Diversidade genética e seleção de genótipos de mandioca por meio de caracterização morfoagronômica e molecular em Angola

Abstract

Manihot (Manihot esculenta Crantz) is considered the most Brazilian of the cultures, being native to Brazil and cultivated in all tropical countries. Its exploitation is basically made by small producers in marginal areas of agriculture because of their rusticity and the ability to produce relatively well under conditions where other species would not even survive. The objective of this work was to evaluate the population structure, genetic diversity and selection of cassava genotypes of Angola by means of agronomic characteristics and molecular markers. The field experiment was conducted in the agricultural years of 2015-2016 and 2017-2018 in Malanje, Angola, with forty cassava genotypes in the randomized block design with 4 replicates and each plot consisted of five lines of 10 plants with one spacing of 0.90 x 0.90 m. The data were submitted to analysis of individual and joint variance, when significant, the means were grouped by the Scott-Knott test. Character entropy levels, population structure, Pearson correlation coefficients, pooled analysis of quantitative, qualitative variables, Mulamba and Mock index for selection and indices were determined to determine the most informative ISSR primers such as polymorphic information content, marker index and resolution power. The morphoagronomic characterization of the evaluated genotypes indicates the existence of promising materials that can be used in the diversification of cassava planting in Angola. The most promising cassava varieties are Tio Jojo, Ngana Yuculu and Kimbanda. The molecular characterization revealed that there is genetic diversity within each studied population. The indices used to determine the most informative primers allowed the discrimination of different primers, which could be used in future studies of cassava populations. There was genetic structuring among the populations studied. There is genetic variability from the morphoagronomic characteristics of the varieties of cassava evaluated.