Anuario 2018 de INTA Salta Estación Experimental Agropecuaria Salta

ABAN, CARLA LUCIANA; TABOADA, GISEL; SPEDALETTI, YAMILA; CASALDERREY NORMA B.; GALVÁN, MARTA Z.

Ediciones INTA

Año: 2018 p. 93

978-987-8333-70-0

White mould, caused by Sclerotinia sclerotiorum, is one of the most threatening fungal diseases occurring across major bean production regions worldwide. In Argentina, under favourable weatherconditions, up to 100% seed yield los- ses occur on susceptible common bean cultivars. The aim of this study was to characterize the diversity of S. sclero- tiorum isolates from six dry bean fields in the main production area of Argen- tina by means of molecular, morpho- logical (mycelium colour, number and pattern of sclerotia distribution) and pathogenic approaches. Among 116 isolates analyzed, high genotypic and morphological variability was observed. A total of 52 mycelial compatibility groups (MCGs) and 59 URPs (universal rice primers) molecular haplotypes were found. All the MCGs were location specific, while only 12% of the URP haplotypes were shared among locations. The mole- cular analysis of variance revealed a signi- ficant differentiation among populations, with higher genetic variability within the populations analyzed than among them. The aggressiveness of the isolates towards bean seedlings was assessed in the green- house. Most of the isolates were highly aggressive, while no variation among lo- cations was observed. The information generated in the present study provides, for the first time, information on the variability of S. sclerotiorum associated with white mould in the main common bean production area in Argentina. In addition, the findings suggest the occurrence of both clonal and sexual reproduction inthe populations analyzed. This work contributes to the development of sustainable management strategies in bean production aimed to minimize yield losses due to white mould.