English

Kakuturu Jyothi,Salim Kinza,Charyulu Subhashini,Potlakayala Shobha,Menon Shyam,J Chorney Michael,Rudrabhatla Sairam,Pc Josekutty,L Goldman Stephen,Adeyiga Rafiyat,Reitzel Mathew

doi:10.5897/ajb2014.13936

Abstract

Callus induction for somatic embryogenesis from Simarouba glauca DC leaf explants of three genotypes (S. glauca 5, S. glauca 19 and S. glauca 21) was studied. Leaf explants (leaf segments from basal, middle and tip of the leaves) were cultured on two types of nutrient media; SGC1 and SGC2. Both media contained Murashige and Skoog (MS) medium with vitamins: 100 mg/L ascorbic acid, 0.5 mg/L 6-benzylaminopurine (BAP), 0.5 to 5.0 mg/L NAA (1-napthaleneacetic acid), and 3.0 g/L sucrose. The SGC2 media additionally contained 0.5 to 5.0 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D). SGC2 media generated better callusing response compared to SGC1, thus displaying the importance of using 2,4-D in combination with NAA for callus induction. MS medium containing 2.5 mg/L NAA (SGC1.5) was noted to be the most effective in the initiation of friable embryogenic callus. On the other hand, MS medium containing a combination of 2.0 mg/L NAA and 2.0 mg/L 2,4-D was effective in the early initiation of friable embryogenic callus. In addition, a higher frequency of callus formation was observed from basal leaf segment as compared to that from middle and apical leaf segments. A random amplified polymorphic DNA (RAPD) analysis was also performed to see the genetic differences between the three S. glauca genotypes used in this study. The performance of S. glauca 5 and S. glauca 19 for higher callus frequency over the S. glauca 21 could be attributed to the genotypic differences between these genotypes. Overall, our protocol using SGC 2.4 media yielded optimal results and is suitable for large scale micropropagation of S. glauca. Key words: Simarouba glauca, somatic embryogenesis, callus, plant growth regulators, RAPD and biofuel.

Highlights

Simarouba glauca DC, commonly known as “paradise tree”, is an emerging and promising plant for biofuel production
The genotypes in the present study showed a wide range of response for callus induction on SGC1 and SGC2 media with different levels of Naphthaleneacetic acid (NAA) and 2,4-D
Our study shows that NAA, along with 2,4-D, is more efficient in initiating callus from leaf explants than NAA alone

Summary

Introduction

Simarouba glauca DC, commonly known as “paradise tree”, is an emerging and promising plant for biofuel production. At approximately 65% oil seed content, when compared to current sources of biofuels, such as Camelina‟s 43% oil seed content, the S. glauca tree produces a much higher oil yield (Zubr, 1997). S. glauca has the potential to be an effective second generation biofuel crop, it requires a long pre-bearing period (5 to 6 years) to mature and bear seeds (Mansai and Gaikwad, 2011). Somatic embryogenesis via callus route is preferred to the in vitro regeneration method because it is a useful tool for recovery of large number of plants with little somaclonal variation and to recover genetically modified plants (Manasi and Gaikwad, 2011). Despite its promise as an effective biofuel source, little scientific research has been performed on in vitro propagation of S. glauca.

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