Sorghum Asia Hybrid Seed Parent Program
The number of parents, crosses and progeny per cross in seed parent program
Crossing
\(\sigma\), i
Finding the optimal number of parents, crosses and progeny will maximize rate of gain per dollar invested
Treatment | Description |
---|---|
50-50-300 | Current scheme, using 50-60 new parents in the crossing block making about 50 crosses and generating 300 progeny per cross |
GRID | A grid of #of parents (25-75), crosses (40-60), progeny per cross (200-400) constraining from 14,000 to 20,000 generated individuals entering the SSD pipeline |
A 20 year burn-in period was modeled using the current breeding scheme. The burn-in was followed by a 50 year evaluation period to measure rates of genetic gain for all treatments
Genetic gain was measured by assessing changes in genetic merit in the F2 and F7 population
All evaluations were conducted using 15 replications
We simulated 1 complex to be behind the genetic merit and inferred through a selection index with 0.5 dominance effect
At F2 population, by year 70, the best crossing strategy (45-50-400) produces 3.01% increase in gain than current practice (50-50-300)
At F7 population, by year 70, the best crossing strategy (25-60-300) produces 12.83% increase in gain than current practice (50-50-300)
Based on F7, we recommend reducing slightly the number of parents (i.e. 25), and using a convenient #of crosses and progeny (i.e. 25-60-300) to maximize the genetic gain in the medium term (~50 years) given the current selection scheme