Avaliação morfoagronômica e bromatológica dos acessos da coleção do cará (Dioscorea trifida L.) da Universidade Federal do Amazonas

Abstract

The yam (Dioscorea trifida L.) is a rustic plant native to the Amazon, which produces an edible tuber rich in carbohydrates, essential in the diet of several riverside and Indigenous communities. In Amazonas, the most cultivated genotypes come from the selection process conducted informally by farmers. However, the lack of knowledge about the production system, proper management, and access to productive and quality varieties, limits the productivity and expansion of the yam culture. In this context, the present study aimed to evaluate and characterize from a morphoagronomic and bromatological point of view the yam plants from the collection of the Federal University of Amazonas. For this, an experimental plantation with fifty-seven accessions was installed, adopting a completely randomized block design. The experimental plots consisted of three plants from each of the fifty-seven accessions (except one, with only two plants) in 3 blocks, totaling 510 plants. For the morphoagronomic and genetic diversity characterization, we adopted the set of specific descriptors for the genus Dioscorea, developed by the International Plant Genetic Resources Institute (IPGRI). Additionally, the accessions underwent bromatological evaluation, by means of the analysis of the weighing, grinding, drying, and burning processes, the moisture content, crude protein, total lipids, ash, nifext fraction and total energy value. The results obtained for the analyzed parameters (morphoagronomic and bromatological) were then submitted to analysis of variance (ANOVA) with the aid of the GENES software and their means were compared with each other using the Scott Knott test at p<0.05. A high percentage of emergence (98%) was obtained, with greater failures being observed for D. trifida accessions containing the long white variety as one of the parents. Significant statistical differences were also identified for the following variables: stem diameter, internode length, leaf width, leaf length and petiole length. And yet, by the Tocher method, the formation of four distinct groups was detected, with a certain degree of genetic diversity. As for the bromatological analysis, the performance of the accessions was variable, with differences at the level of p< 0.05 being identified for all parameters evaluated. The results obtained here demonstrate that the germplasm collections are fundamental for the maintenance of the genetic diversity of the yam. And that the evaluation from the morphoagronomic point of view when associated with other techniques, such as bromatology, can provide advantageous information for the selection of genotypes with characteristics of interest.