Androgenetic vs. Gynogenetic Doubled Haploids of Tobacco

Cultivar development by doubled haploid (DH) methods employing in vitro anther culture has not been highly successful in tobacco, Nicotiana tabacum L., because of the low yielding ability of DH lines. The objective of this study was to compare DH lines developed from androgenetic and gynogenetic haploid sporophytes from the same parental plants. Single plants from ‘Ky10’, ‘Ky15’, and ‘Kyl7’ were self‐pollinated, crossed with pollen of N. africana Merx. and Buttler, and immature buds were anther cultured. Haploid sporophytes arising from embryo sac nuclei and vegetative nuclei of pollen were chromosome doubled and self‐pollinated. Ten random androgenetic DH lines (ADHs), 10 random gynogenetic DH lines (MDHs), and selfed progenies of the parental plant were assigned to a set, or cultivar family, and grown in three replications in each set in two environments. Data were collected for eight characters. Sixteen second cycle MDH lines were produced from one random first cycle line, Ky 10 MDH 1, and compared with the original Ky 10 parent, a first cycle MDH line composite, and Ky 10 MDH 1. The ADH and MDH lines were significantly different for all characters measured. The MDH lines were agronomically superior to ADH lines and more closely resembled the cultivars. The ADHs and MDHs yielded 79.9% and 91.5%, respectively, of the cultivars. A second cycle of MDH line production resulted in no further yield reduction. A model of heterozygosity and inbreeding depression in the parental cultivars could explain the results for yield of the MDH lines; it would not account for differences between ADH and MDH lines.