Are floral characters efficient in the phenotypic differentiation of cassava landraces?

Abstract

Manihot esculenta Crantz assumes a prominent role in the world for being one of the most cultivated foods in the tropics. The aim of this study was to verify whether floral characters are efficient to detect phenotypic variability among cassava landraces cultivated in the northern region of Mato Grosso state, Brazil. For this, at six months after planting, the period of the first flowering, the phenotypic characterization of the female and male flowers of 20 cassava landraces was carried out, using the characters: color of the sepals, color of the disc, color of the ovary, color of the stigma and color of the anthers. The relative frequency of the phenotypic classes of each descriptor was analyzed. Qualitative data were subjected to genetic diversity analysis by the procedure for multicategorical data (multiple classes). The floral characters were efficient in the phenotypic differentiation of the cassava landraces. The color of the sepals, color of the disc and color of the ovary were the characters that contributed to the variation found, therefore, they are useful for preliminary evaluations of the species. The UPGMA method grouped the cassava landraces into four distinct groups, which showed the phenotypic variability and confirmed the efficiency of the floral characters in separating the landraces evaluated in different groups and subgroups. With the analyses carried out, it was possible to propose a new phenotypic class for the color of the sepals (greenish purple), going from three to four classes, which allowed a better distinction among the evaluated material.