Breeding method of yunnan fragrant soft rice

Abstract

The application discloses a breeding method of Yunnan fragrant soft rice, which comprises the following steps: step one is to excavate specific rice resources, step two is to create new germplasm backbone parents, step three is to perform 'two-way' separation expression and single recessive relative trait elimination, and step four is to perform excellent trait balanced selection. In the application, indica rice or semi-indica rice resources from 1450-1650m warm and cool rice areas in Yunnan are collected, apparent morphological identification is performed on the resources and low-heat valley rice area materials, excellent materials with complementary traits are screened, and fragrant soft rice breeding intermediate materials and backbone parent reserves are created. In addition, parent populations with far genetic distance and different ecotypes are created, excellent genes with far genetic distance are introduced into Yunnan fragrant soft rice materials, according to the physiological characteristics of similar ecotype rice, affinity is improved, blood penetration and fusion are increased, backbone parents with rich and varied gene types are created, and'sticky + waxy' and 'colored vs. non-colored' parents are selected to perform hybridization, recessive trait materials are selected or eliminated, and the breeding efficiency can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of rice genetic breeding design, and particularly relates to a breeding method of Yunnan fragrant soft rice. BACKGROUND

[0002] Rice is the main food crop in China, and the total production of rice is in the world's top ranks. In addition, China is also the world's largest rice consumer, and more than 60% of the population mainly eats rice. For a long time, the primary indicator of rice breeding is high yield. With the improvement of living standards, people's demand for high-quality rice is increasing day by day, and the production is also changing from single pursuit of high yield to high quality and stable yield. "Tasty and good variety" has become a new trend of rice variety research and breeding. 90% of the components in rice are starch, and starch is composed of amylose and amylopectin. The content of amylose is the most important factor affecting the eating quality of rice. The content of amylose in fragrant soft rice is low, the rice has strong aroma, good elasticity and no retrogradation after cooling, so it is favored by the market.

[0003] In addition, the existing breeding method has the following disadvantages in use:

[0004] (1) In the existing breeding method, the genetic distance of the intermediate material and the backbone parent in fragrant soft rice breeding is close, and different ecotypes of parent populations cannot be selected;

[0005] (2) The existing breeding method has low affinity, and cannot create a rich and colorful backbone parent of gene type;

[0006] (3) The breeding efficiency of the existing breeding method is low, and the purebred genotype meeting the target traits cannot be obtained in a short time. SUMMARY

[0007] The technical problem to be solved by the present application is to overcome the above technical defects, and to provide a breeding method of Yunnan fragrant soft rice.

[0008] In order to solve the above problems, the technical scheme of the present application is as follows:

[0009] Step one: specific trait rice resource exploration, using "Yunnan-Guizhou plateau warm and cool rice region resource comparison identification method" to explore complementary specific rice resources;

[0010] Step two: new germplasm backbone parent creation, designing "different regions, similar ecotypes and distant cross mode" to create new germplasm backbone parents;

[0011] Step three: "two-way" separation expression, single recessive relative trait elimination method, using the dominance and recessive inheritance of single trait genes controlling rice colored and colorless, sticky and waxy, according to the genetic law of independent distribution of genes, and the separation performance of 3:1, "gene inheritance + phenotype" selection is carried out.

[0012] Step four: excellent trait balanced selection, build "carrying aroma gene, rice length-width ratio greater than 3, chalkiness rate less than 5%, amylose content 10-16%, gel consistency 80-100mm, resistance to rice blast" and other excellent gene polymerization trait balanced selection system, taking into account the synergistic expression of multiple excellent traits of offspring separation individuals, eliminating "special materials" with outstanding rice quality but low yield and resistance, or high yield but ordinary rice quality.

[0013] Further, the parent selection in step one is the cold-resistant, disease-resistant indica material "red fragrant soft rice" at 1560 meters above sea level, which carries the aroma gene, low amylose, resistance to rice blast, japonica wide compatibility gene and cold resistance gene, as an improved parent to be combined with the blood germplasm in the low-heat valley rice area.

[0014] Further, the parent selection in step two is the combination of the medium-mature late indica soft rice variety in the upper reaches of the Yangtze River and the double-season late indica variety in the middle reaches of the Yangtze River.

[0015] Further, the parent selection in step two can also be the combination of the medium-mature late indica fragrant soft rice variety in the upper reaches of the Yangtze River and the late indica variety in the lower reaches of the Yangtze River.

[0016] Further, the medium-mature late indica soft rice variety in the upper reaches of the Yangtze River is Yunhui 290, the growth period thereof is 163 days, and the characteristics thereof are low AC and soft gel consistency; the double-season late indica variety in the middle reaches of the Yangtze River is Xiangwanxian 10, the growth period thereof is 163 days, and the characteristics thereof are low AC, soft gel consistency and less chalkiness.

[0017] Further, the medium-mature late indica fragrant soft rice variety in the upper reaches of the Yangtze River is Diantun 502, the characteristics thereof are low AC and soft gel consistency; and the late indica variety in the lower reaches of the Yangtze River is Zibaoxiang 1, the characteristics thereof are fragrant softness, disease resistance and high yield.

[0018] Further, the parent selection in step three is the combination of the Yunnan fragrant glutinous rice variety Wenmi 4 and the low amylose content material "red fragrant soft rice".

[0019] Further, the parent selection in step three can also be the combination of the Yunnan fragrant glutinous rice variety and Wennuo 1, two fragrant glutinous rice parents, and then introducing the low amylose content gene of Yunhui 290.

[0020] Further, step four is screened by the "five-step" optimization method, and the "five-step" optimization method is respectively different ecological environment field investigation, natural induction and inoculation identification elimination, economic trait index determination, rice appearance grading and chewing screening and cooking taste identification.

[0021] Compared with the prior art, the present application has the following advantages:

[0022] 1. The present application provides a breeding method of Yunnan fragrant soft rice, collecting indica or semi-indica resources from 1450-1650 meters of warm and cool rice areas in Yunnan, planting and observing 17 main indexes such as agronomic characters and resistance in Yunnan Funing (620 meters), Yunnan Wenshan (1240 meters), Yunnan Yanshan (1540 meters), identifying the apparent morphology with low-heat valley rice area materials, screening excellent materials with complementary traits, creating fragrant soft rice breeding intermediate materials and backbone parent population with far genetic distance and different ecotypes;

[0023] 2. The present application provides a breeding method of Yunnan fragrant soft rice, introducing excellent genes with far genetic distance into Yunnan fragrant soft rice materials, improving affinity according to the physiological characteristics of similar ecotype rice, increasing blood penetration and fusion, and creating backbone parents with rich and diverse gene types;

[0024] 3. The present application provides a breeding method of Yunnan fragrant soft rice, selecting "sticky + waxy" and "colored vs. colorless" parents for hybridization, and after chromosome exchange and recombination and offspring population separation, selecting or removing recessive trait materials with phenotypic traits (waxy, semi-transparent, colored) of homozygous recessive genes, and performing single plant directional selection according to breeding targets in low generation (F2 begins), combining with indoor shelling identification of rice appearance, performing single grain sowing and tracking selection in the next season, obtaining homozygous genotypes with target traits in a short time, and improving breeding efficiency and accelerating breeding process. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a flowchart of step three.

[0026] Figure 2 is a flowchart of the present breeding method.

[0027] Figure 3 is a detection report of the breeding method Figure 1 .

[0028] Figure 4 is a detection report of the breeding method Figure 2 .

[0029] Figure 5 is a detection report of the breeding method Figure 3 .

[0030] Figure 6 is a detection report of the breeding method Figure 4 .

[0031] Figure 7 is a resistance identification report of the breeding method Figure 1 .

[0032] Figure 8 is a resistance identification report of the breeding method Figure 2 .

[0033] Figure 9 Resistance identification report of selection method Figure 3 . DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application; based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative labor fall within the protection scope of the present application.

[0035] As shown in Figure 1 and Figure 2 , comprising the following steps:

[0036] Step one: specific trait rice resource exploration, using "Yunnan-Guizhou Plateau cool rice resource comparison identification method", to explore complementary specific rice resources;

[0037] Step two: new germplasm backbone creation, designing "different regions, similar ecotype distant crossing mode", to create new germplasm backbone;

[0038] Step three: "two-way" separation expression, single recessive relative trait elimination method, using the dominant and recessive inheritance of single trait genes controlling rice colored and colorless, sticky and waxy, according to the genetic law of independent distribution of genes, in line with the 3:1 separation performance for "gene inheritance + phenotype" selection;

[0039] Step four: excellent trait balance selection, building "carrying aroma gene, rice length-width ratio greater than 3, chalkiness rate less than 5%, amylose content 10-16%, gel consistency 80-100mm, resistance to rice blast" and other excellent gene aggregation trait balance selection system, taking into account the synergistic expression of multiple excellent traits of offspring separation individuals, eliminating "special materials" with outstanding rice quality but low yield and decreased resistance, or high yield but ordinary rice quality.

[0040] Further, the parent selection in step one is the cold-resistant, disease-resistant, indica rice material "red soft rice" at an altitude of 1560 meters, carrying aroma gene, low amylose, resistance to rice blast, japonica wide compatibility gene, cold resistance gene, as an improvement parent and low-heat valley rice area blood germplasm.

[0041] Further, the parent selection in step two is the combination of the medium-mature late indica soft rice variety in the upper reaches of the Yangtze River and the double-season late indica variety in the middle reaches of the Yangtze River.

[0042] Further, the parent selection in step two can also be the combination of the medium-mature late indica soft rice variety in the upper reaches of the Yangtze River and the late indica variety in the lower reaches of the Yangtze River.

[0043] Further, the soft rice variety in the middle reaches of the Yangtze River is Yunhou 290, the growth period of which is 163 days, and the characteristics of which are low AC and soft gel consistency. The double cropping late indica variety in the middle reaches of the Yangtze River is Xiangwanxian No. 10, the growth period of which is 163 days, and the characteristics of which are low AC, soft gel consistency and less chalkiness.

[0044] Further, the soft rice variety in the middle reaches of the Yangtze River is Yunhou 290, the growth period of which is 163 days, and the characteristics of which are low AC and soft gel consistency. The double cropping late indica variety in the middle reaches of the Yangtze River is Xiangwanxian No. 10, the growth period of which is 163 days, and the characteristics of which are low AC, soft gel consistency and less chalkiness.

[0045] Further, the soft rice variety in the middle reaches of the Yangtze River is Yunhou 290, the growth period of which is 163 days, and the characteristics of which are low AC and soft gel consistency. The double cropping late indica variety in the middle reaches of the Yangtze River is Xiangwanxian No. 10, the growth period of which is 163 days, and the characteristics of which are low AC, soft gel consistency and less chalkiness.

[0046] Further, the soft rice variety in the middle reaches of the Yangtze River is Yunhou 290, the growth period of which is 163 days, and the characteristics of which are low AC and soft gel consistency. The double cropping late indica variety in the middle reaches of the Yangtze River is Xiangwanxian No. 10, the growth period of which is 163 days, and the characteristics of which are low AC, soft gel consistency and less chalkiness.

[0047] Further, step four is screened by the "five-step" selection method of soft rice, and the "five-step" selection method is respectively different ecological environment field investigation, natural induction and inoculation identification elimination, economic trait index determination, rice appearance grading and chewing screening and cooking taste identification.

[0048] In the specific operation process, reference is made to FIG. 1, and the method comprises the following steps: Figures 1 to 2

[0049] Step one: specific trait rice resource exploration;

[0050] The complementary specific rice resources are explored by using the "Yungui Plateau warm and cool rice area resource comparison and identification method". The indica or partial indica resources from the Yungui Plateau 1450-1650 meters warm and cool rice area are collected, and are planted and observed in Fuding, Yunnan (620 meters), Wenshan, Yunnan (1240 meters), Yanshan, Yunnan (1540 meters) for 17 main indexes such as agronomic traits and resistance, and are morphologically identified with the low-heat valley rice area materials, and the excellent materials with complementary traits are screened to create the soft rice breeding intermediate materials and the backbone parent population with far genetic distance and different ecotypes.

[0051] The breeding practice is to explore the cold-resistant and disease-resistant indica material "red soft rice" at an altitude of 1560 meters, which carries the aroma gene, low amylose, rice blast resistance, japonica wide compatibility gene and cold resistance gene, as an improved parent to be combined with the low-heat valley rice area blood germplasm.

[0052] Step two: new germplasm backbone parent creation;

[0053] ​Design "different regions, similar ecological type distant hybrid model", create new germplasm backbone parents, introduce excellent genes with far genetic distance into Yunnan fragrant soft rice materials, improve affinity according to physiological characteristics of similar ecological type rice, increase blood penetration and fusion, and create gene type rich and varied backbone parents.

[0054] Breeding practice is that, first, a long-yang upstream medium-mature late indica soft rice variety (Yunhu 290, growth period 175 days, low AC, soft and thick) is matched with a double-season late indica variety in the middle reaches of the Yangtze River (Xiangwan indica 10, growth period 163 days, low AC, soft and thick, and less chalky), which shows strong affinity and offspring separation advantage, and creates fragrant soft rice backbone parent 10290-11. This material can be compatible with high-yield plant type, rice fragrance, transparent appearance, low AC, soft and thick, and other excellent genes, and can be used as an excellent donor parent. Second, a long-yang upstream medium-mature late indica fragrant soft rice variety (Diantun 502, low AC, soft and thick) is matched with a late indica variety in the lower reaches of the Yangtze River (Zibaoxi 1, fragrant soft, disease-resistant, and high-yield), which successfully fuses high-yield genes and fragrance genes to breed fragrant rice high-yield material Wenbaoxi 502-8, and breeds an ideal high-yield plant type chassis material.

[0055] Step three: "two-way" separation expression, single recessive relative trait elimination method;

[0056] According to the independent distribution of genes and the genetic rule of 3:1 separation performance, "gene inheritance + phenotype" selection is performed on the "sticky + waxy" "colored to colorless" parent combination hybridization with relatively obvious relative traits. After chromosome exchange recombination and offspring population separation, the phenotype of homozygous recessive genes (waxy, semi-transparent, and colored) is selected or eliminated, single plant directional selection is performed according to breeding targets in a low generation (F2 begins), and indoor shelling is combined with rice appearance identification, single grain sowing is performed in the next season for tracking selection, and pure genotypes meeting target traits are obtained in a short time, which can improve breeding efficiency and accelerate breeding process.

[0057] Breeding practice is that, Yunnan fragrant waxy rice variety Wenmai 4 is selected and hybridized with low amylose content material "red fragrant soft rice" to create a new low amylose content offspring population and breed a new fragrant soft rice variety. Wenmai 4 and Wenmai 1, two fragrant waxy rice parents, are selected for single crossing, and then the low amylose content gene of Yunhu 290 is introduced to create an offspring population with continuous change of amylose content, and breed a fragrant waxy rice variety with high-yield plant type, good economic traits, and disease resistance.

[0058] Step four: excellent trait balanced selection;

[0059] The construction of "carrying the aroma gene, the length-width ratio of rice is greater than 3, the chalkiness rate is less than 5%, the amylose content is 10-16%, the gel consistency is 80-100mm, and the resistance to rice blast" and other excellent gene aggregation trait balance selection system, taking into account the collaborative expression of multiple excellent traits of offspring separation individuals, discarding the "special material" with outstanding rice quality but low yield and resistance decline, or the yield level is improved but the rice quality is ordinary. Two is to establish the "five-step" optimization method of fragrant soft rice. It is "different ecological environment field investigation, natural induction and inoculation identification elimination, economic trait index determination, rice appearance grading and chewing screening, cooking taste identification".

[0060] The breeding practice is to use the Sanya winter breeding base, prepare combinations, plant mixed crops for two generations a year, and fully maintain the rich genetic traits of the offspring. F4 begins to shuttle breeding in different ecological regions such as Wenshan (1240m), Jinghong State Agricultural Station base in Xishuangbanna (700m), Baoshan (1300m), Yanshan County Panlong Town in Wenshan (1540m) and so on. The field is eliminated by "natural induction + inoculation identification". According to the breeding target, the field comprehensive agronomic traits and resistance are observed, the single plant is numbered, the indoor economic traits of single plant are investigated, the rice appearance quality is observed by artificial shelling, the phenotypic characteristics are recorded, the rice appearance transparent single plant is removed, the groups are numbered according to the chewing aroma and no aroma, F5 is planted according to the collection of single plants, the field focuses on the investigation of plant leaf morphology, population structure, resistance and yield, the indoor taste quality is comprehensively identified from aroma, appearance and palatability, the balanced expression of target traits is comprehensively analyzed, and the key strain is determined to enter the advanced selection and test procedure.

[0061] It should be noted that, in the present document, relational terms such as first and second and the like can be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0062] Although embodiments of the present application have been shown and described, it is to be understood that various modifications, substitutions, replacements and changes can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

[0063] The above describes the present application and its embodiments, which are not limited, and the drawings only show one of the embodiments of the present application, and the actual structure is not limited thereto. In general, if a person skilled in the art is inspired thereby, without departing from the purpose of the present application, without creative design, similar structure and embodiments of the technical solution are not creative, and should belong to the protection scope of the present application.

Claims

1. A method for breeding Yunnan fragrant soft rice, characterized in that, Includes the following steps: Step 1: Discovery of rice varieties with specific traits: Collect rice or rice varieties from the cool and temperate rice-growing areas of Yunnan (1450-1650 meters above sea level). Plant them in Funing, Wenshan, and Yanshan in Yunnan. Observe a total of 17 major indicators of agronomic traits and resistance. Compare and identify the phenotypes of the rice varieties with those from low-heat valley rice-growing areas. Select superior materials with complementary traits to create a parent population of fragrant and soft rice with a large genetic distance and different ecotypes. Step 2: Creation of new germplasm backbone parents: Using parents from different regions and with similar ecotypes, distant hybridization is carried out to introduce superior genes with large genetic distances into Yunnan fragrant soft rice materials. Based on the physiological characteristics of rice varieties with similar ecotypes, the hybridization affinity is improved and the bloodline penetration and fusion are increased, thereby creating new germplasm backbone parents with rich and diverse gene types. Step 3, "Two-way" segregation expression and single recessive trait elimination: Select a cross between parents that have a single dominant-recessive genetic difference in rice stickiness versus glutinousness, and color versus colorlessness. In the segregating population of their offspring, use the phenotypic trait controlled by the homozygous recessive gene as a marker to carry out targeted selection or elimination in lower generations. At the same time, combine indoor hulling to identify the appearance of rice and carry out single-grain sowing tracking selection to quickly obtain homozygous genotypes that meet the target traits. Step 4: Balanced selection of superior traits: Establish a balanced selection system for traits such as aroma aggregation gene, length-to-width ratio of rice greater than 3, chalkiness rate less than 5%, amylose content of 10-16%, gel consistency of 80-100 mm, and resistance to rice blast. Through a five-step optimization method including field investigation in different ecological environments, natural induction and inoculation identification and elimination, determination of economic trait indicators, rice appearance grading and chewing screening, and steaming and tasting evaluation, the progeny materials are comprehensively evaluated and screened, and special materials with unbalanced traits are discarded.

2. The method for breeding Yunnan fragrant soft rice according to claim 1, characterized in that: In step one, the complementary and unique rice resources discovered are the cold-resistant and disease-resistant rice material "Hongxiang Ruanmi" at an altitude of 1560 meters. It carries aroma genes, low amylose content, resistance to rice blast, wide affinity genes for japonica rice, and cold-resistant genes. It is used as an improved parent to crossbreed with bloodline germplasm from low-heat river valley rice areas.

3. The method for breeding Yunnan fragrant soft rice according to claim 1, characterized in that: In step two, the pair of parents undergoing distant hybridization are a mid-maturing late-ripening soft rice variety from the upper reaches of the Yangtze River and a double-cropping late-ripening rice variety from the middle reaches of the Yangtze River.

4. The method for breeding Yunnan fragrant soft rice according to claim 1, characterized in that: In step two, the pair of parents undergoing distant hybridization are a mid-maturing late-maturing fragrant rice variety from the upper reaches of the Yangtze River and a late-maturing rice variety from the lower reaches of the Yangtze River.

5. The method for breeding Yunnan fragrant soft rice according to claim 3, characterized in that: The medium-maturing late-season soft rice variety from the upper reaches of the Yangtze River is Yunhui 290, with a growth period of 163 days and characteristics of low amylose content and soft gel consistency; the double-season late-season soft rice variety from the middle reaches of the Yangtze River is Xiangwanxian 10, with a growth period of 163 days and characteristics of low amylose content, soft gel consistency, and less chalkiness.

6. The method for breeding Yunnan fragrant soft rice according to claim 4, characterized in that: The mid-maturing late-season fragrant and soft rice variety from the upper reaches of the Yangtze River is Diantun 502, characterized by low amylose content and soft gel consistency; the late-season fragrant rice variety from the lower reaches of the Yangtze River is Zibaoxiang No. 1, characterized by its fragrant and soft texture, disease resistance, and high yield.

7. The method for breeding Yunnan fragrant soft rice according to claim 1, characterized in that: In step three, the parental lines for preparing the hybrid combination are the Yunnan fragrant glutinous rice variety Wendao No. 4 and the low amylose content material "Hongxiangruanmi".

8. The method for breeding Yunnan fragrant soft rice according to claim 1, characterized in that: In step three, the Yunnan fragrant glutinous rice variety Wendao 4 and Wennuo 1 are first crossbred, and then the low amylose content gene of Yunhui 290 is introduced into their offspring.

9. The method for breeding Yunnan fragrant soft rice according to claim 1, characterized in that: The "five-step" optimization method in step four specifically involves: conducting field surveys in different ecological zones; using natural induction and artificial inoculation to identify and eliminate diseased plants; measuring the economic traits of individual plants; grading the appearance of the rice and conducting preliminary screening by chewing; and finally conducting steaming and tasting evaluations to comprehensively assess the taste quality.

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