Can elite maize landraces help to improve forage yield and quality? A genetic analysis

Abstract

Broadening the genetic base of maize breeding program is a significant concern for plant breeders, since it restricts the magnitude of genetic gain. Identification of promissory exotic elite maize (Zea mays L) germplasm would be useful to increase the genetic variation within typically used heterotic groups and to improve the forage yield and quality. This study is aimed to assess the genetic potential of a group of elite maize landraces to improve forage yield and quality related traits and to broaden the genetic base of three temperate heterotic groups. Mean values and landrace general combining ability effects (GCAl) revealed that some landraces could be considered as a valuable genetic resource to broaden the current genetic base through introgression of forage yield and quality favorable alleles. When stover and ear dry matter yield were considered, ARZM17035 was the best landrace since it produced the best performing landrace × inbred line crosses that also were stable across environments. Additionally, this landrace showed high GCAl. Considering quality traits, ARZM07134 was the most promising source of favorable alleles. The use of B73 as tester in a recurrent selection scheme would be the most efficient strategy, since both mentioned landraces crossed to B73, showed the highest yield and quality values. Additionally, evaluated traits were mainly controlled by additive effects, so it is expected to obtain a positive response by selection.