A breeding method of large-spike indica-japonica subspecies hybrid rice

Abstract

The application discloses a breeding method of large-spike indica-japonica subspecies hybrid rice, which comprises the following steps: taking partial dense spike type or dense spike type rice germplasm resources as parents to cross with long-spike indica-japonica intermediate type wide compatibility restorer line to obtain hybrid F1 seeds; planting the F1 and self-crossing to obtain F2 seeds; selecting single plant with excellent plant leaf morphology and large-spike and multi-grain type from the separated F2 population, continuously self-crossing for multiple generations to obtain indica-japonica intermediate type wide compatibility restorer line with excellent plant leaf morphology and large-spike and multi-grain type; and using the bred indica-japonica intermediate type wide compatibility restorer line with large-spike and multi-grain type to cross with two-system or three-system sterile line to obtain strong-dominant large-spike indica-japonica hybrid rice. Compared with the prior art, the three-system or two-system sterile line is used to cross with the large-spike indica-japonica intermediate type wide compatibility restorer line to breed the large-spike indica-japonica subspecies hybrid rice, the number of grains per spike is close to 300, the number of rice grains per spike of the hybrid rice is greatly increased, and the yield of rice is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of rice breeding, and in particular to a breeding method of large-spike indica-japonica subspecies hybrid rice. BACKGROUND

[0002] As one of the three major crops in the world, rice is the main food for more than half of the world's population, especially in Asia. Improving rice yield has always been the top priority in rice breeding.

[0003] The yield of rice is mainly affected by genetic factors in addition to growth conditions such as fertilizer and water, especially the genes closely related to agronomic traits such as effective panicle number, panicle size (panicle number), and grain weight (1000-grain weight). Therefore, increasing the panicle number of rice through genetic breeding is an important way to increase rice yield. The panicle number of different rice varieties varies greatly, and the panicle number of current conventional rice varieties is usually more than 100, and the panicle number of more than 200 varieties is very few. Some indica-japonica subspecies hybrid rice varieties have a panicle number of 150, such as Zhongyou 177 and Lian 9805. Therefore, breeding large-spike indica-japonica subspecies hybrid rice will help to further improve the yield of rice in China. SUMMARY

[0004] The purpose of the present application is to provide a breeding method of large-spike indica-japonica subspecies hybrid rice which solves the above problems.

[0005] In order to achieve the above purpose, the technical solution adopted by the present application is as follows: A breeding method of large-spike indica-japonica subspecies hybrid rice, the method steps are as follows,

[0006] First, take a dense panicle type or dense panicle type rice germplasm resource as a parent and cross it with a long-spike indica-japonica intermediate type wide compatibility restorer line to obtain hybrid F1 seeds;

[0007] Second, plant F1 and self-cross to obtain F2 seeds;

[0008] Then, select a single plant with excellent plant leaf morphology and large-spike multi-grain type from the separated F2 population, and harvest seeds. For large-spike multi-grain type materials, continuously self-cross for more than 4 generations, investigate the panicle type structure of each generation, and select the plant leaf morphology to obtain a large-spike multi-grain type indica-japonica intermediate type wide compatibility restorer line with excellent plant leaf morphology;

[0009] Finally, cross the two or three sterile lines with the selected large-spike multi-grain type indica-japonica intermediate type wide compatibility restorer line, investigate the hybrid vigor, and obtain strong advantage large-spike indica-japonica hybrid rice.

[0010] Compared with the prior art, the advantage of the present application is that the present application utilizes three-line or two-line sterile lines and large-eared indica-japonica intermediate wide compatibility restorer lines to cross, breeds large-eared indica-japonica subspecies hybrid rice, and the number of grains per ear of the variety with higher number of grains per ear is close to 300 grains, the present application greatly increases the number of grains per ear of hybrid rice through the breeding of large-eared indica-japonica subspecies hybrid rice, which is beneficial to improve the yield of rice and exert the hybrid vigor of subspecies hybridization. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 Figure of ear type of large-eared indica-japonica subspecies hybrid rice of the present application;

[0012] Figure 2 Figure of ear type comparison of large-eared indica-japonica subspecies hybrid rice of the present application and conventional japonica rice. DETAILED DESCRIPTION

[0013] The breeding method of a large-eared indica-japonica subspecies hybrid rice of the present application will be further described below, the method steps are as follows, take the dense ear type or dense ear type rice germplasm resource-Chunjiang 163 as the parent and cross with the long-eared indica-japonica intermediate wide compatibility restorer line CH50, obtain hybrid F1 seeds, plant F1 and self-cross, obtain F2 seeds, select the seeds of single plant with excellent plant leaf morphology and large-eared and many-grained type in the separated F2 population, directly eliminate the small-eared type strain in the low generation, continuously self-cross (more than 4 generations) the large-eared and many-grained type material, investigate the ear grain type structure in each generation, and select the plant leaf morphology, obtain the large-eared and many-grained type indica-japonica intermediate wide compatibility restorer line with excellent plant leaf morphology, the obtained restorer line has large ear and many grains, and the number of grains per ear can reach more than 300 grains, then utilize two-line or three-line sterile lines to cross with the bred large-eared and many-grained type indica-japonica intermediate wide compatibility restorer line, investigate the hybrid vigor, and screen to obtain strong advantage large-eared indica-japonica hybrid rice.

[0014] The present application utilizes two-line or three-line sterile lines to cross with the large-eared and many-grained type indica-japonica intermediate wide compatibility restorer line, investigates the hybrid vigor, and obtains strong advantage large-eared indica-japonica hybrid rice-Chunyou Su Jing 022, the number of grains per ear of the strong advantage indica-japonica hybrid rice can reach about 300 grains. Taking the cross of three-line sterile line and large-eared and many-grained type indica-japonica intermediate wide compatibility restorer line in the present application as an example, the number of grains per ear of indica-japonica hybrid rice can reach 310 grains, see Figure 1 . The large-eared indica-japonica subspecies hybrid rice-Chunyou Su Jing 022 created by the present application has large ear type, and the number of grains per ear far exceeds that of conventional japonica rice, see Figure 2 .

[0015] The present application has simple steps, convenient operation, and non-redundant breeding method, and the obtained strong advantage indica-japonica hybrid rice has the characteristics of large ear and many grains, the number of grains per ear of the variety with higher number of grains per ear is close to 300 grains, which greatly improves the rice yield per unit in China.

[0016] The breeding method of the large-spike indica-japonica subspecies hybrid rice provided by the present application is described in detail above, and the principles and implementation manners of the present application are described by using specific examples in this paper. The above description of the examples is only used to help understand the method of the present application and its core idea. Meanwhile, for those skilled in the art, according to the idea of the present application, changes will be made in the specific implementation manners and application ranges, and changes and improvements of the present application will be possible without exceeding the concept and range defined in the appended claims. In summary, the content of the specification should not be understood as a limitation of the present application.

[0017] The breeding method of the large-spike indica-japonica subspecies hybrid rice provided by the present application is described in detail above, and the principles and implementation manners of the present application are described by using specific examples in this paper. The above description of the examples is only used to help understand the method of the present application and its core idea. Meanwhile, for those skilled in the art, according to the idea of the present application, changes will be made in the specific implementation manners and application ranges, and changes and improvements of the present application will be possible without exceeding the concept and range defined in the appended claims. In summary, the content of the specification should not be understood as a limitation of the present application.

Claims

1. A method for breeding large-panicle intersubspecific indica-japonica hybrid rice, characterized by: The method steps are as follows: First, the dense panicle rice germplasm resource Chunjiang 163 was used as a parent and hybridized with the long panicle intermediate indica-japonica wide-compatibility restorer line CH50 to obtain hybrid F1 seeds. Second, the F1 is planted and self-pollinated to obtain F2 seeds; Then, from the segregating F2 population, individual plants with excellent plant and leaf morphology, large panicles, and multiple grains were selected for seed harvest. For these large panicle and multiple grain materials, they were self-pollinated for more than four generations, and the panicle and grain structure was examined in each generation. Selection was also made for plant and leaf morphology to obtain a wide-compatibility restorer line intermediate between indica and japonica with large panicles and multiple grains and excellent plant and leaf morphology. Finally, the two-line or three-line sterile lines were hybridized with the selected large-panicle and multi-grain intermediate wide-compatibility restorer lines of indica and japonica to examine hybrid vigor and obtain strong-advantage large-panicle indica-japonica hybrid rice.

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