Descritores morfológicos e produtivos de variedades crioulas de arroz: (Oryza sativa) oriundas da agricultura familiar do estado do Maranhão

Abstract

Maranhão has a large number of traditional varieties (landrace) that can significantly contribute to rice genetic breeding programs. However, there is little information about these varieties. As a result, the objective of this study was to describe the morphological and agronomic profile through qualitative and quantitative descriptors, to characterize the landrace rice varieties from family farming in the state of Maranhão. The method used was the Distinguishability, Homogeneity and Stability test (DHE tests), applied for cultivar protection certification by the National Cultivar Protection Service (SNPC) with some adjustments to the methodology. Twenty-three qualitative and three quantitative inheritance descriptors were adopted. For the qualitative inheritance descriptors, a dendrogram was elaborated, based on a dissimilarity matrix. The studies were carried out in the Diamante Negro/Jutaí settlement, located in the municipality of Igarapé-do-Meio, state of Maranhão. The experimental design was in randomized blocks with 21 treatments (varieties) and four replications (blocks). The results for the 23 descriptors of culinary qualitative inheritance that there were representative phenotypic differences between the varieties, being the main characteristics: leaves (Green=85.71%; Erect=57.14%; Smooth=90.48%); ligule (Split=100%; Colorless to Green=100%); flag leaf (Intermediate=42.86%; Average=71.43%); internode (Light green=57.14%); stem (Long=80.95%); grain release (Easy=80.95%); panicle (Long=47.62%); lodging resistance (Strong stalk=71.43%); leaf senescence (Late=42.86%); panicle emission (Total Emission=95.24%); (Average=66.67%); motto and palea colors (Straw/Gold and Reddish both with 47.62%); sterile glume colors (Straw/Gold=100%); grain shape (Elongated=42.86%); grain class (Long-fine=47.62%); pericarp colors (White=100%). The dendrogram formed 3 distinct sets, where the III set encompassed the largest number of varieties, in addition to showing that there is dissimilarity between the varieties. The varieties Edinho, Pé Roxo, Codozinho and Palha Murcha showed the highest panicle production among the cultivated varieties. The qualitative descriptor of grain number per panicle was more expressive in the Quechi variety and the best results for number of tillers were presented by the Edinho variety. We conclude that the creole varieties present a wide diversity in characteristics, which allows adaptation to the most diverse conditions and needs of family farming.