Assessing genetic diversity of Tecomella undulata (Sm) - an endangered tree species using amplified fragment length polymorphisms-based molecular markers

Tecomella undulata is an important agro-forestry tree in the western parts of India, which has been included in the list of endangered plant species due to over exploitation. There is an urgent need to formulate appropriate conservation and breeding strategies to save this versatile tree. Quantification of genetic diversity in the existing populations of T. undulata prevalent in India, is an essential first step towards this objective. The present work was undertaken to investigate the utility of amplified fragment length polymorphism (AFLP) markers in the assessment of genetic diversity and phenetic relationship among 42 T. undulata plants collected from different regions of India. Eight AFLP primer combinations generated a total of 338 bands across the 42 T. undulata accessions screened. On an average, 42 AFLP fragments were amplified per reaction. Of the total 338 AFLP fragments, 71.7% was polymorphic across all the accessions. From the AFLP data, a similarity matrix based on Jaccard's coefficient was calculated which was used for constructing a phenetic dendrogram using UPGMA analysis. T. undulata accessions represented high levels of genetic variation as indicated by GS values ranging from 0.721 to 0.83, at which 42 T. undulata accessions grouped together. The pattern of grouping in the phenogram was highly consistent as indicated by high values of cophenetic correlation (r = 0.87, P = 1) as also by high bootstrap values at the key nodes. Principal correspondence analysis also Cited By since 1996 This article has been cited 0 times in Scopus. Inform me when this document is cited in Scopus: E-mail Alert Find related documents In Scopus based on On the Web based on title Document Type: Article View references (31) references authors keywords authors keywords Page 1 of 5 Scopus - Current Science: Assessing genetic diversity of Tecomella undulata (Sm.) - An endangered... 02/04/2008 http://www.scopus.com/scopus/record/display.url?view=basic&eid=2-s2.0-3 revealed that T. undulata accessions were scattered on the plot. Based on our study, it may be concluded that there is a high level of genetic diversity in T. undulata accessions analysed, which may be attributed to its out-crossing nature. Our study may be useful in identifying diverse genetic stocks of T. undulata, which may then be conserved on priority basis. Author Keywords AFLP; Conservation; Genetic diversity; Molecular makers; Tecomella undulata References (31) view in table layout Select: Page 1. (1982) The Wealth of India, 10, pp. 134-136. Publications and Information Directorate, CSIR, New Delhi, Anon 2. Jindal, S.K., Kackar, N.L., Solanki, K.R. Evaluation of Tecomella undulata (Sm.) SEEM germplasm from western Rajasthan in situ (1985) Trans. Indian Soc. Desert Technol. Univ. Cent. Desert Stud, 10, pp. 33-37. 3. Jindal, S.K., Solanki, K.R., Kackar, N.L. Phenology and breeding systems of Rohida (Tecomella undulata (Sm.) SEEM) (1985) Indian J. For, 8, pp. 317-320. 4. Jindal, S.K., Kackar, N.L., Solanki, K.R. Germplasm collection and genetic variability in Rohida (Tecomella undulata (Sm.) Seem) in western Rajasthan (1987) Indian J. For, 10, pp. 52-55. 5. Rao, A., Kiran-Bala, V., Lahiri, A.N., Bala, K. Influence of trees on microorganisms of aridisol and its fertility (1989) Indian For, 115, pp. 680-683. 6. Azam, M.M. Anti-HIV agents and other compounds from Tecomella undulata (1999) Orient. J. Chem, 15, pp. 375-377. Cited 2 times. 7. Dushyent, G., Bohra, A. Toxic effects of various plant part extracts on the causal organism of typhoid fever (2000) Curr. Sci, 78, pp. 780-781. Cited 4 times. 8. Ahmad, F., Alam Khan, R., Rasheed, S. Preliminary screening of methanolic extracts of Celastrus paniculatus and Tecomella undulata for analgesic and antiinflammatory activities (1994) Journal of Ethnopharmacology, 42 (3), pp. 193-198. Cited 12 times. doi: 10.1016/0378-8741(94)90085-X 9. Jain, S.K., Rao, R.R. An assessment of threatened plants of India (1983) Botanical Survey of India, Howrah, p. 334. Page 2 of 5 Scopus - Cur

Characteristics of the nuclear (18S, 5.8S, 28S and 5S) and mitochondrial (12S and 16S) rRNA genes of Apis mellifera (Insecta: Hymenoptera): structure, organization, and retrotransposable elements

As an accompanying manuscript to the release of the honey bee genome, we report the entire sequence of the nuclear (18S, 5.8S, 28S and 5S) and mitochondrial (12S and 16S) ribosomal RNA (rRNA)-encoding gene sequences (rDNA) and related internally and externally transcribed spacer regions of Apis mellifera (Insecta: Hymenoptera: Apocrita). Additionally, we predict secondary structures for the mature rRNA molecules based on comparative sequence analyses with other arthropod taxa and reference to recently published crystal structures of the ribosome. In general, the structures of honey bee rRNAs are in agreement with previously predicted rRNA models from other arthropods in core regions of the rRNA, with little additional expansion in non-conserved regions. Our multiple sequence alignments are made available on several public databases and provide a preliminary establishment of a global structural model of all rRNAs from the insects. Additionally, we provide conserved stretches of sequences flanking the rDNA cistrons that comprise the externally transcribed spacer regions (ETS) and part of the intergenic spacer region (IGS), including several repetitive motifs. Finally, we report the occurrence of retrotransposition in the nuclear large subunit rDNA, as R2 elements are present in the usual insertion points found in other arthropods. Interestingly, functional R1 elements usually present in the genomes of insects were not detected in the honey bee rRNA genes. The reverse transcriptase products of the R2 elements are deduced from their putative open reading frames and structurally aligned with those from another hymenopteran insect, the jewel wasp Nasonia (Pteromalidae). Stretches of conserved amino acids shared between Apis and Nasonia are illustrated and serve as potential sites for primer design, as target amplicons within these R2 elements may serve as novel phylogenetic markers for Hymenoptera. Given the impending completion of the sequencing of the Nasonia genome, we expect our report eventually to shed light on the evolution of the hymenopteran genome within higher insects, particularly regarding the relative maintenance of conserved rDNA genes, related variable spacer regions and retrotransposable elements

Production of hybrids, amphiploids and backcross progenies between a cold-tolerant wild species, Erucastrum abyssinicum and crop brassicas

Three intergeneric hybrids were produced between a cold-tolerant wild species, Erucastrum abyssinicum and three cultivated species of Brassica, B. juncea, B. carinata and B. oleracea, through ovary culture. The hybrids were characterized by morphology, cytology and DNA analysis. Amphiploidy was induced in all the F1 hybrids through colchicine treatment. Stable amphiploids and backcross progenies were obtained from two of the crosses, E. abyssinicum × B. juncea and E. abyssinicum × B. carinata. The amphiploid, E. abyssinicum × B. juncea was successfully used as a bridge species to produce hybrids with B. napus, B. campestris and B. nigra. These hybrids and backcross progenies provide useful genetic variability for the improvement of crop brassicas

Characterization of species-specific repeated DNA sequences from B. nigra

The construction and characterization of two genome-specific recombinant DNA clones from B. nigra are described. Southern analysis showed that the two clones belong to a dispersed repeat family. They differ from each other in their length, distribution and sequence, though the average GC content is nearly the same (45%). These B genome-specific repeats have been used to analyse the phylogenetic relationships between cultivated and wild species of the family Brassicaceae