EFS12- Book of abstracts - Contact
EFS12- Book of abstracts - Contact
EFS12- Book of abstracts - Contact
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SESSION 4: GENETICS OF HOSTS – PLANT RESISTANCE TO FUSARIUM,<br />
VARIETY DEVELOPMENT<br />
P86 - Selection <strong>of</strong> aggressive Fusarium isolates for<br />
breeding<br />
M. Ittu 1 , I. Ciocazanu 2<br />
1 National Agricultural Research Development Institute (NARDI) Fundulea, 1 N. Titulescu street,<br />
915200 Romania; 2 Pioneer Hi-Breed Seed Agro SRL, com. Ganeasa, sat Sindrilita DN 2, km 19,7, jud.<br />
Ilfov, 077010, Romania<br />
E-mail: ittum@ricic.ro<br />
Fusarium species from Gibberella fujikuroi complex (F.verticillioides,<br />
F.proliferatum and/or F. subglutinans) are important fungal pathogens that cause<br />
pink ear rot (PER), a disease <strong>of</strong> maize with devastating impact on yield losses<br />
and food safety. Use <strong>of</strong> reliable Fusarium isolates for assessment <strong>of</strong> host<br />
resistance and understanding <strong>of</strong> relation between phenotypic scoring and<br />
Fumonisin (FUM) accumulation are crucial for developing strategies to minimize<br />
the associated risks to disease.<br />
The objectives <strong>of</strong> this study were to evaluate: i) selection <strong>of</strong> aggressive isolates<br />
for large scale inoculums production in several Fusarium populations, sampled<br />
from South Romania and ii) relation between disease scores and FUM content<br />
under artificial field inoculation.<br />
New pathogenic isolates are obtained each two years, by specific procedures.<br />
Aggressiveness <strong>of</strong> the new isolates was evaluated under artificial inoculation in<br />
seedling stage, data being expressed as reduction <strong>of</strong> coleoptyle length in<br />
inoculated seedlings vs. noninoculated ones (as % <strong>of</strong> control). Isolates causing<br />
greatest reduction in coleoptiles growth were considered as most aggressive and<br />
were selected for large scale production <strong>of</strong> inoculum for breeding purposes.<br />
Multienvironment assessment <strong>of</strong> resistance under artificial field inoculations<br />
performed with highly aggressive F. verticillioides isolates, obtained in this way,<br />
revealed a very close negative correlation between pink ear rot rating (1=very<br />
sensitive, 9=very resistant) and FUM content (ppm) across years, according to<br />
correlation index that ranged from r=-0.729, N=61 (2008) to r=-0,815, N=15<br />
(2010).<br />
Based on these findings it could be assumed that selection for reduced symptoms<br />
(pink ear rot score) should fairly allow identification <strong>of</strong> genotypes with reduced<br />
FUM content.<br />
Keywords: aggressiveness, Fumonisin (FUM), resistance, maize<br />
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