Stability of Slash Pine Families with Major Gene and Partial Resistance to Single-Gall and Mixed-Gall Inocula of Cronartium quercuum fusiforme in Greenhouse Studies

Forests

Karina P. Gramacho²  Robert A. Schmidt¹ 

[1] School of Forest Resources and Conservation, Institute of Food and Agricultural Sciences, University of Florida, P.O. Box 110410, Gainesville, FL 32611-0410, USA; E-Mail:;Plant Pathology Department, Cocoa Research Center, Executive Commission of the Plan for Cocoa Farming, Ex. PO 07, 45600-970, Itabuna, BA, Brazil; E-Mail:

关键词: Pinus elliottii var. elliottii;    fusiform rust;    pathogen virulence;   

DOI  :  10.3390/f4020488

来源: mdpi

【 摘 要 】

Single-gall and mixed-gall inocula from fusiform rust (Cronartium quercuum fusiforme) galls in field studies were used in greenhouse tests to investigate their pathogenic variability and the temporal and spatial stability of fusiform rust incidence of resistant slash pine (Pinus elliottii var. elliottii) seedlings. Analyses of variance showed significant main effects for families and inocula and for the interactions of families and inocula indicating abundant pathogenic variation and differential family resistance. Averaged over all families and inocula, there were no significant differences between sequential inocula, i.e., inocula from successive generations of the pathogen. However, when analyzed separately Family R1 with segregated major gene resistance showed increased rust incidence with successive generations of the pathogen. Also Family R1 accounted for a major portion of the temporal (51.4%) and spatial (49.6%) interaction sum of squares. In contrast the other resistant families each accounted for a minor portion of this statistic. These results indicate pathogen virulence toward major gene resistance, possible selection for virulence and the relative instability of Family R1 compared with other resistance families.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland.