Crossbreeding method for trichosanthes kirilowii maxim

Abstract

The invention discloses a method for cross breeding of trichosanthes kirilowii maxim, which belongs to the technical field of breeding and comprises the following steps: performing sister line inbreeding through female plants and male plants in the same trichosanthes kirilowii maxim, planting seed seedlings according to plant rows in the second year, combining field phenotype identification, eliminating bad single plants, selecting single plant groups with excellent characters, and further performing sister line inbreeding homozygosis to obtain the trichosanthes kirilowii maxim. The method comprises the following steps: continuously inbreeding compulsory sister lines for 3-4 years, eliminating bad allelic genes, identifying the homozygous degree of different sites of a whole genome by using SSR molecular markers to obtain inbred lines with excellent comprehensive characters, calculating genetic distances of different inbred lines according to genotypes, and selecting the inbred lines as parents in combination with phenotypic character complementation and breeding target requirements of the inbred lines. The method comprises the following steps: carrying out cross breeding on snakegourd fruits, selecting single plants with excellent comprehensive characters from filial generations, carrying out propagation through root tuber or tissue culture, and carrying out yield and related quality comparison so as to breed more new snakegourd fruit varieties with high yield, high quality, disease resistance and excellent comprehensive characters.

Description

Technical Field

[0001] The invention relates to the technical field of breeding, and in particular to a method for hybrid breeding of Trichosanthes kirilowii. Background Art

[0002] As an important medicinal plant and leisure food, Trichosanthes kirilowii has formed variety resources that adapt to the ecological environment of various places in China during the long-term historical evolution process, with extensive genetic diversity and a broad genetic basis. However, Trichosanthes kirilowii is dioecious, and long-term outcrossing has accumulated a large number of recessive adverse alleles, resulting in the degeneration of Trichosanthes kirilowii varieties. With the cultivation of Trichosanthes kirilowii in recent years, some varieties have been seriously harmed by anthracnose. Therefore, it is urgent to select new Trichosanthes kirilowii varieties with high yield, high resistance and excellent quality through the innovation of germplasm resources and breeding utilization. Summary of the invention

[0003] The purpose of this section is to summarize some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0004] In view of the above problems and / or the problems existing in the existing method for hybrid breeding of Trichosanthes kirilowii, the present invention is proposed.

[0005] Therefore, the purpose of the present invention is to provide a method for hybrid breeding of Trichosanthes kirilowii, which accelerates the homozygosity of Trichosanthes kirilowii genes through continuous sister line inbreeding, eliminates bad genes, and combines SSR molecular markers for genotype identification, effectively avoiding the presence of dominance and gene interaction in the low-generation heterozygous state, inaccurate phenotypic identification, and cannot fully represent the phenotypic results of the final homozygous line, shortening the improvement cycle, and improving breeding efficiency through the application of molecular marker calculations.

[0006] To solve the above technical problems, according to one aspect of the present invention, the present invention provides the following technical solutions:

[0007] A method for crossbreeding of Trichosanthes kirilowii, comprising:

[0008] S1. Selecting comprehensive and excellent Trichosanthes germplasm resources and planting them in rows, after flowering, selecting female plants with comprehensive and excellent traits, selecting flower buds that are about to open from the plants, bagging them with paper caps on the same day, and selecting male plants from the same row the next day, removing the paper caps, clamping the filaments with tweezers and placing them on the stigma of the female flowers, and then wrapping the female flowers with dining paper, and waiting for them to become melons after hybridization;

[0009] S2. After the melons are ripe, select the melons obtained by inbreeding with excellent comprehensive traits, plant them in rows according to the operation in step S1, eliminate the poor individual plants, and carry out the second round of sister inbreeding. Repeat 3-4 rounds of sister inbreeding to obtain an inbred line with high homozygosity and excellent comprehensive traits;

[0010] S3, selecting 64 pairs of SSR markers from the whole genome of Trichosanthes kirilowii, genotyping the obtained inbred lines, calculating the homozygosity of the inbred lines and the genetic distance between the inbred lines, selecting inbred lines with a homozygosity of more than 90%, a long genetic distance, and complementary traits, and assembling hybrid combinations according to the operation in step S1;

[0011] S4. Plant the obtained melons in rows, select superior individual plants with excellent comprehensive traits and high disease resistance consistent with the breeding goal, propagate the seedlings of the individual plants through tissue culture or tuber root propagation, conduct multi-year multi-point yield comparison and resistance identification with the control, as well as production tests and field phenotype identification, and obtain new varieties through comprehensive investigation;

[0012] S5. Repeat steps S1 and S2 in a cycle to further improve the basic population and select more excellent inbred lines.

[0013] As a preferred embodiment of the method for hybrid breeding of Trichosanthes kirilowii described in the present invention, the method for improving the inbred line of Trichosanthes kirilowii is applied in the breeding of Trichosanthes kirilowii varieties, wherein the self-pollination is 2-4 generations of inbreeding.

[0014] As a preferred embodiment of the method for hybrid breeding of Trichosanthes kirilowii described in the present invention, in the step S1, the Trichosanthes kirilowii germplasm resource with excellent comprehensive traits is a Trichosanthes kirilowii with heavy weight and high seed yield.

[0015] As a preferred embodiment of the method for hybrid breeding of Trichosanthes kirilowii described in the present invention, in the step S1, the time for bagging is from 3:00 to 7:00 p.m. on the same day.

[0016] As a preferred embodiment of the method for hybrid breeding of Trichosanthes kirilowii described in the present invention, in the step S1, the time for removing the caps is from 7 to 9 am the next day.

[0017] Compared with the existing technology: the homozygosity of Trichosanthes genes is accelerated through continuous sister line inbreeding, bad genes are eliminated, and genotype identification is performed in combination with SSR molecular markers, which effectively avoids the presence of dominance and gene interaction in the low-generation heterozygous state, inaccurate phenotypic identification, and cannot fully represent the phenotypic results of the final homozygous line, shortening the improvement cycle, and improving breeding efficiency through the application of molecular marker calculations. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the present invention will be described in detail below in combination with the accompanying drawings and detailed embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0019] Figure 1 The flower buds that are about to open are selected by the present invention;

[0020] Figure 2 For the present invention, the flower buds are bagged with paper caps in the afternoon of the same day;

[0021] Figure 3 For the present invention, the filaments of the male plants are placed on the stigma of the female flowers;

[0022] Figure 4 Wrap the female flowers with the table paper of the present invention;

[0023] Figure 5 It is the melon after hybridization of the present invention. DETAILED DESCRIPTION

[0024] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0025] Secondly, the present invention is described in detail with reference to schematic diagrams. When describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0026] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0027] The present invention provides a method for hybrid breeding of Trichosanthes kirilowii, which accelerates the homozygosity of Trichosanthes kirilowii genes through continuous sister line inbreeding, eliminates bad genes, and performs genotype identification in combination with SSR molecular markers, effectively avoiding the presence of dominance and recessiveness and gene interaction in a low-generation heterozygous state, inaccurate phenotypic identification, and failure to fully represent the phenotypic results of the final homozygous line, shortening the improvement cycle, and improving breeding efficiency by applying molecular marker calculations.

[0028] Example 1

[0029] First hybridization operation:

[0030] First, prepare a large amount of Trichosanthes kirilowii;

[0031] Select a high-quality germplasm from the Trichosanthes, that is, a Trichosanthes with a heavy weight and a high seed yield, take the seeds from the Trichosanthes and plant them in rows;

[0032] Wait for the seeds of Trichosanthes to bloom, select female plants with excellent comprehensive traits, and select the flower buds that are about to open from the female plants, and put them in paper cap bags between 3-7 pm on the same day;

[0033] Wait overnight, and select male plants from the same row at 7-9 am the next day, remove the paper caps on the outside of the flower buds, use tweezers to pull out the filaments of the male plants and place them on the stigma of the female flowers, cover the female flowers with paper caps again, and wait for hybridization to produce melons.

[0034] Second to fourth handover operations:

[0035] After waiting for the first hybridization operation to mature, according to the previous seed selection requirements, select a Trichosanthes with heavy weight and high seed yield from the inbred Trichosanthes, take the seeds and plant them in rows;

[0036] After waiting for the Trichosanthes seeds to bloom, select female plants with excellent comprehensive traits and cover their buds that are about to open with paper caps between 3-7 pm on the same day;

[0037] At 7-9 am the next day, male plants were selected from the same row, the paper caps on the outside of the flower buds were removed, the filaments of the male plants were pulled out with tweezers and placed on the stigma of the female flowers, and the female flowers were bagged with paper caps again, waiting for hybridization to produce melons. After that, the hybridization process was carried out twice in sequence, and each time, high-quality germplasm of Trichosanthes was selected for inbreeding breeding, and poor individual plants were eliminated to obtain inbred Trichosanthes with high homozygosity and excellent comprehensive traits.

[0038] The fifth hybridization operation:

[0039] First, 64 pairs of SSR markers were selected from the whole genome of Trichosanthes kirilowii, and genotyping was performed on the inbred lines of Trichosanthes kirilowii with high homozygosity and excellent comprehensive traits that remained after four inbreeding operations. The homozygosity of the inbred lines and the genetic distance between the inbred lines were calculated, and the inbred lines of Trichosanthes kirilowii with a homozygosity of more than 90%, a long genetic distance, and complementary traits were selected. From these Trichosanthes kirilowii, the ones with high-quality germplasm were selected for breeding, and the seeds were planted in rows after the seeds were taken.

[0040] By observing the plants, we can select superior individual plants with excellent comprehensive traits and high disease resistance that are consistent with the breeding goals, propagate the seedlings of the individual plants through tissue culture or root tubers, and conduct multi-year multi-point yield comparison and resistance identification with the control, as well as production trials and field phenotypic identification, to obtain new varieties through comprehensive investigation;

[0041] According to the inbreeding screening steps in the previous steps, the Trichosanthes kirilowii is inbred and bred many times, and after the breeding, it is propagated through root tubers or tissue culture, and the yield and related quality are compared to further improve the basic population, and then more new varieties of Trichosanthes kirilowii with excellent comprehensive traits of high yield, high quality and disease resistance are bred.

[0042] Although the present invention has been described above with reference to the embodiments, various modifications may be made thereto and parts thereof may be replaced by equivalents without departing from the scope of the present invention. In particular, as long as there is no structural conflict, the various features in the embodiments disclosed in the present invention may be used in combination with each other in any manner, and the fact that these combinations are not exhaustively described in this specification is only for the sake of omitting space and saving resources. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method for crossbreeding of Trichosanthes kirilowii, characterized in that: The following steps are involved: S1. Selecting comprehensive and excellent Trichosanthes germplasm resources and planting them in rows, after flowering, selecting female plants with comprehensive and excellent traits, selecting flower buds that are about to open from the plants, bagging them with paper caps on the same day, and selecting male plants from the same row the next day, removing the paper caps, clamping the filaments with tweezers and placing them on the stigma of the female flowers, and then wrapping the female flowers with dining paper, and waiting for them to become melons after hybridization; S2. After the melons are ripe, select the melons obtained by inbreeding with excellent comprehensive traits, plant them in rows according to the operation in step S1, eliminate the poor individual plants, and carry out the second round of sister inbreeding. Repeat 3-4 rounds of sister inbreeding to obtain an inbred line with high homozygosity and excellent comprehensive traits; S3, selecting 64 pairs of SSR markers from the whole genome of Trichosanthes kirilowii, genotyping the obtained inbred lines, calculating the homozygosity of the inbred lines and the genetic distance between the inbred lines, selecting inbred lines with a homozygosity of more than 90%, a long genetic distance, and complementary traits, and assembling hybrid combinations according to the operation in step S1; S4. Plant the obtained melons in rows, select superior individual plants with excellent comprehensive traits and high disease resistance consistent with the breeding goal, propagate the seedlings of the individual plants through tissue culture or tuber root propagation, conduct multi-year multi-point yield comparison and resistance identification with the control, as well as production tests and field phenotype identification, and obtain new varieties through comprehensive investigation; S5. Repeat steps S1 and S2 in a cycle to further improve the basic population and select more excellent inbred lines.

2. The method for hybrid breeding of Trichosanthes kirilowii according to claim 1, wherein: The application of the method of rapid improvement of Trichosanthes inbred lines in Trichosanthes variety breeding, with self-pollination being 2-4 generations of inbreeding.

3. A method for hybrid breeding of Trichosanthes kirilowii according to claim 1, characterized in that, In the step S1, the comprehensive traits of excellent Trichosanthes kirilowii germplasm resources are selected from a Trichosanthes kirilowii with heavy weight and high seed yield.

4. The method for hybrid breeding of Trichosanthes kirilowii according to claim 1, characterized in that: In step S1, the bagging time is from 3:00 to 7:00 p.m. on the same day.

5. The method for hybrid breeding of Trichosanthes kirilowii according to claim 1, characterized in that: In step S1, the time for removing the hat is from 7 to 9 am the next day.

Images