RD119, a Non-glutinous Rice Variety

Abstract

Thai fragrant, non-glutinous rice, with aroma and sticky texture when cooked and photoperiod insensitivity allowing year-round cultivation, is in high demand but the production is insufficient for market demands. Because some of those varieties have low yields, they are not resistant to blast disease, have long growth duration, and their yield and quality vary depending on the area and environmental conditions in each season. Therefoe, breeding photoperiod insensitive, non-glutinous, fragrant rice varieties with short growth duration, high yield and resistance to blast disease is another option. This type of rice variety has been developed under the cooperation of Phitsanulok Rice Research Center and the National Science and Technology Development Agency (NSTDA). The single cross between IR738349 and SPR91062 was made, then crossbred it with the Pin Kaset rice variety at NSTDA. Growing of F₁ seeds followed by pedigree selection of F₂ to F₇ populations were conducted at Chai Nat Rice Research Center resulted in the outstanding line BioH95-CNT-60-1-1-1-2-1. This line had been under the processes of observation, yield trials, evaluation for resistance to major diseases and insect pests, nitrogen fertilizer response, physical and chemical properties of grain, milling and cooking qualities. The total period of this varietal development was during 2013-2023. The Thailand Rice Variety Board agreed to release it in the name of RD119 in 2025. It is a non-glutinous, photoperiod insensitive and fragrant rice variety, has a maturity from planting of 95-100 days (germinated seed broadcasting) and 105-115 days (transplanting) considerably shorter than that of Pathum Thani 1 rice variety, an average height of 109-115 cm with erect culm and stiff stem, green leaves, and a flag leaf length and width of 40.60 and 1.20 cm, respectively. It holds medium compact panicle just above the exertion from the flag leaf with a length of 30.10 cm, 141 filled grains/panicle and shattering. The highest yield was 993 kg/rai, with an average yield of 777 kg/rai, approximately 13% higher than that of Pathum Thani 1 rice variety. Its seed dormancy was four weeks, weight of 1,000 dry paddy was 28.66 g, a straw-colored paddy with 11.20 mm length, 2.59 mm width, and 2.01 mm thickness. The length of brown rice was 8.31 mm with 2.13 mm width and 1.87 mm thickness, together with 7.93 mm milled rice length, 2.07 mm width and 1.82 mm thickness, considered a slender shape. It has good milling quality, with whole kernel and head rice of 40.58%. This variety has low amylose content (17.21%), soft gel consistency, and low gelatinization temperature with 9.54% protein in brown rice. The quality of cooked rice is soft and sticky with aroma (2AP: 1.61 ppm). It showed moderate resistance to leaf blast at the seedling stage in Chai Nat, Phitsanulok, Lop Buri, and Prachin Buri provinces. It is moderately susceptible to populations of brown planthopper from Chai Nat, Phitsanulok and Lop Buri provinces but susceptible to isolates of bacterial leaf blight from Phitsanulok Rice Research Center. RD119 is suitable for planting in irrigated rice production systems in the lower northern, central, and upper northern parts of Thailand, where no regular outbreaks of brown planthopper and bacterial leaf blight were found.