Systemic movement of <i>Pseudomonas syringae</i> pv <i>actinidiae</i> in kiwifruit vines in New Zealand

Abstract

Systemic movement of Pseudomonas syringae pv actinidiae (Psa) was investigated in inoculated potted kiwifruit vines in a greenhouse and in naturally infected mature vines in the orchard In the potted vine experiment trunks of 2yearold Actinidia chinensis Hort16A on the rootstock A deliciosa Bruno were woundinoculated with Psa After 151 days Psa was detected up to 95 cm from the point of inoculation Psa moved upwards and downwards within the trunks and through the scion and the rootstock at similar rates In the orchard experiments samples were taken from mature kiwifruit vines at intervals along the vines during autumn winter and spring Psa moved systemically throughout mature Hort16A and A deliciosa Hayward kiwifruit vines and was detected in symptomless tissues In both greenhouse and field situations Psa was not inhibited by the graft union and was able to move into the rootstock and down to the base of the vine