In vitro genebanking for taro (Colocasia esculenta Schott) germplasm conservation
Taro is one of natureRSQUOs healthiest foods, and is used in many food and health products. The increasing requirement of the health food industry for suitable taro cultivars heightens the need to intensify cultivar development programs. Germplasm collection or genebanking is the lifeblood of breeding programs and supports the development of climate-resilient agriculture. Genebanks of vegetatively propagated crops like taro and other root crops are conventionally maintained in the field and are subject to damage or loss due to natural disasters, unfavorable climate and pest attack. In vitro genebanks may be free of risks from field factors but require frequent subculturing if the normal growth medium is used, thereby increasing the cost of maintenance and the risk of culture contamination and loss of genetic material. This research was undertaken to establish a slow-growth protocol that can minimize subculturing and maintain the viability and traits of stored tissues. Abscisic acid (ABA) and mannitol were tested as growth retardant additives to the modified Murashige and Skoog (MS) medium. ABA-amended medium retarded shoot and root initiation but did not reduce growth of plantlets, and hence was not a promising slow-growth treatment. Mannitol at concentrations lower than 4% was also not effective in reducing growth rate, while at 6-10%, tissue browning occurred. At 4.5-5.5% mannitol, cultures were maintained for more than 12 months without subculture. Without mannitol, subculturing has to be done after 1 month from inoculation. VG-1, VG-4, VG-5 and NSIC G7 taro lines showed almost the same response to mannitol treatment. Plantlet regeneration was best with whole shoot tips. Half or quarter shoot tips hardly produced roots and shoots. Normal plantlets were regenerated from 1‑year-old cultures without any phenotypic variations.
Acedo, V.Z., Damasco, O., Laurena, A., Sta Cruz, P., Namuco, L. and Lalusin, A. (2017). In vitro genebanking for taro (Colocasia esculenta Schott) germplasm conservation. Acta Hortic. 1179, 327-332
plant genetic conservation, slow-growth technique, mannitol