Desempenho agroindustrial, adaptabilidade, estabilidade e divergência genética entre clones RB de cana-de-açúcar em Pernambuco

Abstract

Brazil is the world's largest producer of sugarcane (Saccharum spp.), whose culture interacts with the most varied environments. The replacement of varieties has contributed greatly to an effective increase in productivity. Thus it studies of genotype x environment (G x E) interaction, the analysis of phenotypic adaptability and stability, and the selection of parents for hybridization are essential for the indication of varieties suited to different soil and climatic conditions. The objective of this research was to evaluate the agribusiness behavior, adaptability and phenotypic stability of 11 RB sugarcane clones in the final phase of the trial, in sugarcane micro regions in the State of Pernambuco, Brazil Northeast, for three consecutives harvests, as well as assisting the selection of potential parents to be used in future crossings by conducted by Sugarcane Breeding Program (PMGCA) of Network for the Development of Alcohol and Sugar (RIDESA) of Experimental Station Sugarcane Carpina (EECAC) of Federal Rural University of Pernambuco (UFRPE). The experiments were carried out in five Pernambuco sugar mills, in the months of july and august 2006, using the experimental design of randomized blocks with four replications and plots with five eight-meter furrows and spacing of 1.0 m. The results were subjected to analysis of variance, comparison of averages by Scott & Knott test and studies of adaptability, stability and genetic divergence. In each section the variables were measured as ton of pol per hectare (TPH), ton of cane per hectare (TCH); fibre (FIB), Pol% corrected (PCC), purity (PZA), soluble solids (BRIX) and total recoverable sugar (TRS). Based on the results, the best RB genotypes of sugarcane were G1, G6 and G9 in environment I, G1 and G11 in environment II, G1 and G9 in environment III, G3 for environment IV and G1 the environment V. Among the best clones, those with wide adaptability are: G1 and G11, and those with adaptability to environments are: G6 and G9. The genotypes most indicated for use in hybridizations are G1 and G6, as they showed the greatest genetic dissimilarity.