ST. LOUIS — Monsanto Co. on June 18 filed a patent-infringement lawsuit against E.I. du Pont de Nemours and Co. and its Pioneer Hi-Bred International, Inc. unit alleging the latter is copying Monsanto’s patents covering a method known as seed chipping.

In its lawsuit, filed in the U.S. District Court Eastern District of Missouri, Monsanto described the patents as a cornerstone of its technology enabling the convergence of breeding and biotechnology.

“Those innovations are methods and systems for the automated sampling of material from seeds while maintaining germination viability (known in the industry as ‘seed chipping’ or ‘chipping’) which allow for the high-throughput testing of individual seeds in a population of seeds before the seeds are plants,” Monsanto said in its filing. “Those methods and systems reliably and accurately (a) sample and test tissue taken from each seed while maintaining seed viability, (b) track the relationship between each of the thousands of seeds and genes therein and the corresponding tissue samples and (c) bulk seed populations with the desired trait by culling individual seeds based on the test results.”

Monsanto said the technology is “revolutionizing plant breeding by allowing faster and more precise development of better crops and by allowing insight and understanding of plant performance, genetics, DNA linkage and thus improved agronomics and yield. By allowing Monsanto to individually test every seed in large plant breeding programs and select those with desired characteristics, the patented inventions greatly speed up the advancement selection processes and enable dramatic increases in the quantity of a particular hybrid or inbred seed.”

Monsanto said it filed for many of its patents in 2004 and 2005, and first publicly demonstrated its “seed chipper” system in 2007. Within months of Monsanto’s publication of the seed chipper applications Pioneer filed for similar applications, and in 2008 debuted the “Laser-Assisted Seed Selection” system, Monsanto said.

In its lawsuit filing, Monsanto said Pioneer’s marketing materials describe the Laser-Assisted Seed Selection system as “technology that removes tissue from a corn kernel to analyze its genetics without affecting seed viability. Seeds containing favorable genetics are therefore identified before they are planted.”

Responding to the allegations, Daniel Turner, a spokesperson for DuPont, said, “We believe this latest suit by Monsanto is without merit, and we will vigorously defend our position in court. Monsanto continues to use litigation in an attempt to limit Pioneer from being an effective competitor. This tactic has not worked in previous cases, and it will not work in this matter.”