Characterization of species of Lasiodiplodia associated with grapevines in Mexico

RANGEL-MONTOYA EDELWEISS; PAOLINELLI MARCOS; HERNÁNDEZ-MARTÍNEZ RUFINA

Penticton

Workshop; 11TH INTERNATIONAL WORKSHOP ON GRAPEVINE TRUNK DISEASES; 2019

Botryosphaeria dieback is one of the most aggressive diseases of grapevine caused by fungi from the Botryosphaeriaceae family. The fungi invade the vascular system mainly through pruning wounds, which can lead to perennial cankers, necrotic lesions, general decline and death of vines. Among these fungi, members of the genus Lasiodiplodia, have been reported as the most virulent. In recent years, the taxonomy of this genus has revised. As a result, eighteen new species have been described worldwide. This study aimed to define the Lasiodiplodia species associated with grapevine in Mexico. Samples of wood with cankers were obtained from ten vineyards established on the states of Sonora, and Baja California and isolations were intended in PDA medium. From colonies showing smoke-gray abundant aerial mycelia, twenty-two isolates with hyaline and pigmented longitudinally striate, dark brown conidia were selected. The phylogenetic analysis of the molecular markers, EF1-α and ITS revealed the presence of six Lasiodiplodia species. Eight isolares from of L. exigua, eight of L. theobromae; two of L. gilanensis, two of L. crassispora, and one isolate for each species of L. parva and L. brasiliensis. Furthermore, in the pathogenicity assay, 2-months post inoculation, the isolates of L. parva VSM16a and L. gilanensis MXCS01 were the most virulent, both developing lesions up to 7 cm in length; while isolates of L. crassispora Vid5 and VSM1b, as well L. theobromae VSM6a caused lesion below 3 cm. Except for L. theobromae, all the identified species are new reports for Mexico.