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ARS Home » Pacific West Area » Riverside, California » National Clonal Germplasm Repository for Citrus » Research » Publications at this Location » Publication #316314
Title: Screening a core collection of citrus genetic resources for resistance to Fusarium solani (Mart) Sacc

Author
item Krueger, Robert
item BENDER, GARY - University Of California - Cooperative Extension Service

Submitted to: Acta Horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/31/2013
Publication Date: 2/1/2015
Publication URL: http://handle.nal.usda.gov/10113/60757
Citation: Krueger, R., Bender, G.S. 2015. Screening a core collection of citrus genetic resources for resistance to Fusarium solani (Mart) Sacc. Acta Horticulture Proceedings. 1065:155-163.

Interpretive Summary: A causal agent for Dry root rot (DRR) of citrus has not been definitively identified, but the organism most consistently associated with DRR is Fusarium solani (Mart.) Sacc. A core collection of the national germplasm collection of citrus genetic resources was screened for resistance to F solani. Inoculated and uninoculated seedlings of core collection accessions were evaluated for three parameters: recovery from girdling; amount of DRR; and percentage of healthy feeder roots. Thirty-three accessions showed no significant difference in recovery from girdling between inoculated and uninoculated seedlings and 11 of these accessions showed good recovery from girdling (> 2.7). Twenty-four accessions showed no significant difference in DRR between inoculated and uninoculated seedlings, and 12 of these accessions showed low development of DRR (< 1). Twenty-four accessions showed no significant difference in % healthy feeder roots between inoculated and uninoculated seedlings and 8 of these showed a high percentage (> 80 %) of healthy feeder roots. Five accessions were superior in all thee parameters: 'Fremont' mandarin (PI 539507), 'Lamas' lemon (PI 539226), 'Mato buntan' pummelo (PI 529398), 'Olivelands' sour orange (PI 539164), and 'South Coast Field Station' citron (PI 539435). These accessions would probably represent the best candidates for further study of F. solani resistance.

Technical Abstract: A causal agent for Dry root rot (DRR) of citrus has not been definitively identified, but the organism most consistently associated with DRR is Fusarium solani (Mart.) Sacc. To efficiently screen a citrus germplasm collection for resistance to F. solani, a core subset of the collection was evaluated. Seedlings of forty-five accessions were wounded by girdling. Treatment consisted of inoculation with F. solani, with uninoculated controls. Three parameters were evaluated: recovery from girdling (0 - 3); amount of DRR (0 - 4); and percentage of healthy feeder roots. Thirty-three accessions showed no significant difference in recovery from girdling between inoculated and uninoculated seedlings and 11 of these accessions showed good recovery from girdling (> 2.7). Twenty-four accessions showed no significant difference in DRR between inoculated and uninoculated seedlings, and 12 of these accessions showed low development of DRR (< 1). Twenty-four accessions showed no significant difference in % healthy feeder roots between inoculated and uninoculated seedlings and 8 of these showed a high percentage (> 80 %) of healthy feeder roots. Five accessions were superior in all thee parameters: 'Fremont' mandarin (PI 539507), 'Lamas' lemon (PI 539226), 'Mato buntan' pummelo (PI 529398), 'Olivelands' sour orange (PI 539164), and 'South Coast Field Station' citron (PI 539435). These accessions would probably represent the best candidates for further study of F. solani resistance.