Mycotoxin contamination of the maize (Zea mays L.) grain is a worldwide threat to safety of both human food and animal feed. Hence, the development of maize genotypes with reduced mycotoxin accumulation in grain is an important topic. In order to find maize germplasm sources of resistance to fumonisin accumulation, 34 Italian and six public inbred lines were evaluated by means of artificial inoculation in field experiments during 2009 and 2010; in addition, the correlation between ear rot and fumonisin concentration in the ear was investigated. Primary ears were challenged with a mixture of two F. verticillioides isolates from Northern Italy, through kernel inoculation; controls were non-inoculated and sterile water-inoculated ears. The disease severity was estimated by counting the kernels with visible symptoms of infection at the inoculation site The percentage of internally contaminated kernels was also detected. The average number of visibly contaminated kernels per ear, after inoculation, ranged from 2 to 68 during 2009 and from 0 to 120 during 2010. Fumonisin concentrations in the inoculated ears were, significantly higher than in the controls, during both years. Variability was found among the inbred lines: fumonisin accumulation ranged from 0.56 to 240.83 mg kg-1 in 2009 and from 1.09 to 190.60 mg kg-1 in 2010. During both years, six inbred lines showed high fumonisin content (≥ 100 mg kg-1), while the other genotypes were almost equally partitioned in two groups, respectively: low (≤ 10 mg kg-1) and medium (from 11 to 100 mg kg-1). The number of contaminated kernels after artificial inoculation significantly correlated with fumonisin concentration both during 2009 (r = 0.94; P<0.01) and 2010 (r = 0.67; P<0.01). Additionally, the percentage of internally contaminated kernels correlated positively with FUM concentration (r = 0.37; P<0.01) and with the number of contaminated kernels (r = 0.29; P<0.05). This research clearly evinced that: i) the Italian germplasm is a valid source of genetic factors conferring resistance to fumonisin accumulation; ii) a strong association of visible symptoms of Fusarium ear rot with FUM concentration exists, suggesting that selection in maize for reduced visible moulds should reduce risk of mycotoxin contamination.
|Autori:||Balconi, C.;Berardo, N.;Locatelli, S.;Lanzanova, C.;Torri, A.;Redaelli, R.|
|Data di pubblicazione:||2014|
|Titolo:||Evaluation of ear rot (Fusarium verticillioides) resistance and fumonisin accumulation in Italian maize inbred lines|
|Appare nelle tipologie:||1.1 Articolo in rivista|