NISCAIR Online Periodicals Repository Collection: IJEB Vol.50(02) [February 2012]

Regeneration of plantlets from mature embryo calli of Western Ghats land race cultivar of rice, Oryza sativa L.

Title: Regeneration of plantlets from mature embryo calli of Western Ghats land race cultivar of rice, Oryza sativa L.

Authors: Gnanesh, A U; Krishna, V; Kumar, R Shashi; Venkatesh; Kumar, S R Santosh; Shashidhar, H E

Abstract: The Malnad region located in the Western Ghats of Karnataka is known for the cultivation of indigenous rain fed land race cultivar of rice. The present study was to investigate the callogenic and caulogenic potentialities of the two indigenous rice cultivar namely Karimundaga and Kanadatumba using dehusked mature embryo explants. For callus and shoot bud differentiation, the explants were cultured on Murashige and Skoog (MS) medium supplemented with 2,4-D (1–3 mg/L), IAA (1–2 mg/L), Kn (1–4 mg/L) and BAP (1–4 mg/L). The morphogenic potentialities of the two rice cultivar differed in texture of callus. In both the cultivar callogenic frequency was optimized at 1 mg/L 2,4-D concentration, it was 94% in Karimundaga and 58% in Kanadatumba. Supplementation of IAA either alone (1–2 mg/L) or in combination with Kn or BAP at 1 to 4 mg/L concentration of each induces shoot bud differentiation from the calli. In the cultivar Karimundaga caulogenic frequency was highest (10.60±2.55) at 1.0 mg/L IAA and 4.0 mg/L BAP concentration. While in the cultivar Kanadatumba highest number of shoot buds (7.90±2.69) was differentiated at 1.0 mg/L IAA and 4.0 mg/L Kn concentration. The calli derived regenerants were successfully acclimatized in the greenhouse and agro-morphological variations were evaluated. The growth characteristics and yield related parameters exhibited by in vitro plants were lower than the in vivo plants.

Page(s): 164-170

Influence of mating histories and age on female remating behaviour in a few closely related species of Drosophila nasuta subgroup

Title: Influence of mating histories and age on female remating behaviour in a few closely related species of Drosophila nasuta subgroup

Authors: Shruthi, B; Chayakumari; Ram, K Ravi; Ramesh, S R

Abstract: Female remating with more than one male leads to coexistence of sperm from different males in the same female, thus creating a selection pressure on sperm. To understand the extent of divergence in the reproductive behaviour among closely related species, in the present study, the influence of first mating histories like mating latency, duration of copulation and age of flies have been analysed on female remating behaviour in closely related Drosophila nasuta subgroup species with varying levels of reproductive isolation. The time taken for the once mated females to remate varied from 7 days in D. s. sulfurigaster to 19 days in D. s. neonasuta after first mating. The female remating frequency varied from a minimum of 29% in D. s. neonasuta to a maximum of 95% in D. s. sulfurigaster. The younger flies, which had remating latency of three times less than aged flies, show 100% remating frequency. In addition, it was observed that the duration of copulation in the first mating influences the remating behaviour among the nasuta subgroup members. The results revealed that D. nasuta subgroup members despite being closely related differ in their reproductive behaviour.

Page(s): 156-163

Developmental and neurobehavioural toxicity study of arsenic on rats following gestational exposure

Title: Developmental and neurobehavioural toxicity study of arsenic on rats following gestational exposure

Authors: Gandhi, D N; Panchal, G M; Patel, K G

Abstract: To characterize developmental and behavioral alterations induced by arsenic exposure, Albino rats were exposed to arsenic (0, 1.5, 3.0 and 4.5 mg/kg/day/po) from gestation day 8 to till parturition and the offspring were observed over the first 3 postnatal weeks, until they were weaned on post-natal day (PND) 21. Once the pups were delivered (PND0), the treatment was discontinued. All pups were assessed for physical development, reflex development, strength and motor coordination from standard neurobehavioural developmental test batteries beginning on PND1. Gestational administration of arsenic at tested dose levels, showed no significant changes in the day of appearance of eye opening, startle reflex, negative geotaxis and spontaneous alteration performance in comparison to the control group. The number of live fetuses, mean fetal body weight and percentages of resorptions or malformations per litter were not affected by arsenic exposure. No treatment-related malformations or developmental variations were noted at any exposure level, suggesting that arsenic exposure at this dose level did not adversely affect behavioural endpoints of developmental toxicity.

Page(s): 147-155

Protective effect of Tribulus terrestris linn on liver and kidney in cadmium intoxicated rats

Title: Protective effect of Tribulus terrestris linn on liver and kidney in cadmium intoxicated rats

Authors: Lakshmi, G Dhana; Kumar, P Ravi; Bharavi, K; Annapurna, P; Rajendar, B; Patel, Pankaj T

Abstract: Administration of cadmium (Cd) significantly increased the peroxidation markers such as malondialdehyde and protein carbonyls along with significant decrease in antioxidant markers such as super oxide dismutase and reduced glutathione in liver and kidney tissues. Cadmium also caused a significant alteration in hepatic and renal functional markers in serum viz. total protein, albumin, alanine transaminase, blood urea nitrogen and creatinine. Prominent pathological changes observed in liver were severe vascular and sinusoidal congestion with diffuse degenerative changes and mononuclear infiltration into peripheral areas, while the kidney showed vascular and glomerular congestion, cloudy swelling of tubular epithelium. Co-administration of ethonolic extract of T. terrestris or vitamin E along with Cd significantly reversed the Cd induced changes along with significant reduction in Cd load.

Page(s): 141-146