13 results about "Directional selection" patented technology

The invention discloses a breeding method and application of fragrant soft rice two-line hybrid rice with an off-white anti-counterfeiting mark, and belongs to the technical field of rice breeding. According to the method, soft rice genes with recessive grey white endosperm markers, genic male sterility character genes and the like are subjected to synchronous phenotype aggregation directional selection for the first time, the problem that the genic male sterility character and excellent taste quality character are difficult to synchronously select in the earliest segregation generation is solved for the first time, and in addition, the technical link of taste quality detection and identification can be saved; the selection efficiency is improved; meanwhile, the problem that the taste quality and control genes thereof need to be detected and identified for multiple times during mating and parent selection of high-quality hybrid rice is solved for the first time; besides, the soft rice character gene with the recessive grey white endosperm marker is synchronously introduced into a two-line hybrid rice parent, through main target character aggregation response identification, the fragrant soft rice two-line hybrid rice with the grey white marker and the aromatic flavor is successfully created for the first time, the yield is increased, and infringement and loss of independent brand fragrant rice products can be prevented.

The invention discloses a wheat haploid accurate identification and breeding method based on molecular markers, and belongs to the technical field of agricultural biology. The method comprises the following steps: hybridizing a created multifunctional haploid induction line HIP-Plus serving as a male parent with a target female parent, and saving immature embryos to obtain seedlings; a three-stage identification system comprising visual preliminary screening, molecular confirmation and early selection is adopted to carry out accurate screening on seedlings: firstly, preliminary screening is carried out based on embryo color, then haploid confirmation and transgenic component detection are carried out by utilizing TaMTL allele specific markers, and finally genetic typing is carried out through important character function markers to screen out elite haploids; and carrying out chromosome doubling to obtain a double haploid homozygous line. According to the method, the haploid identification accuracy is improved, the breeding period is shortened, the early directional selection of the target agronomic traits in the haploid stage is realized, and the breeding efficiency and accuracy are greatly improved.

Provided are a high-stability recombinant type I collagen and a use thereof, relating to the technical field of collagens. By means of the directional selection of existing amino acid sequences, potential enzyme cutting sites and unstable sequence fragments are avoided during sequence design, enabling efficient expression in Pichia pastoris; and in addition, after being purified, the recombinant type I collagen still has high stability. The recombinant type I collagen takes into account factors such as related biological active sites and hydrophilicity, has related biological activity while maintaining high stability, and has good practicability.

The invention provides a breeding method of a drought-resistant and high-temperature-resistant millet variety. The breeding method comprises the steps of parent selection, cross pollination, F planting and screening, F and offspring planting and multi-generation screening, stable strain identification and the like. According to the method, parents with obvious drought resistance and high temperature resistance are selected for hybridization, drought stress and high temperature treatment are set in different growth stages, quality screening is combined, and the millet strain with stable characters is bred in multiple generations. The method can accurately and directionally select, accelerates character stability and shortens the breeding period. The bred millet variety has the characteristics of drought resistance and high temperature resistance, the yield reduction range is small under the high-temperature drought condition, and the quality is good. According to the method, the breeding efficiency is improved, the grain yield and quality are guaranteed, agricultural sustainable development is promoted, and the requirement of the market for the high-quality stress-resistant millet variety is met.

The invention discloses a directional breeding method for high-temperature-resistant offspring seeds of crassostrea sikamea. The directional breeding method comprises the following steps: determining a medial lethal temperature LT50 and selecting parents. According to the directional breeding method for the high-temperature-resistant offspring seeds of the crassostrea sikamea, the semi-lethal temperature LT50 of the crassostrea sikamea is measured, the high-temperature-resistant parents are screened at the semi-lethal temperature LT50 and used for breeding high-temperature-resistant strains of the crassostrea sikamea, and the method has the advantages of being simple, efficient, scientific and reliable. According to the method disclosed by the invention, a mode of combining multi-gradient temperature stress and an SPSS logistic regression model is adopted, the median lethal temperature LT50 is accurately positioned as a key screening temperature, and individuals which still can survive at the median lethal temperature LT50 are directly screened as breeding parents, so that a technical support is provided for directionally breeding the crassostrea sikamea high-temperature-resistant strain; according to the method, genetic improvement of the heat resistance character of the crassostrea sikamea can be more accurately achieved, high-temperature-resistant fries are obtained, and therefore the survival rate of the crassostrea sikamea at the high temperature frequently occurring in summer is increased.

The invention relates to the technical field of crop breeding, and discloses an efficient breeding method for directionally improving comprehensive characters of winter wheat, which comprises the following steps: step (1) cross parent selection and preliminary gene polymerization; (2) early generation gene pool construction and high-pressure disease resistance screening; (3) high generation selection and homozygous acceleration; (4) identifying the eurytopic adaptability of multiple ecological regions; and (5) carrying out directional selection on agronomic characters in the whole growth period. According to the method, a single-spike continuous selection strategy is adopted in F2-F4 generations, compared with traditional single plant selection, more inter-plant variation can be contained, gene differences in the same plant can be reserved, a breeding material gene pool is enriched, recessive excellent gene loss caused by only paying attention to external forms is avoided through collaborative screening of agronomic phenotypic characters, early stress resistance and quality preliminary screening, and the breeding quality is improved. The polymerization probability of high-yield, high-quality, disease-resistant and other target genes is remarkably improved, the pain point of waste of early generation gene resources in the traditional breeding technology is effectively solved, and a solid gene foundation is laid for multi-character collaborative improvement; f5 and above ear row / single plant rapid homozygous stable new materials and guarantee the uniformity of offspring, the breeding efficiency can be improved, and provincial and above regional tests can be participated 2-3 years in advance.

The application discloses a method for domesticating and directional breeding of wild schisandra chinensis, which is applied to a cultivation frame. The cultivation frame comprises a windproof base assembly, a supporting rod, a first support and a second support; the supporting rod is connected to the windproof base assembly; the first support is sleeved on the supporting rod, the distance between the first support and the bottom end of the supporting rod is greater than or equal to 1.2 meters, and the diameter of the first support is greater than or equal to 1.2 meters; the second support is sleeved on the supporting rod, the distance between the second support and the bottom end of the supporting rod is greater than or equal to 1.8 meters, and the diameter of the first support is greater than or equal to 0.6 meters; the first support and the second support both comprise a plurality of frame rods which are arranged outwardly with the axis of the supporting rod as the center. The cultivation frame provides a stable and reliable standardized cultivation frame, improves the cultivation conditions and growth environment of the schisandra chinensis, and promotes the healthy growth, stable fruiting, yield and quality of the schisandra chinensis.

The invention relates to the technical field of cotton variety breeding, and particularly discloses a saline-alkaline-tolerant, high-quality and high-yield cotton variety breeding method which comprises the following steps: S1, parent selection and hybridization: taking an upland cotton germplasm A with outstanding saline-alkaline tolerance as a female parent and an upland cotton variety B with excellent fiber quality and good yield as a male parent, and performing hybridization to obtain F1-generation seeds; s2, early-stage multi-dimensional comprehensive screening: adopting a multi-stage screening system integrating genotype, phenotype and physiological indexes from F2 to F4 generations, and directionally selecting and polymerizing single plants with saline-alkaline tolerance and high-quality and high-yield potential. According to the breeding method of the saline-alkali-tolerant, high-quality and high-yield cotton variety, through organic combination of strategic parent selection and matching and a multi-dimensional early screening system, excellent genes can be directionally polymerized, and breakthrough varieties which are excellent in both saline-alkali soil and non-saline-alkali soil are stably bred.

The present invention discloses an apple fruit sugar content regulatory protein MdSWEET9b, its encoding gene and applications. The present invention provides a protein obtained from Malus pumila, named MdSWEET9b protein, which is a protein composed of the amino acid sequence shown in Sequence 1 in the sequence listing. The gene encoding the MdSWEET9b protein, named MdSWEET9b gene, also belongs to the scope of protection of the present invention. The present invention also protects the application of the MdSWEET9b protein in regulating the sugar content of plants. The regulation is positive regulation. When the content of the MdSWEET9b protein increases, the sugar content of the plant increases. The present invention can be used for apple breeding related to the sugar content of apple fruits, and shorten the breeding period through directional selection breeding.

The present invention belongs to the technical field of molecular markers, and specifically discloses a primer for detecting a molecular marker of adult chicken body slant length and its application. By performing phenotypic determination of chicken adult (300-day-old) body slant length and whole-genome resequencing on the 19th generation population of 587 AH distant deep hybridization line resource populations constructed by the Institute of Animal Science, Guangdong Academy of Agricultural Sciences, and conducting a genome-wide association analysis, it is found that the locus Chr1:169650555 has a very high genetic correlation with body slant length and can be effectively used for molecular marker-assisted selection breeding of chicken body slant length traits; by directionally selecting individuals with genotypes of TT (long body slant length), TC (medium body slant length), and CC (short body slant length) at the molecular marker locus Chr1:169650555 as breeding chickens, the genetic selection progress for specific body slant length requirements of chicken breeding lines can be rapidly improved.

This invention provides a method, apparatus, device, and medium for medical feature selection, relating to the field of medical data processing technology. It addresses the technical problem of insufficient accuracy in selecting optimal feature subsets. The method comprises: constructing an improved aurora optimization algorithm that includes an archive-driven population evolution strategy and a directional selection mechanism based on a reference feature subset. The former uses a search mode with the centroid of failed archives as the reference feature subset in the early stages of iteration, guiding the population away from the centroid of failed archives to avoid inferior feature regions; in the later stages of iteration, it uses a search mode with the centroid of successful archives as the reference feature subset, guiding the population to converge towards the centroid of successful archives. The latter constructs a directional update direction vector based on the difference between the reference feature subset selected by the archive-driven population evolution strategy and the current feature subset, guiding the directional update of the feature subset. This can select the optimal feature subset that better meets the data analysis needs of the target medical dataset.

The present invention provides a lightweight pose estimation method and system based on directional feature selection. The method includes the following steps: performing ground point cloud segmentation on the original laser point cloud to screen out the ground point cloud and obtain the point cloud in space; based on the polar coordinate grid representation method of the concentric region model, dividing the point cloud in space into blocks and then obtaining the planarity index, normal vector, and degradation direction of the point cloud within the block; obtaining the feature score of the current environment, and obtaining the importance score of each unit space according to the feature score, planarity, and normal vector of the current environment; screening the feature set according to the importance score of the unit space, and adding the point cloud set with a high score to the feature subset; inputting the screened features into the laser odometer module for pose estimation. By performing directional selection on the laser point cloud features, the present invention can reduce the algorithm time consumption by about half under the condition of ensuring almost the same accuracy, and improve the real-time performance of the algorithm.

The invention relates to a rapid breeding method for breeding an excellent-taste rice variety, and belongs to the technical field of rice genetic breeding design. The rapid breeding method is characterized by comprising the following steps: (1) selecting three-level high-quality rice, japonica rice 'Salt rice No.8' with high stripe disease resistance, rice blast resistance, medium sheath blight resistance, moderate ripening period and high and stable yield as a female parent, and selecting a high-quality rice variety with no white heart and belly and no rice; the method comprises the following steps: (1) taking japonica rice 'Size 10' which has the rice quality reaching the ministerial high-quality rice first grade and medium resistance to bacterial blight, rice blast and stripe blight as a male parent, carrying out artificial hybridization and matching to obtain F0 seeds, (2) planting the F0 seeds into F1, and carrying out anther (microspore) culture on the F1 to form seedlings, and (3) after doubling, carrying out continuous directional selection for many years by adopting a pedigree method to breed the rice with the advantages of high and stable yield, high quality, disease resistance, moderate ripening period and high yield. The adaptability is wide, and the like. Breeding is rapid, and the breeding period is shortened.