18 I EUROPEAN SEED I EUROPEAN-SEED.COM O ver the past few years, there have been regular discussions about the use of biomolecular tech- niques in the testing for Distinctness, Uniformity and Stability (DUS), which are the primary prerequisites for grant- ing plant breeders rights to a new plant variety. With many applicants and exam- ination offices in favour of the application of such techniques in DUS testing, and others expressing their concerns, it was time for European Seed to dive into this topic. We sat down with Barry Nelson, research scientist at DuPont Pioneer, and Paul Nelson, corn breeder at Monsanto. EUROPEAN SEED (ES): WHY IS IT NECESSARY TO ADD THESE TECHNIQUES TO THE TOOLBOX OF THE DUS EXAMINER? BARRY NELSON (BN): Research has shown that morphological traits, which are the cornerstone of the current UPOV system, do have limitations as a character- ization method. This assertion is largely due to morphological expression being the result of genotype by environment interac- tions, which cause a great amount of error in variety assessment. UPOV has devel- oped huge volumes of complex statistical methodologies with the objective to take into account and minimize the clouding effects of environmental interactions on the expression of morphology (e.g. plant height, leaf angle, leaf numbers, etc.). However, even when using these proto- cols, it is still possible to characterize the same variety as different when grown in different environments. DNA markers do not have that interaction because charac- terization is done on the DNA code itself in a controlled laboratory environment. Opportunistic competitors can ‘access’ proprietary genetics, then grow the exact same variety in a different loca- tion for DUS testing. When submitted for plant breeders’ rights (PBR), examiners have been compelled to grant each a PBR because the morphology changes within the environment. Thus, distinctness cri- teria were met, even though the genetics were exactly the same. This is clearly a problem. Also, PBR examiner groups have been under pressure for years because of the growing size of reference variety sets. Particularly, field crop species have large reference sets and numerous new applica- tions annually. The cost of trying to grow and compare all varieties of a species has become resource intensive. UPOV has allowed the introduction of markers in DUS testing, when the marker is a sur- rogate for a morphological characteristic and to help in the management of refer- ence collections. PAUL NELSON (PN): Breeding efforts around the globe are expanding, as is the use of intellectual property protection, thus the number of varieties of common knowledge is increasing rapidly. Further, breeders are recycling highly productive lines within elite germplasm pools and successive generations are bred towards an ideal type. The result is greater pro- ductivity in farmer’s fields, but this also renders morphology less discriminant than in the past; this is where molecular techniques can assist in distinguishing between varieties. DNA marker tech- niques also facilitate germplasm move- ment between countries, as they provide a 'common language' for communication between PBR authorities. ES: WHAT ARE THE ADVANTAGES OF THE USE OF SUCH TECHNIQUES IN DUS TESTING? AND DRAWBACKS? PN: One advantage is that DNA markers provide a common language for coopera- tion between breeders and PBR author- ities around the globe, and in this way, transcend environmental influences which are highly interactive with mor- phological characteristics. At the same time, molecular techniques can increase precision in DUS examination and aug- ment the classical morphology approach. A drawback is that because these are new techniques in the context of DUS, there will be some startup hurdles which may slow the pace of adoption. Proper training for examiners and PBR authorities can reduce the impact of such hurdles. BN: Reductions in cost, time, increased precision, and harmonization among countries are the key advantages. Breeders globally have widely integrated DNA markers into breeding programs, trait integration, quality assurance test- ing and even enforcement. The benefits of markers are many and experience in the public and private sectors have shown that. Also, the questions that breeders have been answering using DNA mark- Augmenting Morphology HOW DOES THE SEED INDUSTRY VIEW THE APPLICATION OF MOLECULAR TECHNIQUES IN DUS TESTING? BY: MARCEL BRUINS Paul Nelson is a corn breeder at Monsanto. Barry Nelson is a research scientist at DuPont Pioneer.