Author
SUAREZ, ISIDRO - UNIV. OF FLA. TREC | |
Schnell Ii, Raymond | |
KUHN, DAVID - FLORIDA INTERNATIONAL UNV | |
LITZ, RICHARD - UNIV. OF FLA. TREC |
Submitted to: Plant Cell Tissue and Organ Culture
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 5/6/2005 Publication Date: 1/2/2006 Citation: Suarez, I.E., Schnell Ii, R.J., Kuhn, D.N., Litz, R.E. Recovery and indexing of avocado plants (persea americana mill.) from embryogenic nucellar cultures of an avocado sunblotch viroid-infected tree. Plant Cell Tissue And Organ Culture 84:27-37 2006. Interpretive Summary: Genetic variants of ASBVd have been reported from a single tree and are known to produce different symptoms of the disease on different avocado plants. This research reports on finding variants that have arisen during the tissue culture procedure and these have changes similar to those found in mature trees. New variants were found that had not been described before. These findings are useful for researchers wishing to study the evolution of these viroids as they can now be maintained and manipulated in the lab. Technical Abstract: Avocado (Persea americana Mill.) plants were recovered from somatic embryos derived from the nucellus of an avocado sunblotch viroid (ASBVd)-infected tree ('Vero Beach' SE2). Somatic embryos germinated on semi solid MS (Murashige and Skoog) medium supplemented with 4.44 'M BA and 2.89 'M GA3 and (in mgl-1) thiamine HCl (0.4), myo-inositol (100) and sucrose (30,000). Plants were maintained on semi solid MS medium supplemented with (in mgl-1) thiamine HCl (0.4), sucrose (30,000) and myo-inositol (100). Leaf tissue from nucellar plants and floral tissues from field-grown 'Vero Beach' SE2 were demonstrated to be ASBVd-infected after indexing using RT-PCR. There were 43 ASBVd variants isolated from 90 sequenced clones. Most of the nucleotide variations occurred in the right and left terminal region of the ASBVd molecule. Twenty five ASBVd sequences not previously reported were found within the cloned population. Newly sequenced variants were unique to the individual plant tissue from which they were isolated. |