There's no "silver bullet" gene or gene region that controls so-called complex traits in maize, commonly known as corn.
Instead, in two research papers published this week in the journal Science, North Carolina State University crop scientists and colleagues show that lots of small changes in a number of gene regions affect complex traits like flowering time or reproductive ability in corn.
Finding out more about the mechanisms behind complex traits like flowering time as well as even more difficult-to-map traits like yield or drought tolerance, for example has the potential to help plant breeders build the best traits into tomorrow's corn plants, says Dr. Jim Holland, NC State professor of crop science, research geneticist for the U.S. Department of Agriculture-Agriculture Research Service (USDA-ARS) and one of the lead authors of the Science papers.
Holland and Dr. Major Goodman, NC State professor of crop science, joined with researchers from Cornell University, the University of Missouri and other institutions to assemble a set of genetic maize varieties called the maize nested association mapping population. They found a number of chromosomal regions called quantitative trait loci (QTL) affecting flowering time in corn.
Identifying QTLs can help scientists get closer to figuring out the actual genes involved in certain traits. Holland likened it to looking for a specific house in a large city, with the QTL providing the correct street, but not necessarily the right house.
The scientists found that an average of 29 to 56 QTLs affected flowering time; the effects of these QTLs were small.
That finding contrasts with studies of Arabidopsis, or mustard weed, the ubiquitous lab rat of the plant world. In that plant, small numbers of QTLs have large effects on genetic variance.
The scientists also studied more than 1,100 marker genes that characterize genetic inheritance. In o
|Contact: Dr. Jim Holland|
North Carolina State University