NOTE: This item is not available outside the Texas A&M University network. Texas A&M affiliated users who are off campus can access the item through NetID and password authentication or by using TAMU VPN. Non-affiliated individuals should request a copy through their local library's interlibrary loan service.
The effect of double-stranded (DS) RNA on Monosporascus cannonballus culture morphology and virulence
MetadataShow full item record
Attempts to eliminate double-stranded (ds) RNA elements in Monosporascus cannonballus by subculturing on PDA amended with various concentrations of cycloheximide (O to 15 pg/ml) and incubating at elevated temperatures were partially effective. Elevated incubation temperature (37'C), but not cycloheximide, resulted in a change of dsRNA banding profiles in one isolate (TX 93-449') of M. cannonballus. Some of the subcultures lost all dsRNA fragments, while others lost or gained specific fragments. The dsRNA-cured subcultures were used for comparison in their culture morphology and virulence on muskmelon (Cucumis melo) with a dsRNA-free, wild type M.cannonballus isolate. The dsRNA-cured subculture reverted to a dsRNA-free, wild type phenotype both in culture morphology and virulence. Typically, dsRNA' isolates exhibit a degenerated culture morphology, manifested as an uneven and retarded growth rate, reduced number of perithecia, and the development of a specific yellow to brown pigment. However, the dsRNA-cured subculture grew equally fast, produced a normal number of perithecia, and did not develop any pigment, which is similar to behavior of the dsRNA-free, wild type M cannonballus isolate. Also, pathogenicity tests conducted under greenhouse conditions revealed thatthe dsRNA-cured subcultures were equally virulent on muskmelon as the dsRNA-free, wild type isolate. In addition to the elimination of dsRNA from one isolate, dsRNA from a dsRNAcontaining isolate was transferred to a dsRNA-free, wild type isolate via hyphal anastomosis. Random amplified polymorphic DNA (RAPD) markers were developed for each strain and were used to confirm the transfer. The new dsRNA-containing isolates (TX 90-25 +44') resulted in the development of typical degenerated culture morphology and hypovirulence to muskmelon. The occurrence of two different mycelium interactions among isolates of M. cannonballus was observed. In a macroscopic study, one interaction was considered as vegetatively compatible and was characterized by lack of a distinctive mycelium interaction zone. The other reaction was considered as vegetatively incompatible and was characterized by the presence of a dense mycelium interaction zone. However, in the microscopic study, no difference was detected among the different interactions as anastomosis apparently occurred in both compatible and incompatible interactions.
DescriptionDue to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to email@example.com, referencing the URI of the item.
Includes bibliographical references: p. 88-94.
Issued also on microfiche from Lange Micrographics.
Park, Yunjung (1996). The effect of double-stranded (DS) RNA on Monosporascus cannonballus culture morphology and virulence. Master's thesis, Texas A&M University. Available electronically from
Request Open Access
This item and its contents are restricted. If this is your thesis or dissertation, you can make it open-access. This will allow all visitors to view the contents of the thesis.