traits, maintains predictable performance characteristics.

The patent applies segmentation by dividing the breeding process into distinct phases: first developing homozygous inbred lines through self-pollination (P1), then using those inbreds as parents for controlled cross-pollination to create the hybrid (P2). This segmentation allows the breeder to achieve genetic uniformity in the inbred stage while preserving breeding flexibility in the hybrid stage, where the cross between two different inbreds introduces desirable traits from both parents.

The patent applies parameter changes by utilizing cytoplasmic male sterility (CMS), which is a genetic parameter that enables controlled cross-pollination without requiring manual emasculation. This CMS system allows the hybrid to be produced in a single cross between a male-sterile inbred and a fertile inbred, dramatically reducing the breeding cycle time compared to traditional methods that require multiple generations of selfing and selection. The CMS parameter enables direct production of uniform F1 hybrids from stable inbred parents.