Book excerpt: RFLP markers were used to map quantitaive trait loci for maturity and correlated traits in maize. A linkage map was obtained forhe cross A662 x B73 using data from 63 RFLP markers. A total of 151 F3 lines form A662 X B73 were evaluated in per se and in testcrosses in three Minnesota location in 1992. MAPMAKER-QTL was used to analysis the F3 data an single factor ANOVA considering only the two homozygous parental marker classes was used for analyze the testcross data. Five unlinked chromosomal regions (chromosomes 1, 3, 5, 8 and 9) were shown to be associated with early maturity in this cross. A major maturity factor was identified on chromosome 8 close to the marker UMC12. This region was also strongly associated with node number. The maturity regions identified in general were also linked to plant height or to one of the plant height components, suggesting the possibility of pleiotropy. However, our data are not sufficient to distinguish between pleiotropy and tight linkage. Plant height is controlled by both node number and internode length and these last two traits are controlled by different chromosomal regions. No evident was found for marker class x location interaction. F3 per se evaluation and testcross results showed the same chromosomal regions as important in controlling maturity in the cross studied. Results from the F3 per se analysis agree with the conclusions from a previous study (Kim, 1992) using backcross derived lines from the cross A662 x B73.