PHENOTYPICAL VARIATION OF AGRONOMIC TRAITS IN SOYBEAN GENOTYPES

Abstract

SOYBEAN BELONGS TO THE FABACEAE FAMILY, WHICH CORRESPONDS TO ONE OF THE LARGEST FAMILIES OF ANGIOSPERMS. THE CULTIVATION OF THIS OILSEED ON A COMMERCIAL SCALE BEGAN ON THE ASIAN CONTINENT MORE THAN A THOUSAND YEARS AGO. IN BRAZIL IT WAS INTRODUCED IN 1882, BUT ONLY IN 1935 IT WAS COMMERCIALLY GROWN IN RIO GRANDE DO SUL. CURRENTLY BRAZIL IS THE SECOND LARGEST PRODUCER AND THE WORLD'S LEADING SOY EXPORTER. THE OBJECTIVE OF THIS WORK WAS TO ESTIMATE THE PHENOTYPIC VARIATION IN SOYBEAN GENOTYPES, BASED ON THE PERFORMANCE OF AGRONOMIC CHARACTERS AND PRODUCTION COMPONENTS. THE EXPERIMENT WAS CARRIED OUT ON A FARM OWNED BY THE VERA CRUZ AGROPECU�RIA GROUP IN THE MUNICIPALITY OF GOIAN�SIA-GO. THE EXPERIMENTAL DESIGN WAS A RANDOMIZED BLOCK DESIGN, WITH 36 SOYBEAN CULTIVARS AND FOUR REPLICATES. THE EVALUATED VARIABLES WERE: HEIGHT OF PLANTS AT MATURITY, HEIGHT OF FIRST POD INSERTION, PLANT ARCHITECTURE, NUMBER OF PODS, NUMBER OF GRAINS, NUMBER OF NODES, APPARENT GRAIN DENSITY AND PRODUCTIVITY. A GENETIC DISSIMILARITY ANALYSIS WAS CARRIED OUT AMONG THE CULTIVARS, USING THE GENERALIZED DISTANCE OF MAHALANOBIS. THE CULTIVARS THAT PRESENTED THE DESIRABLE CHARACTERISTICS FOR NUMBER OF NODES WERE: BMX �ŠNICA, NS 7505, BMX FOCO, BRB 1220587 AND RK 16I027. WE HIGHLIGHT THE EARLY CYCLE GENOTYPES TMG 7067 IPRO, TMG 7063 IPRO AND SYN 15640 IPRO; AND THE MIDDLE CYCLE: BMX B�NUS IPRO, BRSGO 7755 RR AND BAYER (LIN 7945). THERE WAS DIVERGENCE BETWEEN THE GENOTYPES USED.