Resistance of Musa balbisiana accessions of the Philippines to banana bunchy top virus

Mitigation of banana bunchy top disease (BBTD) is still a challenge worldwide. BBTD is caused by banana bunchy top virus (BBTV), the most important virus affecting banana. Currently, no cultivar or accession of banana has complete resistance to BBTD. A total of 36 wild Musa spp. accessions, including 34 Musabalbisiana and two M . acuminata subsp. errans (‘Agutay’), were screened for resistance against BBTV. In greenhouse tests using viruliferous banana aphids (Pentalonia nigronervosa ), all M. balbisiana accessions remained symptomless and BBTV was not detected in any of these plants by PCR at three- and six-months post inoculation. In contrast, 100% disease incidence was recorded in M. acuminata subsp. errans and in cv. Lakatan susceptible control plants. The PCR-negative M . balbisiana plants were then transferred to a field with high BBTV inoculum pressure where they remained symptomless and PCR-negative for up to five years, while all cv. Lakatan developed BBTD. This study confirmed the resistance of wild M . balbisiana accessions to BBTV. It is therefore expected to provide a resource for conventional and marker assisted breeding.