RD24 (Sakon Nakhon 72), a Glutinous Rice Variety

Abstract

Nowadays, glutinous rice production in Thailand is mainly consumed domestically, as only 9% is exported. RD6 is the most popular variety because of its outstanding cooking quality with aroma. However, this variety is tall, vulnerable to lodging, susceptible to blast disease, and low yield potential. Though, the release of RD18 with resistance to rice blast disease but still having tall stature and lodging leading to low yield potential. Recent collaborative research between the Rice Department (RD) and the National Center for Genetic Engineering and Biotechnology (BIOTEC) has developed a new variety with semi-dwarf plant type, lodging tolerance and blast disease resistance better than RD6 and RD18 while remaining good cooking quality. A single cross between a glutinous rice line RGDU07585-7-MAS35-4 (a semi-dwarf variety with blast disease resistance and bacterial blight disease resistant genes) as a female parent, and RGDU07123-12-22-5 (a tall variety with broad-spectrum resistance to blast disease with outstanding cooking quality) as a male parent. The promising line named RGDU10017-1-MAS-49-4-1-NKI-1-3-1-2 outperformed other lines in the same pedigree. The average yield from multiple field trials was 663 kg/rai. In addition, this line was highly responsive to nitrogen fertilizer (potential yield at about 1,002 kg/rai), has excellent milling and cooking quality, and has resistance to leaf blast. On the occasion of His Majesty the King Rama 10’s 72nd birthday in the year 2024, this line was released as glutinous rice variety “RD24” (Sakon Nakhon 72). This variety is photosensitive, making it only able to be planted in the wet season with an optimal harvesting date of November, 23. It is a semi-dwarf variety with an average plant height of 96 cm and is lodging tolerant. The average milling head is 42.2% with the length of brown rice of 7.08 mm, 2.22 mm width, and 1.76 mm thick considered as slender shape. Though, RD24 is a non-aromatic variety but it has soft texture after cooking. It is recommended to be grown predominantly under rainfed condition in the northeastern part of Thailand where leaf blast disease always occurs. It is susceptible to neck blast disease, bacterial blight disease, rice gall midge, and brown planthopper.