Bo ii you 15 (Rice)

[basic situation] the hybrid rice combination of Boyou Ⅱ superior system is the dominant combination of late rice in Guangdong, Guangxi and Hainan provinces. However, Boyou 903 and Boyou 3550 have some problems such as yield potential degradation and disease resistance weakening after planting for many years, resulting in a significant decrease in planting area. In the early season of 1996, Bo Ⅱ A, a male sterile line cultivated by Agricultural Science Institute of Bozi County, Guangxi, was crossed with our newly selected high quality restorer line HR15 (Ai Huangzhan × Qingliuai 1). Qingcheng Bo Ⅱ you 15 showed outstanding performance in regional and production tests of rice in Guangdong and southern China. It had the characteristics of high and stable yield, strong resistance to rice blast, good adaptability and good rice quality. It was welcomed by farmers in production demonstration, and the planting area expanded rapidly. It is expected to become the main extension combination of the new generation of late rice in South China.

[characteristics] Boyou 15 belongs to a weak photosensitive combination, and the whole growth period of planting in South China in late season is about 118 days, which is basically the same as that of II 903. The tillering ability is medium, the plant type is moderate, the stem is stout, fertilizer-resistant and lodging-resistant, the panicle type is large, the upper functional leaves are thick and erect, and the color is good in the later stage. Plant height 101~110cm, effective panicle 2.4 million ~ 2.7 million / hm2, total grain 140,160 per panicle, seed setting rate about 85%, 1000-grain weight 22.5~23.Og.

Determined by the Rice and products quality Supervision and Inspection Center of the Ministry of Agriculture, brown rice rate is 81.2%, milled rice rate is 73.1%, head rice rate is 62.0%, alkali elimination value is 6.4, these four indicators meet the first-class standard of high-quality rice issued by the Ministry; grain length 6.Omm, length-width ratio 2.6, transparency grade 2, gel consistency 42.0mm, these four indicators meet the second-class standard of high-quality rice issued by the Ministry; chalkiness 6.6%, amylose content 25.8%. Evaluated by Guangdong Grain and Oil testing Center, the appearance quality of Boyou 15 is grade 2, which is the same as that of Boyou 903.

Identified by Guangdong crop disease and pest forecasting station, Bo II you 15 is resistant to rice blast (the whole population resistance ratio is 85.0%, of which the resistance to group C of rice blast is 84.61%), and the total resistance to bacterial blight is grade 7. According to the identification of southern rice regional test, the average level of leaf blast, panicle blast and bacterial blight were 3, 1 and 7 respectively. Planted in many rice blast areas in Guangdong Province, BoII you 15 showed resistance to rice blast.

Joined Guangdong Province in 1999. In the regional test of weak photosensitive group in late season, the average yield of 6.68t/hm2 ranked second in the combination tested, which increased by 7.49% and 3.18% compared with Boyou 903 (CK1) and Boyou 3550 (CK2). In the late season of 2000, he participated in the regional trial retrial and production test in Guangdong Province. the average output of the regional test was 6.48t/hm2, which was 1.19% lower than that of the control Boyou 122, and the average output of 16 pilot production trials was 7.17t/hm2. In the regional trial of South China late Indica Group in 2000, the average yield of 7.7Ot/hm2 was 9.96% and 8.82% higher than that of Boyou 903 (CK1 and Japonica Indica 89 (CK2), respectively), which reached a very significant level and ranked first among the 9 tested combinations. In the late season of the same year, II you 15 demonstrated 2Ohm2 in Sanhe Village, Shengjiang Town, Luoding City, with an average unit yield of 8.36t/hm2. Zhu Shaoyuan farmers planted 870m2, and the average yield per unit area was 10.00t/hm2.

[cultivator] Agricultural College of Zhanjiang Ocean University

[region and technology] a) sowing and raising strong seedlings at the right time. In the late season in South China, II you 15 should be sowed in early July and transplanted from the end of July to the beginning of August. The sowing date should not be too late, which would delay the heading date and shorten the vegetative growth period and affect the yield. Sparse sowing to raise strong seedlings, generally sowing amount of 130~150kg/hm2 in seedling field and seed amount of 15.0~22.5kg/hm2 in field. The seedling field should apply sufficient basic fertilizer, apply good weaning fertilizer, see Miao Qiao apply marriage fertilizer, spray good marriage medicine.

B) reasonable close planting and full insertion of basic seedlings. Generally, the planting density is 300000 holes / hm2, the row spacing can be 13cm × 25cm or 16cm × 20cm, and the basic seedling is 900000 ~ 1 million / hm2.

C) Field fertilizer and water management. On the premise of applying sufficient basal fertilizer, tillering fertilizer should be applied early to achieve early growth and rapid development, strong panicle and flower protection fertilizer should be re-applied in the middle stage, and attention should be paid to the combined application of nitrogen, phosphorus and potassium so as not to be greedy in the later stage. In terms of water layer management, transplanting seedlings with thin water or throwing seedlings with muddy water, turning green in an inch of water, promoting tillering in shallow water, drying the field in time, wet irrigation in the middle stage, heading and raising flowers in shallow water, dry and wet in the later stage, do not cut off the water too early, so as not to affect the seed setting rate and 1000-grain weight.

D) Pest control Attention should still be paid to the prevention and control of rice blast in the areas with high incidence of rice blast and in the years of heavy occurrence, and attention should be paid to the control of sheath blight and pests such as rice stem borer, rice planthopper, rice leaf roller and so on.

The male parent HR15 has strong tillering ability, tall plant, large panicle and many grains, sufficient pollen, sensitive to temperature, fertilizer and "920" response, and has great difference in growth period in warm and cold years. The female parent IIA had medium tillering ability, strong lodging resistance, fertilizer tolerance, larger panicle, good flowering habit, high stigma exposure rate, high outcrossing rate and sensitive to "920". The difference of leaf age between parents of Bo II you 15 in early spring seed production in Leizhou Peninsula was about 5.5leaf. In winter seed production in Sanya, Hainan, the difference of leaf age was about 14 ±3d, and the leaf age difference was about 3.8leaf. Other cultivation and management techniques are the same as those of general hybrid rice combinations.