Introduction to the Rice Variety T You 7889

[Basic Information]The College of Crop Science of Fujian Agriculture and Forestry University, in cooperation with the Fujian Provincial Seed Station, started with improving the quality of three-line sterile lines and bred the high-quality sterile line T78A. The hybrid combination T You 7889, produced by crossing it with Early Restorer 89, has strong heterosis and excellent grain quality, and was the winning combination at the 2001 Fujian Province early rice high-quality grain bidding meeting.

Using the maintainer lines Longtepu B, Digu B and Zhenshan 97B, which have complementary traits, composite crossing was carried out to breed a high-quality maintainer line, and then through test crossing and backcrossing with Zhenshan 97A, a high-quality sterile line was bred. In the spring of 1992, the single-cross combination Longtepu B/Digu B was made in Fuzhou; in the autumn the first hybrid generation was planted, and at heading time Zhenshan 97B was used as the male parent for a multiple cross. Starting from several generations of the multiple cross, individual plants with excellent grain quality and good agronomic traits were selected as male parents to cross with Zhenshan 97A, and continuous backcrossing over multiple generations was carried out. In 1997, the sterile line T78A was bred, with uniform agronomic traits, excellent grain quality, good outcrossing characteristics and stable sterility. This sterile line passed appraisal by the Fujian Provincial Science and Technology Department in July 2000.

[Characteristics]The milled rice of T You 7889 is relatively transparent, with small chalkiness and excellent quality. When tested by the Rice Quality Supervision and Testing Center of the Ministry of Agriculture on grain grown in the early season in Fujian, 4 indicators reached the first-class standard for high-quality rice issued by the Ministry: milled rice rate (73.0%), alkali spreading value (grade 5.8), amylose content (21.0%) and protein content (9.3%); 7 indicators reached the second-class standard for high-quality rice issued by the Ministry: brown rice rate (80.9%), head rice rate (58.2%), grain length (6.1mm), length-to-width ratio (2.7), chalkiness degree (3.8%), transparency (grade 2) and gel consistency (5Om). On tasting, it has good palatability. It was the winning combination at the 2000 Fujian Province early rice high-quality grain bidding meeting, received project funding from the Fujian Provincial Major Agricultural Science and Technology Project, and is being rapidly promoted and applied.

In the 1998 early season, T You 7889 took part in the variety comparison trial of the College of Crop Science of Fujian Agriculture and Forestry University, with a yield of 6.39t/hm2, ranking first among the 8 combinations tested and increasing yield by 1.23% over the control Weiyou 77. In the 1999 early season, it took part in the multi-location trial of Fujian Agriculture and Forestry University, and at Jinshan in Fuzhou, Loutou in Putian and Minhou County it all increased yield over the control Weiyou 77, with increases of 3.6%-11.8%.

In 1999, T You 7889 took part in the Fujian Province early rice high-quality rice group regional trial, with an average yield of 6.56t/hm2, ranking 1st and increasing yield by 7.12% over the control 78130, reaching an extremely significant level. In the 2000 early season it continued in the trial, with an average yield of 6.88t/hm2, increasing yield by 8.61% over the control 78130, reaching an extremely significant level and ranking 2nd. In 2000, T You 7889 took part in the national southern rice region late indica early-maturing group regional trial, with an average yield of 6.9Ot/hm2, increasing yield by 3.04% over the control Shanyou 64, reaching a significant level.

In the 2000 early season, T You 7889 entered the Fujian Province production demonstration ahead of schedule, with 2.Ohm2 demonstrated and planted at each of 9 demonstration sites: Fuzhou, Xiamen, Putian, Quanzhou, Zhangzhou, Longyan, Sanming, Nanping and Ningde, with an average yield of 7.07t/hm2. Among the 7 demonstration sites using Weiyou 77 as the control, T You 7889 increased yield over the control by an average of 10.24%.

T You 7889 has a plant height of about 95cm, a compact plant type, upright leaves, good stem elasticity and strong lodging resistance. In the late stage it keeps green branches and waxy stalks, with good colour conversion. Tillering ability is moderate, generally with 3.3 million effective panicles/hm2, panicle length 21-22cm, about 115 grains per panicle, seed setting rate 80%, 1000-grain weight about 25g, and yield above 6.75t/km2.

When grown as early rice in Fujian, the whole growth period of T You 7889 is about 129d, 1-2d longer than Weiyou 77 and comparable to Weiyou 89. In the 2000 national southern rice region late indica early-maturing group regional trial, the whole growth period of T You 7889 was 115.7d, 1.2d earlier than the control Shanyou 64.

In the 1999 identification in the rice blast disease nursery in Shanghang, Fujian, T You 7889 had grade 1 neck blast, with an incidence rate of 3% (the control Weiyou 64 had grade 7 neck blast, with an incidence rate of 35%). In the 1999 joint identification in the rice blast disease nursery of the Fujian Province early rice regional trial, the leaf blast resistance index of T You 7889 was 71.0%, the neck blast resistance index was 722%, and the overall field rice blast resistance rating was moderately resistant. After many years of trial planting, no damage from bacterial leaf streak or bacterial blight has been found.

[Breeders]College of Crop Science of Fujian Agriculture and Forestry University, Fujian Provincial Seed Station

[Region and Techniques]When grown as early rice in Fujian, sowing may be done in early to mid-March; the seedling age should not be too long, with 25-28d being suitable. The sowing rate in the seedling bed should be 300kg/hm2.

T You 7889 has moderate tillering ability, so it should be planted somewhat densely, with a planting spacing of 17cm x 20cm being suitable. Plant 2 grain seedlings per hill, with a basic population of 750,000-900,000/hm2.

T You 7889 is relatively tolerant of fertiliser, so sufficient base fertiliser should be applied and tillering fertiliser applied early. Keep shallow water to promote tillering, drain the field at the proper time, control ineffective tillering, enhance root vigour and raise the rate of tillers that form panicles.

The sterile line T78A has black-purple stigmas, a high exsertion rate, good flowering habits, high seed production yield, and a growth period similar to V20A. For seed production after tobacco in northern Fujian, the sowing-to-heading period of the female parent T78A is 63d and that of the male parent Early Restorer 89 is about 80d, so a sowing interval of 18d between the parents is suitable.

Because the female parent has a relatively short growth period and small growth volume, the female parent should be raised into strong seedlings with a short seedling age, and the basic population should be planted in full to ensure more effective panicles and increase seed production yield.