Caracterização morfoagronômica e citogenética de capim buffel do banco ativo de germoplasma de Cenchrus

Abstract

The objective of this study was to characterize morfoagronomicamente buffel grass accesses the active germplasm bank (BAG) of Cenchrus of the Embrapa Semiárido checking the variability and efficiency of characters in carrier two consecutive cuts. We used 26 hits and 4 buffel grass cultivars in randomized blocks with three replications and with plot nine plants per access, taking as the central portion useful plant in the plot. The evaluations were performed after two cuts of the aerial part of Buffel grass, each evaluation was performed 90 days after each cut. The characterization of the accessions was based on 15 quantitative and qualitative morphological descriptors. Quantitative descriptors were submitted to analysis of individual and combined variance, considering the two cuts of treatment and then applied the Scott-Knott test at 5% probability. Qualitative descriptors were submitted to descriptive analysis. For divergence analyzes both quantitative and qualitative descriptors were grouped using the methods of Tocher and UPGMA from the Mahalanobis distance (D2). In addition, a dendrogram and calculated the relative importance of characters for the divergence. In the combined analysis, the effects of access and cutting were significant for almost all the features. This result indicates genetic heterogeneity among the accessions and the felling indicates mainly differences in management culture conditions and growth rate of each access in each mowing season. It was also observed significant effect of genotype x environment interaction at 1% probability for three descriptors (NPT, and LIN QIN) and other descriptors (APL, ECO, COF, LFO and CIN) these effects were not significant. The accessions were separated into two groups, the first consisting of 25 hits and 4 cultivars and the second composed of the access 138. The number of tillers / shoot, followed by number of inflorescence and color of the seeds were the most relevant characters in separation of access.