Production of Tetraploid Plants from Cotyledons of Diploid Melia volkensii Gürke

Polyploidy was induced in Melia volkensii (Mukau), a valuable native tree from the semi-arid regions of East Africa. Cotyledons diploid M. (2n = 2x 28) were treated with oryzalin for 0 (control), 1, 2, or 3 h without pretreatment 1.1 µM thidiazuron. 10 mg·L−1 three hours yielded 40% tetraploids. Pretreatment cotyledons thidiazuron 18 days followed by treatment increased tetraploid plant production to 52.5%, but this also more mixoploids. Compared volkensii, vitro and young potted plants compacter, thicker stems, wider leaves, low density longer stomata. In coming years, will be observed field trials serve as basis further breeding efforts.