Detailed Introduction to Rice Variety D You 448
[Basic Information] D You 448 is a new high-quality, high-yield hybrid rice combination developed by the Crop Research Institute of the Sichuan Academy of Agricultural Sciences by crossing D62A with the self-selected wide-compatibility restorer line Chenghui 448, suitable for both medium and late rice.
[Characteristics] The combination participated in the medium-maturity group of the medium indica rice regional trial in Sichuan Province from 1999 to 2000, with an average yield of 8.14 t/hm2 over 2 years, 5.95% higher than the control; in the 2000 provincial production trial, the average yield at 5 sites was 8.26 t/hm2, 9.47% higher than the control. In 2000 it participated in the national southern rice region late rice regional trial, with an average yield of 6.82 t/hm2, 1.86% higher than the control.
When D You 448 is cultivated as medium rice, the whole growth period is 148.5 d, 5-6 d shorter than Shanyou 63, plant height 100 cm, panicle length 25 cm, effective panicles 2.562 million/hm2, earing rate about 84%, average grains per panicle 145.2, seed setting rate 84.17%, 1000-grain weight 27.1 g; when cultivated as late rice, the whole growth period is 125.5 d, 1.7 d longer than the control, plant height 92.6 cm, panicle length 24 cm, total grains per panicle 108.3, seed setting rate 79.9%, 1000-grain weight 27.4 g. The combination has relatively strong tillering ability, relatively coordinated panicle-grain weight, dark green leaf color, a plant type that is appropriately compact and loose, and the flag leaf is relatively wide, short, thick and upright, with relatively good lodging resistance.
According to the identification by 4 rice blast resistance appraisal units designated by the Sichuan provincial regional trial, from 1999 to 2000 D You 448 averaged grade 4 for leaf blast (range 0-7), grade 5 for neck blast (range 0-7), and 12% incidence of neck blast (range 0-41%); the control averaged grade 7 for leaf blast (range 3-9), grade 7 for neck blast (range 3-9), and 45% incidence of neck blast (range 7.4%-92.0%). According to the national regional trial identification, the average rice blast resistance of D You 448 is grade 5 (range 2.1-7.0).
According to tests by the Rice and Rice Products Quality Supervision and Inspection Testing Center of the Ministry of Agriculture, D You 448 has a brown rice rate of 80.2%, milled rice rate of 73%, head rice rate of 55%, grain length 6.7 mm, length-to-width ratio 2.9, chalkiness rate 57%, chalkiness degree 11.1%, transparency grade 2, alkali spreading value 6.4, gel consistency 51 mm, amylose content 21%, and protein content 10.6%. Among these, 5 indicators, namely milled rice rate, grain length, alkali spreading value, amylose content and protein content, reach the first-grade standard for high-quality rice issued by the Ministry; 5 indicators, namely brown rice rate, head rice rate, length-to-width ratio, transparency and gel consistency, reach the second-grade standard for high-quality rice issued by the Ministry.
[Breeder] Crop Research Institute of the Sichuan Academy of Agricultural Sciences
[Region and Technology] D You 448 can be used as a medium-maturity variety of hybrid medium rice and a late-maturity variety of hybrid late rice.
Sow at the proper time and cultivate strong seedlings with many tillers. When cultivated as medium rice, sow from late March to early April; when cultivated as late rice, sow in mid-June. Two-stage seedling raising, plastic-film moist seedling raising or dry seedling raising may be used to cultivate strong seedlings with many tillers.
Appropriately dense planting. Transplant 225,000-270,000 hills/hm2, with 1.8 million basic seedlings/hm2.
Scientific fertilization. For fields of medium fertility, generally apply 150-180 kg of pure nitrogen, 450-525 kg of phosphate fertilizer and 300 kg of potash fertilizer per hectare. Emphasize basal fertilizer and early topdressing, with 80% as basal fertilizer and 20% as topdressing.
Pay attention to the prevention and control of pests and diseases, and promptly prevent and control pests and diseases according to the forecasts of the local plant protection department.
Key points of seed production technology: when Chenghui 448 is spring-sown in the Chengdu area, the period from sowing to heading is 102 d, 7 d shorter than Minghui 63, with an average of 15.5 leaves on the main stem, 1.0-1.5 leaves fewer than Minghui 63. The pollen amount is sufficient, the pollen density is high, and the pollen shedding is good; the flowering period is 10-14 d, the flowering time is relatively concentrated, and 11:30-12:30 on sunny days is the peak flowering period. When Chenghui 448 is crossed with D62A for seed production, the sowing interval between the parents is 7-10 d.