Morphological and Molecular Characterizations of Musa (ABB) ‘Mali-Ong’ in Thailand

SIMPLE SUMMARY: The banana cultivar Musa (ABB) ‘Mali-Ong’ is widely used in the processed food industry in Thailand, where it determines the quality of the products. However, the sub-cultivars of ‘Nam Wa Mali-Ong’ are almost indistinguishable, with few morphological differences and minimal genetic variation. This study used 77 morphological characteristics and two types of molecular markers to distinguish Nam Wa Mali-Ong from other cultivars. The study also assessed the genetic variation of nine ‘Nam Wa Mali-Ong’ clones and compared them with 10 other samples of bananas with different genomes or chromosome sets. The molecular markers grouped the ‘Nam Wa Mali-Ong’ samples. Four clones (A, B, D, and I) were superior and had higher bunch weights. This study will be useful for germplasm evaluation and future ‘Nam Wa Mali-Ong’ improvements. ABSTRACT: Musa (ABB) ‘Mali-Ong’ is an economically important banana cultivar in Thailand. We morphologically and molecularly characterized ‘Nam Wa Mali-Ong’. Leaf blade width was the only statistically different morphological character among the clones. To determine genetic variation, nine ‘Nam Wa Mali-Ong’ clones were compared with 10 samples of Musa ABB, AA, and BB cultivars by fingerprinting using seven pairs of sequence-related amplified polymorphism (SRAP) and eight inter simple sequence repeat (ISSR) markers. The SRAP and ISSR primers generated 65 and 76 amplicons, respectively, of which 57 (87.7%) and 62 (81.6%) amplicons, respectively, were polymorphic; the polymorphic information content was 0.28–0.49. The SRAP data revealed two distinct groups: Group I, comprising two subgroups (one including all ABB samples and the other containing the BB genome accessions), and Group II, comprising the AA genome accessions. The ISSR data revealed two groups: Group I, which incorporated the AA (Hom Champa) genome, and Group II, consisting of two subgroups: Subgroup A, comprising only the AA (Hom Chan) accessions, and subgroup B, comprising all the ABB accessions and wild banana M. balbisiana (BB genome). The ‘Nam Wa Mali-Ong’ samples clustered together, regardless of the markers used. SRAP and ISSR markers will be useful for germplasm evaluation and future Musa (ABB) improvements.