Introduction to the Characteristics and Traits of the Rice Variety Fuyouwan 3

[Basic Information] Fuyouwan 3 (Fuyi A/Wan 3) is a new early indica hybrid combination developed by crossing the restorer line Wan 3, bred by the Hunan Hybrid Rice Research Center, with Fuyi A. Fuyi A is a wild-abortive (WA) type CMS line developed from V41A//IRS24/Tiangu B through the theory of minor restorer genes and the exclusion method, showing such advantages as disease resistance, good quality, high sterility, stable fertility, good glume-opening habit, high outcrossing rate and good combining ability.

[Characteristics and Traits] In 1996 it was entered in the Fujian provincial early hybrid rice regional trial, with an average yield of 6.87 t/ha, 2.24% higher than the control Weiyou 64. From 1996 to 1997 it was entered in the Longyan city early rice regional trial, with average yields of 7.25 and 7.02 t/ha respectively, 3.9% and 26.1% higher than the control Shanyou 77. In 1997 it was entered in the early rice comparison trial in Putian county, with a yield of 6.62 t/ha, 26% higher than the control Shanyou 77. In 1998 it was entered in the early rice comparison trials in Putian county and Bei'an district, with average yields of 6.83 and 6.06 t/ha respectively, 5.7% and 6.4% higher than the control Weiyou 77. In the same year's early season, 58.67 ha were planted for demonstration in Huangshi town, Putian county, with an average yield of 7.36 t/ha, 6.25% higher than the control Shanyou 77. From 1998 to 1999, in Yongding, Wuping, Shanghang and other counties of Longyan city, large-area late-season seedling-throwing cultivation gave an average yield of 7.00 t/ha, more than 5% higher than the control Shanyou 77.

In the 1996 Fujian provincial early indica regional trial, the average growth period across 17 sites was 133.8 d, 4.2 d later than Weiyou 64; in Fuzhou it was 126 d, 2 d later than Weiyou 64; in Longyan it was 129 d, 1 d later than Shanyou 77; in Putian it was 120 d, 1 d later than Weiyou 77, making it a medium-maturity early indica combination. It is suitable for planting as early rice in the rice-growing areas south of Fuzhou, and as late rice in the rice-growing areas of northwestern Fujian and as middle or late rice in the middle and lower reaches of the Yangtze River.

The plant type is moderately compact and spreading, with strong tillering ability, a high productive-tiller rate of up to 60%, and good color change at the late stage. Plant height is 95-105 cm, panicle length 22-24 cm, effective panicles 2.85-3.00 million/ha, total grains per panicle 144.2, seed-setting rate above 81%, and 1000-grain weight 26.5 g. The grain shape is long-oval, the glume tip is purple, and there is no awn.

In 1996, in natural inoculation identification at the rice blast disease areas of Chadi in Shanghang, Baofeng in Minqing and Xiandian in Wuyishan, as well as at 10 rice blast resistance sites in the provincial regional trial, leaf blast was below grade 3 at all sites, panicle blast was grade 0, and the rice blast resistance index was 95.5%. Professor Zhang Xuebo of Fujian Agricultural University used 16 single-spore isolates from 11 physiological races of 3 groups (A, B, C), and 4 mixed strains, for seedling-stage inoculation identification; the rate of resistant strains reached 85%, showing high resistance to the epidemic races ZB9, ZB13 and ZB23 in our province.

The rice quality of Fuyouwan 3 was tested by the Rice and Rice Products Quality Inspection and Testing Center of the Ministry of Agriculture: brown rice rate 80.7%, milled rice rate 73.4%, head rice rate 56.4%, grain length 6.3 mm, length-to-width ratio 2.7, chalkiness rate 89.5%, chalkiness degree 15%, transparency grade 3, alkali spreading value grade 4.3, gel consistency 68 mm, amylose content 25.4%, and protein content 10.2%. When this combination is grown as late rice, its rice quality indices can be improved by one grade; according to reports from the counties of Longyan city, the late-season rice quality is good, with transparent grains, a high head rice rate, reduced amylose, and soft, good-tasting cooked rice.

[Breeder] Rice and Wheat Research Institute, Fujian Academy of Agricultural Sciences

[Region and Techniques] To prevent bakanae disease during the seedling-bed stage, soak the seed in clean water for 24 h, then soak in strong chlorinated lime for 12 h, then rinse thoroughly with clean water several times before sprouting. In the early season, sow in the plains and coastal areas from March 11 to 15, and in mountainous areas sow earlier, in early March; a seedling age of 30 d is suitable. In the late season, sow in early July, with seedling age not exceeding 20 d.

For transplanting spacing, use 18 cm x 20 cm in the early season and 15 cm x 20 cm in the late season, planting 2 grain seedlings per hill, with a sufficient basic population of 0.80-0.87 million hills/ha.

Fuyouwan 3 has relatively wide and long flag leaves and is not tolerant of heavy fertilizer. Fertilization should promote early tillering in the early stage, strengthen stems and plants in the middle stage, and apply as little nitrogen fertilizer as possible in the late stage, with appropriate additional P and K fertilizer in the middle and late stages; the N:P:K ratio is 1:0.6:0.8. Generally, basal fertilizer accounts for 80% of the total fertilizer application, applied evenly one day before transplanting together with puddling and then leveled; tillering fertilizer accounts for 20%, applied in two splits, the first at 5-7 d after transplanting together with chemical weeding in the field, and the second at 12-15 d after transplanting as a stem-thickening fertilizer to promote formation of a high-yielding population. Fuyouwan 3 has strong tillering ability, so after transplanting maintain shallow water and frequent irrigation to promote early tillering; generally 20 d after transplanting, when the number of stems and tillers per hill reaches 20, drain the field naturally to bake the soil and control ineffective tillering. After soil baking, rewater promptly to reduce spikelet degeneration and favor the formation of large panicles; irrigate shallow water at heading and flowering to prevent premature water cutoff in the late stage. At the peak tillering stage, pay attention to controlling sheath blight and rice leaf roller; at the initial heading stage, pay attention to controlling the second and fourth generations of yellow stem borer; and in the late stage, pay attention to controlling rice planthopper.

Fuyi A has 1 more leaf than Zhenshan 97A, belongs to the basic vegetative type, has a relatively stable growth period, large panicles and many grains, with effective panicles per hill reaching 8-10, a flowering period lasting up to 14-15 d, and concentrated flowering time; Wan 3 has a short flowering period and a large, concentrated amount of pollen.

For seed production in the early season, sow the male parent in mid-March, with a 7 d difference between the I and II male parent sowing dates, and sow the female parent about 20 d later than the phase I male parent; for seed production with middle rice (or late rice), the sowing interval between the parents is about 15 d.

The female parent seed rate is 30.0-37.5 kg/ha, and the male parent seed rate is 4.5 kg/ha. The seedling-bed sowing rate is 120-150 kg/ha; sow sparsely and evenly to raise strong seedlings. In the early season the seedling age should be within 30 d, and in the middle and late seasons within 20 d. The row ratio of male to female parents is 2:12. The plant and row spacing for the male parent is 20 cm x 26 cm, and for the female parent 13 cm x 15 cm, with 2 grain seedlings per hill for both.

The total fertilizer application per hectare is 300-330 kg pure nitrogen, 225-255 kg phosphate fertilizer, and 180-210 kg potassium fertilizer. Topdress promptly 5-7 d after transplanting the parents, and in the middle and late stages apply supplementary fertilizer as needed according to seedling growth (do not judge by leaf color depth, because the female parent's leaves are darker green). Promptly control sheath blight, stem borers, rice planthopper and other diseases and pests.

At the initial heading stage of the female parent, cut off 50%-70% of the length of the canopy leaves, and cut off 50% of the length of the canopy leaves of the male parent. Because Fuyi A is relatively insensitive to "920", the dosage per hectare should be increased by 75-90 g compared with Zhenshan 97A, and spraying of "920" should begin when 20%-25% of the female parent has headed, with heavy spraying continued over 2 days, 120-135 g/ha each time. Fuyi A itself flowers early, has a wide glume-opening angle, a high stigma exsertion rate and strong vigor, and some grains show glume splitting; therefore it is not suitable to spray regulators such as Duoweiling. During the flowering and seed-setting period, maintain a shallow water layer in the field to ensure field humidity, so as to reduce seed glume splitting and improve seed quality.