Morphological and Histological Observation of Embryogenic Calli Derived from Immature Embryo of BRRI Dhan28 (Oryza sativa L.) Variety

Somatic embryogenesis is the most common method for regeneration in rice. In vitrostudies of indica rice (Oryza sativa L.) variety BRRI dhan28 was used for obtainingembryogenic calli from immature embryo culture on Murashige & Skoog mediumsupplemented with 2.5 mg/l dichlorophenoxyacetic acid (2,4-D) and 0.5 mg/lnaphthaleneacetic acid (NAA) showed the highest percentage (91%) of callus induction. Inthis combination 80% embryogenic calli were formed uneven with a crisp texture, loosestructure and salient multicellular structures on the surface while non embryogenic calliwere compact with a smooth surface. Under microscopic observation, embryogenic cells weresmaller, globular and abundant in cytoplasm with one or two big nuclei. Non embryogeniccells were little cytoplasm and few large vacuoles with no or only a small nucleus and wideintercellular spaces. Non embryogenic cells had a very low cell division capability whileembryogenic cells had a high capability for cell division and continued to divide andproduced somatic pro-embryos with a well–defined protodermis which could developfurther through the typical globular, heart, torpedo and cotyledonary stages. Only 80% ofembryogenic cells were induced high differentiation rate and developed 65 globular, 52heart-shape, 43 torpedo and 37 cotyledonary embryos of embryogenic cells after 30 to 45 daysof induction

A simplistic approach of algal biofuels production from wastewater using a Hybrid Anaerobic Baffled Reactor and Photobioreactor (HABR-PBR) System.

The current technologies of algal biofuels production and wastewater treatment (e.g., aerobic) process are still in question, due to the significant amount of fresh water and nutrients requirements for microalgae cultivation, and negative energy balance in both processes, especially when considered in the context of developing counties around the world. In this research, a simplistic sustainable approach of algal biofuels production from wastewater was proposed using a Hybrid Anaerobic Baffled Reactor (HABR) and Photobioreactor (PBR) system. The study suggests that the HABR was capable of removing most of the organic and solid (>90% COD and TSS removal) from wastewater, and produced a healthy feedstock (high N: P = 3:1) for microalgae cultivation in PBRs for biofuels production. A co-culture of Chlorella vulgaris, Chlorella sorokiniana, and Scenedesmus simris002 showed high lipid content up to 44.1%; and the dominant FAMEs composition (C16-C18) of 87.9% in produced biofuels. Perhaps, this proposed low-cost technological approach (e.g., HABR-PBR system) would connect the currently broken link of sustainable bioenergy generation and wastewater treatment pathway for developing countries

Establishment of an Efficient Protocol for in Vitro Callus Induction and Regeneration System Using Mature Embryo in Elite Rice (Oryza sativa L.) Cultivars

The present investigation was undertaken to determine a suitable media compositions for callus induction and plant regeneration of rice (Oryza sativa L.) through somatic embryogenesis. Murashige and Skoog (MS) media composition and phytohormones (i.e. auxin; 2, 4-D, IAA, IBA and cytokinin; BAP, KIN) were tested for high callus induction and plant regeneration. Mature seeds of six rice cultivars namely BRRI dhan28, BRRI dhan29, BRRI dhan30, BRRI dhan34, BRRI dhan56 and BRRI dhan57 were used for the experimentation. 2.0 mg/l of 2,4-D + 0.5 mg/l of NAA were found suitable inducing high amount of calli and 2.0 mg/l of BAP+ 1.0 mg/l of NAA + 1.5 mg/l of KIN were found most effective for plant regeneration. Among cultivars for callus induction, BRRI dhan29 shows the highest percentage and BRRI dhan30 less and remaining cultivars (BRRI dha28, BRRI dhan34, BRRI dhan56 and BRRI dhan57) show moderate results in the experiments. Among cultivars for regeneration, BRRI dhan29 shows the highest percentage and BRRI dhan30 less and remaining cultivars (BRRI dha28, BRRI dhan34, BRRI dhan56 and BRRI dhan57) show moderate results. The investigation will provide valuable information for Agrobacterium mediated genetic transformation

Somatic embryogenesis and plant regeneration in Wedelia calendulacea Less. an endangered medicinal plant

In this work, plant regeneration via somatic embryogenesis was achieved from leaf and internode derived callus of Wedelia calendulacea, an endangered medicinal plant. Primary callus was induced by culturing leaf disc and internode explant on Murashige and Skoog medium supplemented with 2.0 mg L-1 of 2,4-D under light condition. Transfer of embryogenic callus on a reduced concentration of 2,4-D facilitated somatic embryo development while calluses remained unorganized at the same 2,4-D level. A histological analysis confirmed somatic embryo by revealing the presence of a closed vascular system in the developing embryos and lack of a vascularconnection with surrounding callus tissues. Somatic embryos germinated into plantlets upon transfer on MS medium containing 1.0 mg L-1 BAP plus 0.5 mg L-1 GA3. Plantlets were acclimatized successfully and survived under soil condition. This is the first on somatic embryogenesis of W.calendulacea. This result could facilitate genetic transformation of this important medicinal plant