International Rice Congress 2023
Published October 16, 2023 | Version v1
Conference paper Open

Estimation of genetic gain in the post modernization phase of medium maturity irrigated breeding pipeline

Creators

  • 1. International Rice Research Institute, India
  • 2. International Rice Research Institute
  • 3. International Rice Research Institute, Bangladesh
  • 4. International Rice Research Institute, South Asia Hub, Hyderabad, India
  • 5. International Rice Research Institute, Kenya
  • 6. International Rice Research Institute, Burundi
  • 7. Ricetec, Texas, USA

Description

Breeding program modernization is a key component to increase the rate of genetic gain in rice. Previous studies in the former irrigated breeding program using historical data have reported a lower but positive rate and a nonlinear trend of genetic gain. Multiple reasons such as longer cycle time, variable breeding targets over different periods of time, complex crossing strategy and direct introduction of non-improved material into the crossing block could be associated with the lower rate of genetic gain. To overcome this, the breeding program at IRRI has implemented breeding modernization interventions such as identification and usage of genetically elite lines as parents, adopting recurrent selection strategy, rigorous testing of lines in the TPE and usage of genetic relationship matrices using molecular markers. In our study we analyzed 120 recent yield trials conducted in different countries from South Asia and Eastern Southern Africa between 2015 and 2021. The mixed model approach was used to compute the phenotypic best linear unbiased estimator (BLUE) values of grain yield for all the individual trials. And then a multiyear analysis was conducted to adjust for the year effects through common breeding lines. The genetic gain of grain yield for the medium maturity long and soft grain type pipeline formerly irrigated breeding program was estimated between 0.85 to 1.05 % per year. This reported rate of genetic gain does not include any change in the actual genetic material yet as the crosses made from the at the start of modernization efforts are entering into the yield testing now.

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Estimation_of_genetic_gain_in_the_post_modernization_phase_of_medium_maturity_irrigated_breeding_pipeline.pdf

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