Symptom expression and resistance of some banana cultivars to banana bunchy top virus infection

Abstract

Importance of the work: Bunchy top is a damaging disease of bananas. Considering the scarcity of resistant plants, it is vital to conduct screening for the resistant cultivars
Objectives: To determine symptom expression and screen some banana cultivars for resistance.
Materials and Methods: A survey was undertaken to collect some banana cultivars with different typical symptoms. An artificial inoculation method was applied to screen the resistant cultivars of some banana cultivars. Polymerase chain reaction was used to detect the banana bunchy top virus (BBTV), while ultraviolet-visible spectrometry was used to analyze the chlorophyll.
Results: Several different symptoms of banana bunchy top diseases (BBTD) were identified among the banana cultivars but the most prevalent ones were stunting, narrow leaves, upright growth, yellow leaves and a rosette. Some cultivars showed brittle and rigid leaves. Molecular detection showed similar characteristics of DNA R, with a nucleotide 1104 bp long in all infected plants. Chlorophyll b was more affected by BBTV than chlorophyll a, with a mean (± SD) chlorophyll content of 0.0050 ± 0.013 g/L. The screening test of some bananas indicated that cultivar Tanduk (AAB), Klutuk Wulung (BB) and wild banana M. acuminata subsp. halabanensis (AA) had higher resistance levels than the others, where the parentheses indicate the genome. All three of these bananas had the longest incubation period, 0–20% disease incidence, 0–6.67% disease severity and 0.00–0.006 susceptibility level.
Main findings: The symptoms of BBTV varied based on the cultivar. Cultivar Tanduk, Klutuk Wulung and the wild banana subspecies halabanensis were resistant to BBTV. This information might be useful in banana breeding programs, primarily in the development of new, resistant cultivars.