46results about How to "High doubling efficiency" patented technology

The invention discloses a method for doubling management of corn haploid. The method for doubling management of corn haploid comprises the following steps: (1) cutting the tip of coleoptile of the corn haploid bud, but not damaging the main leaf and the growing point to obtain the corn haploid bud with coleoptile tip cut; and (2) soaking the corn haploid bud with coleoptile tip cut with a mixed solution of colchicine, dimethyl sulfoxide and water to obtain a chromosome doubled corn bud. The method for doubling management of the corn haploid can remarkably improve the doubling efficiency of the corn haploid, and the tassel pollination rate is over 30 percent which is much higher than the contrast tassel pollination rate (lower than 5 percent). The method solves the vital technical problem of low doubling efficiency in the haploid breeding process, so that the haploid breeding efficiency is greatly improved, and large-scale application of the haploid breeding technology becomes possible.

The invention discloses a method for inducing corn haploids. The method comprises the following steps: pollinating a female parent by a male parent corn haploid induction line with a higher corn haploid inductivity than a corn haploid induction line CAU5, and harvesting hybridized F1 generation grains to obtain corn haploids. A method for realizing the corn haploid induction line comprises the following steps: 1, introducing coding gene of a specific centromere histone mutant into a hybrid first generation plant of a corn inbred line HiIIA and a corn inbred line HiIIB to obtain a transgenic corn plant; and 2, hybridizing the specific histone mutant as a female parent with the CAU5 to obtain an F1 generation, hybridizing the F1 generation as a female parent with the CAU5 to obtain a BC1F1 generation, hybridizing the BC1F1 generation as a female parent with the CAU5 to obtain a BC2F1 generation, and continuously selfing the BC2F1 generation at least five generations to obtain the corn haploid induction line.

The invention relates to cultivation gynogenetic fish, in particular to a method for cultivating gynogenetic carps. The method comprises the following steps of: performing artificial induced spawning on male megalobrama amblycephala and female ordinary carps which serve as male and female parent fish, mixing megalobrama amblycephala sperms inactivated by ultraviolet rays and mature ova of the ordinary carps, activating for 1 to 2 minutes, performing cold shock on the activated ova at the temperature of between 0 and 4 DEG C for 30 to 40 minutes, and incubating embryos obtained by the cold shock at the water temperature of between 20 and 21 DEG C to obtain diploid gynogenetic carps. The gynogenetic carps cultivated by the method have excellent descendant properties, high survival rate and stable inheritance, and have the great significance for the study on biological genetic breeding.

The invention belongs to the technical field of flower breeding, in particular to a method for doubly improving a marigold genotype by utilizing chromosomes, which is characterized in that male sterile dual-purpose line of a seed or a stem tip of marigold is treated by adopting a colchicine solution so as to enable the number of the chromosomes of the marigold to be doubled, thereby providing a breeding starting material of the improvement of the marigold genotype. The method comprises the following steps of: bud forcing treatment, colchicine doubling treatment, rinsing relief treatment, cultivation management, chromosome ploidy authentication and the like. The preferable treatment is described as follows: applying colchicine solution with concentration of 0.05 percent to marigold germinating seeds and soaking for 3 to 6 hours, and thus, the survival rate of plants is high, and the doubling efficiency also reaches 88.89 percent. The invention can effectively control the environment temperature and humidity when the seeds germinate; the repeatability of a test is high, the operation is convenient and time and labor are saved. The invention is suitable for the improvement of the marigold genotype.

The invention provides a method for doubling cone haploids. The method comprises the following steps: 1, cutting off the tips of coleoptiles of buds of corn haploids; and 2, soaking embryos of the buds of the corn haploids without the tips of coleoptiles in mixed liquid of colchicines and dimethyl sulfoxide, so as to obtain corn buts with doubled chromosome. The method for doubling cone haploids, which is provided by the invention, can remarkably improve the survival rate and maturing rate of the corn haploids, wherein the survival rate is higher than 70%, which is far higher than the survival rate of a control group which is generally lower than 50%, the maturing rate is higher than 10%, which is far higher than the maturing rate of the control group which is generally about 5%; moreover, the use amount of colchicines is 5-6 times. When applied to a haploid breeding system, the method can effectively promote the reform of the corn breeding technology to realize large-scale and engineering haploid breeding.

The invention discloses a method for cultivating a corn haploid inducer with higher corn haploid inductivity than a corn haploid inducer CAU5. The method comprises the following steps: 1, inducing coding gene of a specific histone mutant into a hybrid first generation plant of a corn inbred line HiIIA and a corn inbred line HiIIB to obtain a transgenic corn plant containing the specific histone mutant; and 2, hybridizing the specific histone mutant as a female parent with the corn haploid inducer CAU5 to obtain an F1 generation, hybridizing the F1 generation as a female parent with the corn haploid inducer CAU5 to obtain a BC1F1 generation, hybridizing the BC1F1 generation as the corn haploid inducer CAU5 to obtain a BC2F1 generation, and continuously selfing the BC2F1 generation five generations to obtain the corn haploid inducer with higher corn haploid inductivity than the corn haploid inducer CAU5.

The invention discloses a chemical corn double haploid young embryo processing method. After a haploid is selected to induce pollination of a system for 28 days or so, a haploid kernel young embryo is selected, the selected young embryo is placed in amiprophos-methl to be processed for 2 hours, and processing concentration of propyzamide is under 60 micrometer moles per liter. According to the technology, chemical doubling of the haploid is carried out in early phase, the chemical processing time is shortened, the processing concentration is reduced, consumption of chemicals is reduced, personal injury suffered by processing staff is small, and above all, doubling efficiency of the haploid is improved.

The invention relates to a method for creating corn autotetraploid. The method comprises the following steps: treating corn filaments by adopting a conventional chromosome doubling agent and a conventional treatment method; doubling somatic chromosomes in induced organs without the need of pollination, so as to directly obtain autotetraploid seeds; then carrying out microscope examination on chromosome ploidy and screening the autotetraploid; carrying out fruitfulness breeding when the fructification percentage is relatively low; preparing autotetraploid hybrid seeds by utilizing an autotetraploid selfing line after the fructification percentage reaches the requirements. The method provided by the invention has the beneficial effects that the method is simple and feasible; seed germination, germ low-temperature treatment and seedling transplanting processes of an existing treatment method are omitted; the doubling efficiency is improved, and the problem that a chromosome ploidy chimerarepels tetraploid cells due to competitive advantages of diploid cells in a somatic cytotropism development process is avoided, so that the doubling efficiency is improved; the yield and quality areimproved and the purity is easy to ensure.

The invention discloses a preparation method for corn double haploid. Based on a haploid young embryo identification technology, a haploid young embryo doubling technology and a young embryo direct seeding formation technology, a haploid tissue culture identification and doubling technology system can be established, the novel method for rapidly obtaining corn double haploid can be provided; and the method has characteristics of being rapid, efficient and easy in scale operation. Compared with haploid doubling conventional methods, time can be greatly shortened, the scale operation of tissue culture doubling can be more easily, and therefore, the method is suitable for demands of future haploid engineering seed breeding and has large application values in future haploid seed breeding.

The invention relates to a plant breeding technology, in particular to a method for breeding a double haploid of corn*rice distant hybridization. The method comprises the steps that a corn hybrid is used as a female parent, a rice variety is used as a male parent, and a corn haploid is obtained by distant hybridization and treated with a chromosome doubling solution to obtain a double haploid cornplant. The method can effectively improve the double haploid induction efficiency, and the application value is large. The invention also provides a brush device which has the functions of measuringa liquid, injecting and brushing by simple modification with a syringe as an original device.

The invention belongs to the field of crop biological technology and genetic breeding technology, and particularly discloses a method for improving the doubling efficiency for inducing triploid echinacea chromosome by colchicine. The method comprises the following steps: transferring a triploid echinacea root explant to a culture medium containing 120mg/L colchicine and culturing for 18-25 days. The root is used as the explant and the ratio of successively obtaining hexaploid echinacea is up to 64.71% so that the success rate is at least increased by 41.21% when being compared with the success rate for doubling the echinacea in the prior art. According to the method disclosed by the invention, the problems that the doubling effect of the triploid echinacea chromosome is poor and a hexaploid strain is difficult to obtain are effectively overcome.

The invention discloses a method for culturing wheat haploid embryo test-tube seedlings. The method comprises the following steps that when each of the wheat haploid embryo test-tube seedlings grows to have 2-3 leaves, the seedlings are transferred to a strong seedling culture box for strong seedling culture; when 50% of strong seedlings in the strong seedling culture box reach a three-leaf stage, strong seedling culture is performed; after the strong seedling culture is performed for 2-3 weeks, nutritional supplementing liquid is added; when the test-tube seedlings are cultured to produce 2-3 tillers, the seedlings are transferred to a culture box for over-summering, over-summering culture is performed, and nutritional supplementing liquid is added; from the last ten days of October to the first ten days of November, the culture conditions of the strong seedling culture box are recovered, the seedlings are transplanted and hardened when the field temperature is reduced to 15 DEG C or below, and the seedlings are transplanted in open ground in 2-3 days after seedling hardening. The nutritional supplementing liquid is added at different stages, the wheat haploid embryo test-tube seedlings can grow into one-step strong seedlings through one step, the over-summering decline and fall of the test-tube seedlings are simply and effectively relieved, the survival rate of the test-tube seedlings and survival rate of bottling out and transplantation are improved, and the doubling efficiency of the haploid seedlings is improved indirectly.

An electron multiplier body, a photomultiplier tube, and a photomultiplier are disclosed. The invention provides the electron multiplier body including a main body portion, an electron incidence portion provided in the main body portion to be opened at one end surface of the main body portion in the first direction, and a channel provided in the main body portion to be opened at the other end surface of the main body portion in the first direction and reach the electron incidence portion and configured to emit secondary electrons, in which the channel includes a first inner surface and a second inner surface facing each other, the first inner surface includes a convex first bent portion and a concave second bent portion, and a plurality of first inclined surfaces, the second inner surface includes a convex third bent portion and a concave fourth bent portion, and a plurality of second inclined surfaces, and an interval between a tip of the first bent portion and a tip of the third bent portion, a distance between the first inclined surface and the second inclined surfaces facing each other, an angle between a pair of first inclined surfaces defining the first bent portion, and a length of the channel satisfy predetermined expressions.