A method for breeding a wide-compatibility restorer line of large-spike indica-japonica intermediate variety.

Abstract

This invention discloses a method for breeding a large-panicle type intermediate-range wide-compatibility restorer line between indica and japonica rice. The method involves hybridizing dense-panicle or dense-panicle rice germplasm resources with a long-panicle type intermediate-range wide-compatibility restorer line between indica and japonica rice to obtain F1 seeds. F1 seeds are then planted and self-pollinated to obtain F2 seeds. Seeds are harvested from individual plants with excellent plant and leaf morphology, exhibiting large panicles and multiple grains, selected from the segregated F2 population. This process is repeated for multiple generations of self-pollination, with panicle-grain structure examined and plant and leaf morphology selected at each generation to obtain a large-panicle type intermediate-range wide-compatibility restorer line with excellent plant and leaf morphology. Compared with existing technologies, this invention utilizes dense-panicle or dense-panicle rice materials to hybridize with a long-panicle type intermediate-range wide-compatibility restorer line between indica and japonica rice, and then continuously self-pollinates for multiple generations to obtain a large-panicle type intermediate-range wide-compatibility restorer line. The steps are simple and convenient, the breeding method is not cumbersome, and the obtained restorer line has large panicles and many grains, which can be used to increase rice yield.

Description

Technical Field

[0001] This invention relates to the field of rice breeding, and more particularly to a method for breeding a wide-compatibility restorer line of large-panicle type indica-japonica intermediate variety. Background Technology

[0002] With global population growth, the food crisis facing humanity is becoming increasingly severe, and only by continuously increasing food production can this crisis be effectively addressed. Rice, as one of the world's three major food crops, is the staple food for more than half of the global population, especially in Asia, where the proportion of the population relying on rice as a staple food is even higher. In China, over 65% of the population relies on rice as a staple food. To ensure food security, increasing rice yield has always been a top priority in rice breeding.

[0003] Rice yield, besides being influenced by growth conditions such as fertilizer and water, is mainly regulated by genetic factors, particularly those closely related to agronomic traits such as the number of effective panicles, panicle size (number of grains per panicle), and grain weight (thousand-grain weight). Therefore, increasing the number of grains per panicle through genetic breeding is an important way to increase rice yield. The number of grains per panicle varies considerably among different rice varieties. Currently, conventional rice varieties typically have only around 100 grains per panicle, with very few exceeding 200. Some inter-varietal hybrid rice varieties can reach 150 grains per panicle, such as Zhongyou 177 and Lian 9805, while inter-subspecies hybrid rice has an even higher number of grains per panicle. Further increasing the number of grains per panicle will help further increase rice yield. The high number of grains per panicle in inter-subspecies hybrid rice is mainly due to the large panicle size of the restorer line. Therefore, breeding wide-compatibility restorer lines with large panicles between indica and japonica will be an important method to increase the number of grains per panicle. Summary of the Invention

[0004] The purpose of this invention is to provide a method for breeding a large-spike type indica-japonica intermediate wide-compatibility restorer line that solves the above-mentioned problems.

[0005] To achieve the above objectives, the technical solution adopted by this invention is: a method for breeding a wide-compatibility restorer line of large-spike type indica-japonica intermediate variety, the method steps of which are as follows:

[0006] First, hybridization was carried out between dense-panicle or dense-panicle rice germplasm resources and long-panicle intermediate wide-compatibility restorer lines to obtain hybrid F1 seeds;

[0007] Secondly, F1 seeds were planted and self-crossed to obtain F2 seeds;

[0008] Then, select individual plants with excellent plant and leaf morphology and large spikes with many grains from the separated F2 population to harvest seeds. For the large spike and many grains type materials, self-pollinate for multiple generations (more than 4 generations). In each generation, examine the spike and grain structure and select plants and leaves based on their morphology.

[0009] Finally, a wide-compatibility restorer line with large spikes and many grains, exhibiting excellent plant and leaf morphology, was obtained.

[0010] Compared with existing technologies, the advantages of this invention are as follows: This invention utilizes dense-panicle or dense-panicle rice materials, crosses them with long-panicle, wide-compatibility indica-japonica intermediate restorer lines, and continuously self-pollinates for multiple generations combined with field phenotypic identification (grain type is examined in each generation) to obtain large-panicle, wide-compatibility indica-japonica intermediate restorer lines. The steps are simple, the operation is convenient, and the breeding method is not cumbersome. The resulting restorer lines have large panicles and many grains. Large-panicle, wide-compatibility indica-japonica intermediate restorer lines can be used to breed inter-subspecies hybrid rice, increasing the number of grains per panicle and improving rice yield. Attached Figure Description

[0011] Figure 1 This is a diagram of the spikelet shape of the large-spike, multi-grain indica-japonica intermediate wide-compatibility restorer line Sujing 022 of the present invention. Detailed Implementation

[0012] The following describes a method for breeding a wide-compatibility restorer line of large-panicle type indica-japonica rice. The method involves the following steps: Chunjiang 163, a rice germplasm resource with a dense or high-panicle type, is used as the parent and crossed with CH50, a wide-compatibility restorer line of long-panicle type indica-japonica rice. F1 seeds are obtained. F1 plants are planted and self-pollinated to obtain F2 seeds. From the segregated F2 population, single plants with excellent plant and leaf morphology and large panicles with many grains are selected for seed harvesting. Small-panicle type lines are directly eliminated in early generations. For large-panicle, multi-grain type materials, continuous self-pollination is performed for multiple generations (more than 4 generations). The panicle and grain structure are examined in each generation, and plant and leaf morphology is selected to obtain the large-panicle, multi-grain type indica-japonica wide-compatibility restorer line Sujing 022, which has excellent plant and leaf morphology. The steps are simple, the operation is convenient, and the breeding method is not complicated. The resulting restorer line Sujing 022 has large panicles and many grains, with each panicle containing more than 300 grains. (See also...) Figure 1 .

[0013] This invention significantly increases the number of grains per panicle in an intermediate-type wide-compatibility restorer line between indica and japonica rice, thereby increasing rice yield and improving rice production per unit area in my country. By crossing a two- or three-line sterile line with the large-panicle intermediate-type wide-compatibility restorer line Sujing 022 obtained in this invention, hybrid vigor was observed, and the resulting strong-vibration indica-japonica hybrid rice, Chunyou Sujing 022, achieved approximately 300 grains per panicle.

[0014] The above provides a detailed description of the breeding method for a large-spike indica-japonica intermediate wide-compatibility restorer line provided by the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Modifications and improvements to the present invention are possible without exceeding the concept and scope specified in the appended claims. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for breeding a large-spike, intermediate-type, wide-compatibility restorer line of indica and japonica rice, characterized in that: The steps are as follows: First, the rice germplasm resource Chunjiang 163, which is either a dense panicle type or a dense panicle type, was used as the parent and crossed with CH50, a long-panicle type indica-japonica intermediate wide-compatibility restorer line, to obtain hybrid F1 seeds; Secondly, F1 seeds were planted and self-pollinated to obtain F2 seeds; Then, seeds were harvested from individual plants with excellent plant and leaf morphology and large spikes with many grains from the separated F2 population. For the large spike and many grain materials, they were self-pollinated for more than 4 generations. The spike and grain structure was examined in each generation, and plant and leaf morphology was selected. Finally, a wide-compatibility restorer line with large spikes and many grains, exhibiting excellent plant and leaf morphology, was obtained.

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