Cold tolerance evaluation in Chilean rice genotypes at the germination stage

Abstract

Low temperature is the most important abiotic stress affecting rice (Oryza sativa L.) yield in Chile. Rice in Chile is usually planted when the minimum air temperatures are below 12 °C. This temperature is lower than the optimum needed for normal rice germination. Therefore, the aim of this study was to evaluate cold tolerance in 20 experimental lines from the Rice Breeding Program of the Instituto de Investigaciones Agropecuarias (INIA), Chile, at the germination stage. Coleoptile length reduction (CRED), coleoptile length after cold treatment (CLEN), coleoptile length recovery (CREC), and coleoptile regrowth (CREG) were evaluated at 13 °C for 4 d using 'Diamante-INIA' as the cold-tolerant control. To find genotypes with cold tolerance (low CRED value and high CLEN, CREC, and CREG values), genotypes were ranked, a biplot of principal components, and cluster analysis were performed. No differences were found among genotypes in the ranking based on CREC value so this trait was not considered. Analysis showed that only three experimental lines had cold tolerance similar to that of 'Diamante-INIA'; all other experimental lines exhibited intermediate to low cold tolerance. These results showed low cold tolerance of some Chilean genotypes at the germination stage, thus confirming the need to evaluate the rest of the germplasm from the Rice Breeding Program.

Phenotypic Variation and Selection for Cold-Tolerant Rice (Oryza sativa L.) at Germination and Seedling Stages

“…We observed significant variation in response to cold stress at the germination stage among the studied varieties ( Figure 2). Our results are consistent with a previous study by Ñanculao et al [14]. Shakiba et al suggested a wide range of variation in germination index among experimental rice varieties [15].…”

Agro-Morphological Evaluation of Rice (Oryza sativa L.) for Seasonal Adaptation in the Sahelian Environment

“…In these studies, analysis of variance for grain yield and related traits for the 224 rice genotypes showed that performance of genotypes varied significantly between sowing dates. These findings were in agreement with previous works, which allowed to discriminate cold tolerant from the sensitive genotypes [8,10,11]. The implication is that separate breeding for adaptation to dry or wet season cultivation should be undertaken.…”

“…For instance, in a study on more than 700 japonica cultivars collected from Japan, Europe, China, Russia and other regions, Kotaka and Abe (1988) found a high genetic variability for seedling germinability [9]. In addition, an evaluation of 20 Chilean rice genotypes and 192 Japanese accessions at 13˝C, led to the identification of cold tolerance genotypes, based on coleoptile length reduction, coleoptile length after cold treatment, coleoptile length recovery and coleoptile regrowth [10,11]. Similar studies were carried out in 477 landraces from five cropping regions in Yunnan, China, which is considered the center of genetic diversity and cold tolerance [12].…”

Arroz tipo especial fertirrigado por gotejamento subsuperficial com efluente tratado de laticínio

“…O efeito da temperatura pode ser observado em todas as fases de desenvolvimento das plantas de arroz. As baixas temperaturas durante a germinação inibe ou reduz o crescimento dos coleóptilos (Donoso Ñanculao et al, 2013), estrutura fundamental para o estabelecimento das mudas, e na fase vegetativa reduz a taxa de crescimento da cultura e o acúmulo de biomassa (Deng et al, 2015), com redução do número de panículas, peso dos grãos e características relacionadas à qualidade (Huang et al, 2013). Como uma forma de aclimatação das plantas, as altas temperatura reduzem a taxa fotossintética e aumentam a taxa transpiratória, durante a fase vegetativa (Sánchez-Reinoso et al, 2014).…”