Written by: Dennis O’Brien
An Agricultural Research Service (ARS) plant geneticist in El Reno, Oklahoma, has developed a new tool for fescue breeders: a unique annual ryegrass that can be used to produce tall fescue plants with superior genetics.
Bryan Kindiger also has secured an ARS patent on his technique for exploiting the ability of the unique Italian ryegrass line, called IL1. When the IL1 line is crossed with tall fescue, the resulting generation will produce offspring with all the ryegrass chromosomes eliminated, and with tall fescue chromosomes that are “fixed” for their genes and genetic traits.
Tall fescue breeders would prefer to know that genes that confer important traits are “fixed”—that is, those genes will be inherited in subsequent generations. So the approach is more efficient than traditional breeding methods where advantageous genes can be lost in subsequent generations, according to Kindiger, who works at the ARS Grazinglands Research Laboratory at El Reno.
Tall fescue is the most commonly used cool-season forage grass in the world. Italian rye grass is also commonly used around the world as a cool-season forage grass.
Crossing the IL lines with tall fescue also produces a unique type of hybrid known as an “amphidiploid,” which retains an equal balance of chromosomes and genes from both parents. Such hybrids can be developed as new forage grasses, since they offer the productivity and stress tolerance of tall fescue, along with the nutritional qualities of the ryegrass. All of the materials generated are also free of toxic fungal endophytes that can retard livestock growth and reproduction.
Preliminary research shows that Kindiger’s discovery also may open the door to developing new varieties of cool-season grass forages using an approach known as gamete selection, which allows breeders to sample and evaluate a single pollen grain and reproduce its genome intact in the next generation. Corn breeders have used a type of gamete selection to produce inbred lines of corn for years.
This work was partially funded by Barenbrug USA Research of Albany, Oregon, through cooperative research and development agreements.
ARS is the principal intramural scientific research agency of the U.S. Department of Agriculture (USDA), and this research supports the USDA priority of promoting international food security.
FOR FURTHER READING:
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Dairy farmer finds unusual forage grass
Grass germplasm collection also includes fungal endophytes