Somatic Embryogenesis in Papaya (Carica papaya L. cv. TNAU Papaya CO.8)

Abstract

An efficient indirect somatic embryogenesis protocol for Carica papaya var TNAU Papaya CO.8 was developed using immature zygotic embryos as an explant. Two growth regulators namely 2,4-D and picloram each at 1, 2, 3 mg/L were tested for callus induction and the highest callus induction frequency (83.33%) was observed in MS medium supplemented with 3 mg/L 2,4-D. However the rate of conversion into somatic embryos was highest (63.33%) on MS medium supplemented with 2 mg/L 2,4-D. Maturation of somatic embryos was studied by using MS medium with different concentrations of abscisic acid (ABA) and benzyl amino purine (BAP) along with glutamine (400 mg/L). The maturation of globular embryos was observed to be higher in the combination of ABA (1.5 mg/L), BAP (0.4 mg/L) along with glutamine (400 mg/L). Even though regeneration was observed from cotyledonary stage embryos in presence of different growth regulators like BAP, α-naphthalene acetic acid (NAA), phloridzin dehydrate kinetin and gibberellic acid, further growth was not observed due to abnormal regenerative structures. Regeneration of cotyledonary stage somatic embryos were highest (77.4%) in half strength MS medium without growth regulators. The well-developed plantlets with shoots and roots were subsequently transferred for hardening.

Induksi Kalus Embriogenik Pepaya (Carica papaya L.) Kultivar Caliso dan Callina

“…Penggunaan 2,4-D dalam konsentrasi rendah 9.05 µM dengan sukrosa 30 g L -1 menghasilkan persentase eksplan berkalus yang lebih tinggi pada pepaya Callina den-gan rerata 100% dibandingkan pada perlakuan 2,4-D dalam konsentrasi tinggi 45.2 µM dan sukrosa 60 g L -1 yaitu rerata 50.8%. Demikian juga dalam penelitian Rajesh et al (2020), media MS yang mengandung 2,4-D 3 mg L -1 menghasilkan eksplan berkalus 83.33% pada pepaya kultivar TNAU CO.8. Aplikasi auksin 2,4-D dengan konsentrasi rendah pada induksi kalus embriogenik pepaya sangat penting, dibandingkan dengan konsentrasi tinggi yang dapat menyebabkan perubahan genetik, variasi somaklonal dan embrio somatik yang dihasilkan tumbuh abnormal sehingga tidak mampu berkembang menjadi tanaman normal (Anandan et al 2012).…”