Agrobacterium mediated genetic transformation and regeneration in elite rice (Oryza sativa L.) cultivar BRRI dhan56

Agrobacterium-mediated genetic transformation of rice (Oryza sativa L.) cultivar BRRI dhan56 was  carried out in this study. Agrobacterium tumefaciens strain LBA 4404, which harbors the plasmid pIG121  that carries the genes for ß-glucuronidase gene, served as a reporter gene in the histochemical assay and  the neomycin phosphotransferase ΙΙ (NPT ΙΙ) gene for the identification of resistance to kanamycin was  used for genetic transformation. Twenty days old embryogenic calli from mature embryos of highly  regenerating rice cultivar BRRI dhan56 were used to co-cultivate with 0.8 to 0.9 OD600 Agrobacterium  for 25 min and the cultured was continued on agar medium for this study. The transformed colonies were selected by using 50 mg/L kanamycin and 50 mg/L rifampicin and confirmed by colony PCR. The PCR  positive colonies were isolated to transform by using calli of indica rice cultivar BRRI dhan56. Putative  leaf and root segments from  plantlets obtained from transformation experiment with the plasmid pIG121  were GUS positive. Integration of the introduced gene into the genome was  demonstrated by PCR. The  maximum transformation efficiency of 32% was obtained by using 500 mg/L cefotaxime as a  bacteriostatic agent to inhibit growth of Agrobacterium. In this study, 100 µM acetosyringone in  co-cultivation medium and co-cultivation for 3 days were the optimum conditions for maximum  transformation. The expression of GUS gene revealed that the calli were successfully transformed. The  results of this study would be an effective tool for crop improvement and gene-function studies on the  model monocot plant rice. Key words: Agrobacterium, Oryza sativa L., acetosyringone, β-glucuronidase, cefotaxime, plasmid, phosphotransferase, rice, transformation. Abbreviation: GUS, β-Glucuronidase; PCR, polymerase chain reaction; MS, Murashige and Skoog; 2,4-D, 2,4-dichlorophenoxyacetic acid; MCI, callus induction medium; OD, optical density; NAA, 1-naphthaleneacetic acid; BAP, 6-benzylaminopurine. 

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

Nutritionally Enhanced Staple Food Crops

Crop biofortification is a sustainable and cost-effective strategy to address malnutrition in developing countries. This review synthesizes the progress toward developing seed micronutrient-dense cereals and legumes cultivars by exploiting natural genetic variation using conventional breeding and/or transgenic technology, and discusses the associated issues to strengthen crop biofortification research and development. Some major QTL for seed iron and zinc, seed phosphorus, and seed phytate in common bean, rice,J;md wheat have been mapped. An iron reductase QTL associated with seed-iron ~QTL is found in common bean where the genes coding for candidate enzymes involved in phytic acid synthesis have also been mapped. Candidate genes for Ipa co segregate with mutant phenotypes identified in rice and soybean. The Gpe-B1 locus in wild emmer wheat accelerates senescence and increases nutrient remobilization from leaves to developing seeds, and another gene named TtNAM-B1 affecting these traits has been cloned. Seed iron-dense common bean and rice in Latin America; seed iron-dense common bean in eastern and southern Africa;....

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

In vitro propagation of Citrullus lanatus Thumb. from nodal explants culture

A standard protocol was established for rapid in vitro propagation of watermelon (Citrullus lanatus Thumb.) from nodal explants of field grown plant. Multiple shoot proliferation was achieved from nodal explants on MS medium supplemented with 1.0 mg/l BAP + 0.2 mg/l NAA within 30 days of inoculation. The elongation of shoots was obtained on the same medium. Highest percentage of root induction was achieved on MS medium supplement with 1.0 mg/l IBA within 25 days of culture. Well rooted plantlets were transferred to small pots and after proper acclimatization the plantlets were transplanted in the field condition, where 80% plantlets were survived and grew successfully

MULTIPLE SHOOT REGENERATION IN DENDROBIUM FIMBRIATUM HOOK AN ORNAMENTAL ORCHID

ABSTRACT The prime objective of the present study was to optimize and develop efficient regeneration protocol for in vitro germination, micropropagation and root induction of the orchid plant Dendrobium fimbriatum. Three investigated culture media were Phytamax (Sigma, USA; PM), Murashige and Skoog (MS) and Modified Vacin and Went (MVW) were used. Among these media PM was found to be the most effective medium for germination of orchid seedlings. In this medium, the germination rate was 100 percent. Twelve different combinations of plant growth regulators were tested for the elongation of germinated seedlings. It was revealed that MS medium fortified with 2.0 mg/l 6-benzylaminopurine (BAP) and 0.01 mg/l indole-3-butyric acid (IBA) was the most effective for shoot elongation. The average elongation rate was 4.10 cm after 30 days of culture. Sixteen different combinations of plant growth regulators were used for induction and elongation of adventitious shoots from the nodal zone of shoot explants. MS medium supplemented with 1 mg/l BAP and 0.5 mg/l Picloram was proven to be the best for multiple shoot formation and elongation. In this medium the average number of induced shoots per explant was 4.35. Furthermore, shortest duration (16 days) for shoot induction was recorded on this medium. Half MS medium supplemented with 1.0 mg/l indole-3-acetic acid (IAA) was found suitable for effective induction and growth of adventitious roots on the micro-propagated orchid plantlets

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

VARIABILITY AND INTERRELATIONSHIP AMONG YIELD AND YIELD CONTRIBUTING CHARACTERS IN ONION (ALLIUM CEPA L.)

A study was conducted using seven varieties of onion (Allium cepa L.) and observations were recorded on yield and yield components in order to obtain informations on genetic variability and character association of onion. Higher genotypic coefficients of variations were recorded in number of seeds per scape (NSPS), final plant height (FPH), final scape height, fresh weight of bulb and bulb length. These characters also exhibited high heritability along with high genetic advance as percentage of mean. Phenotypic correlation coefficients showed that bulb length, bulb diameter and scape diameter were positively and significantly correlated with fresh weight of bulb. The number of seeds per scape, final scape height, final plant height and number of pseudostem branches at maximum flowering stage were also positively and significantly correlated with seed yield per scape