Modeling the response of germination rate of different rice genotypes to temperature

Sabouri, Hossein; Sabouri, Atefeh; Dadras, Ahmad Reza

Modeling the response of germination rate of different rice genotypes to temperature

Document Type : Research Paper

Authors

¹ Assist. Prof., Dept. of Plant Production, College of Agriculture and Natural Resources, Gonbad Kavous University

² Assist. Prof., Dept. of Agronomy and Plant Breeding, University of Guilan

³ Ph. D. Student, Dept. of Agronomy and Plant Breeding, University of Guilan

Abstract

The germination and emergence are the most critical stages of plant life, because seeds are exposed to unfavorable environmental factors at this stage and plant establishment is confronted with difficulty. Therefore, prediction of germination time is one of the main goals of simulation researchers. In this regard mathematical techniques such as determination of the best nonlinear regression function which can quantify response of germination rate to temperature and estimate the cardinal temperatures would be very informative about characteristics and plants thermal requirements at this stage. The present study was conducted using a factorial experiment arranged in completely randomized design with three replications in 2010. The experimental factors including 19 temperature levels (12-48˚C at intervals of 2˚C from each other) and six rice (Oryza sativa L.) genotypes namely Binam, Hashemi, Anbarbou (landrace varieties), Dasht, Gil3 (Iranian improved cultivars) and IR64 (IRRI improved cultivar). Analysis of variance showed that there are significant differences between studied genotypes and genotype×temperature interaction effect for germination rate. The models of beta, quadratic, curvilinear, dent-like and segmented were applied to describe the relationship between germination rate and temperature. The comparison of different criteria for evaluating of the studied models showed different precision of the fitted models so that the segmented model for Hashemi variety, the beta model for Dasht and Gil3 varieties, the curvilinear model for Anbarbou and IR64 varieties and the beta and curvilinear models for Binam variety were the better than the other models. Results of current study showed that the mentioned models and their estimated cardinal temperatures can be used to predict the germination time and simulation of the studied rice varieties.

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