Plant Tissue Culture and Molecular Laboratory Department of Genetics and Plant Breeding, College of Agriculture, University of Agricultural Sciences, Raichur, India
Author
Correspondence author
Molecular Plant Breeding, 2013, Vol. 4, No. 33 doi: 10.5376/mpb.2013.04.0033
Received: 26 Aug., 2013 Accepted: 11 Oct., 2013 Published: 15 Oct., 2013
Bangaremma et al., Sesame Shoot Regeneration-Using Different Combinations of Growth Regulators, Molecular Plant Breeding, Vol.4, No.33 267-269 (doi: 10.5376/mpb.2013.04.0033)
Sesame (Sesamum indicum L.) is the oldest oil seed crop known to man (Brar and Ahuja 1979) and believed to have originated from South-Western Africa, nicked as “Queen of oil crops", owing to excellent oil stability due to the presence of natural antioxidants such as sesamolin, sesamin, sesamol and alfa-tocopherol (Brar and Ahuja, 1979). Genetic improvement of sesame through conventional breeding methods is not rapid unlike other crops (Sardana, 1998). Recent advances in tissue culture techniques offer an immense promise for sesame improvement yet it has remained a trance. The successful application of these techniques depends on the callusing ability and shoots regeneration, the former has been achieved by several workers while the later, undeniably, is considered to be a bottleneck (Rao et al., 1997; Taskin and Turgurt, 1997; Kim Young Hee, 2001; Kariyllappa, 2003; Kariyallappa et al., 2003; Shashidhara, 2005). Intriguingly shoot regeneration is a vital step in tissue culture.
Globally, the best-achieved in vitro shoot regeneration in Sesame is placed up to 46 per cent (Japan) and up to 66% in India (Shashidhara, 2005). However, Seo et al (2006) reported high regeneration ability of deembryonated cotyledon explants via adventitious shoot formation. It is sober that in India, the shoot regeneration has been very low (<2%). Hence, it was felt necessary to enhance shoot regeneration of indigenous sesame genotypes which are land races/varieties but popular at farmer’s level. This could become a crucial breakthrough to further advance the genetic improvement of sesame through biotechnological ways like transgenic development or in vitro cell lines selection that are resistant to biotic and abiotic stresses. Hence, an attempt was made to achieve high frequency regeneration of shoots via callus in sesame. The results have been discussed in the light of sesame improvement through biotechnological ways particularly in vitro cell line selections.
Results and Discussion
Shoot regeneration is a vital step in tissue culture attempts in sesame. Indeed, it is found that the shoot induction via callus in sesame crop is a bottleneck (Taskin and Turgut, 1997; Kim 2001; Kariyallappa, 2003). Explants, genotypes and growth regulators are critical factors for shoot organogenesis and somatic embryogenesis (Venkatachalam et al., 1999). A variety of explants were used for organogenesis and regeneration but hypocotyls were found better followed by cotyledon. There are several reports of regeneration obtained from hypocotyls explants either from root or shoot or both (Lee et al., 1988; Shi and Cai, 1989; Batra et al., 1991; Rao and Vaidyanath, 1997; Kim 2001). The highest percentage of shoot regeneration was observed from hypocotyls derived callus on MS with TDZ 25 µM and 3 µM of IAA with 83.3% in variety DS-1 followed by 58% in variety E8 and 50% in variety TL with 53.2% of shoot regeneration and 1.5 mean number of shoots per callus. The shoot regeneration was also observed on MS with TDZ 25 µM and 2 µM of IAA with 75% in variety DS-1 followed by 58% in variety TL and 50% in variety E8 with 51.5% of mean shoot regeneration and 1.6 mean number of shoots per callus (Table 1; Figure 1). TDZ (Thidiazuran), a cytokinin-a synthetic phenylurea, is considered to be one of the most active cytokinins for shoot induction in plant tissue culture (Huetteman and Preece, 1993; Murthy et al., 1998) and known to induce shoot regeneration from different explants of many recalcitrant species (Thomas and Puthur, 2004). Several reports suggested that TDZ results in shoot regeneration better than other cytokinins (Thomas, 2003). TDZ-induced morphogenesis probably depends on the level of endogenous growth regula- tors and TDZ modulates endogenous auxin level. Multiple high frequency shoot induction in several crops by TDZ is known (Kumar et al., 2003). However, the report of its usage in Sesame crop is scares except (Shashidhara, 2005).
Table 1 Shoot regeneration on MS with 25 μM TDZ with variable concentrations of IAA
|
Figure 1 Shoot regeneration of sesame genotypes on MS with TDZ and Variable IAA
|
Materials and Methods
Five genotypes/varieties of Sesamum indicum were used for study viz. Tumkur Local (TL) and Gulbarga local white (GLW): the two land races; Western-II (W-II) (released variety from Rajasthan which is moderately tolerant to Alternaria blight and Phyllody), E-8 (white seeded, nationally released variety and most widely grown but susceptible to Alternaria blight and phyllody) and Dharwad Selection-1 (DS-1) (a white seeded variety released from UAS Dharwad, susceptible to Alternaria, phyllody and powdery mildew but resistant to Cerospora leaf spot. (Prakash, 2001). The surface sterilized seeds with 0.05% HgCl2 were directly inoculated on to MS supplemented with the growth regulators (NAA 0.5 mg/L, BAP 1.5 mg/L, Kn 1.5 mg/L) and incubated in the dark and transferred to continuous illuminating light at 1,500 lux in culture room temperature maintained at 27℃ as per the direct seeding method (Shashidhara, 2005; Lokesha et al., 2007). Callus induction was achieved within 15~17 days from different explants. The callus of hypocotyls region was separated and used for shoot induction studies. Thirtyday‐old callus were subcultured on MS supplemented with 0.5 mg/L NAA, 1.5 mg/L Kn and 1.5 mg/L BAP. Every fortnight, the callus was subcultured. Light green, healthy and moderately compact callus, sub‐cultured for two cycles, was taken as small pieces of 1.5 cm3 and were inoculated on to MS supplemented with TDZ and variable concentrations of IAA (Ahn et al., 2006) Four callus pieces were inoculated per flask or bottles and were replicated three times for each concentration. All the flasks and bottles were incubated to 55~65 days for shoot regeneration.
Ahn Y., Vang L., Mckeon T.A., and Chen G.Q., 2006, High‐frequency plant regeneration through adventitious shoot formation in castor (Ricinus communis L.), In Vitro Cellular and Development Biology, 43: 9-15
Brar G.S., and Ahuja K.L., 1979, Sesame: its culture, genetics, breeding and biochemistry, In: Malik, C.P. (Ed.). Kalyani publishers, New Delhi, pp. 245-315
Huetteman C.A., and Preece J.E., 1993, Thidiazuron: a potent cytokinin for woody plant tissue culture, Plant Cell and Tissue Organ Culture, 33: 105-119
http://dx.doi.org/10.1007/BF01983223
Kariyallappa D.K., 2003, In vitro regeneration and cell line selection for Alternaria resistant callus in sesame (Sesamum indicum L.), M.Sc. Thesis, Uni. Agric. Sci. Dharwad
Kariyallappa D.K., Lokesha R., Naik M.K., and Treertha Prasad D., 2003, Breeding for Alternaria blight resistant in sesame-classical v/s biotechnological approaches” National Seinar on Advances in Genetics and Plant Breeding, Impact of DNA Revolution. Uni. Agric. Sci. Dharwad, pp. 157-158
Kim Young Hee, 2001, Effects of BA, NAA, 2-4,D and AgNO3 treatments on the callus induction and shoot regeneration from hypocotyls and cotyledon of Sesame (Sesamum indicum L.)” Journal of The Korean Society and Horticultural Science, 42(1): 70-74
Kumar P., Srivastava G.C., Panwar J.D.S., Chandra R., and Raghuveer P., 2003, Efficiency of thidiazuran on in vitro shoot regeneration from cotelydonary node explants in mungbean” Indian Journal Plant Physiology 8 (4): 398-401
Lokesha R., Shashidhara N., and Janagoudar B.S., 2007, Callus induction and plant regeneration in sesame (Sesamum indicum L.) through direct seedling, Journal of Plant Cell Biotechnology and Molecular Biology 8 (1&2): 85-88
Murthy B.N.S., Murch S.J., and Saxena P.K., 1998, Thidiazuron: a potential regulator of in vitro plant morphogenesis, In vitro Cellular and Developmental Plant Biology, 34: 267-275
Prakash R. Chavan, 2001, Phenotypic and molecular characterization of wild, land races and cultivated types of sesame, M.Sc. Thesis, Uni. Agric. Sci. Dharwad
Rao R.K., and Vaidyanath K., 1997 Somatic embryogenesis and regeneration from different explants of Sesamum indicum L., National Symp. Commercial aspects of Pl. Tiss. Cult. Mole. Bio. and Medici. Pl. Biotechnol. Jamia Hamdard, New Delhi
Sardana J., 1998, In vitro studies on growth and morphogenesis of some oil containing plant species through tissue culture”. Ph.D Thesis, Uni. Agric. Sci. Rajasthan, Jaipur
Seo H.Y., Kim Y.J., Park T.I., Kim H.S., Yun S.J., Park K.H., Oh M.K., Choi M.Y., Paik C.H., Lee Y.S., and Choi Y.E., 2007, High-frequency plant regeneration via adventitious shoot formation from deembryonated cotyledon explants of Sesamum indicum L. In Vitro Cellular and Develop. Biol. Pl. 43(3): 209-214
Shashidhara N., 2005, Shoot regeneration via rapid method of callusing in sesame (Sesamum indicum L.)” M.Sc. Thesis, Uni. Agric. Sci. Dharwad.
Taskin K.M., and Turgut K., 1997, In vitro regeneration of sesame, Turkish Journal. Bot., 21(1): 15-18
Thomas D.T., and Puthur J.S., 2004, Thidiazuron induced high frequency shoot organogenesis in callus from Kigelia pinnata L. Bot. Bull. Acad. Soc., 45: 307-313