Caracterização morfoagronômica de acessos de arroz (Oryza sativa L.) de terras altas

Abstract

Rice is the primary food source in many developing countries in the world, primarily for those located in Asian. The Oryza genus has 24 species, but only two are cultivated: O. glaberrima Steud. in the West of Africa and O. sativa L. in all part of the world. Those species are naturally hydrophytes, however the evolutionary process they become adapted for many different ecosystems as lowland and upland. The breeding method used in the last decades increased the narrowing genetic base and the vulnerability of rice cultivation for plagues and diseases. However, it is necessary to use divergent genitors for development of new cultivars. In this context, the characterization of germplasm accesses from bank and collection could bring facilities in order to use them in breeding programs. The aim of this work was characterizer 146 accesses of upland rice Japanese by morphoagronomical traits in order to bring information that could bring facilities for chose genitors in rice breeding programs. In this case, the morphologic mark could give important information about genetic resource by simple, efficient and cheap way. There were studied 14 qualitative traits and 16 quantitative in a randomized blocks design experiment withthee replicates. For the 14 quantitative traits only two were not polymorphic and there was significative difference (P<0.05) for all 16 quantitative traits. The genetic variance was highest than environmental one and the heritability was higher than 80% for the evaluated characters. The genetic variation coefficient varied from 1.81 to 39.58 for different characteristics and b index was highest than 1 for all characters. The results showed that the rice access of UFRPE germplasm collection have great genetic variability and high potential for use in rice breeding programs.