Detailed introduction to the rice variety II You Xie 8

[Basic information] II You Xie 8 is a new hybrid rice combination developed by the Crop Research Institute of the Sichuan Academy of Agricultural Sciences by crossing the high-quality, high-combining-ability, disease-resistant wide-compatibility restorer line Chenghui 448, selected from the progeny of a cross between 871028 and Iemont, with II-32A. In recent years, through trials and demonstrations in various regions (cities) of Sichuan Province, II You 448 has shown characteristics such as high quality, high yield, disease resistance, early maturity and wide adaptability.

[Characteristics] This combination participated in the 1996-1997 Sichuan Province medium-indica medium-maturity group regional trial, with a 2a average yield of 8.52 t/hm2, an increase of 14.57% over the control; in the 1997 production trial, the average yield was 8.08 t/hm2, an increase of 8.73% over the control; in 1997 it participated in the rice-vegetable-@#@245@#@(rapeseed) triple-cropping trial in Guanghan City, with a yield of 8.97 t/hm2, an increase of 8.76% over the control Fuyou 63, and it matured 3 d earlier. In 1998, II You 448 participated in the variety comparison trial in Nanjiang County, with a yield of 9.36 t/hm2, an increase of 34.4% over the control Shanyou Wan 3; in the seedling-throwing trial in Jingyang District, II You 448 yielded 9.53 t/hm2, an increase of 5.33% over the control Shanyou 63; in the Deyang City rice regional trial, it increased yield by 4.34% over the control Shanyou 63 and matured 6 d earlier. In 1998, II You 448 participated in the late indica medium-late maturity group regional trial in the southern rice region, with a yield of 6.57 t/hm2; its yield level was comparable to the control Shanyou 46 (Shanyou 10), and its growth period was similar.

This combination has strong ratooning ability and high ratoon rice yield. According to a 1996 trial in Shuangjiang County, Yunnan, at an altitude of 1100 m, the main crop yield was 7.95 t/hm2, the ratoon rice yield was 8.36 t/hm2, and the two-season yield was 16.31 t/hm2.

According to the appraisal by the Rice and Rice Products Quality Supervision, Inspection and Testing Center of the Ministry of Agriculture (2a average for 1997 and 1998): II You 448 had a brown rice rate of 79.1%, milled rice rate of 72.5%, head rice rate of 64.9%, rice length-to-width ratio of 2.6, chalky grain rate of 40%, chalkiness degree of 6.2%, transparency grade 2.5, alkali spreading value 6.0, gel consistency 41 mm, and amylose content 21.4%. In 1998, the total rice quality score in the southern rice region regional trial was 55 points, far higher than the control Shanyou 46 (49 points) and Weiyou 64 (46 points). This indicates that the appearance quality, processing quality, cooking quality and eating quality of II You 448 rice are significantly improved compared with the main combinations currently promoted in production. The rice is glossy and has good palatability.

In 1997, according to the appraisal by the "Characteristics Identification and Evaluation" collaborative group of the "Ninth Five-Year Plan" national rice breeding project, II You 448 had leaf blast grade 2.6, average panicle blast grade 4.6, bacterial blight grade 5.0, and heat tolerance grade 3.6. The 1998 resistance identification results of the late rice regional trial in the southern rice region showed that II You 448 was significantly better than the control Shanyou 46 and Weiyou 64 in resistance to rice blast, bacterial blight and brown planthopper; in particular, the incidence of neck blast was very low, at grade 0-1. According to the appraisal by the Rice and Sorghum Research Institute of the Sichuan Academy of Agricultural Sciences: II You 448 had leaf blast grade 4, panicle blast grade 1, and incidence rate 1.2%, while the control Shanyou 195 had leaf blast grade 9, panicle blast grade 9, and incidence rate 64.6%; the resistance spectrum frequency of II You 448 was 83.6%, while that of Shanyou 63 was only 6.1%.

When cultivated as medium rice in Sichuan, II You 448 has a whole growth period of 144 d, generally 5-7 d shorter than Shanyou 63. When cultivated as late rice in the southern rice region, the whole growth period is 123.6 d, 0.9 d longer than Shanyou 46. When cultivated in mid-mountain areas (altitude 600-800 m), the whole growth period is about 155 d, comparable to Shanyou Wan 3.

II You 448 grows vigorously in the early stage, has medium to above-medium tillering ability, relatively dark leaf color, good plant and leaf type, narrow and upright leaves, plant height 100 cm, good color conversion in the later stage, relatively high panicle-forming rate, effective panicles 2.82 million/hm2, average grains per panicle 143, seed-setting rate 86%, and 1000-grain weight 27 g.

[Breeder] Crop Research Institute of the Sichuan Academy of Agricultural Sciences

[Region and techniques] Sow at the appropriate time and cultivate strong multi-tiller seedlings. For medium rice, sow in northwestern Sichuan at the end of March to early April, and in southeastern Sichuan in mid-March; for late rice, sow in mid-June. Use two-stage seedling raising, increase the application of phosphorus and potassium fertilizers, and cultivate short, strong, multi-tillering seedlings. b) Appropriate close planting. II You 448 has a compact plant type and upright flag leaves, and is suitable for close planting; the usual transplanting spacing is 20 cm x 20 cm. Reasonable fertilization. For fields of medium fertility, the usual pure nitrogen rate is 150-180 kg per hectare, phosphate fertilizer 375-450 kg, and potassium fertilizer 225-300 kg. d) Timely control of diseases and insect pests. According to the forecasts of the local plant protection department, timely control borers, rice skipper, planthoppers, bacterial blight, sheath blight and rice blast to ensure a bumper harvest.

Chenghui 448 is spring-sown in the Chengdu area, with a sowing-to-heading period of 102 d, 7 d shorter than Minghui 63, an average main stem leaf number of 15.5 leaves, sufficient pollen quantity, high pollen density, good pollen shedding, strong pollen vigor, flowering period 10-12 d, relatively concentrated flowering time, and the full flowering period on sunny days is 11:30-12:30.

When Chenghui 448 is combined with II-32A for seed production, the sowing interval is correspondingly shortened compared with producing II You 63. For the remaining techniques, please refer to the seed production techniques for II You 63.