The Relationship between Pollen Viability and Filled Grains in Native Indonesian Rice Cultivars under High Temperature at Flowering Stage

Abstract

Background: The research was conducted to screen rice cultivars with resistance ability to high-temperature conditions and analyze the relationship between pollen viability and filled grain of native Indonesia rice cultivars. Methods: The rice seeds were germinated, sown into a tray and then transplanted into pots filled with sandy loam and compost 3:1. After 20% of flowering, four pots of each cultivar were kept under ambient temperature (28-32°C) and the other four pots were transferred to high-temperature (33-38°C) conditions. Pollen stainability and pollen germination were conducted using IKI solution and by germinating them under in vitro conditions respectively before being viewed under the light microscope. Yield characters were analyzed to obtain a relationship with pollen viability. Result: Percentage of pollen germination, filled and empty grains of rice cultivars significantly differed between the two conditions by t-test. Ciherang and Sigeudop were two resistant cultivars for high-temperature treatment, with filled grain percentage more than 85%. There was a strong relationship between pollen germination and filled grains at ambient temperature (r=0.95; p less than 0.01) and high temperature (r=0.94; p less than 0.01). Rice cultivars that show high pollen germination under high-temperature conditions would produce a high percentage of filled grains.