Huiyou Aolong Silmiao

Variety Name: Huiyou Aolong Silmiao

Approval Number: National Rice Variety Approval No. 20216206

Breeding Institution: Hunan Aopulon Technology Co., Ltd.

Variety Origin: Hui 28A × Aolong Simiao

Characteristics: An indica three-line hybrid rice variety. When grown as a single-season mid-season rice in the upper reaches of the Yangtze River, its total growth period is 148.3 days, 2.4 days earlier than the control F You 498. Plant height is 110.0 cm, panicle length 25.2 cm, with 148,000 effective panicles per mu; each panicle bears 171.5 grains, with a seed-setting rate of 87.8% and a 1,000-grain weight of 27.9 g. Resistance: the comprehensive blast disease index over two years was 5.1 and 6.0, respectively; the panicle-neck blast damage rating reached the highest level of 7; brown planthopper resistance is rated at level 9; heat tolerance is rated at level 3, while cold tolerance is rated at level 7. The variety is susceptible to blast, highly susceptible to brown planthopper, exhibits relatively strong heat tolerance but weaker cold tolerance. Key grain-quality parameters include: brown-rice yield 79.7%, milled-rice yield 66.2%, grain length 6.4 mm, length-to-width ratio 3.5, chalkiness 2.0%, translucency grade 1, alkali-labile starch value 6.0, gel consistency 62 mm, and amylose content 16.6%, meeting the Grade II standard stipulated in the agricultural industry standard “Quality of Edible Rice Varieties” (NY/T 593–2013). When cultivated as a double-cropping late-season rice in South China, the total growth period is 110.3 days, 4.5 days earlier than the control Boyou 998. Plant height is 104.9 cm, panicle length 23.2 cm, with 164,000 effective panicles per mu; each panicle bears 170.6 grains, with a seed-setting rate of 82.0% and a 1,000-grain weight of 23.7 g. Resistance: the comprehensive blast disease index over two years was 4.0 and 6.0, respectively; the panicle-neck blast damage rating reached the highest level of 5; bacterial leaf blight resistance is rated at level 9; brown planthopper resistance is also rated at level 9. The variety is highly susceptible to bacterial leaf blight and brown planthopper, but moderately susceptible to blast. Key grain-quality parameters include: milled-rice yield 69%, chalkiness 0.7%, amylose content 15.2%, gel consistency 75 mm, alkali-labile starch value 7, and length-to-width ratio 3.1, meeting the Grade I standard stipulated in the agricultural industry standard “Quality of Edible Rice Varieties.”

Yield Performance: In 2019, the variety was included in the regional trial for the late-maturing medium-grain indica rice group in the upper reaches of the Yangtze River, achieving an average yield of 587.4 kg per mu, a 2.1% increase over the control. In the follow-up trial in 2020, the average yield was 620.9 kg per mu, up 4.2% from the control. Over the two-year regional trial period, the average yield was 604.1 kg per mu, representing a 3.1% increase over the control. In the 2021 production trial, the average yield was 609.6 kg per mu, a 4.2% increase over the control. When grown as a double-cropping late-season rice in South China, the variety participated in the regional trial for the photoperiod-sensitive late-season indica rice group in 2018, with an average yield of 459.67 kg per mu, 3.25% higher than the control variety Boyou 998. In the 2019 follow-up trial, the average yield was 508.21 kg per mu, 2.68% higher than the control Boyou 998. Over the two-year regional trial period, the average yield was 483.94 kg per mu, 2.96% higher than the control Boyou 998. In the 2019 production trial, the average yield was 510.71 kg per mu, 2.32% higher than the control Boyou 998.
Key cultivation techniques: For single-season medium-duration rice cultivation in the upper Yangtze River region, sowing is generally carried out from early March to early April, with a seed rate of 10.0 kg per mu in the nursery and 1.0–1.2 kg per mu in the main field. Transplanting is done when the seedlings have about six leaves, with a transplant age kept within 30–40 days. The planting spacing is 20.0 cm × 30.0 cm, ensuring at least 70,000 tillers per mu. Apply fertilizer and manage water according to scientific principles. Other field management, cultivation, and harvesting practices should follow the standard methods for this variety type. Timely control of rice blast, sheath blight, brown planthopper, stem borers, and other pests and diseases is essential. For double-cropping late-season rice cultivation in South China, sowing is typically around July 15. In the nursery, the seed rate for transplanting into the main field is 1.5 kg per mu; for direct seeding with dense planting, the seed rate is 1.5–2 kg per mu. Transplanting is carried out at the five-leaf stage, with an optimal seedling age of 18–25 days. The transplant spacing is 20 cm × 20 cm, with three seedlings transplanted per hill, ensuring at least 80,000 tillers per mu. Fertilization involves applying sufficient base fertilizer—25 kg of high-concentration compound fertilizer or 30–35 kg of ordinary compound fertilizer per mu—and early application of tillering fertilizer—6–8 kg of urea and 6–8 kg of potassium chloride per mu 5–7 days after transplanting. A panicle-filling fertilizer should also be applied during the mid-podding stage, at 10–12 kg of potassium chloride per mu. Water management includes maintaining shallow water for green-up, alternating between shallow and moist conditions during tillering, drying the field once adequate tillers have formed, keeping shallow water during panicle initiation and heading, implementing alternate wet-and-dry irrigation during grain filling, and draining the field 6–8 days before harvest. Pest and disease control should be carried out promptly. During the seedling stage, apply pesticides in a timely manner to control brown planthoppers and prevent southern black-streaked dwarf disease. During the main-field stage, based on pest and disease forecasts, apply appropriate pesticides in a timely manner to control stem borers, white-backed planthoppers, bacterial leaf blight, sheath blight, and other pests and diseases. In areas prone to recurrent rice blast, special attention should be paid to its control.

Review and Approval Opinion: This variety meets the national standards for rice variety approval and has been officially approved. It is suitable for single-season mid-season rice cultivation in the paddy-growing areas of the plains and hilly regions of Sichuan Province, Guizhou Province (excluding the Wuling Mountain area), the low- and medium-altitude indica rice-growing areas of Yunnan Province, the areas of Chongqing Municipality (excluding the Wuling Mountain area) below 800 meters in elevation, and the rice-growing areas in southern Shaanxi Province where blast disease occurs at low incidence; however, it is not recommended for cultivation in areas with severe blast disease outbreaks. In addition, according to the 2021 official approval (Approval No.: National Rice Approval 20216206), this variety is suitable for late-season rice cultivation in the double-cropping rice areas of Guangdong Province (excluding the northern Guangdong rice-growing region), southern Guangxi, Hainan Province, and southern Fujian Province, provided that these areas are free from severe outbreaks of blast and bacterial leaf blight; cultivation is not recommended in areas with severe bacterial leaf blight outbreaks.