PEDIGREE DIVERSITY WITHIN THE LANCASTER SURECROP HETEROTIC GROUP OF MAIZE

Maize (Zea mays L.) breeders commonly classify inbred lines into heter otic groups based on pedigree information and/or combining ability. Th ese heterotic groups influence how germplasm is used, and have increas ed the efficiency of breeding programs. The most widely recognized and exploited heterotic pattern in the U.S. Corn Belt is that of Reid Yel low Dent by Lancaster Surecrop. Pedigree information was used to exami ne the diversity present in 37 publicly developed inbreds of the Lanca ster Surecrop heterotic group, and to investigate the evolution to its present state. All of the Lancaster Surecrop germ-plasm in the public ly developed inbreds included in the modern Lancaster Surecrop heterot ic group was derived from two inbreds, Oh40B and C103. Furthermore, th e amount of true Lancaster Surecrop germplasm is 50% or less in 36 of these inbreds, with >20 non-Lancaster Surecrop sources contributing ge rmplasm to this heterotic group. The Lancaster Surecrop heterotic grou p has been modified considerably, with a reduction in Lancaster Surecr op germplasm and an increase in non-Lancaster Surecrop germplasm inclu ding Reid Yellow Dent.