Author

Qiang Q. Guo

Date of Graduation

Spring 2013

Degree

Master of Science in Plant Science (Agriculture)

Department

College of Agriculture

Committee Chair

Wenping Qiu

Keywords

badnavirus, grapevine, phylogenetic analysis, host specificity, tissue specificity

Subject Categories

Plant Sciences

Abstract

Grapevine vein clearing virus (GVCV) is a new badnavirus in the family Caulimoviridae that is closely associated with an emerging vine decline and vein-clearing disease in the Midwest region of the United States. Three open reading frames (ORFs) are predicted to be encoded by its genome of 7753 bp. In this study, two genomic regions, Reverse Transcriptase (RT) region of 570 bp and Zinc Finger (ZF) region of 540 bp, were selected for analyzing the genetic diversity of GVCV populations. A total of 39 recombinant plasmids of three individual clones from each of the 13 isolates were sequenced. The sequence variants of GVCV cannot be phylogenetically grouped into clades according to geographical locations and grape varieties. The qPCR assays indicated that GVCV accumulates abundantly in the phloem and least in the root tip tissues. Upon grafting of GVCV-infected buds onto four major grape cultivars, GVCV was not detected in the grafted Chambourcin vine, but present in the grafted Vidal Blanc, Cayuga White, and Traminette vines, suggesting that Chambourcin is resistant to GVCV. The results provide a genetic snapshot of GVCV populations, which will yield knowledge important for monitoring GVCV epidemics and for preventing the damage to grape production caused by GVCV. In addition, the extraction of high-yield of clean DNA from Norton by a CTAB-based method can be used for Illumina sequencing, which will benefit the breeding of new grape varieties with good qualities of Norton.

Copyright

© Qiang Q. Guo

Campus Only

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