title: A new method for evaluation of the resistance to rice kernel cracking based on moisture absorption in brown rice under controlled conditions.
abstract: We developed and evaluated the effectiveness of a new method to detect differences among rice cultivars in their resistance to kernel cracking. The method induces kernel cracking under laboratory controlled condition by moisture absorption to brown rice. The optimal moisture absorption conditions were determined using two japonica cultivars, 'Nipponbare' as a cracking-resistant cultivar and 'Yamahikari' as a cracking-susceptible cultivar: 12% initial moisture content of the brown rice, a temperature of 25°C, a duration of 5 h, and only a single absorption treatment. We then evaluated the effectiveness of these conditions using 12 japonica cultivars. The proportion of cracked kernels was significantly correlated with the mean 10-day maximum temperature after heading. In addition, the correlation between the proportions of cracked kernels in the 2 years of the study was higher than that for values obtained using the traditional late harvest method. The new moisture absorption method could stably evaluate the resistance to kernel cracking, and will help breeders to develop future cultivars with less cracking of the kernels.
authors.affiliation: Fukui Agricultural Experiment Station , 52-21 Ryomachi, Fukui 918-8215 , Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hayashi
authors.affiliation: Fukui Agricultural Experiment Station , 52-21 Ryomachi, Fukui 918-8215 , Japan.
authors.forename: Asako
authors.initials: A
authors.lastname: Kobayashi
authors.affiliation: Fukui Agricultural Experiment Station , 52-21 Ryomachi, Fukui 918-8215 , Japan.
authors.forename: Katsura
authors.initials: K
authors.lastname: Tomita
authors.affiliation: Fukui Agricultural Experiment Station , 52-21 Ryomachi, Fukui 918-8215 , Japan.
authors.forename: Toyohiro
authors.initials: T
authors.lastname: Shimizu
keywords: kernel cracking; late harvest method; moisture absorption; rice; varietal differences