Compositional Assessments of Key Maize Populations: B73 Hybrids of the Nested Association Mapping Founder Lines and Diverse Landrace Inbred Lines

The
present study provides an assessment of the compositional diversity
in maize B73 hybrids derived both from the Nested Association Mapping
(NAM) founder lines and from a diverse collection of landrace accessions
from North and South America. The NAM founders represent a key population
of publicly available lines that are used extensively in the maize
community to investigate the genetic basis of complex traits. Landraces
are also of interest to the maize community as they offer the potential
to discover new alleles that could be incorporated into modern maize
lines. The compositional analysis of B73 hybrids from the 25 NAM founders
and 24 inbred lines derived from landraces included measurements of
proximates (protein, fat, ash, and starch), fibers, minerals, amino
acids, fatty acids, tocopherols (α-, γ-, and δ-),
β-carotene, phytic acid, and raffinose. Grain was harvested
from a replicated trial in New York, USA. For each data set (NAM and
landrace) canonical discriminant analysis allowed separation of distinct
breeding groups (tropical, temperate, flint, mixed/intermediate) within
each data set. Overall, results highlighted extensive variation in
all composition components assessed for both sets of hybrids. The
variation observed for some components within the landraces may therefore
be of value for increasing their levels in modern maize lines. The
study described here provided significant information on contributions
of conventional breeding to crop compositional variation, as well
as valuable information on key genetic resources for the maize community
in the development of new improved lines.