Somatic Embryogenesis and Plant Regeneration of Farmer-Preferred Passion Fruit Varieties Grown in Kenya

Abstract

In vitro regeneration of passion fruit has great prospects for mass production of disease-free planting materials. The objective of this study was to develop an in vitro regeneration system through somatic embryogenesis for farmer-preferred genotypes grown in Kenya. Callus induction and somatic embryogenesis were carried out using leaf and immature seed explants. The explants were cultured on Murashige and Skoog medium augmented with different concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) alone and 2,4-D combined with 1.0 mg L−1 thidiazuron (TDZ). Data were recorded and subjected to analysis of variance. The highest number of somatic embryos was obtained from KPF4 genotype using MS medium supplemented with 8 mg L−1 2,4-D and 1 mg L−1 TDZ. The embryos were converted to plants on germination medium comprising of MS augmented with 0.5 mg L−1 6-benzyl amino purine (BAP). The plantlets were hardened for 4 weeks in plastic pots. The survival rate during hardening of in vitro regenerated plants was 77.8%. The present study reports a regeneration system through somatic embryogenesis for KPF4 passion fruit grown in Kenya. The in vitro regeneration system can be utilized for mass propagation and genetic improvement of KPF4 variety grown in Kenya.