Production of Tetraploid Plants from Cotyledons of Diploid <i>Melia volkensii</i> Gürke
Constantin Dushimimana,
Katrijn Van Laere,
Titus Magomere,
Guy Smagghe,
Stefaan P. O. Werbrouck
Affiliations
Constantin Dushimimana
Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653 and Valentin Vaerwyckweg 1, B-9000 Ghent, Belgium
Katrijn Van Laere
Plant Sciences Unit, Flanders Research Institute for Agricultural, Fisheries and Food Research (ILVO), Caritasstraat 39, B-9090 Melle, Belgium
Titus Magomere
Department of Plant Science and Crop Protection, University of Nairobi, Kangemi, Nairobi P.O. Box 29053-00625, Kenya
Guy Smagghe
Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653 and Valentin Vaerwyckweg 1, B-9000 Ghent, Belgium
Stefaan P. O. Werbrouck
Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653 and Valentin Vaerwyckweg 1, B-9000 Ghent, Belgium
Polyploidy was induced in Melia volkensii (Mukau), a valuable native tree from the semi-arid regions of East Africa. Cotyledons of diploid M. volkensii (2n = 2x = 28) were treated with oryzalin for 0 (control), 1, 2, or 3 h with or without pretreatment with 1.1 µM thidiazuron. Cotyledons treated with 10 mg·L−1 oryzalin for three hours yielded 40% tetraploids. Pretreatment of cotyledons with thidiazuron for 18 days followed by treatment with oryzalin increased tetraploid plant production to 52.5%, but this also yielded more mixoploids. Compared to diploid M. volkensii, the tetraploid in vitro and young potted plants were compacter, with thicker stems, wider leaves, and a low density of longer and wider stomata. In the coming years, tetraploid M. volkensii plants will be observed in field trials and serve as a basis for further breeding efforts.
