“Yeoreumi,” an Early Maturing Rice Cultivar Adaptable for Early-Transplanting Cultivation in the Chungnam Plain Area

Abstract

Early maturing rice cultivars grown in plain areas have an undesirable appearance due to high temperatures during the grain-filling stage. Therefore, developing early maturing rice cultivars with desirable appearance traits in plain areas is the primary goal of rice breeding programs. This study aimed to develop an early maturing rice cultivar adaptable to early transplanting cultivation in the Chungnam plain area. To develop "Yeoreumi," two breeding materials were used, good-quality "Joami" from the Chungnam plain area and "Hokuto" having the fastest heading date among the genetic resources and originating from Japan. These two resources were crossed in 2010 to develop the "Yeoreumi" cultivar using the pedigree method. A yield trial was conducted in 2015-2016, and a local adaptability test was conducted in 2017-2019. The heading date of "Yeoreumi" was July 10, when it was transplanted early in the Chungnam plain area, and it could be harvested at August end, which was sufficient to produce a fresh stock of rice before "Chuseok, which is the Korean Thanksgiving Day." The yield of milled rice was approximately 5.29 MT/ha in the local adaptability test, which was 0.47 MT/ha higher than that of "Jinbuolbyeo." Additionally, its grain quality was good, with 89.9% head rice and 67.6 glossiness of cooked rice. Overall, the results of this study indicated that "Yeoreumi" was suitable for early transplanting cultivation in the Chungnam plain area for "Chuseok," and could be used as a representative early maturing rice cultivar in Chungcheongnam-do (Registration No. 8597).