Submitted to: Plant Cell Tissue and Organ Culture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/5/2007
Publication Date: 2/19/2008
Citation: Sacks, E.J. 2008. Ovule Rescue Efficiency of Gossypium Hirsutum x G. Arboreum Progeny from Field-Grown Fruit is Affected by Media Composition and Antimicrobial Compounds. Plant Cell Tissue And Organ Culture. DOI 10.1007/s11240-007-9316-2.
Interpretive Summary: Crosses between upland cotton (Gossypium hirsutum L.) and Asian diploid cotton (G. arboreum) do not readily produce viable seed, though it would be desirable to obtain hybrids for breeding. Collection of field-grown pollinated ovules (seed producing organs) from these interspecific crosses, followed by their growth in an aseptic environment in the laboratory, can be used to save the developing seed from death. To maximize efficiency of recovering hybrid cotton plants, nine different tissue culture media and the addition of antimicrobial compounds to the media were compared. More hybrid seedlings germinated on some of the media than on others. The use of antimicrobial compounds greatly improved the efficiency of obtaining interspecific cotton progenies from field-grown fruit by limiting contamination in the laboratory-grown tissue cultures. The knowledge gained in this study will enable workers to more efficiently hybridize different cotton species and thus aid cotton improvement efforts.
Technical Abstract: Upland cotton (Gossypium hirsutum L.) is reproductively isolated from G. arboreum L. via post-zygotic breeding barriers. Literature on somatic embryogenesis of cotton suggests a number of media modifications that might also prove useful for ovule rescue of interspecific crosses. Additionally, endogenous microbes are common in field grown cotton and these potential contaminants must be controlled if interspecific progeny are to be obtained via large scale field crossing followed by ovule or embryo culture. This study compared nine tissue culture media and two antimicrobial overlay treatments in a factorial design. The overlay treatments were: a 2 ml overlay of 250 mg/l cefotaxime, 50 mg/l tetracycline HCl, 2.5 mg/l amphotericin B and 50 mg/l benomyl applied when the ovules were plated, and no overlay. All of the media in the factorial also contained 250 mg/l cefotaxime. Crosses were made in a field at Stoneville, MS between the upland cultivar DeltaPine 90 and the G. arboreum accession A2-190. Antimicrobial compounds greatly improved the efficiency of obtaining interspecific cotton progenies from field-grown fruit. Germination was not affected by the overlay nor did overlay treatment interact with media. Media significantly affected germination. Of the media studied, the highest frequency of germination was observed for MSB with 1.9 g/l additional KNO3. The addition of 0.5 g/l asparagine and 1 g/l glutamine did not affect the number of seedlings obtained. A filter paper growing surface or the addition of 0.5 mg/l NAA and 0.05mg/l kinetin were disadvantageous.