NISCAIR Online Periodicals Repository Collection: IJEB Vol.46(01) [January 2008]

Abnormal anther development and high sporopollenin synthesis in benzotriazole treated male sterile Helianthus annuus L.

Sat, 29 Dec 2007 22:58:59 GMT

Title: Abnormal anther development and high sporopollenin synthesis in benzotriazole treated male sterile Helianthus annuus L.

Authors: Tripathi, S M; Singh, K P

Abstract: Foliar application of 1.5% benzotriazole induced 100% pollen sterility in H. annuus. Pollen abortion in treated plants was mainly associated with abnormal behaviour of tapetum. A limited number of anther locule showed early degeneration of tapetum followed by disintegration of sporogenous tissues. On the other hand, some locules showed normal development of tapetum at initial stages. However, this tapetum exhibited degenerated and non-functional cell organelles. In both these situations tapetum failed to provide proper nourishment to developing microspores. The ultrastructure of both tapetum and microspores is different from that of control material with irregularities of exine deposition, endopolyploidy of tapetal nuclei and an alteration of organelle composition being correlated with sterility. Pollen grains thus developed were devoid of nucleus and cell organelles and were complete sterile.

Page(s): 71-78

Micropropagation of Elaeis guineensis Jacq. ‘Dura’: Comparison of three basal media for efficient regeneration

Sat, 29 Dec 2007 22:58:59 GMT

Title: Micropropagation of Elaeis guineensis Jacq. ‘Dura’: Comparison of three basal media for efficient regeneration

Authors: Muniran, F; Bhore, Subhash J; Shah, Farida H

Abstract: Three basal plant tissue culture media, namely, N₆, MS, and modified Y₃,were compared to optimize micropropagation protocol for E. guineensis. Full strength media were used separately to regenerate plantlets directly using immature zygotic embryos (IZEs), and through somatic embryogenesis of calli obtained from IZEs. The plantlets regenerated by direct regeneration on three media were examined for shoot length and rooting percentage. For the induction of callus, somatic embryogenesis, and rooting modified Y₃ medium was the most effective. In conclusion, the results indicate that modified Y₃ medium is the most suitable for direct regeneration, callus induction and somatic embryogenesis in E. guineensis.

Page(s): 79-82

PCR-based detection of microcystin-producing cyanobacterial blooms from Central India

Sat, 29 Dec 2007 22:58:59 GMT

Title: PCR-based detection of microcystin-producing cyanobacterial blooms from Central India

Authors: Ghosh, Shubhro Kamal; Das, Palash Kumar; Bagchi, Suvendra Nath

Abstract: Microcystin synthetase-gene-specific primers were used to identify hepatotoxic microcystin producing genotypes in six Microcystis spp.-dominant water blooms. Four blooms gave positive PCR reaction. They produced microcystin-RR and –LR amounting to 0.037 to 0.095% of the dry mass.

Page(s): 66-70

Role of ion channel modifiers in reversal of morphine–induced gastrointestinal inertia by prokinetic agents in mice

Sat, 29 Dec 2007 22:58:59 GMT

Title: Role of ion channel modifiers in reversal of morphine–induced gastrointestinal inertia by prokinetic agents in mice

Authors: Sandhiya, Selvarajan; Dkhar, Steven Aibor; Krishna, Peddy Reddy Murali; Ramaswamy, Subramanian

Abstract: Prokinetic drugs like mosapride, domperidone etc, are used to treat gastrointestinal delay. Though the receptor-mediated actions of these agents have been studied, involvement of ion channels in reversing morphine-induced gastrointestinal inertia by prokinetic agents has not been explored. Charcoal meal test was used to measure small intestinal transit (SIT) in adult male Swiss albino mice. Animals were given ion channel modifiers and prokinetic drugs intragastrically. Reversal of morphine-induced gastrointestinal delay by mosapride was decreased significantly by CaCl₂, minoxidil and glibenclamide. Similarly, domperidone’s effect on morphine was decreased by CaCl_2,nifedipine, minoxidil and glibenclamide significantly. The results reveal that ion channel modifiers counteract the prokinetic effects of mosapride or domperidone.

Page(s): 60-65