This May, Professional Seed Research Inc. (PSR Inc.) transplanted 4000 seedlings from 47 populations in the field with its RI (Rapid Inbreeding®) Breeding Program.  “That’s 4000 inbreds produced in just one generation, using only .17 acres of nursery space,” notes Jim Dodd, President of PSR Inc.  The RI Breeding Program saves client companies four generations of considerable costs in harvesting, packeting, planting, pollinating and recording.  In this year alone, PSR’s RI Breeding Program will produce over 5000 lines.

“Instead of the four to five generations of selfing needed to reach a reliable level of homozygosity before test crossing, we can do it in one season,” says Dr. Dodd.  

For example, PSR Inc. will return about 50-70 seedlings, selected from a population of 1000-10,000 seeds, that can be transplanted and selfed in the customer’s field or winter location.  These plants can be used to make test crosses or simply selfed.  The breeder typically discards some of these because of agronomics. The remaining plants are then grown ear to row for further selection as well as making test crosses. 

With the RI program, any breeder can quickly evaluate potential inbreds from a population, without the problem of heterozygosity of S2 testing.  “We find that breeders are not only using RI Breeding to efficiently tap new populations, they also are recycling the successful new lines as part of a recurrent selection program,” adds Dr. Dodd.  “I think RI will integrate extremely well with marker-assisted breeding populations.”

Professional Seed Research Inc. has specialized in maize genetic purity, pathology and breeding services for domestic and international seed companies for over 15 years.