Differential response to Penicillium allii infections among argentine garlic cultivars

SALINAS PALMIERI, M. C.; FERNANDEZ, A.; MORALES, A.; GALMARINI, C. R.; CAVAGNARO, P. F.

Simposio; 7th International Symposium on Edible Alliaceae; 2015

Worldwide, one of the main economic losses  in garlic (Allium Sativum L.) production is blue mold disease, caused by Penicillium allii.  Previously, partial resistance against P. allii was reported in Argentinegarlics, as evaluated in inoculated actively growing plants. However, a largeproportion of the garlic infections with P.allii are produced during the conservation and packaging of garlics, wherebulbs are dormant. In this study, we evaluated P. allii infections in dormant cloves of 11 Argentine garliccultivars, monitoring the fungal growth in terms of ?colony area? (CA) and ?sporeproduction? (SP). To this end, garlic cloves were peeled, surface sterilized andinoculated with 3*105 spores, and incubated for 12 days at 25 ° C indarkness. Significant variation in colony area (P=0.002) and number of conidiaper clove (P=0.0014) was found, and both variables were significantlycorrelated (r=0.77). The most tolerant cultivars, i.e., those showing weakestinfections  were Morado INTA, Perla INTAand Castaño INTA, whereas  Fuego INTA andGran Fuego INTA were most susceptible. These results are in general agreementwith our previous results in metabolically active plants indicating Morado andFuego as the tolerant and susceptible extremes, respectively. Ongoing analysesof thiosulfinates and polyphenols content in these garlic bulbs (thesecompounds were previously reported as antimicrobial agents) may shed lightregarding possible associations between these compounds and resistance.