Root development at the seedling stage is an important trait for the early growth of rice. In this study, the root length and weight of 211 Korean landrace rice at the seedling stage were evaluated, and the average root length and weight were 6.94 cm and 48.18 mg, respectively. Principal component analysis (PCA) of 211 accessions based on 70,849 SNPs presented three subgroups. Two quantitative trait loci (QTLs) associated with root length were detected on chromosomes 3 and 6 using genome-wide association study (GWAS). Four haplotypes were identified using associated SNPs for the two root length QTLs. The average root length of Hap2 and Hap 3 was 7.32 cm and 6.56 cm, respectively, and were significantly different. Gene expression analysis in the candidate regions of QTLs for root length at the seedling stage showed that several genes were expressed in the root. QTLs associated with root length at the seedling stage identified in this study may be applied to improve the root length trait and detect candidate genes.

‘Golden queen 3’, an aromatic rice variety, was developed by Seedpia inc. (Suwon, Korea) breeding company in 2014. This cultivar was derived from a cross between ‘HJ-11’, a high-yield, aromatic line, and ‘JCH33M-15-1-9-1’, which has a low amylose content. During the F₃-F₈ generation, breeding lines were selected using a pedigree breeding method. The most promising line (JS9-3-73-15-5-1-5-3-1-1) was advanced and named ‘SP005’ in 2013. This variety was headed on August 13, two days later than ‘Hwayeong’ in the ‘in middle plane’ is commonly used to distinguish rice cultivation areas in Korea, so I think it's no problem to the understanding for readers (including farmers). The culm and panicle lengths of this variety were 75.7 cm and 20.1 cm, respectively. It has approximately 14.7 tillers per hill and 104.8 spikelets per panicle, and the 1000-grain weight was 21.8 g. The yield performance was 5.47 MT/ha in the local adaptability test, and the amylose content of this variety was 12.5%. 2-Acetyl-1-pyrroline was detected as the major volatile ingredient in aromatic rice, and a 1 bp insertion on the 14th exon (badh2.7 allele) was identified in the Badh2 gene. (Registration No. 7308).

The Jinsang 2 cultivar is a new late-maturing, low amylose rice variety with a medium to short culm created by the Seedpia Inc. breeding company in 2012. This variety was derived from a cross between Junam, a high-yield and lodging tolerant source, and DM3-8-72-9, which was derived from a cross between Donjinchal and Milkyqueen, with a low amylose content and superior agronomic traits. A general single seed descent method was applied to develop Jinsang 2 in the F3-F4 generations. During the F5-F8 generations, the breeding lines were selected through a pedigree breeding method. A promising line, JS6-B-52-8-3-5-1-B-B-B, was selected and named HJ-6 in 2011. This variety headed on the 25^th of August, which was 14 days later than Hwayoung. The culm and panicle length of the variety was 71.6 cm and 19.9 cm, respectively. The milled rice from the variety had a dull and medium- to short-grain, and the 1,000-grain weight was around 20.0 g. It had a low amylose content of 12.2% and a low protein content of 6.8%. The yield performance of Jinsang 2 milled rice was about 5.36 MT/ha from the ordinary culture replicated yield trial test.