Comparison of in vitro regeneration and transformation efficiency among five vietnamese indica rice cultivars

L.Q. Cao¹†, P.D. Nguyen¹, X.H. Pham¹, V.H. La², X.V. Nguyen², T.D. Nguyen²*

¹Department of Molecular Pathology, Institute of Agricultural Genetics, Vietnam Academy of Agricultural Sciences, Hanoi 11956, Vietnam
²Institute of Biotechnology and Food technology, Thai Nguyen University of Agriculture and Forestry, Thai Nguyen 24153, Vietnam
*Correspondence: dungnt@tuaf.edu.vn

Abstract:

This study optimized the in vitro regeneration and transformation processes for five popular indica rice cultivars in Vietnam named as BC15, Bac Thom 7 (BT7), Khang Dan 18 (KD18), OM5451, and TBR225. The highest callus induction rates (83-93.67%) were achieved on a medium containing 2.5 mgL^-l 2,4-D, supplemented with 500 mg L^-l each of L-proline, L-glutamine, and casein. Higher or lower concentrations of 2,4-D resulted in reduced callus induction. Among tested cultivars, BT7 exhibited the highest callus induction rate of 93.67%. Shoot regeneration was optimized on a medium with a combination of 0.5 mg L^-l kinetin, 2.0 mg L^-l BAP, and 0.5 mg L^-l NAA, resulting in regeneration rates ranging from 80.23% to 90.77% across cultivars, with BT7 exhibiting the highest regeneration rate (90.77%). Hygromycin at 20 mg L^-l was optimal for selecting transgenic calli, with BT7 showing the highest transformation efficiency opdetermined to be optimal for selecting transgenic calli, with BT7 achieving the highest transformation efficiency (44% hygromycin-resistant callus and 29% GUS expression). PCR analysis confirmed a high proportion (87.5%) of transgenic plants in the BT7 cultivar. These findings indicate that the BT7 is the most suitable cultivar for genetic transformation and gene editing applications.

Key words:

In vitro effects of regulators on growth and morphogenesis of Ocimum basilicum L. ‘Alfavaca Green’ stem apexes

J.R. Trettel, M. D.S. Queiroz, M.M. Andrade and H.M. Magalhães*

University Paranaense, Department of Biotechnology, Mascarenhas de Moraes Square, 4282, BR87502-210 Umuarama, Paraná, Brazil
*Correspondence: helidamara@prof.unipar.br

Abstract:

Large-scale cultivation of contamination free plants requires a good standardization protocol and production methods. Basil is widely used for cosmetics, food and pharmaceutical industries as it is rich in many bioactive compounds. This present study aimed to evaluate the growth and in vitro anatomical aspects of apical buds of basil grown under different concentrations rowth regulators like: NAA (Naphthalenoacetic Acid), BAP (6-benzylaminopurine), and KIN (Kinetin). The in vitro establishment was evaluated every 20 days to calculate the, the percentage of plants with calluses, appearance of the roots, any abnormal seedlings, any oxidized seedlings, and the number of sprouts per plant. Growth, physiological, and morpho-anatomical evaluations were performed at 80 days. Basal callogenesis was observed when cytokinin’s and auxins are used in combination. Auxin treatments caused hyperhydricity in the stems and leaves. Medium A2 (0.05 mg L^-1 of NAA and 0.1 mg L^-1 of BAP), and A3 (0.05 mg L^-1 of NAA and 0.1 mg L^-1 of KIN) resulted in the best development of basil plants, cultivar ‘Alfavaca Green’. The A2 produced plants with greater numbers of leaves, an average bud length of 59.81 mm, and the best root properties. A2 and A1 have a higher percentage of hyperhydricity (83 and 67%). The A3 resulted in an acceptable number of leaves (range: 21–39), and this treatment produced the best shoot properties as well as fewer plants with hyperhydricity. In addition, the A3 treatment produced plants with a shoot length, high shoot fresh and dry mass (2.82 and 0.23 g), high chlorophyll index and leaf anatomy that was similar to the control. Excluding the control, the other treatments presented more than 90% of the explants with calluses in their bases.

Key words:

callus, hyperhydricity, Lamiaceae, leaf tissues, morphological processes