NISCAIR Online Periodicals Repository Community: IJBT Vol.06 [2007]

Plant regeneration in different genotypes of indica rice

Fri, 28 Sep 2007 22:58:59 GMT

Title: Plant regeneration in different genotypes of indica rice

Authors: Biswas, Anusrita; Mandal, Asit B

Abstract: Of 10 indica rice varieties assessed, Annada showed the best in vitro culture response in respect of callus induction, plantlet regeneration and number of plantlets/seed callus. Other high yielding varieties, viz. Kasturi, IR 72 and Karnal Local, also displayed appreciable performance. Callus induced and proliferated in dark and gave high plantlet regeneration and more plantlets/seed callus across genotypes. Among three shock treatments, viz. heat (37°C for overnight), cold (4°C for over night) and dehydration, dehydration significantly enhanced the plantlet regeneration and number of plantlets/seed callus. Of 3-dehydration treatments (6, 12 and 24 h duration), the maximum plantlet regeneration and number of plantlets/seed callus were observed in the calli dehydrated for 12 h. Of three tested media, viz. MS, LS, and N₆, MS emerged the best for callus induction, plantlet regeneration and number of plantlets/seed callus. In contrast, among the modified media formulations, modified N6 [5 mM (NH₄)₂ SO₄] produced maximum plantlets/seed callus across varieties. Increased (5 mM) (NH₄)₂SO₄ content in the medium was found to be better than the higher dose of KNO₃or its normal level in the respective media formulations. Across genotypes, 2 mg L^-1 2,4-D in the callus induction medium (CIM) was the most suitable for callus induction. However, 2,4-D in combination with other growth regulators, such as 2 mg L^-1 2,4-D and 1 mg L^-1 Kn, performed better. In regeneration medium (RM), 2 mg L^-1 BAP with 1 mg L^-1 Kn and 0.5 mg L^-1 NAA, or 2 mg L^-1 BAP with 0.5 mg L^-1 NAA, were optimum for the maximum plantlet regeneration. Across varieties, coconut water (10%) was found to be the most effective to enhance the in vitro culture response as evident from prolific callus induction, increased plantlet regeneration and more plantlets/seed callus.

Page(s): 532-540

Biolistic-mediated DNA delivery and transient expression of GUS in hypocotyls of Feronia limonia L.—A fruit tree

Fri, 28 Sep 2007 22:58:59 GMT

Title: Biolistic-mediated DNA delivery and transient expression of GUS in hypocotyls of Feronia limonia L.—A fruit tree

Authors: Purohit, S D; Raghuvanshi, S; Tyagi, A K

Abstract: Feronia limonia L. (Rutaceae) is an important fruit tree of arid horticulture. To be able to introduce genes of interest for its improvement, biolistic-mediated DNA delivery method has been standardized. The hypocotyls explants were bombarded with plasmid pBI121 having gus reporter gene driven by CaMV 35S promoter and npt II under control of nos promoter as selectable marker. The best transient expression of GUS was recorded when tungsten particles coated with DNA were bombarded at a disc pressure of 1350 and 1100 psi from a distance of 9 cm. Some of the bombarded explants are being maintained to obtain viable regenerates for their analyses.

Page(s): 504-507

Isolation of pigeon pea (Cajanus cajan L.) legumin gene promoter and identification of conserved regulatory elements using tools of bioinformatics

Fri, 28 Sep 2007 22:58:59 GMT

Title: Isolation of pigeon pea (Cajanus cajan L.) legumin gene promoter and identification of conserved regulatory elements using tools of bioinformatics

Authors: Jaiswal, Rajani; Nain, Vikrant; Abdin, M Z; Kumar, P A

Abstract: A seed specific legumin gene promoter from pigeon pea was isolated by PCR amplification. Database assisted sequence analysis of this promoter revealed several putative cis-acting regulatory elements. Comparative analysis of 15 seed-specific legumin gene promoters from six species, viz. Cajanus cajan, Cicer arietinum, Pisum sativum, Glycine max, Vicia faba and Arachis hypogaea, revealed several conserved motifs in promoter sequences; maximum conservation was observed upstream to transcription start site. Most of the conserved motifs have known transcription factor binding sites. One unknown conserved motif of seven base pair (AG/TGTGTA) was found 19 bp upstream to legumin box, putatively named as L-19. Study of nucleosome formation potential showed that putative linker DNA is more prone to mutations as compared to DNA involved in nucleosome formation. A chimeric construct was made with pigeonpea legumin promoter and β-glucuronidase (GUS) gene. Analysis of GUS expression at different developmental stages of transgenic tobacco plant’s parts revealed that the reporter gene was expressed at a high level only in mature seeds, specifically in embryo, endosperm and in cotyledonary leaves of developing seedling. These data showed that GUS gene transcription was regulated in a tissue specific and temporally regulated manner.

Page(s): 495-503

In vitro shoot regeneration from leaf and nodal explants of Vernonia cinerea (L.) Less

Thu, 28 Jun 2007 22:58:59 GMT

Title: In vitro shoot regeneration from leaf and nodal explants of Vernonia cinerea (L.) Less

Authors: Seetharam, Y N; Rajanna, L N; Jyothishwaran, G; Aravind, B; Sharanabasappa, G; Mallikharjun, P B

Abstract: Multiple shoots were obtained from leaf and nodal explants of Vernonia cinerea on MS media supplemented with different concentrations of BAP. Maximum numbers of shoots were obtained from leaf and nodal explants at 3.0 mg L^-1and 2.5 mg L^-1 concentrations of BAP, respectively. Shoot multiplication and their development was better on MS medium supplemented with BAP (2.0 mg L^-1) along with NAA (1.5 mg L^-1) for both the explants. Rhizogenesis was observed when in vitro shoots were subcultured in half strength MS medium containing IAA (1.5 mg L^-1). The in vitro raised plantlets were acclimatized and established successfully in the field.

Page(s): 418-420