Breeding and Application of Tianfengyou 269, a High-Yield, High-Quality, Multi-Resistant Hybrid Indica Rice
1 Breeding Process
Tianfengyou 269 (formerly named Yanyou 269) is a new high-yield, high-quality, multi-resistant three-line hybrid indica rice combination bred in 2002 by the Institute of Agricultural Sciences of the Coastal Region of Jiangsu, by crossing Tianfeng A, developed by the Guangdong Academy of Agricultural Sciences, with the restorer line Yanhui 269, which was self-bred by our institute. The self-bred restorer line Yanhui 269 was produced in the summer of 1995 by making a cross with Yanhui 559 as the female parent and Yanhui 469 (an intermediate material of our institute) as the male parent, obtaining 26 hybrid seeds, which were brought to Sanya, Hainan in the winter of the same year to plant the P1 generation, and the seeds were harvested in bulk. In the summer of 1996, the P2 generation was planted at our institute; the segregating population showed many types, with large panicles and many grains, high seed-setting rate, and good late-stage ripening appearance, and 10 superior individual plants were selected and retained; in the winter of the same year, they were brought to Sanya, Hainan to plant P1 plant rows, and superior individual plants were selected. In the summer of 1997, the P4 plant rows were planted at our institute, and 8 superior individual plants were selected; in the winter of the same year, a plant-row nursery was planted in Sanya, Hainan, and 3 superior individual plants were selected. In the summer of 1998, a plant-row nursery was planted at our institute, and 5 superior individual plants were selected; in the summer of 1999, a plant-row nursery was planted at our institute, and 5 superior individual plants were selected; in the summer of 2000, a plant-row nursery was planted at our institute, and the traits were uniform and consistent, at which point Yanhui 269 was basically stabilized. In the winter of 2000, test-restorer plant rows were planted in Sanya, Hainan, and small-scale manual seed production was carried out. In the summer of 2001, it entered the new hybrid rice combination identification nursery of our institute, and Yanyou 269 was very outstanding in yield, resistance and other comprehensive traits. In 2002, Yanyou 269 participated in the new hybrid rice combination variety comparison trial of our institute and likewise showed the characteristics of high and stable yield, moderate maturity, relatively good grain quality, and strong disease resistance. From 2003 to 2005, Yanyou 269 participated in the Jiangsu Province hybrid indica rice regional trial and production trial, with outstanding performance. In January 2006, it passed the approval and naming of the Jiangsu Provincial Crop Variety Approval Committee (Tianfengyou 269). In 2006, an application was filed for plant variety rights protection with the Ministry of Agriculture.
2 Yield Performance
In 2002, it participated in the new hybrid rice combination variety comparison trial of our institute, with an average yield of 635.5 kg per mu, an increase of 12.60% over the control Shanyou 63. From 2003 to 2004, it participated in the Jiangsu Province hybrid indica rice regional trial, with a two-year average yield of 558.4 kg per mu, an increase of 5.0% over the control Shanyou 63. In 2005, it participated in the Jiangsu Province hybrid indica rice production trial, with an average yield of 460.0 kg per mu, an increase of 12.1% over the control Shanyou 63.
While participating in the provincial intermediate trials, Tianfengyou 269 was also tested in multi-site demonstration plantings in production, generally yielding about 650 kg per mu, with a yield potential of about 750 kg. For example, in 2005, at the Yanyou 269 demonstration plot in Shangzhuang Town, Yandu District, with an area of 35 mu, the average yield was 630.5 kg per mu, an increase of 11.5% over the adjacent field of Shanyou 63.
3 Characteristics and Traits
Tianfengyou 269 seedlings are short and sturdy, with short, thick, light purple coleoptiles, short and upright leaves, and light green leaf color; tillering ability is medium to strong, tillering occurs early and concentrated, with many low-node tillers. The mature plant type is moderately compact, with a plant height of about 115 cm; the main stem produces 17 to 18 leaves over its life, and the upper three functional leaves are upright with a good light-receiving posture; at maturity, the flag leaves are erect, forming a grass-canopy top, and the culms remain green while the grains turn yellow, giving a good ripening appearance. The effective panicles per mu are about 160,000, the panicle type is relatively large, the panicle length is about 25 cm, the total grains per panicle are more than 180, the filled grains per panicle are about 150, the seed-setting rate is above 85%, and the 1000-grain weight is 26 to 27 g. The grains are yellow and well filled; the milled grains are plump with good transparency, small white belly and center, relatively good grain quality, and good palatability. According to testing in 2004 by the Rice and Rice Products Quality Supervision, Inspection and Testing Center of the Ministry of Agriculture: brown rice rate 81.0%, milled rice rate 72.4%, head rice rate 63.0%, grain length 7 mm, length-to-width ratio 3.2, chalkiness rate 33%, chalkiness degree 3.3%, transparency grade 2, alkali spreading value grade 5, gel consistency 60 mm, amylose content 23.18%, and physicochemical score 53. According to the inoculation identification results in 2003 by the Institute of Plant Protection of the Jiangsu Academy of Agricultural Sciences: resistant to the bacterial blight pathogen strain JS49-6 (grade 1), moderately resistant to the bacterial blight pathogen strains Zhe 173 and PX079 (grade 3), and moderately susceptible to the bacterial blight pathogen strain KS-6-6 (grade 5); immune to six physiological races of rice blast, namely ZB5, ZC5, ZD5, ZE3, ZF1 and ZG1, all with disease grade 0; highly resistant to neck blast (grade 1), moderately resistant to sheath blight (0.1713), moderately resistant to stripe disease (MR), and strongly lodging-resistant. According to records from various trial sites, Yanyou 269 has relatively strong field resistance. Tianfengyou 269 is cultivated as wheat-stubble mid-season rice in Jiangsu, with a whole growth period of 140 to 150 days, similar to Shanyou 63; it belongs to the medium-maturing indica three-line hybrid rice type, has good stubble adaptability, and can be planted after large @#@245@#@ stubble; it is suitable for promotion and planting under medium-to-upper fertility and water conditions in Jiangsu Province and the single-season mid-season indica rice areas of the middle and lower reaches of the Yangtze River.
4 Cultivation Techniques
Tianfengyou 269 is a heavy-panicle type variety, and high-yield cultivation should adopt the strategy of "striving for sufficient panicles, focusing on large panicles, and improving the seed-setting rate and 1000-grain weight to achieve high yield." In terms of measures, promote early development in the early stage to lay the foundation for sufficient panicles; stabilize the seedlings and strengthen the plants in the middle stage to promote the formation of large panicles; and nourish the roots and protect the leaves in the late stage to improve the seed-setting rate and 1000-grain weight.
4.1 Sowing at the appropriate time and cultivating strong seedlings When planted as single-season rice in Jiangsu, sowing is generally done in early to mid-May. For water-raised seedlings, the sowing rate is 25 to 30 kg per mu of seedling field; for dry-raised seedlings, the sowing rate is 35 to 40 kg per mu of seedling field; the seed rate per mu of main field is 1.2 to 1.5 kg, and the seedling age is 30 to 35 days. The seedling field should be given sufficient basal fertilizer, with early application of weaning fertilizer and timely application of pre-transplanting fertilizer, to cultivate strong seedlings with multiple tillers.
4.2 Reasonable dense planting and uniform transplanting with sufficient seedlings The general plant-row spacing is about 13 cm x 25 cm, with a transplanting density of 18,000 to 20,000 hills per mu, and 1 to 2 seedlings per hill. For fertile-bed dry-raised sparse planting, the plant-row spacing is 15 cm x 30 cm, with 1 to 2 seedlings per hill, and sufficient basic seedlings of 70,000 to 80,000 per mu should be established, with shallow and uniform transplanting.
4.3 Scientific fertilization to promote early seedling development For high-yield cultivation of Tianfengyou 269 at 650 kg per mu, the total fertilizer requirement of the main field is equivalent to 15 to 18 kg of pure nitrogen, and the ratio of basal, tillering and panicle fertilizers should preferably be 5:3:2. Fertilizer management strategy: 1) Apply sufficient basal fertilizer. The basal fertilizer should be mainly organic fertilizer, combined with phosphate and potassium fertilizers. On the basis of straw return, apply 200 to 300 kg of pig manure, 10 kg of urea and 8 kg of diammonium phosphate per mu as basal fertilizer; in potassium-deficient fields, add 5 to 7 kg of potassium chloride per mu. 2) Apply heavy tillering fertilizer. Apply 10 to 15 kg of urea per mu 5 to 6 days after transplanting, and then apply another 10 kg of urea per mu after 7 days, ensuring that the expected number of stems and tillers is reached 20 days after transplanting. Then drain the field to control seedlings, keeping the peak number of seedlings from exceeding 250,000 per mu. 3) Apply panicle fertilizer early. After field draining, once the leaf color fades, apply 8 to 10 kg of urea per mu 4 to 5 days before panicle differentiation, both to gain some unstable tillers and increase the panicle-forming rate, and to provide sufficient nutrition for young panicle differentiation. 8 to 10 days after the first application of panicle fertilizer, apply another 5 kg of urea per mu, after which no more fertilizer should in principle be applied, ensuring that the leaf color fades before heading.
4.4 Good water management to coordinate the population Water management should follow the principle of "shallow water for transplanting, 1-cun water for seedling establishment, thin water for tillering, water retention for heading and flowering, and alternate wetting and drying for grain filling." In the early stage, irrigate frequently with shallow water to promote early development; in the middle stage, alternate wetting and drying to strengthen culms and roots; in the late stage, moist irrigation to keep the plants alive and maturing well to the end. It is required that sufficient panicle seedlings be developed 20 days after transplanting; that is, when the stems and tillers per mu reach 160,000, drain the field promptly for a soft drying of 2 to 3 days, then add shallow water for 3 to 5 days, and after natural drying, drain the field again for 3 to 5 days, then alternate wetting and drying until booting; maintain a shallow water layer from booting to flowering; alternate wetting and drying after full heading; and dehydrate 5 days before harvest, and by no means cut off water too early.
4.5 Control diseases and pests to protect seedlings and increase panicles During the growth period, pay close attention to disease and pest forecasts. In the seedling field, focus on the control of rice thrips, aphids, planthoppers and other diseases and pests; during the main field period, focus on the control of the first and second generations of striped stem borer, pink stem borer, leaf roller, rice planthopper, and sheath blight and other diseases and pests, ensuring normal growth of rice seedlings and protecting seedlings and increasing panicles for high yield.
5 Key Points of Seed Production and Multiplication Techniques
5.1 For Tianfeng A multiplication, the male parent is divided into two phases: the first-phase male parent is sown 3 days later than the female parent, and the second-phase male parent is sown 7 days later than the female parent; the row ratio of male to female parents is 2:8 to 10, and other management measures are similar to those for Longtepu A multiplication.
5.2 For Tianfengyou 269 seed production, the male parent is divided into two phases: the first-phase male parent is sown at the end of April, and the second-phase male parent is sown 10 days later than the first-phase male parent; the sowing interval between the female parent and the first-phase male parent is 30 days, with a leaf difference of 6.0 to 6.5 leaves, and the row ratio of male to female parents is 2:12 to 14. Other management measures are the same as for Teyou 559.