NISCAIR Online Periodicals Repository Collection: IJBT Vol.11(1) [January 2012]

Isolation and characterization of a multiple herbicide resistant strain [Av(MHR)^Ar,Al,B,D] of diazotrophic cyanobacterium Anabaena variabilis

Title: Isolation and characterization of a multiple herbicide resistant strain [Av(MHR)^Ar,Al,B,D] of diazotrophic cyanobacterium Anabaena variabilis

Authors: Singh, Surendra; Datta, Pallavi; Tirkey, Archna

Abstract: The present study was aimed to isolate a multiple herbicide resistant strain [(MHR)^Ar,Al,B,D]of Anabaena variabilis exhibiting resistance against four common rice-field herbicides, viz., Arozin, Alachlor, Butachlor and 2,4-D. The multiple herbicide resistant (MHR) strain was isolated by spontaneous mutational techniques. Of the four spontaneously occurring mutants, Arozin resistant mutant (Ar-R) exhibited 92-98% survival in lethal concentrations of Arozin, Alachlor, Butachlor and 2,4-D, and was designated as MHR strain, Av(MHR)^Ar,Al,B,D. The MHR strain exhibited faster growth rate, substantial increase in macromolecular contents, photosynthesis, nitrogenase and glutamine synthetase (GS) activity not only in graded concentration of herbicides but below (0-25 mg L^-1) and above the lethal dosages (25-80 mg L^-1), and even in the presence of combined lethal dosages of all four herbicides as compared to wild type as well as Alachlor, Butachlor and 2,4-D resistant strains. The cross resistance relationship in Arozin resistant (Ar-R) mutant strain of A. variabilis with lethal dosages of Alachlor, Butachlor and 2,4-D did indicate that it was a single mutational event and resistance to Arozin was associated with the acquisition of resistance to Alachlor, Butachlor and 2,4-D. Evidently such improved Av(MHR)^Ar,Al,B,D strain of diazotrophic cyanobacterium A. variabilis under herbicide(s) stressed agro-ecosystem, particularly rice-fields, would likely to serve as efficient biofertilizer.

Page(s): 77-85

Genetic variation and diversity of two brachyuran crab species (Sesarma brockii and Grapsus strigosus) in an artificially developed mangrove ecosystem

Title: Genetic variation and diversity of two brachyuran crab species (Sesarma brockii and Grapsus strigosus) in an artificially developed mangrove ecosystem

Authors: Thangaraj, M; Thirumaraiselvi, R; Subburaj, J

Abstract: The random amplified polymorphic DNA (RAPD) analysis was used to estimate the genetic relationships and diversity of two brachyuran crab species (Sesarma brockii & Grapsus strigosus) in an artificially developed mangrove ecosystem. Ten arbitrary primers were screened to identify species-specific RAPD markers in S. brockii and G. strigosus. On average about 26% scorable RAPD bands were specific to each species. Gene diversity (H) in S. brockii and G. strigosus was 0.0589±0.0457 and 0.0056±0.0052, respectively. The genetic distance between S. brockii and G. strigosus was 1.2714. Phylogenetic analysis revealed that these two species grouped into separate clusters emphasizing the distinct species status.

Page(s): 111-113

In vitro plant regeneration from immature seeds of Murraya koenigii (L.) Spreng.

Title: In vitro plant regeneration from immature seeds of Murraya koenigii (L.) Spreng.

Authors: Rani, Uzma; Sharma, M M; Ismail, Najma; Batra, Amla

Abstract: An efficient and reproducible in vitro protocol was developed for the large scale propagation of Murraya koenigii (L.) Spreng. from immature seeds. Direct shoot proliferation was achieved from intact seedlings on Murashige and Skoog (MS) medium supplemented with BAP (2.5 mg L^-1). The raised multiple shoots (19.85) were dwarf. Therefore, they were transferred to shoot elongation medium comprising of MS salts fortified with GA₃ (0.4 mg L^-1). The elongated shoots (5.6 cm) were then rooted on ½ MS medium supplemented with IAA (0.5 mg L^-1). The plantlets were hardened and acclimatized in plant growth chamber at 26±2°C temperature and 80% humidity under 16/8 h light and dark photoperiod by cool white fluorescent tube light of about 3000 lux. Finally, the plantlets were transferred to field conditions, where they survived with 80% survival rate.

Page(s): 108-110

Micropropagation of Stachytarpheta jamaicensis (L.) Vahl—A medicinally important plant

Title: Micropropagation of Stachytarpheta jamaicensis (L.) Vahl—A medicinally important plant

Authors: Rajender, K; Thirupathi, M; Raju, D; Reddy, K Jaganmohan

Abstract: An in vitro-protocol for micropropagation of Stachytarpheta jamaicensis (L.) Vahl was developed through nodal explants. Murashige and Skoog (MS) medium with BA 0.5 mg/L and IBA 0.5mg/L was found to be the best for multiple shoot formation from nodal explants. The maximum response of shoot induction was observed on a medium containing 1.0 mg/L Kn. The regenerated shoots were excised and transferred to rooting medium containing IBA at different concentrations. Highest of 84% rooting was observed at 0.5 mg/L level of IBA and BA. The in vitro derived plantlets were hardened and acclimatized in soil. About 75% of plantlets survived in the field condition.

Page(s): 105-107

NISCAIR Online Periodicals Repository Collection: IJBT Vol.11(1) [January 2012]

Isolation and characterization of a multiple herbicide resistant strain [Av(MHR)Ar,Al,B,D] of diazotrophic cyanobacterium Anabaena variabilis

Genetic variation and diversity of two brachyuran crab species (Sesarma brockii and Grapsus strigosus) in an artificially developed mangrove ecosystem

In vitro plant regeneration from immature seeds of Murraya koenigii (L.) Spreng.

Micropropagation of Stachytarpheta jamaicensis (L.) Vahl—A medicinally important plant

Isolation and characterization of a multiple herbicide resistant strain [Av(MHR)^Ar,Al,B,D] of diazotrophic cyanobacterium Anabaena variabilis