Publication Date
1993
Description
Several methods of population improvement in alfalfa (Medicago saliva L.) are available, but more information is needed to enable breeders to make the best choice among them. This study was conducted to compare selection based on topcross (TX) progeny performance with selection based on polycross (PX) progeny performance. X and TX families were generated from 100 genotypes, Progenies were tested for annual green matter yield in 2 locations for 2 successive years. The PX families outyielded the TX families by about 20%. The TX had similar or broader yield range among its families than the PX. The genotypic variance among TX families was double that among PX families, and resulted in a higher heritability estimate for the TX (0.40) than for the PX progeny test (0.29). However, the genotype X environment interaction components of variance were 2-fold larger for TX. The phenotypic correlation between PX and TX families for green matter yield was positive and highly significant (r = 0.50). Predicted response indicated that selection based on TX progeny performance should be better than selection based on PX progeny performance.
Citation
Michaud, Real; Viands, D R.; and Christine, B R., "Comparison of Polycross and Topcross Progeny Testing in Alfalfa" (2024). IGC Proceedings (1993-2023). 40.
https://uknowledge.uky.edu/igc/1993/session12/40
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Plant Biology Commons, Plant Pathology Commons, Soil Science Commons, Weed Science Commons
Comparison of Polycross and Topcross Progeny Testing in Alfalfa
Several methods of population improvement in alfalfa (Medicago saliva L.) are available, but more information is needed to enable breeders to make the best choice among them. This study was conducted to compare selection based on topcross (TX) progeny performance with selection based on polycross (PX) progeny performance. X and TX families were generated from 100 genotypes, Progenies were tested for annual green matter yield in 2 locations for 2 successive years. The PX families outyielded the TX families by about 20%. The TX had similar or broader yield range among its families than the PX. The genotypic variance among TX families was double that among PX families, and resulted in a higher heritability estimate for the TX (0.40) than for the PX progeny test (0.29). However, the genotype X environment interaction components of variance were 2-fold larger for TX. The phenotypic correlation between PX and TX families for green matter yield was positive and highly significant (r = 0.50). Predicted response indicated that selection based on TX progeny performance should be better than selection based on PX progeny performance.
