Detailed Introduction to the Shanyou 122 Rice Variety

[Basic Information] Shanyou 122 is a temperature-sensitive, medium-late maturing hybrid combination developed by crossing the newly bred high-quality restorer line Guanghui 122 (Lian 836-1 Minghui 63/Guanghui 3550) with Zhenshan 97A. It has accumulated a promotion area of 76,900 hm2 in our province, becoming the leading medium-late maturing hybrid rice combination in our province.

[Characteristics] When grown as early rice, the whole growth period of Shanyou 122 is 122-128 d, 6 d later than the medium-maturing control variety Shanyou 96 and 5 d earlier than the late-maturing control variety Shanyou 63. When grown as early rice in Meizhou, Heyuan and other places, it can fully utilize local solar energy to increase its yield. When grown as late rice, the whole growth period is about 110 d, which not only provides a certain growth period but also fits the local safe heading stage and its optimal grain-filling stage, making it the best maturity period for some rice-growing areas in our province.

In the blast resistance identification of the early-season medium-maturing group regional trial of hybrid rice in Guangdong Province, the overall resistance ratio of Shanyou 122 to rice blast was 80%, among which group A was 50%, medium group B was 100%, medium group C was 66.67%, medium group D was 100%, medium group E was 100%, medium group F was 80%, and medium group G was 100%; it is not resistant to bacterial blight (overall resistance rating of 7). When planted in various places in our province, it showed resistance to rice blast, and no disease-related losses were found.

The appearance quality of early rice in the Guangdong provincial regional trial was rated grade 3, one grade higher than both the control Shanyou 96 and Shanyou 63. The rice quality analysis results: grain length 6.26 mm, grain width 2.22 mm, length-to-width ratio 2.82, chalkiness rate 50%, chalkiness degree 13.5%, amylose 22.1%, gel consistency 91 mm. These indicators all showed significant improvement over Shanyou 96 and Shanyou 63, especially amylose and gel consistency, showing moderate hardness and softness of rice quality, good taste and palatability of cooked rice, and suitability for the general public's taste.

Plant height 99.3-99.9 cm, panicle length about 22 cm, 121-123 grains per panicle, seed-setting rate 83%-85%, 1000-grain weight 25-26 g. The growth period is similar to that of Shanyou 46. During the vegetative growth stage, it emerges early and grows quickly, with strong tillering ability and vigorous growth; during the reproductive growth stage, the leaves are compact and erect, with good solar energy utilization and little response to temperature and light. It has good flexibility in seedling age, relatively stable growth amount and growth period, short and thick stems, good lodging resistance, strong cold tolerance, easy planting and management, and good ripening color at the later stage. Under better fertilizer and water conditions, the yield is high and stable, adapting to farmers' current planting and management levels.

The male parent of this combination, Guanghui 122, has strong tillering ability, many effective panicles, a large amount of pollen, and good flowering time. In 1998, our institute produced 11.33 hm2 in Hainan in spring, with an average yield of 3.21 t/hm2, of which 3 hm2 reached 3.59 t/hm2. It is generally 525-600 kg/hm2 higher than other Shanyou combinations, with good economic benefits for seed production.

In the early season, it participated in the medium-maturing group regional trial of hybrid rice in Guangdong Province, with an average yield of 7.23 t/hm2, an increase of 11.24% over the control Shanyou 96, a highly significant increase, and a daily yield of 56.55 kg/hm2, an increase of 6.19% over the control. In the early season of 1998, it participated in the re-test of the late-maturing group of hybrid rice, with an average yield of 6.55 t/hm2, a decrease of 2.84% compared with the control Shanyou 63, a non-significant decrease, and a daily yield of 53.7 kg/hm2, an increase of 1.12% over Shanyou 63. In the early season, its maturity is 6 d later than Shanyou 96 and 5 d earlier than Shanyou 63. In the late season of 1998, 7,260 hm2 were planted in Meizhou City, with a general yield of 7.5 t/hm2 and high-yield fields reaching more than 9.0 t/hm2. Large-area planting in Meizhou, Heyuan, Shaoguan and other places in Guangdong Province showed broad adaptability and high stability. Especially in the late season in high-cold mountainous areas and areas with more cold damage, its high and stable yield performance was even more prominent, making it an indispensable hybrid rice combination in some rice-growing areas of our province.

[Breeder] Rice Research Institute, Guangdong Academy of Agricultural Sciences

[Region and Technology] a) Pay attention to sparse and uniform sowing, and cultivate young tillering strong seedlings, with a seedbed sowing rate of 150.0-187.5 kg/hm2. b) Sow at the right time and transplant in time; the suitable seedling age is 30 d for early season and 18-20 d for late season. c) Reasonable close planting, insert enough basic seedlings; the general planting spacing is 16.5 cm x 19.8 cm, and it is suitable to insert 2-grain seedlings per hill. d) Implement a water management method combining shallow water, exposure, and drying, achieving shallow water transplanting, inch water for seedling survival, thin water for tillering, and drying the field when enough seedlings are reached. e) Apply sufficient base fertilizer, apply tillering fertilizer early and heavily to promote early and rapid tillering, and apply panicle fertilizer as appropriate at the later stage. Timely control pests to achieve high and stable yield.

Key points of seed production technology: a) The male parent of this combination, Guanghui 122, has strong tillering ability and many effective panicles, generally reaching 1.5-1.8 million panicles/hm2 in seed production fields. For spring seed production in Hainan, sow in late December, seedling age 28-30 d, sowing-to-heading period 103-105 d, and the number of leaves on the main stem is 17.2; for autumn seed production in Guangdong, the sowing-to-heading period is 72-74 d, and the number of leaves on the main stem is 15.5. The flowering duration of a single plant is 8-10 d, the flowering peak is 3-7 d after heading, the flowering duration of a single panicle is 4-5 d, and the full flowering period is 10:20-11:00. For autumn seed production in Guangdong, the sowing interval between male and female parents is preferably 15 +/- 2 d, and the leaf age difference is 4.2 leaves; for spring seed production in Hainan, the sowing interval between male and female parents is preferably 25 +/- 2 d. The male parent is sown in two stages, preferably 3 d apart. b) Cultivate strong seedlings of suitable age with tillers, plant reasonably closely, and establish a reasonable population structure. The seedbed sowing rates of the male and female parents are 112.5 and 150.0 kg/hm2 respectively; the planting spacing is 16.7 cm x 23.3 cm for the male parent and 10.0 cm x 3.3 cm for the female parent; the row ratio of male to female parents is 2:(14-16). c) Scientific fertilization and rational water use. Adopt the fertilization principle of early promotion, mid-stage control, and later supplementation; inch water for regreening, thin water for tillering, drying the field when enough seedlings are reached, and combining dry and wet conditions at the later stage.

d) Spray "920" at the right time and perform artificial pollination well to improve outcrossing seed-setting rate. Timely prevent and control pests and diseases and strictly remove impurities and inferior plants to ensure quality.