Genetic diversity and dispersion pattern based on morphological traits among selected farmer-bred pigmented and glutinous maize varieties

Domestic cultivation of glutinous and pigmented maize is utilized as an alternative food source. Agro-morphometric data of 100 pigmented and 162 glutinous farmer-bred maize varieties were evaluated to assess their genetic differences across regions to identify germplasm accessions for developing populations and hybrids. Euclidean similarity test and average link clustering method (UPGMA) were used to make dendrogram from the morphological data. The average taxonomic distance matrix ranged from 0.81 to 13.23 and 0.9 to 17.81 for pigmented and glutinous varieties, respectively. Based on general ear appearance, Euclidean distance data showed highest dissimilarity between CLRD7(CAR) and CLRD82(Region6) accessions, and GLUT43(Region6) and GLUT158(Region2) accessions for pigmented and glutinous varieties, respectively. For general agronomic and phonological appearance, Euclidean distance showed highest dissimilarity between CLRD35(Region6) and CLRD83(Region7) accessions, while GLUT5(Region2) and GLUT121(Region6) for pigmented and glutinous accessions, respectively. For the overall phenotype, Euclidean distance data showed highest dissimilarity between CLRD29(Region6) and CLRD85(Region7), and GLUT43(Region6) and GLUT156(Region2) accessions for pigmented and glutinous accessions, respectively. Crosses between the highly dissimilar accessions are more likely to produce desirable segregants. For instance, principal component analysis revealed dispersion pattern for pigmented accessions between group 1a ((CLRD7(Car), CLRD86(Region13)) by group 2a ((CLRD29(Region6), CLRD30(Region6), CLRD61(Region6), CLRD94(Region2)). For the glutinous accessions, dispersion pattern were observed between GLUT8(CAR) and GLUT124(Region1); GLUT124(Region1) by any of the GLUT158(Region 2) and GLUT139(Region10) aggregate; and among GLUT32(Region4.1) by the aggregate of GLUT4(Region2) and GLUT29(Region4.1). This study suggested that assessment of maize genetic diversity through morphological characters yields baseline information for germplasm resource conservation and utilization for future breeding programs.