Doubled-haploid versus single-seed descent and S sub(1)-family variation for testcross performance in a maize population

• Published in: Euphytica 2007-03, Vol.154 (1-2), p.41-51
• Main Authors: Bordes, J, Charmet, G, Vaulx, RDumas, Lapierre, A, Pollacsek, M, Beckert, M, Gallais, A
• Format: Article
• Language: English
• Subjects: Zea mays
• ISSN: 0014-2336
• DOI: 10.1007/s10681-006-9266-5

Progress made in the in situ gynogenesis technique since 1990 now allows production of a high number of maize (Zea mays L.) doubled-haploid (DH) lines. The aim of the study was to compare DH lines versus selfing lines for testcross performance. DH and single-seed descent (SSD) lines were produced from random S sub(1) progenies of a broad-base population. For grain yield, kernel moisture, plant height, ear height and leaf length, the three population means were similar. Except for kernel moisture, the genetic variance of DH lines was nearly twice as high as the genetic variance of S sub(1) families, as expected. On the other hand, genetic variance among SSD lines was only 1.5 times higher than the genetic variance of S sub(1) families. This lower variance could be due to a selection bias in the method of production of SSD lines. However, for all traits, heritability of SSD or DH lines was higher than heritability of S sub(1) families. Epistasis effects in DH progenies were not significant. The consequence was a high correlation between S sub(1) testcross progenies and DH or SSD testcross progenies, meaning that the S sub(1) testcross value can be used to select the best families from which DH lines will be extracted. As a whole, the observed variation in DH lines appeared to be more in accordance with the observed variation among S sub(1) families than with the observed variation among SSD lines.