Resumo

ORTIZ DOMINGUEZ, Aída; MIRANDA, Rubén; FIGUEROA, Rosana  e  RAMIS, Catalina. Morphological characterization of seeds and productivity of a F₂ progenies obtained from natural crossing between rice variety and red rice (part II). Agronomía Trop. [online]. 2008, vol.58, n.3, pp.309-319. ISSN 0002-192X.

The objective of this research was to evaluate certain characteristics of F₂ progenies obtained by crossing a rice variety with red rice. Descriptive statistics were used to analyze the data and the test of Ji-square for % of fertility. Ten attributes related to productivity and morphology of seeds were evaluated. Results indicated that the F₂ showed segregation for all characteristics, mainly in minimum, maximum and average values for the following attributes: 3; 166 and 40.56 panicles per plant; 0; 177.50 and 49.68 grains per panicle; 0; 4.64 and 1.17 for panicle weight (g); 0; 98,38 and 55.46% for fertility of panicle; 0; 79.78 and 17.51% panicle shattering; 12.85; 35.05 and 24.02 cm of panicle length ; 6.31; 10.39 and 6.31 mm of paddy grains length; 2.01; 7.58 and 2.64 mm of paddy grains width; 1.43; 2.68 and 1.84 mm of paddy grains thickness; 2.54; 4.71 and 3.60 of grain length width relation. In addition they presented 62.12% of grains with glumes of black color and 37.88% straw color; 60.80% displayed red pericarp and 39.20% beige; and 96.56% did not show awn and 3.41% had short awn in greater amount in those of glumes of black color. The presence of phenotypes with long seeds, glumes of straw color without awn, combined with small plants and an erect growth habit (data shown in another publication) indicates that they could evolve into weedy rice-variety types (WRVT) in rice seed fields.

Palavras-chave : Oryza sativa L; red rice; F₂; productivity; morphology; seeds.