23 results about "Backcrossing" patented technology

The invention discloses application of TBR2 protein as well as a coding gene and a molecular marker thereof in resisting tomato brown wrinkled fruit virus diseases, and belongs to the technical field of gene engineering. According to the invention, a novel anti-disease gene TBR2 for resisting the tomato brown wrinkled fruit virus disease is identified on a chromosome 4 of tomatoes; the disease-resistant gene has stable disease resistance, and the resistance of the variety to the tomato brown crinkled fruit virus disease can be obviously improved by backcrossing and transbreeding the disease-resistant gene into a sensitive cultivar. Based on the anti-disease gene TBR2, the invention further develops molecular markers related to the tomato brown wrinkled fruit virus disease resistance, and the molecular markers can be used for identifying plant materials resistant to the tomato brown wrinkled fruit virus disease and cultivating plant varieties resistant to the tomato brown wrinkled fruit virus disease. The method is of great significance in accelerating the breeding process of disease-resistant tomatoes.

The invention discloses a mulberry important character QTL fine positioning method based on a chromosome segment replacement line, and relates to the technical field of molecular breeding. Comprising the following steps: S1, constructing a genotype-phenotype incidence matrix: screening backcross populations through high-heterozygosity parent hybridization and multi-generation backcross, and marking genomes of the screened backcross populations through targeted sequencing and recombination hot spots; s2, phenotype determination modeling: performing sample collection according to a test plant, and obtaining a hybrid model according to the environmental effect of the test plant and a covered CSSL line; and S3, gene screening: carrying out hub gene screening through the constructed co-expression network model and the hybrid model. According to the method, through multi-generation backcrossing, targeted sequencing and recombination hotspot analysis, dynamic labeling is performed on the genome, and a stepped coverage CSSL library is constructed, so that a QTL interval is effectively compressed, and the problem of fuzzy positioning caused by limited recombination events of a traditional F2 or RIL population is solved.

This invention provides a rice gene Bph54 for resistance to brown planthopper and its application. The rice provided by this invention... Bph54 Genes are of great significance for breeding new rice varieties resistant to brown planthoppers. This invention successfully cloned the rice Bph54 gene using map-based cloning, and performed functional annotation and identification. This gene exhibits complete dominance, and both homozygous and heterozygous genotypes confer equal resistance to brown planthoppers in rice. This characteristic is beneficial for the application of this gene in breeding. Based on this, the Bph54 gene can be introduced into brown planthopper-susceptible plant varieties through traditional breeding techniques such as hybridization and backcrossing, or through genetic engineering, to cultivate new varieties of plants resistant to brown planthoppers with stable genetic traits. This invention provides important germplasm resources for effectively reducing insect damage and achieving increased and stable crop yields.

This invention belongs to the field of plant genetic engineering, specifically disclosing a method for creating bifunctional haploid inducible lines of Brassica napus based on the BnaKNL2 gene and its application. Research revealed that the BnaKNL2 gene is a key gene affecting the fertility of Brassica napus. By knocking out the KNL2 gene in Brassica napus, bifunctional haploid inducible lines with maternal or paternal haploid induction capabilities can be created. The haploid induction rate after hybridization with different Brassica napus varieties can reach 0.45%–2.7%. Furthermore, by combining this with a cytoplasmic male sterility system and through hybridization and backcrossing, the CMS-HI line, carrying both sterile cytoplasm and haploid induction capabilities, can be rapidly created. This provides a new approach for haploid breeding of Brassica napus and the improvement and creation of CMS lines, with broad application prospects.

This invention discloses a method for creating a stress-resistant, high-quality, and unique purple-fruited sesame germplasm, belonging to the field of plant breeding technology. The method utilizes the purple-fruited material "Tieqing Sesame" for genetic improvement of the sesame variety "Zhongzhi 14," which has poor stress and disease resistance. Through a systematic breeding method involving one generation of hybridization, six generations of self-pollination, one generation of backcrossing, and six generations of self-pollination, a homozygous and stable high-quality inbred line is created, which is the stress-resistant, high-quality, and unique purple-fruited sesame germplasm. Experimental results show that the sesame germplasm resource "25SP19" obtained according to the method provided by this invention has advantages such as purple capsules, a high number of capsules per plant, a low initial capsule position, short and pointed empty tips, strong disease and stress resistance, high oil content, and normal self-pollination and seed setting. It represents a significant improvement over the original parent "Zhongzhi 14" in all aspects. This invention not only provides new germplasm resources for the breeding of new sesame varieties but can also be directly used for large-scale cultivation.

The application provides a low-gluten high-dietary fiber excellent flavor rice as well as a breeding method and application thereof, and relates to the technical field of rice breeding. The breeding method uses a high-dietary fiber rice variety as a female parent and a low-gluten flavor rice variety as a male parent to perform hybridization, and then performs genotype detection on the F2 generation by using Badh-M2 and Lgc1 molecular markers respectively, and combines with agronomic trait selection to realize efficient polymerization of three functional genes of flavor, low gluten and high dietary fiber. The method significantly improves the selection efficiency, avoids trait loss and cycle extension caused by multiple backcrossing. The bred rice has the effects of rich flavor, significantly reduced rice gluten content, obviously increased dietary fiber content and reduced blood glucose generation index, and meanwhile, maintains the effects of high yield, early maturity, excellent plant leaf morphology and good ecological adaptability, and can meet the nutritional needs of chronic kidney disease, diabetes and obese people for functional staple food.

The invention relates to the technical field of tussah genetic breeding, in particular to a tussah egg color genetic marker assisted breeding method which comprises the following steps: S1, hybridizing: hybridizing a yellow tussah variety as a female parent and a brown tussah variety as a male parent to obtain F1-generation tussah; s2, backcrossing: taking the F1-generation tussah as a male parent and performing backcrossing on the F1-generation tussah and the yellow-egg-color female parent to obtain BC1-generation tussah; s3, selfing: selecting the BC1-generation tussah with yellow egg color for selfing at least one generation to obtain BC1Fn-generation tussah with stable yellow egg color, and completing breeding; wherein n represents the number of selfing generations. The method is simple and efficient, and the novel tussah germplasm can be obtained within 4-5 years.

The application discloses a breeding method of a rapeseed radish cytoplasm restorer line independent of a recovery source, and relates to the technical field of crop breeding. The breeding method comprises the following steps: crossbreeding or multi-generation backcrossing of rapeseed and a rapeseed radish cytoplasmic male sterile line to form a radish cytoplasm hybrid F1 generation or a stable new radish cytoplasmic male sterile line; pollinating and inducing the radish cytoplasm hybrid F1 generation or the stable new radish cytoplasmic male sterile line by using a rapeseed double haploid induction line without radish cytoplasm recovery genes; bagging and screening fertile single plants in offspring obtained by pollination; continuously self-crossing the fertile single plants from which the radish cytoplasm recovery genes are induced for 2-3 generations; re-crossing; and if all the offspring after re-crossing is fertile, breeding a stable rapeseed radish cytoplasm restorer line with the radish cytoplasm recovery genes. The application has the advantages of short improvement cycle, high efficiency and low cost, and effectively solves the problems of a long breeding cycle of the radish cytoplasm restorer line, genetic instability of the radish cytoplasm restorer line, and negative effects of short siliques and poor seed setting of the radish cytoplasm restorer line and the radish recovery source.

The invention relates to a breeding method of a fluoride-resistant and polyhedrosis-resistant bombyx mori strain, and belongs to the technical field of bombyx mori genetic breeding. In order to solve the technical problems that an existing silkworm variety cannot resist fluoride poisoning and pyosis at the same time, and resistance is prone to loss, the method comprises the following steps: hybridizing a germplasm carrying a fluorine-resistant major gene and a germplasm carrying an antiviral dominant major gene to obtain an F1 generation, and backcrossing the F1 generation with a fluorine-resistant parent after fluorine-resistant screening to obtain a BC1 generation; and finally, fluorine-resistant and antiviral characters are synchronously screened and improved through selfing generations, and directional breeding is carried out by combining whole-course recorded development and cocoon quality characters. According to the method, a new silkworm strain with double resistance is successfully bred, and the method is mainly used for solving the problem of low survival rate of silkworm breeding in a fluorine pollution area and a virus high incidence area in industrial production.

The application discloses a method for breeding and multiplying a flue-cured tobacco cytoplasmic male sterile line MS Guiyan 19, which takes the flue-cured tobacco cytoplasmic male sterile line MSG28 as a cytoplasmic male sterile gene source, takes MSG28 as a female parent, takes a variety Guiyan 19 as a recurrent parent, and is bred into a new cytoplasmic male sterile line MS Guiyan 19 through continuous backcrossing for six generations after hybridization; and the cytoplasmic male sterile line MS Guiyan 19 is bred by taking the sterile line MS Guiyan 19 as the female parent and taking the maintainer line Guiyan 19 as the male parent and is bred and preserved through hybridization. The flue-cured tobacco sterile line MS Guiyan 19 bred by the application has the advantages of stable sterility, excellent agronomic characters, higher yield and output value, good easy-curing and curing properties, good appearance and quality of tobacco leaves, and coordinated chemical components, and provides a new excellent sterile line germplasm for flue-cured tobacco hybridization advantage utilization research work.

The application discloses TBR2 protein and an application of an encoding gene and a molecular marker thereof in resisting tomato brown rugose fruit virus disease, and belongs to the technical field of genetic engineering. TBR2 A new disease-resistant gene of the tomato brown rugose fruit virus disease is identified on the 4th chromosome of the tomato TBR2 ; the disease-resistant gene has stable disease resistance; backcrossing and transformation of the disease-resistant gene into a sensitive cultivar can obviously improve the resistance of the cultivar to the tomato brown rugose fruit virus disease. Based on the disease-resistant gene TBR2 , the application also develops molecular markers respectively related to the resistance of the tomato brown rugose fruit virus disease; the molecular markers of the application can be used for identifying plant materials resistant to the tomato brown rugose fruit virus disease and cultivating plant varieties resistant to the tomato brown rugose fruit virus disease, and have important significance for accelerating the breeding process of the disease-resistant tomato.

The application provides a cotton homozygous type rapid breeding method based on a created marker, and comprises the following steps: step one, using breeding material with a functional marker trait as a donor parent, and crossing the donor parent with an upland cotton with a target excellent trait, and continuously performing multiple generations of backcrossing and sister crossing to create a batch of core marker germplasm which gradually penetrates excellent genes of the upland cotton and stably carries the functional marker trait. The application uses the functional marker trait as a morphological index to realize rapid and nondestructive identification of the target trait in the early generation of cotton breeding, breaks through the technical bottleneck that the target trait is difficult to be accurately identified in the early stage in traditional backcross breeding, and improves the selection efficiency. The core marker germplasm created through multiple generations of backcrossing and sister crossing retains the excellent genes of the upland cotton, and stably carries the functional marker trait, so that the genetic marker provides reliable morphological selection basis for subsequent hybridization breeding, and avoids the problem of genetic background confusion caused by repeated backcrossing.

The invention relates to the technical field of cotton breeding, in particular to a grass-resistant cotton backcross breeding method by utilizing EPSPS, which comprises the following steps: S1, carrying out chemical emasculation treatment on a grass-resistant cotton P1 plant to obtain the emasculated grass-resistant cotton P1 plant; hybridizing by taking the emasculated grass-resistant cotton P1 plant as a female parent and a recurrent parent P2 plant as a male parent to obtain a hybrid F1 plant; s2, performing chemical emasculation treatment on the obtained hybrid F1 plant to obtain the emasculated hybrid F1 plant; taking a hybridized hybrid F1 plant as a female parent, taking a recurrent parent P2 plant as a male parent, and performing backcross to obtain a backcross seed BC1 plant; s3, continuously backcrossing for at least one time according to the backcrossing method in the step S2 to obtain a backcrossing seed BCn plant; s4, selecting plants from the backcross BCn plants obtained by the last backcross in the step S3, selfing for 2-3 generations, and then breeding to finish backcross breeding. The breeding method provided by the invention is high in efficiency, high in sterile plant rate and high in hybrid combination yield, and can realize bidirectional selection and simultaneously breed grass-resistant and non-grass-resistant plants.

The invention provides a construction method of a male sterile line of corn, and relates to the technical field of plant breeding, the method comprises the following steps: designing double sgRNAs on two sides of a key functional region of a nuclear fertility gene of corn, and inducing exon region deletion mutation through Cas9 mediated double-site cutting; introducing the editing element into a donor plant, hybridizing with a receptor selfing line, backcrossing to a BC2 generation, and selfing to obtain a homozygous deletion mutant without the editing element; the method comprises the following steps: constructing a multi-control maintenance breeding construct containing a fertility restoring gene, a pollen inhibition module and a selection marker, enabling the multi-control maintenance breeding construct to exist in a maintainer line in a semi-zygote state, limiting the formation of male gametes containing the construct through the pollen inhibition module, and realizing automatic sorting of sterile line seeds by utilizing the selection marker. According to the scheme, complete and stable sterile characters are ensured through double sgRNA induced large fragment deletion, a non-transgenic homozygous mutant is obtained by combining a backcross selfing strategy, meanwhile, efficient and pure breeding of sterile line seeds is achieved through a multi-control maintenance system, and the hybrid seed production efficiency and the seed purity are remarkably improved.

This invention discloses an improved breeding method for leafy grasses. Using Rumex (hybrid sorrel, abbreviated as Rumex) as the female parent and Rumex rubrotinctum (commonly known as Rumex 'sheep's hoof') as the male parent, a first-generation leafy grass hybrid is obtained. This first-generation hybrid is backcrossed with Rumex to obtain a first-generation backcross. This first-generation backcross is then subjected to 3-4 generations of self-pollination. Through marker-assisted selection and agronomic trait identification, genetically stable leafy grasses without phenotypic segregation are obtained. Finally, improved original seed varieties are obtained through primary seed propagation. The newly added combination of directional backcrossing + multi-generation self-pollination + marker-assisted selection in this invention is the first such disclosure in the field of leafy grass breeding. The leafy grasses obtained by this breeding method have a protein content ≥35%, a 20% increase in salt and alkali resistance, and a genetic stability of over 98%. The breeding process is clearly defined with quantified parameters, allowing for large-scale propagation. It overcomes the technical shortcomings of traditional hybrids and is suitable for commercial cultivation of leafy grasses, possessing significant economic and application value.

The invention discloses a method for rapidly breeding a high-cleanliness silkworm strain, and belongs to the technical field of silkworm variety breeding. According to the breeding method, the high-purity silkworm strain with excellent economic characters is successfully bred by combining breeding modes such as hybridization, backcrossing, test crossing and selfing with the existing practical silkworm strain in combination with a purity detection mode. The application of the strain accurately meets the strict demand of the high-end market for high-grade raw silk, injects strong power for improving the core competitiveness of the silk industry in China, and assists the silk industry in being in a more favorable position in the international market.

The application discloses a silkworm variety molecular breeding method against pyrethroid pesticides, and adopts a strategy of combining genetic breeding with molecular marker assisted breeding, and has the following advantages: (1) the molecular marker breeding method has the advantages that genetic traits of the silkworm variety of Su Hao and Zhong Ye against pyrethroid pesticides are stable, and the silkworm variety is obtained by combining molecular markers, hybridization, backcrossing, single moth directional breeding and other methods and production practice; (2) the silkworm variety of Su Hao and Zhong Ye against pyrethroid pesticides obtained by the method has obvious economic benefits in subsequent production practice, and the genetic traits are stable; (3) the method can be popularized to the introduction of pyrethroid pesticide resistance traits of other practical silkworm varieties.

The invention relates to the technical field of crop molecular breeding, and discloses a high-temperature-resistant machine-harvested cotton molecular breeding method, which comprises the following steps: selecting a machine-harvested character parent material and a high-temperature-resistant parent material, and hybridizing to obtain a segregation population; flowering phase directional high-temperature window treatment is carried out on a fruit branch layer where flowering flowers are located on the current day in the early stage from early flowering to full blooming; then carrying out mechanical harvesting vibration simulation screening treatment on the plants; based on the processing result, constructing a high-temperature-resistant mechanical harvesting comprehensive selection index and screening a target single plant or family; carrying out molecular marker detection on the screened material, carrying out combined selection by combining a molecular marker result and a comprehensive selection index, and finally, carrying out continuous selfing or backcrossing to obtain the high-temperature-resistant machine-harvested cotton material. According to the method, flowering phase directional high-temperature window treatment is carried out in the early stage from early flowering to full bloom of cotton, so that materials which can still complete the boll setting process in a high-temperature environment can be identified in the early stage of breeding, and the selection pertinence of high-temperature-resistant characters is improved.

The application discloses a corn heat shock transcription factor ZmHsf05 gene in improving corn inbred pollen viability, ear grain number and single ear grain weight. ZmHsf05 Firstly, a plant overexpression vector containing the gene is constructed to obtain a corn material overexpressing the gene. ZmHsf05 Through continuous backcrossing and selfing, an improved corn inbred overexpressing the gene is obtained. ZmHsf05 The pollen viability, ear grain number and single ear grain weight of the improved inbred are significantly improved. ZmHsf05 Through pollen transcriptome sequencing, it is found that ZmHsf05 improves pollen viability by regulating target genes in endoplasmic reticulum protein processing, cysteine and methionine metabolism and flavonoid biosynthesis pathways. Therefore, the improved corn inbred overexpressing the gene has good breeding potential in production.

This invention relates to a breeding method for Changfeng native chickens. It involves selecting Sanhuang chickens and Ma chickens as maternal lines, and White Locke chickens and Cobb White-feathered chickens as paternal lines, and conducting directional hybridization using artificial insemination to form the F1 generation hybrid population. Next, based on the weight and meat quality test results at 300 days of age, superior families are selected, and the target traits are gradually fixed through multiple generations of directional hybridization and backcrossing. Simultaneously, genes from high-yielding broiler breeds such as Ross 308 or Cobb 500 are introduced to enhance the breeding performance of the paternal lines. Finally, through refined feeding management and a phased feeding strategy, the breeding effect is further optimized to ensure that the newly bred Changfeng native chicken breed reaches a weight of 3.0 to 3.5 kg at 300 days of age, with a breast muscle ratio of no less than 22%, and a stable egg production of over 170 eggs. This breeding method significantly increases the weight of Changfeng native chickens, while also making the meat firmer and improving its meat quality.

This invention discloses a method for cultivating superior meat sheep breeds, belonging to the field of meat sheep breeding technology. The method uses Australian White sheep as the maternal line, cross-crossing them with Small-tailed Han sheep carrying the FecB homozygous gene, Texel sheep carrying the MSTN homozygous gene, and Hu sheep carrying the TBXT homozygous gene. After two generations of backcrossing, the offspring are cross-crossed to obtain prolific F1, fast-growing F1, and short-tailed F1 generations. The prolific F1 ewes are then cross-crossed with fast-growing F1 rams and short-tailed F1 rams to select prolific fast-growing F2 and prolific short-tailed F2 generations. The prolific fast-growing and prolific short-tailed F2 generations are then cross-crossed to obtain a homozygous F3 generation. The homozygous F3 generation is then closed-crossed for 2-3 generations to fix the prolific, fast-growing, and short-tailed traits, resulting in a superior meat sheep breed with stable beneficial traits. The meat sheep breed cultivated using this method has stable traits and can significantly improve the production efficiency and economic benefits of meat sheep farming.