Coleta de germoplasma e validação de descritores morfológicos em plantas jovens jambu (Acmella spp.).

Abstract

The Knowledge of diversity through morphological descriptors is a tool of great importance for the conservation of genetic resources. Despite widespread use, research on morphological descriptors and genetic variability in jambu Acmella spp., especially in the young plant phase, is non-existent. In this context, the present work aimed to characterize the production areas where local varieties were collected in the municipalities of the metropolitan area of Belém and the northeastern Pará. As well as to propose and validate morphological descriptors for the young plant phase that can be used in genetic variability in jambu. At the time of collection, a questionnaire was administered to identify the main cultural practices adopted in the cultivation areas. For descriptor analysis, an experiment was conducted at the Igarapé-Açu Farm School (FEIGA), in a protected environment. The design used was randomized blocks with three replicates and 19 treatments, with the local jambu varieties collected from different locations in the state of Pará considered as treatments (Jamb-01 to Jamb-19). Quantitative and qualitative descriptors were tested.all in the young plant phase. The data were analyzed through cluster analysis principal component analysis (PCA). It was observed that the variables such as the number of leaves and stem pigmentation showed the greatest contribution, demonstrating the morphological differentiation and variation found in jambu varieties. Regarding stem pigmentation, variety Jamb-17, collected in the municipality of Bragança, differed from the others, presenting green pigmentation. For the leaf descriptor and margin pigmentation variety Jamb- 16 demonstrated an ovate shape and margin pigmentation present. In conclusion, it is possible to identify those morphological descriptors with a greater ability to distinguish among local varieties in the young plant phase. The statistical tool indicated that the groping method UPGMA clustering method, highlighted the existence of three groups demonstrating greater discriminatory power for this method PCA was efficient in validating the morphological descriptors among the native material of Acmella app., with greater discriminative power being useful for a better understanding of the genetic diversity of the collected local varieties. The descriptors that contributed the most to the differentiation among native materials were the number of leaves, stem pigmentation, and leaf shape.