@article{kramer_reed_1988, title={AN EVALUATION OF MATERNAL NULLIHAPLOIDY FOR NICOTIANA-TABACUM-L NULLISOMIC PRODUCTION .1. AN INTERSPECIFIC HYBRIDIZATION APPROACH}, volume={79}, ISSN={["0022-1503"]}, DOI={10.1093/oxfordjournals.jhered.a110439}, abstractNote={The value of a maternal nullihaploidy system for the production of Nicotiana tabacum L. nullisomics was investigated. Five monosmics of the Purpurea genetic background, F, L, M, P, and R, and three of the SC 58 background, C, F, and P, were crossed as females to Nicotiana africana Merxm. Over 99% of the progeny of these crosses were lethal interspecific hybrids, which, as expected, died at the cotyledonary stage. The majority of the surviving plants were aneuploid hybrids, having chromosome numbers ranging from 25 to 90. A few maternal haploids and one paternal haploid were also obtained, but no nullihaploids were isolated. The failure of this maternal haploidy system to produce nullihaploids may have been because of a low rate of induced gynogenesis, seeding conditions that were inadequate to sustain nullihaploid development, and the natural inviability of a nullihaploid plant type. Until these factors are minimized or eliminated, the utility of this interspecific hybridization approach for nullisomic production may be negligible.}, number={1}, journal={JOURNAL OF HEREDITY}, author={KRAMER, MG and REED, SM}, year={1988}, pages={24–27} }
 @article{kramer_reed_1988, title={AN EVALUATION OF MATERNAL NULLIHAPLOIDY FOR NICOTIANA-TABACUM-L NULLISOMIC PRODUCTION .2. A POLLEN IRRADIATION AND OVULE CULTURE APPROACH}, volume={79}, ISSN={["0022-1503"]}, DOI={10.1093/oxfordjournals.jhered.a110553}, abstractNote={The combined use of an irradiated pollen-induced maternal haploidy procedure and ovule culture for the production of nullihaploids of Nicotiana tabacum L. was tested Monosomics F, H, L, M, P, and R of the N. Tabacum genotype ‘Purpurea’ were pollinated with irradiated (50 krad: 60Co) N. glutinosa L. pollen. Fourteen to 16 days after pollination, the ovules were cultured on a chemically defined artificial nutrient medium Of the 58 plants obtained from the ovule cultures, 3 were haploids and 53 were aneuploid interspecific hybrids. The remaining two plants, which came from a single monosomic H cross, were nullihaploids (n = 23). The chromosome number of these plants was doubled through leaf midvein culture to produce nullisomics (2n = 46) Meiotic analysis of the nullisomics revealed the presence of a few univalents. How ever, the degree to which chromosome pairing was disrupted by the absence of chromosome H could not be determined. The presumed nullisomic H plants were male- and female-sterile. Therefore, the usefulness of this particular nullisomic for genetic analysis is extremely limited.}, number={6}, journal={JOURNAL OF HEREDITY}, author={KRAMER, MG and REED, SM}, year={1988}, pages={469–472} }