Breeding of cytoplasmic male sterile line MSguiyan 19 of flue-cured tobacco and its propagation method

Abstract

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.

Description

Technical Field

[0001] This invention belongs to the field of tobacco genetics and breeding technology, specifically relating to the selection and propagation method of MS Guiyan 19, a cytoplasmic male sterile line of flue-cured tobacco. Background Technology

[0002] Flue-cured tobacco exhibits strong heterosis in terms of yield, disease resistance, growth period, and vigor. However, due to the lack of significant heterosis in leaf quality resulting from inter-varietal hybridization, the utilization of heterosis in flue-cured tobacco was once abandoned by tobacco breeders. In recent years, the scarcity of groundbreaking varieties bred in my country's flue-cured tobacco breeding program has led to a single dominant variety across the country, decreased varietal resistance, and widespread pest and disease damage, causing severe losses to my country's flue-cured tobacco production. Because of its strong resistance to adverse conditions and the short breeding cycle and rapid results of heterosis utilization, domestic breeders have begun to refocus on the utilization of heterosis in flue-cured tobacco, viewing it as a quick and effective breeding method.

[0003] The expression of heterosis is related to parental genetic diversity, increasing with increasing parental genetic distance. Therefore, breeding genetically diverse sterile lines of flue-cured tobacco and expanding the available germplasm resources are crucial foundational tasks for utilizing heterosis in flue-cured tobacco. Summary of the Invention

[0004] In response to the need for genetic diversity of sterile lines in the utilization of heterosis in flue-cured tobacco, this invention aims to cultivate new sterile lines for flue-cured tobacco, provide excellent sterile line germplasm for the utilization of heterosis in flue-cured tobacco, and broaden the genetic basis for the utilization of heterosis in flue-cured tobacco.

[0005] To solve the above problems, the technical solution adopted by the present invention is as follows: the sterile flue-cured tobacco line MS Guiyan 19 and its propagation method include the selection and propagation method of the sterile line MS Guiyan 19, using the sterile line MSG28 as the source of sterile cytoplasm and the variety Guiyan 19 as the recurrent parent to select the sterile line MS Guiyan 19; using the sterile line MS Guiyan 19 as the female parent and the maintainer line Guiyan 19 as the male parent to propagate the sterile line MS Guiyan 19.

[0006] The sterile line MS Guiyan 19 of this invention is obtained through the following steps: (1) Hybridization: Using the cytoplasmic male sterile line MSG28 of flue-cured tobacco as the female parent and the variety Guiyan 19 as the male parent, hybridization was carried out to obtain F1 seeds of male sterile hybrid combination. The F1 seeds were mixed and harvested, and the seeds were numbered and stored.

[0007] (2) Continuous backcrossing: In the following year, male-sterile hybrid combination F1 and Guiyan 19 were planted respectively. Using male-sterile hybrid combination F1 as the female parent and Guiyan 19 as the backcross parent, BC1F1 seeds were obtained through backcrossing. The BC1F1 seeds were then mixed and harvested. In subsequent years, combined with Hainan generation, Guiyan 19 was used as the recurrent parent and backcrossed with the backcross offspring for 5 consecutive generations until BC6F1 seeds were obtained. This was to achieve the goal of replacing the MSG28 cell nucleus with the Guiyan 19 cell nucleus and to cultivate a genetically stable, completely sterile cytoplasmic male-sterile line MS Guiyan 19.

[0008] The propagation method of the sterile line MS Guiyan 19 described in this invention comprises the following steps: (1) Planting: MS Guiyan 19 was used as the female parent and Guiyan 19 as the male parent. The parents were sown and transplanted at the same time according to the conventional method. The male parent and the female parent were planted at intervals of 1:4. (2) Remove impurities and inferior plants: When the tobacco plants are budding, strictly remove impurities, inferior plants and diseased plants, and completely remove tobacco branches. Select typical plants according to the parent plant standards and bag them. (3) Artificial pollination: When the tip of the corolla of the sterile line MS Guiyan 19 turns red but does not open, cut off the tip of the corolla with scissors or gently tear the corolla with your fingers to expose the pistil. Then, evenly apply the pollen of the maintainer line Guiyan 19 to the stigma of the sterile line pistil. (4) Timely harvesting: Harvest each batch as it matures according to the order of hybridization and pollination. When the capsules turn brown, the seeds are mature and ready for harvest. The harvested seeds should be air-dried in a cool place, threshed, and stored in a low-temperature, dry, and sealed environment.

[0009] The male-sterile line MS Guiyan 19 developed in this invention has the following characteristics: The floral organ characteristics are as follows: The inflorescence characteristics of the sterile line MS Guiyan 19 are consistent with those of the maintainer line Guiyan 19. It is a compact inflorescence with a pink corolla. The pistil grows normally, while the stamens are degenerate, which means it is a stamen-degenerate sterile line.

[0010] The varietal characteristics are as follows: excellent agronomic traits, good leaf ripening and yellowing, good ease of curing and good curing resistance; strong overall resistance, moderately resistant to bacterial wilt, black shank and root-knot nematode, moderately susceptible to red spot disease and TMV, and susceptible to CMV and PVYN; good appearance quality of tobacco leaves, golden yellow color, medium to strong hue, and good oil content; harmonious chemical composition of tobacco leaves, and good smoking quality.

[0011] Compared with existing technologies, the MS Guiyan 19 sterile tobacco line bred in this invention has the advantages of stable sterility, excellent agronomic traits, high yield and output value, good ease and tolerance to curing, good appearance and internal quality of tobacco leaves, and harmonious chemical composition. It provides a new and excellent sterile line germplasm for the research on the utilization of heterosis in flue-cured tobacco. Attached Figure Description

[0012] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will now be described in further detail with reference to the accompanying drawings, wherein: Figure 1 This invention provides the breeding process for the cytoplasmic male sterile line MS Guiyan 19. Figure 2 Morphological diagram of MS Guiyan 19, a cytoplasmic male sterile line; Figure 3 This image shows the corolla characteristics of the cytoplasmic male sterile line MS Guiyan 19. Detailed Implementation

[0013] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be understood that the preferred embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0014] Example 1. The sterile line MS Guiyan 19 was obtained by the following method and steps: (1) Hybridization: Using the cytoplasmic male sterile line MSG28 of flue-cured tobacco as the female parent and the variety Guiyan 19 as the male parent, hybridization was carried out to obtain F1 seeds of male sterile hybrid combination. F1 seeds were mixed and harvested, and seed numbers were stored. (2) Continuous backcrossing: In the following year, male sterile hybrid combination F1 and Guiyan 19 were planted respectively. The male hybrid combination F1 was used as the female parent and Guiyan 19 was used as the backcross parent. BC1F1 seeds were obtained by backcrossing and the BC1F1 seeds were mixed and harvested. In subsequent years, combined with Hainan generation, Guiyan 19 was used as the recurrent parent and backcrossed with the backcross offspring for 5 consecutive generations until BC6F1 seeds were obtained. This was to achieve the goal of replacing the nucleus of MSG28 cells with the nucleus of Guiyan 19 cells and to cultivate a genetically stable, completely sterile cytoplasmic male sterile line MS Guiyan 19.

[0015] The propagation method of the sterile flue-cured tobacco line MS Guiyan 19 is as follows: (1) Planting: MS Guiyan 19 was used as the female parent and Guiyan 19 as the male parent. The parents were sown and transplanted at the same time according to the conventional method. The male parent and the female parent were planted at intervals of 1:4. (2) Remove impurities and inferior plants: When the tobacco plants are budding, strictly remove impurities, inferior plants and diseased plants, and completely remove tobacco branches. Select typical plants according to the parent plant standards and bag them. (3) Artificial pollination: When the tip of the corolla of the sterile line MS Guiyan 19 turns red but does not open, cut off the tip of the corolla with scissors or gently tear the corolla with your fingers to expose the pistil. Then, evenly apply the pollen of the maintainer line Guiyan 19 to the stigma of the sterile line pistil. (4) Timely harvesting: Harvest each batch as it matures according to the order of hybridization and pollination. When the capsules turn brown, the seeds are mature and ready for harvest. The harvested seeds should be air-dried in a cool place, threshed, and stored in a low-temperature, dry, and sealed environment.

[0016] MS Guiyan 19 was planted at the Jinhua flue-cured tobacco variety breeding and propagation base in Fenggang County, Zunyi City, Guizhou Province in 2023. The results are as follows: 1. Characteristics MS Guiyan 19 has a pyramidal plant type, oblong leaves, green color, wrinkled surface, wavy margins, acute leaf tip, small auricles, medium-thick midrib, medium stem-leaf angle, and medium leaf thickness. The inflorescence is concentrated, and the flowers are pale red. The field growing period is 128.3 days. The plant height is moderate, averaging 104.82 cm, with an average of 21 leaves. The stem circumference is moderate, averaging 10.05 cm, with an average internode distance of 4.59 cm. The average length of the middle leaf is 73.21 cm, and the average width is 27.76 cm.

[0017] 2. Economic characteristics MS Guiyan 19 average yield: 2473.95 kg / hm 2 Output value: 52,490.10 yuan / hm 2 The average price was 21.06 yuan / kg, with a top-grade tobacco rate of 41.23% and a medium-grade tobacco rate of 76.68%.

[0018] 3. Tobacco leaf quality 3.1 Appearance Quality MS Guiyan 19, the original tobacco from the central part, is mainly golden yellow in color, with a slightly higher proportion of bluish smoke. Its maturity is mature to fairly mature, its structure is loose to fairly loose, its quality is medium to slightly thin, it has some to some oil content, and its color is medium.

[0019] 3.2 Main Chemical Components MS Guiyan 19 has the following main chemical components in its tobacco leaves, all within suitable ranges: average nicotine content 2.47%, total nitrogen 1.87%, reducing sugar 25.11%, total sugar 30.45%, potassium 1.81%, and chlorine 0.52%.

[0020] 3.3 Sensory quality MS Guiyan 19 has a slightly above-average aroma quality, with a moderate to moderately strong aroma, medium to moderately strong smoke concentration, a pleasant to pleasant aftertaste, some off-flavors, a moderate strength, and some irritation. Overall, its sensory quality is slightly above average to good.

[0021] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for breeding the flue-cured tobacco cytoplasmic male sterile line MS Guiyan 19, characterized in that: This method uses the sterile line MSG28 as the source of sterile cytoplasm and the variety Guiyan 19 as the recurrent parent to breed the sterile line MS Guiyan 19; and uses the sterile line MS Guiyan 19 as the female parent and the maintainer line Guiyan 19 as the male parent to propagate the sterile line MS Guiyan 19. The sterile line MS Guiyan 19 was obtained through the following methods and steps: (1) Hybridization: Using the cytoplasmic male sterile line MSG28 of flue-cured tobacco as the female parent and the variety Guiyan 19 as the male parent, hybridization was carried out to obtain F1 seeds of male sterile hybrid combination. F1 seeds were mixed and harvested, and seed numbers were stored. (2) Continuous backcrossing: In the following year, male sterile hybrid combination F1 and Guiyan 19 were planted respectively. The male hybrid combination F1 was used as the female parent and Guiyan 19 was used as the backcross parent. BC1F1 seeds were obtained by backcrossing and the BC1F1 seeds were mixed and harvested. In subsequent years, combined with Hainan generation, Guiyan 19 was used as the recurrent parent and backcrossed with the backcross offspring for 5 consecutive generations until BC6F1 seeds were obtained. This was to achieve the goal of replacing the nucleus of MSG28 cells with the nucleus of Guiyan 19 cells and to cultivate a genetically stable, completely sterile cytoplasmic male sterile line MS Guiyan 19.

2. The method for breeding the flue-cured tobacco cytoplasmic male sterile line MS Guiyan 19 as described in claim 1, characterized in that: The following methods and steps were used to propagate the sterile line MS Guiyan 19: (1) Planting: MS Guiyan 19 was used as the female parent and Guiyan 19 was used as the male parent. The parents were sown and transplanted at the same time according to the conventional method. The male parent and the female parent were planted at intervals of 1:

4. (2) Remove impurities and inferior plants: When the tobacco plants are budding, strictly remove impurities, inferior plants and diseased plants, and completely remove tobacco branches. Select typical plants according to the parent plant standards and bag them. (3) Artificial pollination: When the tip of the corolla of the sterile line MS Guiyan 19 turns red but does not open, cut off the tip of the corolla with scissors or gently tear the corolla with your fingers to expose the pistil. Then, evenly apply the pollen of the maintainer line Guiyan 19 to the stigma of the sterile line pistil. (4) Timely harvesting: Harvest each batch as it matures according to the order of hybridization and pollination. When the capsules turn brown, the seeds are mature and ready for harvest. The harvested seeds should be air-dried in a cool place, threshed, and stored in a low-temperature, dry, and sealed environment.

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