NOPR Collection:

Standardization of in vitro protocol in Chrysanthemum cv. Madam E Roger for development of quality planting material and to induce genetic variability using -radiation

Mon, 01 Jan 2007 00:00:00 GMT

Title: Standardization of in vitro protocol in Chrysanthemum cv. Madam E Roger for development of quality planting material and to induce genetic variability using -radiation Authors: Misra, Pratibha; Datta, S K Abstract: ‘Madam E Roger’, a greenish white large flowered chrysanthemum cultivar- was selected for in vitro propagation and mutagenesis to induce further genetic variability. A protocol has been standardized to develop large-scale quality planting material for commercial exploitation. Shoot bud differentiation could be achieved in ray florets in the presence of 0.5 mg L^-1 NAA+ 2.0 mg L^-1 BA. The differentiated shoots were further proliferated in the same medium, rooted in the presence of 0.5 mg L^-1 NAA and hardened to grow in the field. Genetic variability in the form of a solid mutant of yellow colour has been obtained from this cultivar, when the freshly inoculated ray florets were treated with 1.0 Gy -radiation dose. Page(s): 121-124

Direct regeneration from apical bud explants of Withania somnifera Dunal

Mon, 01 Jan 2007 00:00:00 GMT

Title: Direct regeneration from apical bud explants of Withania somnifera Dunal Authors: Sivanesan, I Abstract: Effecient multiplication of Withania somnifera was achieved through culture of shoots tips of mature plants on Murashige and Skoog (MS), Schenk and Hildebrandt (SH) and Gamborg (B₅) media. However, MS medium was found superior to SH and B₅. MS medium supplemented with BAP+IAA (each at 2.0 mg/L) was optimal for induction of shoot buds; whereas, MS supplemented with 0.3 mg/L GA₃ was the most suitable for shoot elongation. Elongated shoots were rooted on half strength MS containing with 2.0 mg/L IBA. The rooted plantlets were successfully established in field. Page(s): 125-127

Initiation of embryogenic suspension culture and plant regeneration in onion (Allium cepa L.)

Mon, 01 Jan 2007 00:00:00 GMT

Title: Initiation of embryogenic suspension culture and plant regeneration in onion (Allium cepa L.) Authors: Tiwari, S; Tripathi, M K; Khare, U K; Rana, R Abstract: A rapidly growing and maintainable embryogenic suspension culture of Allium cepa L. was accomplished with two different approaches, either by culturing mature embryos directly or by transferring embryogenic callus cultures in liquid media. The cultures obtained were inundated with clumps of proliferating globular embryos with very little non-embryogenic tissues. The number and size of somatic embryo clumps was measured to quantify growth of embryogenic tissues under various conditions. The suspensions were subcultured every 15 d by replacing the old medium with an equal volume of fresh medium. Initiation and proliferation of such embryogenic suspension culture depended upon the genotypes, method of suspension culture initiation and various exogenous growth regulators supplemented to the culture medium at variable quantity. For the establishment of suspension cultures, the liquid MS media fortified with 4.0 mg L¹2,4-D in combination with 0.5 mg L^-1 BAP was found to be the most effective. For subsequent subculturing, the reduced level of 2.0 mg L^-12,4-D in combination with 0.5 mg L^-1 BAP promoted faster development of embryos. Frequent and efficient plantlet regeneration occurred on MS medium with 0.5 mg.L^-1each of NAA,BAP and kinetin. Regenerated plants were found to be phenotypically normal and true to the type. Page(s): 100-106

Molecular characterization of Begomovirus infecting sweet pepper in Oman

Mon, 01 Jan 2007 00:00:00 GMT

Title: Molecular characterization of Begomovirus infecting sweet pepper in Oman Authors: Khan, Akhtar J; Al-Saady, Nadiya A; Al-Mahruki, Madleen S; Al-Oufi, Muna; Al-Subhi, Ali M Abstract: Whitefly transmitted tomato yellow leaf curl is one of the most devastating viral disease of cultivated sweet pepper (Capsicum frutescens grossum) and other vegetables in Oman. Infected sweet pepper plants showed typical begomovirus symptoms as upward leaf curling, interveinal and leaf chlorosis, and growth stunting. Begomovirus infecting sweet pepper in Oman was detected by polymerase chain reaction (PCR) using begomovirus specific degenerate primers (PAL1v1978/PAR1c496 and AV494/AC1048). Core region (74-604 bp) of coat protein gene of the begomovirus was amplified by PCR with tomato yellow leaf curl virus (TYLCV) specific degenerate primers (TycpV369/TycpC1023). Core region of coat protein gene contains highly conserved regions and is used to identify the begomovirus infecting sweet peppers. Virus identification was performed by percent sequence identity and parsimony analysis using core coat protein gene sequences of sweet pepper virus with complete genome, core region of coat protein and coat protein gene sequences from reference begomoviruses. The core region sequence identity of coat protein gene of sweet pepper virus from Oman was 92.2, 96.5, 94.0, 93.8, and 96.5% with TomGV-Lebanon, TYLCV-Guadeloupe, TYLCV-Israel, TYLCV-Kuwait, and TYLCV-Mexico, respectively. Phylogenetic trees and percent sequence identity with reference to begomoviruses permitted the identification of sweet pepper virus as TYLCV based on tree position and extent of sequence identity. Phylogenetic analysis revealed that sweet pepper tomato yellow leaf curl virus clustered with its closest relatives from Middle East regions but formed a separate strain. Page(s): 45-51