2017 ASHS Annual Conference

The open-pollinated tomato (Solanum lycopersicum) variety ‘Rutgers’ was bred during 1926-1932 and released publically in 1934. Following world-wide use as a fresh market and processing variety in the mid-10th century, ‘Rutgers’ was replaced by emerging F₁ hybrid fresh market and processing varieties. Rutgers University and the Campbell Soup Co. sought to recapitulate an updated version of ‘Rutgers’ starting in 2010, using the same general approach (modified pedigree program) as the original 1934 release. That program culminated in the development of the ‘Rutgers 250’ tomato, an open-pollinated garden variety released in 2016 and in celebration of the 250th anniversary or Rutgers University. ‘Rutgers 250’ possesses vine and fruit attributes that transcend the range embodied by the parents, ‘JTD’ and ‘Marglobe’ (both prominent heirloom varieties from the early 20th century). The aromatic volatiles emitted from freshly harvested red-ripe fruits and captured and analyzed from ‘Marglobe’, ‘JTD’, the F₁, and ‘Rutgers 250’ using a Shimadzu TG8040 GC/MS Triple Quadrupole MS, with a Headspace Analysis AOC-6000 System with autosampler. While the F₁ was consistent with additive predictions of chromatographic peak locations and areas from the parents, ‘Rutgers 250’ was associated with a completely different pattern of volatile peaks that differed distinctly from that of both parents. We hypothesize that one or more outcrossing events may have occurred during the modified pedigree breeding program, where populations were in close proximity with other breeding materials under summer field conditions. Analysis of SSR phenotypes confirmed that ‘Rutgers 250’ has 4 SSRs out of 15 that are not parental, while the F₁ was 100% parental. One of the parental varieties, ‘JTD’, exhibited exerted stigmas in mature flowers of most individuals, a trait common to wild outcrossing populations, while flowers of ‘Marglobe’ was entirely inserted. All inserted x exerted F₁ individuals were exerted, suggesting the presence of dominant allele interaction, and stigmas of ‘Rutgers 250’ were mostly exerted. Therefore, we hypothesize that the different headspace volatile peak patterns in ‘Rutgers 250’ as compared to the original parent varieties was due to one or more outcrossing events during the breeding process.