Resistance of Musa balbisiana Accessions of the Philippines to Banana Bunchy Top Virus

Banana bunchy top disease (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 Musa balbisiana and 2 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 3 and 6 months postinoculation. 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 5 years, while all cv. Lakatan developed BBTD. Wild M. balbisiana accessions showed a high level of resistance and possibly immunity to BBTV and are expected to provide a resource for conventional and marker-assisted breeding.

Automated summary

Banana bunchy top disease (BBTD) caused by banana bunchy top virus (BBTV) is the most important virus affecting banana. No banana cultivar or accession has complete resistance to BBTD. In screening tests, wild Musa spp. accessions showed resistance against BBTV, with Musa balbisiana remaining symptomless and BBTV-negative while Musa acuminata and susceptible control plants developed the disease. The resistant M. balbisiana accessions can be valuable resources for conventional and marker-assisted breeding.