Abstract

DELGADO-HUERTAS, Hernando; SILVA-PARRA, Amanda  and  GUARIN-GUTIERREZ, Luis Alfonso. Agronomic evaluation of lines of sabana rice (Oryza sativa L.) obtained by population improvement with recurrent selection. rev.udcaactual.divulg.cient. [online]. 2021, vol.24, n.2, e1707.  Epub Dec 06, 2021. ISSN 0123-4226.  https://doi.org/10.31910/rudca.v24.n2.2021.1707.

The classical breeding methods have narrowed the genetic base of rice. The pedigree method with a limited number of elite and genetically related parents, can reduce variability in long term studies. The development of populations with a broad genetic base and the use of breeding methods that allow the continuous accumulation of favorable alleles could overcome these disadvantages. Recurrent selection (SR) allows the improvement of a population through the pyramidation of favorable alleles of diverse donors and of diverse genetic origin. It has been used in Colombia by CIAT/CIRAD for the development and improvement of the genetic stock of Oryza sativa L. rice, a tropical rain-fed Japonica type in acid savannas. They were evaluated in complete blocks at random with three repetitions, 50 advanced lines of this project, together with the commercial control Corpoica Llanura 11. There was a significant difference between rice lines for the dependent variables grain yield, days to flowering, vigor and incidence of Pyricularia in leaves and spotted of grain. Lines 39 and 37 of the PCT-11 population presented the highest yields, with 6.471 and 6.192kg ha-1, respectively, significantly different from the control and nine late cycle lines of the PCT-4 population, which presented very low yields. Especially line 39 showed a lower incidence of the Pyricularia fungus on leaves than the commercial control Corpoica Llanura 11. The present results and others obtained in Colombia and Brazil, show the utility of SR in savanna rice to generate superior lines in yield, resistance to diseases, adaptation to acid savannas and the potential to contribute to the diversification of the genetic base.

Keywords : Genotype; Environment; Adaptation; Yield; Plant health.

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