Can expired proprietary maize (Zea mays L.) industry lines be useful for short-season breeding programs? II. Agronomic traits

Abstract

U.S. Patent and Plant Variety Protection Act protect maize (Zea mays L.) inbreds and hybrids. The overall objective of this research was to assess the usefulness of patent expired maize inbred lines. Factorial crosses were made including North Dakota State University (NDSU) lines, ex-PVP lines, and top industry testers in the 2010 NDSU Fargo summer nursery and in the 2010–2011 NDSU New Zealand winter nursery. Hybrids were planted across six different ND environments in 2011 and 2012 following partially balanced lattice experimental designs. Combining ability analyses were performed following a factorial design with fixed parents. Our research identified ex-PVP inbreds PH207, Q381, PHP02, S8324, PHK76, CR1Ht, PHT77, LH205, LH54, and PHJ40 as above average lines in hybrid combinations to increase yield. Our trials suggest most ex-PVP lines are not useful directly for commercial purposes but could be used as potential breeding sources for short-season maize breeding programs. Improvements in intellectual property and re-thinking of breeding rights access are encouraged to explore more suitable hybrids for northern U.S. farms. Current industry lines have important trait weaknesses for northern U.S. climates that public sector breeders in strategic breeding locations could improve in order to develop better hybrids for farmers. Our preferred choice would be to partner with industry in order to improve current industry lines with known weaknesses, especially for northern U.S. and Canada environments.