Cyphomandra betacea is a woody plant belonging to the Solanaceae family. It is commonly known as Tamarillo or tree tomato (Correia et al., 2009). The name “Tamarillo” was adopted in New Zealand and has become the standard commercial designation for the fruit (Morton, 1987). Tamarillo is grown mainly for their edible fruits and, to a lesser extent, as an outdoor ornamental. They have several culinary uses and can be eaten raw in salads or as dessert but preferably cooked (Guimarães et al., 1996). In Jamaica and the West Indies, the fruits are considered to have beneficial effects in relieving disorders of the liver (Guimarães et al., 1996).
Tamarillo is an important component in Rwanda’s exotic fruit industry and consumption of the fruit is traditionally recommended for people suffering from stomach ailments. In this country, it is mainly used for making jams and juices but unfortunately in low quantities because of low productivity, mainly due to viral diseases. Tamarillo is considered an interesting crop from the nutritional viewpoint as it is comparatively high in protein (1.5–2 g/100 g of food), vitamin C (30–45 mg/100 g), and E (1.85 mg/100 g), provitamin A, mineral elements (K, P), low in carbohydrates (4.7 g/100 g), and in calories (about 28 Kcal/100 g) (McCane and Widdowson, 1992). The plant is propagated mainly through seeds, cuttings, or by grafting (Fouque, 1973; Prohens et al., 2001). Propagation through seeds is not recommended as this method is known to produce high degree of genetic variability that negatively affects fruit color resulting in rejection of fruits on the international market. On the other hand, vegetative propagation by cuttings has been found to transmit deadly viral diseases. Therefore, there is a compelling need to develop alternative methods to propagate the plant in Rwanda. Tissue culture offers a feasible solution to produce large numbers of disease-free planting materials. It is also known that in vitro propagated Tamarillo plants produce higher yields and shorter gestation period compared with traditional methods (The Indian Agriculture Information Wing, 2009). Another advantage offered by tissue culture methods is the large scale availability of planting materials at any time of the year irrespective of the season. This study aimed to developing an efficient and rapid propagation protocol for C. betacea plant through tissue culture techniques.
An increasing number of studies describing in vitro propagation of Tamarillo using axillary buds have been reported (Barghchi, 1998; Obando et al., 1992; Waweru et al., 2011). Somatic embryogenesis has also been reported by Espinosa et al. (2005), Obando and Jordan (2001), Correia et al. (2009), Guimarães et al. (1996), and Correia et al. (2011). However, there are no documented studies on the direct organogenesis in Tamarillo. An important advantage of direct organogenesis is the potential for maintaining genomic stability of regenerated plants, whereas regeneration via an intermediate callus phase increases the possibility of somaclonal variations (Kahia, 1999). Furthermore, a highly efficient and reproducible in vitro regeneration system is an absolute prerequisite for producing transgenic plants.
BarghchiM.1998In vitro regeneration plant improvement and virus elimination of Tamarillo [Cyphomandra betacea (Cav.) Sendt)] p. 173–185. In: M.R. Davey et al. (eds.) Tree biotechnology—towards the millennium. Nothingham University Press Nothingham UK
BurbulisN.BlinstrubienėA.KuprienėR.2011Effect of genotype and medium composition on linseed (Linum usitatissimum) ovary cultureBiologia66465469
CheesmanL.FinnieJ.F.Van StadenJ.2010Eucomis zambesiaca baker:Factors affecting in vitro bulblet induction. SOUTH AFRICJ. Bot.76543549
CorreiaS.I.LopesM.L.CanhotoJ.M.2011Somatic embryogenesis induction system for cloning an adult Cyphomandra betacea (Cav.) Sendt. (Tamarillo)Trees (Berl.) doi: 10.1007/s00468-011-0575-5.
DadjoC.KahiaJ.SilaD.MuthuriC.DibyL.KouameC.2015Induction and regeneration of somatic embryos from Vitex doniana (Lamiaceae) leaf explants. Intl. J. Biotechnol. Mol. Biol. Res. 6:28–34
D’OnofrioC.MoriniS.2005Development of adventitious shoots from in vitro grown Cydonia oblonga leaves as influenced by different cytokinins and treatment durationBiol. Plant.491721
EspinosaO.JohnA.GonzalezT.O.SanchezH.AR.KafrriA.LondonoC.2005Potential of in vitro propagation for the tomato TREE PARTENOCARPIC Cyphomandra betacea Cav. (sendt). Rev. Fac. Nal. Agr. Medellín 58(1):2685–2695
FouqueA.1973Solanacées. Fruits 28:41–42
GuimarãesM.L.ToméM.C.CruzG.S.1996Cyphomandra betacea (Cav.) sendt (Tamarillo) p. 120–137. In: Y.P.S. Bajaj (ed.). Biotechnology in agriculture and forestry trees IV. Springer Verlag Berlin
KahiaW.J.1999In vitro propagation of the new Coffea arabica cultivar-Ruiru 11. University of London London UK PhD thesis
KhanH.SiddiqueI.AnisM.2006Thidiazuron action inhibitor silver nitrate induced somatic embryogenesis and plant. Acta Physiol Plant 26(3):299–305
LataH.ChandraS.WangY.H.RamanV.KhanI.A.2013TDZ-induced high frequency plant regeneration through direct shoot organogenesis in Stevia rebaudiana Bertoni: An important medicinal plant and a natural sweetenerAmer. J. Plant Sci.4117128
ManishaB.P.PatelR.S.2013Impact of plant growth regulators (PGRs) on callus induction from internodal explants of Tecomella undulata (Sm.) seem-A multipurpose medicinal plants. Intl. J. Scientific Res. 3(11)
MaityS.RayS.BanerjeeN.2005The role of plant growth regulators on direct and indirect plant regeneration from various organs of Leucaena leucocephalaActa Physiol. Plant.27473480
MathewM.K.RaoY.S.PradipkumarK.MadhusoodananK.J.PottyS.N.1999In vitro culture system in vanilla. Osmania University Hyderabad India. p. 171–179. (Proc. Natl. Conf. Plant Tissue Cult. Biotechnol. Emerging Trends)
McCaneJ.WiddowsonD.A.1992In: Fruit and nut Suppl. To the composition of food 5th ed. p. 74–77. Unwin & Buss London Holland
MokC.M.MokW.S.D.TurnerJ.E.MujerC.V.1987Biological and biochemical effects of cytokinin-active phenylurea derivatives in tissue culture systemsJ. Hort. Sci.2211941197
MortonJ.F.1987Tree tomato p. 437–440. In: J.F. Morton (ed.). Fruits of warm climates. Miami FL
NdoyeM.DialloI.GassamaY.K.2003In vitro multiplication of the semi-arid forest tree,Balanites aegyptiaca (L.) DelAfr. J. Biotechnol.211421424
ObandoM.GoreuxA.JordanM.1992In vitro regeneration of Cyphomandra betacea (Tamarillo) and Andean fruit speciesCienc. Investig. Agrar.19:125130
RaiM.K.JaiswalV.S.JaiswalU.2009Shoot multiplication and plant regeneration of guava (Psidium guajava L.) from nodal explants of in vitro raised plantlets. J. Fruit Ornam. Plant Res. 17(1):29–38
SubramaniamS.RathinamX.PoobathyR.SinniahU.2008In vitro production of multiple bud clumps (Mbcs) from Cavendish Banana cultivar, Brasilian (AAA)American-Eurasian J. Sustainable Agr.23300307
The Indian Agriculture Information Wing2009Micropropagation of Tamarillo. Agricultural newsletter p. 8. Agricultural Information Offset Press Fruit Garden Meghalaya Shillong India
VasudevanA.SelvarajN.SureshkumarP.GanapathiA.2001Multiple shoot induction from shoot tip explant of cucumber (Cucumis sativus L.)Cucurbit Genet. Coop. Rep.24812
WaweruB.IshimweR.KajugaJ.KagiranezaB.SallahP.Y.K.AhishakiyeV.KalisaS.AsiimweT.KahiaJ.GahakwaD.2011In vitro plant regeneration of Cyphomandra betacea (Tamarillo) through nodal culture. Rwanda J. 24: 58–66
ZaffariG.R.KerbauyG.B.KrausJ.E.RomanoE.C.2000Hormonal and histological studies related to in vitro banana bud formationPlant Cell Tissue Organ Cult.633187192