Molecular variability of plantain ecotypes from the genus Musa (Musaceae)

Abstract

IntroductionBanana (Musa L. species (Musaceae)) is considered as an important food-fruit crop and is cultivated commercially in more than 120 countries. India is a major banana producing nation with an area of 0.79 million hectares and productivity of 28.4 metric tonnes per hectare (NHB, 2011). A wide range of diploids, triploids (2n = 3x = 33), and tetraploid cultivars/landraces of banana are known that have evolved from interspecific hybrids of the 2 wild diploid species, Musa acuminate Colla (contributing ' A' genome) and Musa balbisiana Colla (contributing 'B' genome). Despite botanical homogeneity, plantains manifest wide and unique phenotypic variability regarding plant size, bunch type, bunch and fruit orientation, fruit apex shape, pseudostem, and fruit color. Nendran (Musa AAB group) is one of the leading banana cultivars belonging to the plantain subgroup and is one of the most prized plantain varieties of India. However, biodiversity in the Nendran cultivar is complex and is represented by clones distinguishable by variation in plant stature, bunch, fruit morphology, and degree of development of the male phase (Menon et al., 2002). Therefore, the present study was carried out with the objective to characterize variability in plantain ecotypes of banana using molecular markers. The development and application of molecular markers provide powerful tools to reveal polymorphism, are robust to detect genetic variability (Simmons et al., 2007), and are not influenced by environment or developmental stages of the plant, thus making them an ideal tool for genetic relationship studies. However, the potential usefulness of Abstract: Twelve plantain ecotypes were characterized for molecular variability using random amplified polymorphic DNA (RAPD) and inter simple sequence repeat (ISSR) markers. Out of the 60 RAPD and 40 ISSR primers tested, 16 RAPD and 14 ISSR primers were found polymorphic, and were used for molecular profiling of the plantain ecotypes. The average number of bands per primer, average number of polymorphic bands per primer, mean polymorphic information content (PIC) value, resolving power (Rp), and marker indices (MI) for RAPD primers were 8.63, 3.25, 0.87, 15.49, and 2.86, whereas the respective values for the ISSR assay were 7.93, 4.14, 0.85, 12.49, and 3.55. The genetic similarity coefficient was calculated using the Jaccard coefficient. The unweighted pair group method with arithmetic averages (UPGMA)-based clustering pattern remained more or less similar for RAPD, ISSR, and combined RAPD and ISSR data. Clustering was strongly supported by high bootstrap values. The genotypes Njockkon and Changalikodan (similarity coefficient > 0.94) and Manjeri Nendran (a) and Manjeri Nendran (b) (similarity coefficient > 0.89) were more closely related than the other ecotypes. The principal component analysis (PCA) showed results similar to those of the dendrogram. The results revealed that ISSR would be a better tool than RAPD for evaluation of genetic diversity in plantain ecotypes. Further, huge variab...

Comparison of two different electrophoretic methods in studying the genetic diversity among plantains (Musa spp.) using ISSR markers

“…This is in conformity with the findings of Choudhary et al. where the similarity co‐efficient ranged from 65 to 95%. In CGE analysis, the greatest similarity was observed between Nedu Nendran and Quintal Nendran (84.2%), but it was only 58% in CVGE method.…”

“…The values obtained from both analyses are much higher, confirming the genetic variability among the plantain ecotypes used in the present study than those reported by Choudhary et al. while using RAPD and ISSR markers to study the molecular variability of plantain ecotypes. The highest values for total gene diversity (0.34) and Shannon's information index (0.52) within the population were observed in CVGE analysis.…”

“…They exhibit complex biodiversity and subgrouped based on their variation in plant stature, bunch, fruit morphology and developmental degree of male phase (Supporting Information Table ). Among plantains, Nendran is one of the important varieties highly prized in India . Several elite Nendran clones have been developed but their identical morphology during vegetative stages jeopardize the correct identification, multiplication and supply of required planting material.…”

“…ISSR marker system‐based genetic studies have been carried out in banana and plantain ecotypes; however, these studies were performed only with CVGE parameters. We thus herein demonstrate the separation of PCR amplicons of ISSR markers in fully automated high‐resolution CGE (one of the types of several CE methods ) system.…”

Comparative analysis of hexaploid Avena species using REMAP and ISSR methods

“…This could be accomplished if an appropriate molecular marker system directed towards retrotransposon sequence is used for taxonomic purposes. Alternatively, a marker system directed towards the simple sequence repeats that used to be randomly distributed among chromosomes (Zietkiewicz et al, 1994) could be applied due to its usability for taxonomic purposes (Achrem et al, 2014;Choudhary et al, 2014.…”