Peiza 67 (Rice)

Peiza67, a new two-line hybrid rice combination with good quality, high yield and high resistance, was bred by crossing the low temperature sensitive genic male sterile line Peiza64S with the self-selected high quality indica-japonica hybrid line G67(Copslo17/Haogelao//Xinxiu299).

Peiza67 was tested in Guangdong Province and its yield was 6.84 t/hm2, which was equal to that of Shanyou 63. Peiza67 was tested in 1996 and 1997 and its yield was 6.29 t/hm2 and 6.08 t/hm2, respectively. In 1997, it participated in the national "863" pilot test. The yield of early rice was 6.99 t/hm ~ 2 and that of late rice was 6.55 t/hm ~ 2 in the regional test of South China. Since 1995, trial planting demonstration has been carried out in Yangjiang, Qingyuan, Meizhou and other counties of Guangdong Province. The yield is generally about 6.75 t/hm2, which is equal to or significantly higher than that of local extension varieties. Because of its superior rice quality, it is welcomed by farmers. From 1996 to 1999, more than 1 300 hm ~ 2 were planted in Xinxing County for 7 consecutive years. The yield was 7.05~ 7.50 t/hm ~ 2, and the high yield reached 9.78 t/hm ~ 2. In late season of 1998, it was planted in Guangning County, and the average yield was 7.56 t/hm2. In 1999, it was demonstrated to be planted in Longchuan County, and the average yield was 7.25 t/hm2. Peiza67 has been popularized rapidly and planted 6 606.7 hm ~ 2 by the end of 1999.

Peiza 67 belongs to temperature sensitive medium and late maturity combination, its maturity period is equivalent to Shanyou 63, the whole growth period of early season is 129 days, and that of late season is 118 days. The plant height is 110cm, the plant type is moderate, the stem is thick, the tillering ability is weak, the leaves are hard and straight, the leaves are green and beautiful, the cold resistance is strong, and the late maturity color is good. The total number of grains per panicle was 160~200, the seed setting rate was about 80%, the 1000-grain weight was 19g, and the appearance of early-growing rice was first class. High resistance to rice blast (resistance ratio of whole population 94%), moderate susceptibility to bacterial blight (resistance ratio of whole population 7), field planting performance of rice blast and bacterial blight are slight. The yield of common fertility field can reach 6.75t/hm2, and that of high fertility field can reach 9.5t/hm2.

Cultivated by Department of Agriculture, South China Agricultural University

Key points of regional and technical cultivation techniques: a) seed disinfection and breaking of dormancy. Peiza 67 is no exception, especially for the new varieties used in spring, it is better to use strong chlorine essence to soak seeds and disinfect and break dormancy, so as to make the seedlings neat and consistent, and prevent the seeds from carrying diseases. b) Peiza67 has weak tillering ability and small 1000-grain weight. To give full play to its high yield potential, it should be cultivated with sufficient basal fertilizer and early topdressing. In order to create high yield seedling stand, it is necessary to increase the effective panicle number on the basis of ensuring the original big panicle, and to transplant enough basic seedlings 900 000 ~120 000/hm2. It is also necessary to cultivate strong seedlings, apply fertilizer early, and promote early tillering. c) After enough seedlings, more dew and light sun, control the number of peak seedlings, apply mid-term fertilizer (panicle fertilizer), under the condition of low temperature in late season, the leaves are easy to premature senescence, and keep the field moist. In early season, the plant height was slightly higher, and lodging should be prevented when planting under high fertilizer level.

d) The seedling age should not be too long in late season and autumn cultivation, and 18~ 2Od was suitable to prevent early panicle from affecting yield. It is necessary to strengthen the control of sheath blight, rice planthopper, rice false smut and smut.

Main points of seed production techniques: Peiai 64S has the advantages of concentrated flowering time and high stigma exposure rate, but its stigma is small, stigma vitality decreases rapidly, spikelet opening time is short, glume angle is small, and it is especially insensitive to "920," which brings some difficulties to high yield of seed production. The male parent G67 has small 1000-grain weight, large panicle and many grains, weak tillering ability, large pollen amount, long hole flowering period and general response to "920." Therefore, the following technical measures are proposed.

The seed production of two-line hybrid rice requires not only an optimal heading and flowering stage, but also an optimal safe young panicle differentiation stage to ensure the safe sterility of female parent. Two safe periods should be determined according to climatic conditions and seed production experience over the years, and the sowing time of parents should be arranged reasonably. In Hainan spring system, Pei 'ai 64S usually needs to start heading at the end of April and the beginning of May, so the female parent should be sown on February 10~15, the male parent in stage I should be sown 10~13 days earlier than the female parent, and the male parent in stage II should be sown 5~7 days earlier. In Guangdong Province, seed production in summer, the difference between parents 'original sowing period is basically the same as Hainan seed production.

Pei 'ai 64S has small seed, strong tillering ability but low panicle rate and rapid stigma vitality decline. Therefore, it is necessary to improve seed production by reasonable dense planting and increasing basic seedling number. Generally, the seed amount used in field is 25~ 30 kg/hm2. Because of the poor tillering ability of male parent, it is required to sow sparsely, cultivate strong seedlings with tillers, and insert 3~4 seedlings per hole. The male parent plant is tall, the panicle is big, the grain is many, the pollen quantity is enough, may enlarge the row ratio appropriately, about 2:14 is suitable.

Pei 'ai 64S is a fertilizer tolerant variety and should be applied with sufficient basal fertilizer. 450kg ammonium bicarbonate and 375kg phosphorus powder can be used as basal fertilizer per hectare, the first topdressing is applied 3~ 4 days after transplanting, and the second topdressing is applied 8~10 days after transplanting: ear fertilizer is applied before and after young ear differentiation II stage, and leaf cutting fertilizer is applied again at young ear differentiation V~VI stage. The male parent should apply fertilizer 1~2 times, strengthen water management, attack seedling rack well, ensure enough pollen quantity and long flowering time. The tillering ability of male parent is poor, so it is required to cultivate strong seedlings, early harvest fertilizer to promote tillering, and ensure effective panicle number.

Pei 'ai 64S is insensitive to "920," and using "920" well is the key link to obtain high yield of seed production. "920"330g/hm ~ 2 was sprayed for 3 days at 3%~5% heading stage. K2HP04 and other growth regulators were sprayed in combination to advance the flowering time of female parent and improve stigma vitality and seed setting rate.