Impact of Seed Transmission on the Infection and Development of Pitch Canker Disease in Pinus radiata

Forests

Margarita Evira-Recuenco¹  Eugenia Iturritxa²  Rosa Raposo¹  Jan Stenlid³  Jonas Oliva³ 

[1] Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Centro de Investigación Forestal (INIA-CIFOR), Madrid 28040, Spain; E-Mail:;NEIKER, Granja Modelo de Arkaute. Apdo 46. Vitoria-Gasteiz 01080, Spain; E-Mail:;Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Centro de Investigación Forestal (INIA-CIFOR), Madrid 28040, Spain; E-Mail

关键词: Fusarium circinatum;    nursery;    seed infection incidence;    seed contamination;    seed transmission rate;    persistence;    infection rate;    damping-off;   

DOI  :  10.3390/f6093353

来源: mdpi

【 摘 要 】

The aim of this study was to determine the impact of seed inoculum on subsequent disease development in nurseries, specifically studying incidence of seed infection, transmission rate of seed to seedlings, and rate of disease development from the primary inoculum source. Transmission rate of Fusarium circinatum (F. circinatum) from symptomatic trees of Pinus radiata (P. radiata) to seed was 0.73%, being the fungus mainly on the coat. Seed infection incidence was positively correlated with tree disease severity. Seeds also become contaminated with F. circinatum during storage, where high relative humidity had a great effect regardless of temperature. Transmission rates from seeds to symptomatic seedlings measured at 48 days after seed inoculation with 10⁴ and 10⁶ was 28% and 80%, respectively. Seedlings showed symptoms of wilting and dieback, and eventually died within the total duration of this study (475 days). By this time, there were two remaining symptomless seedlings (1% of the total). F. circinatum was recovered from each of them, demonstrating its persistence in seedlings. Fungus populations in roots were estimated between 10⁵ and 10⁷ cfu/g in symptomatic plants for both inoculum doses and up to 10⁴ cfu/g in asymptomatic plants. Disease infection rate was similar in post-emergence damping-off (up two months growing) and for established seedlings (up to eight months) after seeds were inoculated with 10⁴ spores/mL.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.