Seleksi Generasi Awal untuk Toleransi terhadap Suhu Tinggi pada Padi
The impacts of high-temperature stress on rice growth and productivity can be mitigated by growing tolerant varieties. This research was conducted to estimate the genetic parameters and to select the best genotypes based on the susceptibility stress index (SSI) values. This research was conducted from August 2016 to February 2017. Half of the five weeks seedling tiller of each F3 plant was transferred to new pot culture so that each genotype of the F3 rice population grown in two pots. At the maximum vegetative phase, the parental and F3 populations were treated under two different temperatures: in the open ground area and inside a greenhouse with daily mean temperatures of 38.89/22.67 °C dan 41.62/23.32 °C, respectively. The traits observed were yield and yield components. The results showed that the grain yield of the parents and the F3 population were lower when grown inside the greenhouse. The filled grain number per panicle was controlled by additive gene action in these two environments, and is suggested to be a selection character. Selection based on SSI index obtained 13 genotypes tolerant to heat stress and had higher yield compared to their parents. SSD method combined with shuttle breeding is recommended as a breeding method to produce tolerant and high yielding lines.
Keywords: heat stress, heritability, segregating population, SSI