Method for breeding three-line rice strong restoring line H570

[0020] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

[0021] Such as Figure 1 ~ Figure 2 Shown is an example of the present invention. In order to effectively utilize the heterosis between indica and japonica subspecies, the present invention first systematically studied the segregation changes of progeny under different cross matching modes, and designed four matching modes: ①Japonica type Wide compatible line/indica restorer line; ②Japonica wide compatible line/indica restorer line//Japonica wide compatible line; ③Japonica wide compatible line/Japonica wide compatible line//Indica restorer ④Indica-type sterile line/Indica-type restorer line//Japonica-type wide-compatible line. Studies have shown that the selection effect of the third breeding group ("Indica-Japonica intermediate (or japonica) wide compatible line/Japonica wide compatible line/Indica restorer") is better. It is further clarified that the existing indica-type restorer lines should be used as a bridge through the wide-compatibility line, and the genetic improvement of japonica rice should be appropriately increased. Do not pursue the indica-japonica ratio of offspring materials, as long as the bred progeny restorer lines are intuitively partial The characteristic characteristics, or Cheng's index between 10-18, is an effective way to use the heterosis between indica and japonica subspecies to breed indica-type and wide-compatible restorer lines.

[0022] According to the above thinking, by using the intermediate indica and japonica (Java rice) material WL1312 and the japonica wide-compatible material Reincari 422, the offspring F 4 The selected line was the female parent, and then crossed with Minghui 63, a strong restorer line popularized and applied in a large area in production. After years of multi-generation system selection and resistance evaluation in different ecological regions, the wide compatibility strong restorer line DI508 was successfully bred. The Cheng's index of DI508 is 14, and it is crossed with the unified test species of Indica and Japonica, the hybrid F 1 The seed setting rate of DI508 is 62.4%-73.9%, indicating that DI508 is a partial indica-type and wide-compatible restorer line.

[0023] In recent years, with the rapid expansion of the single-cropping rice area in the southern indica rice area, the DI508 dry seeds have been irradiated in response to the early maturity of DI508, wider leaves, poor resistance to rice blast, and low yield potential of the combination. The super-parent (plant type, rice quality, resistance and other traits) late-maturing mutants were selected from the radiation-mutated offspring mutation population HK2 of DI508, and the restoring line H570 was finally selected through targeted selection in Hainan and Zhejiang. .

[0024] The research on the change of tillering angle and related physiological and ecological characteristics of restorer line H570 (formerly DI508) during the whole growth period showed that H570 has obvious characteristics of cluster growth and fast growth and erect earing after jointing, and the upper three leaves function stable in the late growth period. The angles between the first, second and third tillers of the main stem and the horizontal ground were 59.74°, 62.94° and 68.54° respectively at the beginning of tillering, which was consistent with the performance of semi-scattered rice material; after heading, it was close to 90°, and Upright rice materials behave the same ( figure 2 ). Based on the characteristics of indica rice in South China, academician Huang Yaoxiang proposed the characteristics of rice plant type with the core of "clustering and rapid growth", and Mr. Yang Shouren proposed the characteristics of super high-yielding rice plant with the core of "upright filling and fruiting" based on the late growth restriction factors of northern japonica rice. The organic combination makes it an important breeding material for high-yield plant type improvement.

[0025] The project team used H570 and its derivative materials (Table 1) to formulate Zhongzheyou series combinations such as Zhongzheyou No. 1 and Zhongzheyou No. 8, making full use of the dynamic plant characteristics of H570: leaf drooping at the beginning of tillering , Increase the light-cutting area of ​​the leaves, and improve the utilization of light energy; the flag leaves are straight from the late tillering stage to the mature stage, and the ventilation and light transmission increase the net photosynthetic rate, which changes the soft, thin, thin, and loose leaves of the existing three-line indica hybrid rice. Plant type model. It fully harmonizes the contradiction between high yield and high quality, large ears and high seed setting rate. It is a successful model of combining ideal plant type, excellent quality and heterosis in the current three-line indica hybrid rice breeding. It is also an ideal plant for three-line hybrid rice. A new model of type breeding.

[0026] Table 1H570 is used as the core parent parent for the matching group of Zhongzheyou series combination

[0027]

[0028] The above descriptions are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the present invention. Within the scope of protection.