title: Application of stress indices for low temperature and deep sowing stress screening of rice genotypes.
abstract: Low temperature or cold stress and deep sowing plays a pivotal role in limiting rice (Oryza sativa L.) productivity in the temperate rice growing regions as well as in tropical high lands worldwide. A better understanding of stress tolerance mechanism in rice plants will help to develop rice germplasm with improved field level tolerance under variable temperature and sowing deep conditions. Using previously developed stress indices, this study presents results from low temperature and deep sowing screening of four rice genotypes. A group of 25 seeds per replicate (total of 3 replicates) was subjected to stress by deep sowing (15 cm) while another group was subjected to cold stress (13 degrees C-10 h/18 degrees C-14 h) and the control group remained under optimum conditions (25 degrees C and sowing depth of 1.5 cm). The Geometric Mean (GM), Stress Tolerance Index (STI) and Stress Susceptibility Index (SSI) were used to evaluate the genotypic performance under control and stress conditions. The results indicate that it was possible to identify superior genotypes for tolerance based on their stress indices. The indices although correlated, were found to be effective for the selection of genotypes with good yield potential under control and stress treatments and can now be used for genotypic screening under field conditions.
authors: Universidade Federal de Pelotas, Faculdade de Agronomia Eliseu Maciel, Dep. Fitotecnia, Programa de Pós-graduação em Ciência e Tecnologia de Sementes, Caixa Postal 354, CEP 96.001-970, Pelotas, RS, Brasil.
authors: Caroline Borges
authors: CB
authors: Bevilacqua
authors: Universidade Federal de Pelotas, Faculdade de Agronomia Eliseu Maciel, Dep. Fitotecnia, Programa de Pós-graduação em Ciência e Tecnologia de Sementes, Caixa Postal 354, CEP 96.001-970, Pelotas, RS, Brasil.
authors: Daisy Ramirez
authors: DR
authors: Monzon
authors: Universidade Federal de Pelotas, Faculdade de Agronomia Eliseu Maciel, Dep. Fitotecnia, Programa de Pós-graduação em Ciência e Tecnologia de Sementes, Caixa Postal 354, CEP 96.001-970, Pelotas, RS, Brasil.
authors: Eduardo
authors: E
authors: Venske
authors: 115 Plant Sciences Building, University of Arkansas, Fayetteville, AR-72701, USA.
authors: Supratim
authors: S
authors: Basu
authors: 115 Plant Sciences Building, University of Arkansas, Fayetteville, AR-72701, USA.
authors: Paulo Dejalma
authors: PD
authors: Zimmer
mesh_terms: D003080:Cold Temperature; D058639:Cold-Shock Response / Q000235:genetics*; D018556:Crops, Agricultural / Q000235:genetics* / Q000254:growth & development; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005838:Genotype; D018525:Germination / Q000235:genetics; D012275:Oryza / Q000235:genetics* / Q000254:growth & development; D010641:Phenotype; D012639:Seeds / Q000235:genetics