QTL for yield, earliness, and cell wall quality traits in topcross experiments of the F838 x F286 early maize RIL progeny.

摘要

QTL for cell wall digestibility related traits were investigated in maize (Zea mays L.) topcross experiments of 240 RILs obtained from the F838 x F286 early maize hybrid. Genotype effects were highly significant for all agronomic and cell wall related traits and much higher than genotype x environment (GE) interaction effects for cell wall digestibility traits. Eight quantitative trait loci (QTL) for dry matter (DM) yield were observed, out of which only one increasing allele originated from F286. Conversely, three QTL out of four with alleles increasing DM content at silage harvest stage originated from the earliest F286 line. Out of four QTL increasing starch content, two QTL, which originated from F838, did not colocalize with silking date QTL or any other investigated traits. Ten QTL were observed for lignin content and between six and nine QTL were observed for each of the three cell wall digestibility investigated traits. QTL located in bins 1.02 (position 76-80 cM), 1.07 (position 228-230 cM), and 8.07 (position 134-142 cM) are likely of priority interest when it comes to improving maize cell wall digestibility. Candidate genes underlying cell wall digestibility QTL were searched for on the basis of in silico investigations and with maize, Arabidopsis, poplar, and eucalyptus genomic information. In most of QTL positions, transcription factors regulating cell wall lignification were shown to be the currently most plausible candidates involved in genetic variation of maize cell wall digestibility.