Breeding method of novel rice blast-resistant hybrid japonica rice combination
By selecting the parents of different species of rice blast-resistant genes in northern japonica rice for hybridization and backcrossing, the pi2 and pigm alleles were introduced, and the gene polymerization and stable inheritance were achieved through multi-generation self-crossing and gene detection, the problem of lack of rice blast-resistant genes in northern japonica rice was solved, and the ability of hybrid japonica rice to resist rice blast was significantly improved.
Patent Information
- Application Number
- CN202510270106.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-07
- Publication Date
- 2025-04-29
AI Technical Summary
No original materials containing the rice blast resistance genes pi2 and pigm have been found in northern japonica rice, and alleles on the same chromosome cannot be aggregated into the same variety through conventional means, limiting the ability of hybrid japonica rice to resist rice blast.
By selecting parents of japonica rice varieties containing different anti-rice blast genes for hybridization and backcrossing, pi2 and pigm alleles resistant rice blast genes were introduced, and through multi-generation self-crossing and gene detection, sterile lines and recovery line materials that meet the requirements were selected to achieve gene polymerization and stable inheritance.
The pi2 and pigm alleles of rice blast resistance genes on the same chromosome were successfully aggregated into the same hybrid japonica rice variety, which significantly improved the new combination's anti-rice blast ability and expanded the application scope of hybrid japonica rice.
Abstract
Description
Technical Field
[0001] The embodiment of the present invention relates to the technical field of hybrid japonica rice genetic breeding, and specifically to a breeding method for a new combination of hybrid japonica rice resistant to rice blast. Background Art
[0002] Rice blast has always been one of the important diseases that cause rice production to reduce yield. A large number of studies have shown that the rice blast resistance genes pi2 and pigm have good resistance to rice blast. They are alleles on the same chromosome and are mostly found in southern indica rice resources. There are many varieties of northern japonica rice containing pita and pib, and no original materials containing the rice blast resistance genes pi2 and pigm have been found. In recent years, breeders have continuously created northern japonica rice materials containing pi2 and pigm. Field identification and indoor inoculation have shown that the rice blast resistance of northern japonica rice materials containing pi2 and pigm has been significantly improved. However, pi2 and pigm belong to the same chromosome allele and cannot be aggregated into the same variety by conventional means. Hybrid japonica rice can aggregate different disease resistance genes through parents, and aggregate pi2 and pigm into the same variety through matching, so that the resistance to rice blast of the new combination is improved. This breeding method is of great significance for the breeding of hybrid japonica rice for rice blast resistance. Summary of the invention
[0003] To this end, an embodiment of the present invention provides a method for breeding a new combination of hybrid japonica rice resistant to rice blast. The present invention has created a batch of maintainer lines, sterile lines, and restorer line materials containing different rice blast resistance genes, which can aggregate the pi2 and pigm allelic rice blast resistance genes on the same chromosome into the same variety, thereby improving the rice blast resistance ability of the new combination.
[0004] In order to achieve the above purpose, the embodiment of the present invention provides the following technical solutions:
[0005] A method for breeding a new combination of hybrid japonica rice resistant to rice blast, the method comprising the following steps:
[0006] (1) selecting a conventional japonica rice variety parent A1 containing the rice blast resistance genes pi2 and pita, a conventional japonica rice variety parent A2 containing the rice blast resistance gene pigm, a hybrid japonica rice maintainer parent B that does not contain a known rice blast resistance gene, and a restorer parent C that contains the rice blast resistance gene pib;
[0007] (2) hybridizing with parent B as the female parent and parent A2 as the male parent, and then backcrossing with parent B as the female parent and the resulting hybrid parent as the male parent to obtain F1 seeds; hybridizing with parent C as the female parent and parent A1 as the male parent, and then backcrossing with parent C as the female parent and the resulting hybrid parent as the male parent to obtain F1 seeds;
[0008] (3) The hybrid parents and F1 seeds were self-pollinated continuously in Shenyang and Hainan to F5;
[0009] (4) Testing for rice blast genes and restorer genes in F5 population materials that meet breeding goals;
[0010] (5) Selecting single ears with high stigma exposure and good flowering time from the offspring materials of parent B that contain the rice blast resistance gene pigm and do not contain the restorer gene for line planting, and selecting single ears with rice blast resistance genes pi2, pita, pib and the restorer gene from the offspring materials of parent C for line planting;
[0011] (6) Select the offspring of parent B that meet the requirements in the F6 generation, use the japonica sterile line as the female parent, and continuously carry out backcrossing in the nursery for 6 generations to breed the stable sterile line material of BC6F1. At the same time, analyze the disease resistance and combining ability of the excellent offspring materials containing the rice blast resistance genes pi2, pib, pita and the restorer gene, and select the restorer line material that meets the requirements;
[0012] (7) The selected sterile and restorer materials were used for testing and seed production to obtain rice blast resistance genes containing pi2, pita, pigm, and pib.
[0013] Furthermore, the specific contents of step (2) include:
[0014] Hybridization is performed with parent B as the female parent and parent A2 as the male parent to obtain the combination F1 of parent B / parent A2, and then backcrossing is performed with parent B as the female parent and the combination F1 of parent B / parent A2 as the male parent to obtain F1 seeds of parent B / / parent B / parent A2; hybridization is performed with parent C as the female parent and parent A1 as the male parent to obtain the combination F1 of parent C / parent A1, and then backcrossing is performed with parent C as the female parent and the combination F1 of parent C / parent A1 as the male parent to obtain F1 seeds of parent C / / parent C / parent A1.
[0015] Furthermore, in step (3), the hybrid parents and F1 seeds are the combination F1 of parent B / parent A2, the combination F1 of parent C / parent A1, the F1 seeds of parent B / / parent B / parent A2, and the F1 seeds of parent C / / parent C / parent A1.
[0016] Furthermore, the parent A1 is Longjing 31; the parent A2 is Kongyu 131; the parent B is Liao 485B; and the parent C is C66.
[0017] The embodiments of the present invention have the following advantages:
[0018] 1. Regarding the problem of hybrid japonica rice resistance to rice blast, the resistance to rice blast of hybrid japonica rice parents can be improved by introducing resistance genes to rice blast through different parents.
[0019] 2. By introducing the rice blast resistance genes pi2 and pigm into the parents respectively, the problem that the allelic rice blast resistance genes on the same chromosome cannot be aggregated into the same variety can be solved.
[0020] 3. The same variety contains multiple rice blast resistance genes, which can enhance the rice blast resistance of the new combination and expand the application scope of hybrid japonica rice. DETAILED DESCRIPTION
[0021] The following is a description of the implementation of the present invention by specific embodiments. People familiar with the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0022] The present invention relates to a breeding method for hybrid japonica rice resistant to rice blast, comprising the following steps:
[0023] (1) Select the conventional japonica rice variety Longjing 31 containing the rice blast resistance genes pi2 and pita and the conventional japonica rice variety Kongyu 131 (pigm) containing the rice blast resistance gene pigm; select the hybrid japonica rice maintainer parent B that does not contain the above three rice blast resistance genes and the restorer parent C that contains the rice blast resistance gene pib.
[0024] (2) Parent B was used as the female parent and Kongyu 131 (pigm) was used as the male parent for hybridization to obtain the combination F1 of parent B / Kongyu 131 (pigm), and then parent B was used as the female parent and the combination F1 of parent B / Kongyu 131 (pigm) was used as the male parent for backcrossing to obtain the F1 seeds of parent B / / parent B / Kongyu 131 (pigm), and parent C was used as the female parent and Longjing 31 was used as the male parent for hybridization to obtain the combination F1 of parent C / Longjing 31, and then parent C was used as the female parent and the combination F1 of parent C / Longjing was used as the male parent for backcrossing to obtain the F1 seeds of parent C / / parent C / Longjing 31.
[0025] (3) The obtained combined F1 seeds of parent B / Kongyu 131 (pigm) and parent C / Longjing 31, as well as the backcross F1 seeds of parent B and parent C were continuously self-pollinated to F5 in Shenyang and Hainan.
[0026] (4) Select F5 generation population materials that meet the breeding objectives and conduct rice blast gene and restorer gene testing.
[0027] (5) From the offspring group of parent B, single ears containing the rice blast resistance gene pigm but without the restorer gene, with high exposed stigma and good flowering time were selected for line planting. From the offspring group of parent C, single ears containing the rice blast resistance genes pi2, pib, pita and the restorer gene were selected for line planting.
[0028] (6) In the F6 generation, offspring of parent B that meet the requirements are selected and backcrossed for six generations to BC6F1 using a similar japonica-type sterile line as the maternal parent in a nursery factory to obtain stable sterile lines and maintainer lines containing the rice blast resistance gene pigm. At the same time, disease resistance and combining ability of excellent offspring materials containing the rice blast resistance genes pi2, pib, pita and the restorer gene Rf1 are analyzed to select restorer line materials that meet the requirements.
[0029] (7) The selected sterile line materials and restorer line materials are tested, matched and produced, and the new combination contains broad-spectrum rice blast resistance genes of pi2, pita, pigm and pib, and for the first time, the pi2 and pigm alleles on the same chromosome are aggregated into the same hybrid japonica rice variety, which improves the rice blast resistance of the new variety. Through the directional introduction of different rice blast genes into different parents of hybrid japonica rice proposed by the present invention, excellent rice blast resistance maintainer, sterile and restorer line materials can be obtained. At the same time, pi2 and pigm are introduced into the parents respectively, which can solve the problem that pi2 and pigm as alleles cannot be aggregated in the same variety, improve the rice blast resistance of the hybrid combination, and increase the adaptability of the new combination. This breeding method is of great significance for the breeding of hybrid japonica rice for rice blast resistance.
[0030] Example 1
[0031] This embodiment provides a method for breeding a new combination of hybrid japonica rice resistant to rice blast:
[0032] In late February 2014, conventional japonica rice varieties Longjing 31 containing rice blast resistance genes pi2 and pita and Kongyu 131 (pigm) containing rice blast resistance gene pigm were selected in Hainan; the hybrid japonica rice maintainer parent Liao 485B that does not contain the above three rice blast resistance genes, and the restorer parent C66 that contains the rice blast resistance gene pib; hybridization was carried out with Liao 485B as the female parent and Kongyu 131 (pigm) as the male parent to obtain the combination F1 of Liao 485B / Kongyu 131 (pigm), hybridization was carried out with C66 as the female parent and Longjing 31 as the male parent to obtain the combination F1 of C66 / Longjing 31, and then backcrossing was carried out with C66 as the female parent and the combination F1 of C66 / Longjing 31 as the male parent to obtain the F1 seeds of C66 / / C66 / Longjing 31.
[0033] In August 2014, backcrossing was performed in Shenyang with Liao 485B as the female parent and the combination F1 of Liao 485B / Kongyu 131 (pigm) as the male parent, obtaining F1 seeds of Liao 485B / / Liao 485B / Kongyu 131 (pigm). Backcrossing was then performed with C66 as the female parent and the combination F1 of C66 / Longjing as the male parent, obtaining F1 seeds of C66 / / C66 / Longjing 31.
[0034] From November 2014 to April 2016, the hybrid and backcross F1 seeds of parent Liao 485B and the hybrid and backcross F1 seeds of parent C66 were continuously self-pollinated to F5 in Shenyang and Hainan; the rice blast gene and restorer line gene were tested for the F5 generation population materials with better phenotypes.
[0035] In August 2016, single ears with high stigma exposure and good flowering time in the Liao 485B progeny materials containing the rice blast resistance gene pigm but no restorer gene were planted in Shenyang for ear line planting. Single ears with large ears containing the rice blast resistance genes pi2, pib, pita and restorer genes were selected from the C66 progeny materials for ear line planting.
[0036] In August 2016, the japonica sterile line Liao 485A, which met the breeding goals among the offspring materials of Liao 485B, was used as the female parent for continuous backcrossing in the nursery factory. In August 2017, the 6th generation of backcrossing was transferred to BC6F1, and stable sterile lines and maintainer lines containing the rice blast resistance gene pigm were obtained. At the same time, the disease resistance and combining ability of the excellent offspring materials containing rice blast resistance genes pi2, pib, pita and restorer genes were analyzed to select the restorer line materials that met the requirements.
[0037] In February 2018, the selected sterile and restorer materials were tested and matched in Hainan, and the target new combination contained broad-spectrum rice blast resistance genes of pi2, pita, pigm, and pib. Molecular detection showed that the pi2 and pigm alleles of rice blast resistance genes on the same chromosome were aggregated into the same hybrid japonica rice variety for the first time.
[0038] The new combination was planted in Shenyang in August 2018. Molecular testing showed that the pi2 and pigm allelic rice blast resistance genes on the same chromosome were aggregated into the same hybrid japonica rice variety for the first time. The new combination contains pi2, pita, pigm, and pib disease resistance genes.
[0039] From 2018 to 2020, the new combination was field-tested for resistance to rice blast in suitable ecological zones in the north and Hainan, and showed good resistance to rice blast.
[0040] Although the present invention has been described in detail above by general description and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements can be made to the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all belong to the scope of protection claimed by the present invention.
Claims
1. A method for breeding a new combination of hybrid japonica rice resistant to rice blast, characterized in that: The method comprises the following steps: (1) selecting a conventional japonica rice variety parent A1 containing the rice blast resistance genes pi2 and pita, a conventional japonica rice variety parent A2 containing the rice blast resistance gene pigm, a hybrid japonica rice maintainer parent B that does not contain a known rice blast resistance gene, and a restorer parent C that contains the rice blast resistance gene pib; (2) hybridizing with parent B as the female parent and parent A2 as the male parent, and then backcrossing with parent B as the female parent and the resulting hybrid parent as the male parent to obtain F1 seeds; hybridizing with parent C as the female parent and parent A1 as the male parent, and then backcrossing with parent C as the female parent and the resulting hybrid parent as the male parent to obtain F1 seeds; (3) The hybrid parents and F1 seeds were self-pollinated continuously in Shenyang and Hainan to F5; (4) Testing for rice blast genes and restorer genes in F5 population materials that meet breeding goals; (5) Selecting single ears with high stigma exposure and good flowering time from the offspring materials of parent B that contain the rice blast resistance gene pigm and do not contain the restorer gene for line planting, and selecting single ears with rice blast resistance genes pi2, pita, pib and the restorer gene from the offspring materials of parent C for line planting; (6) Select the offspring of parent B that meet the requirements in the F6 generation, use the japonica sterile line as the female parent, and continuously carry out backcrossing in the nursery for 6 generations to breed the stable sterile line material of BC6F1. At the same time, analyze the disease resistance and combining ability of the excellent offspring materials containing the rice blast resistance genes pi2, pib, pita and the restorer gene, and select the restorer line material that meets the requirements; (7) The selected sterile and restorer materials were used for testing and seed production to obtain rice blast resistance genes containing pi2, pita, pigm, and pib.
2. The method for breeding a new combination of hybrid japonica rice resistant to rice blast according to claim 1, characterized in that: The specific contents of step (2) include: Hybridization is performed with parent B as the female parent and parent A2 as the male parent to obtain the combination F1 of parent B / parent A2, and then backcrossing is performed with parent B as the female parent and the combination F1 of parent B / parent A2 as the male parent to obtain the F1 seeds of parent B / / parent B / parent A2; hybridization is performed with parent C as the female parent and parent A1 as the male parent to obtain the combination F1 of parent C / parent A1, and then backcrossing is performed with parent C as the female parent and the combination F1 of parent C / parent A1 as the male parent to obtain the F1 seeds of parent C / / parent C / parent A1.
3. The method for breeding a new combination of hybrid japonica rice resistant to rice blast according to claim 1, characterized in that: In step (3), The hybrid parents and F1 seeds are the combination F1 of parent B / parent A2, the combination F1 of parent C / parent A1, the F1 seeds of parent B / / parent B / parent A2, and the F1 seeds of parent C / / parent C / parent A1.
4. The method for breeding a new combination of hybrid japonica rice resistant to rice blast according to claim 1, characterized in that: The parent A1 is Longjing 31; the parent A2 is Kongyu 131; the parent B is Liao 485B; and the parent C is C66.