Graduate Thesis Or Dissertation
 

Presence and pathogenicity of Fusarium and Verticillium species in commercial red radish (Raphanus sativus) seed production in the Willamette Valley of Oregon

Pubblico Deposited

Contenuto scaricabile

Scarica il pdf
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/736667834

Descriptions

Attribute NameValues
Creator
Abstract
  • Commercial radish seed producers in the Willamette Valley of Oregon have observed a late season wilt in their seed fields. Twenty-two fields were surveyed for wilt in the Willamette Valley during June through August 2012 and 2013. Plants exhibiting wilt symptoms were collected from the fields and examined for vascular discoloration in the storage root; isolations were made when discolored vascular tissue was found. In 2012, Fusarium species were recovered from 11% of the 440 plants examined, while V. dahliae (=V. longisporium) was recovered from 0.2% of the 440 plants. In 2013, Fusarium and Verticillium species were recovered from 24% and 0.7% of plants, respectively. Greenhouse studies conducted in 2013 with 11 isolates of F. oxysporum, as well as one V. dahliae, and one F. solani, obtained from discolored storage roots in 2012, showed that all isolates evaluated have a degree of pathogenicity on red radish seedlings. This study confirms the presence of pathogenic V. dahliae and F. oxysporum in commercial radish seed fields in the Willamette Valley of Oregon. This is the first report of F. solani causing wilt symptoms on radish. Some Fusarium and Verticillium species, including the species responsible for radish wilt in the Willamette Valley, have been found to seed-borne. Fusarium species were recovered from 0.352% of inbred stock seed treated with a 30 second dip in a 10% household bleach solution [0.006% NaClO] and 2.000% of nontreated stock seed while, no V. dahliae was recovered from stock seed surveyed when seeds were embedded in streptomycin amended Nash-Snyder and water agar mediums. Fusarium proliferatum and F. oxysporum accounted for 59% and 29% of the Fusarium species recovered from seed. Four strains of F. proliferatum and 3 F. oxysporum were evaluated in greenhouse studies during 2013 and all strains tested caused disease on red radish seedlings. To more closely examine the link between wilting seed parent plants and the hybrid daughter seed they produce we surveyed the daughter seed of 35 randomly selected, commercially-grown radish seed parent plants with wilt in addition to the daughter seed of plants where Fusarium or Verticillium species were recovered from vascular discolorations in the storage root. Fusarium oxysporum was recovered from 12% of seed surveyed, while F. culmorum and F. sambucinum were recovered from 0.6% and 0.9%, respectively, of daughter seed surveyed. Forty-two percent of F. oxysporum strains recovered from daughter seed came from parent plants from which F. oxysporum was recovered from discolored vascular tissue. This study confirms that F. oxysporum can be associated with red radish seed and can be vertically transmitted. This is the first report of F. proliferatum as a pathogen on red radish and can be associated with seed.
License
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Committee Member
Academic Affiliation
Non-Academic Affiliation
Subject
Dichiarazione dei diritti
Publisher
Peer Reviewed
Language
Replaces

Le relazioni

Parents:

This work has no parents.

In Collection:

Elementi

Thumbnail Titolo Data caricata Visibilità Azioni
file details BombergerRachelA2014.pdf 2017-08-17 Pubblico Scaricare