Field and laboratory experiments were carried out on the island of Oahu, HI, to compare the susceptibility of the two most commonly grown
banana (Musa sp.)
cultivars in the state ('Dwarf Brazilian' or Santa Catarina [locally known as dwarf apple] and 'Williams') to the aphid-borne
Banana bunchy top virus (genus Babuvirus, family
Nanoviridae, BBTV). Several morphological and physiological features of the two
cultivars were monitored to determine whether the
banana aphid, Pentalonia nigronervosa Coquerel (Hemiptera: Aphididae), transmits BBTV to both
cultivars at a similar rate; and whether after successful
inoculation, does each
cultivar respond similarly to
viral infection. Results from the laboratory experiment showed that a similar percentage of both
cultivars were infected with BBTV by
aphid vectors (> 90% for both
cultivars). However, field results showed a significantly lower percentage of dwarf apple (39%) infected with BBTV compared with Williams (79%). We also found that all physiological and morphological features measured (i.e., plant height,
leaf area, canopy,
chlorophyll level, and
moisture content) for both
cultivars were
impacted similarly by BBTV. The
incubation period, or the time between plant
infection and initial appearance of disease
symptoms, was similar for both
cultivars. Results also showed that BBTV transmission efficiency was lower in the field than in the laboratory, despite that more
aphids per plant were used for field than laboratory
inoculation tests. The results highlight the potential use of less
susceptible cultivars to help manage BBTV and the importance of screening
banana varieties in the field to determine their response to vectors and associated diseases.
