Breeding method of potatoes with high zinc content and high resistant starch content

Abstract

The invention relates to the technical field of potato breeding, in particular to a breeding method of potatoes with high zinc content and high resistant starch content. According to the method, parents are specifically selected, a breeding strategy is formulated in a targeted manner, Zhejiang pink-resistant potatoes with high-resistance starch are selected as female parents for hybridization and backcross, high-zinc potatoes MG56-42 are selected as male parents, it can be guaranteed that expected high-zinc and high-resistance starch potatoes are obtained through breeding, and the method has the advantage of being efficient. The obtained high-zinc and high-resistance starch potatoes serve the provenance agriculture, face food and large health and can meet the current healthy life requirements.

Description

Technical Field

[0001] The invention relates to the technical field of potato breeding, and in particular to a breeding method for high-zinc and high-resistant starch potatoes. Background Art

[0002] Potato is the fourth major staple food crop in my country after rice, wheat and corn in 2015. Compared with the variety diversity of rice, wheat and corn, the breeding objectives and uses of potato are obviously more single, especially there are few new functional and characteristic varieties that are suitable for staple food. In order to fully tap the potential of staple food consumption and the charm of food innovation, functional and nutritious potato breeding is the key.

[0003] Zinc is an important trace nutrient element and is known as the "flower of life". Zinc deficiency is an important target of the global "invisible hunger". Adequate zinc is the key to brain and body development. Deficiency can cause intellectual retardation and lead to "dwarfism". Infants and young children pay special attention to and emphasize zinc supplementation during their growth. Generally, zinc nutritional supplements are often purchased, but long-term use can easily lead to the risk of overdose or poisoning. The Chinese Nutrition Society recommends that zinc be taken from the diet. Zinc is mainly found in animal offal and seafood. The zinc content in daily staple foods and children's favorite foods is very low, and there are few zinc-rich vegetables and fruits. The new functional potato variety with natural high zinc and low heavy metal content is suitable for staple food and convenient for the development of functional snack foods such as mashed potatoes and potato chips. It can improve and prevent a series of diseases caused by zinc deficiency from the source.

[0004] Resistant starch (RS) is a general term for starch and starch degradation products that are difficult to digest and absorb in the small intestine of a healthy human body. It has many important physiological functions, such as lowering blood sugar, lowering blood lipids, controlling weight, and promoting intestinal health. Resistant starch can be mainly divided into five categories: Resistant starch type 1 (RS1, physically embedded resistant starch), resistant starch type 2 (RS2, resistant starch granules, raw starch), resistant starch type 3 (RS3, retrograde starch, formed after starch is cooked), resistant starch type 4 (RS4, chemically modified starch) and resistant starch type 5 (RS5, starch-fat complex). In general, RS2 in raw potatoes is higher, but RS3 after processing and cooking is lower, so how to increase the RS3 content in cooked potatoes still needs to be explored.

[0005] Therefore, breeding high zinc and high RS3 potatoes is particularly suitable for people with specific health needs such as gestational diabetes and zinc deficiency. Summary of the invention

[0006] The present invention provides a breeding method for high-zinc and high-resistant starch potatoes, which can be eaten fresh and are suitable for processing, are rich in various nutrients, and can meet current healthy living needs.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] The present invention provides a breeding method for high-zinc and high-resistant starch potatoes, comprising the following steps:

[0009] (1) Using Zhejiang University resistant powder potato as the female parent and MG56-42 as the male parent, hybridization was performed to obtain F1 generation seedlings;

[0010] (2) F1 generation seedlings were grown in greenhouses. When flowering, the F1 generation was used as the male parent and the Zhejiang University resistant pink potato was used as the female parent for backcrossing to obtain BC1F1 generation seedlings;

[0011] (3) Cultivating BC1F1 generation seedlings in a greenhouse, measuring and selecting tubers with high apparent amylose content, and obtaining asexual S1 generation seed potatoes;

[0012] (4) Planting the S1 generation, measuring and selecting tubers with high RS3 content, and obtaining asexual S2 generation seed potatoes;

[0013] (5) Planting the S2 generation, measuring and selecting tubers with high zinc content, and obtaining the asexual S3 generation seed potatoes;

[0014] (6) Planting the S3 generation in multiple locations, measuring and selecting tubers with high RS3 and zinc content, and obtaining asexual S4 generation seed potatoes;

[0015] (7) The S4 generation was planted in stages to select and breed potatoes with high zinc and high resistant starch.

[0016] Among them, Zhejiang University Resistant Flour Potato is a new variety of high-resistant starch potato bred by Zhejiang University. It has a resistant starch RS3 content of 5.1% and a zinc content of 23.1 mg / kg. It has applied for plant variety protection to the Ministry of Agriculture and Rural Affairs (Announcement No. CNA049181E). For details, please see the Plant Variety Protection Announcement on July 1, 2022; it can be purchased from the Institute of Nuclear Agricultural Sciences of Zhejiang University or Zhejiang Jie Nong Biotechnology Co., Ltd., a cooperative enterprise between industry, academia and research.

[0017] Among them, MG56-42 is a new high-zinc potato variety bred by Zhejiang University, with a zinc content of 36.5 mg / kg and a resistant starch RS3 content of 4.5%, see: Zhang Siyan, Cheng Linrun, Gong Wanxin, etc. Comparative studies on physicochemical properties of three potato varieties different in RS2 and RS3 contents. Journal of Science, Food and Agriculture, 2023, DOI 10.1002 / jsfa.12853; it can be purchased from the Institute of Nuclear Agricultural Sciences of Zhejiang University or Zhejiang Jie Nong Biotechnology Co., Ltd., a cooperative enterprise between industry, academia and research.

[0018] Furthermore, in the step (3), the high apparent amylose content is evaluated by an amylose content ≥ 30.0%.

[0019] Furthermore, in the step (4), the high RS3 content is evaluated by the RS3 content in the cooked potatoes after the cooking process being ≥5.0%.

[0020] Furthermore, in step (5), the high zinc content is evaluated by a zinc content ≥ 30 mg / kg.

[0021] Furthermore, in the step (6), the high RS3 content is evaluated by the RS3 content in the cooked potatoes after steaming and cooking being ≥5.0%, and the high zinc content is evaluated by the zinc content being ≥30 mg / kg.

[0022] Furthermore, in step (6), multi-location planting refers to planting in three or more different counties and cities.

[0023] Furthermore, in step (7), the breeding method is: RS3 content ≥5.0% and zinc content ≥30 mg / kg in cooked potatoes after steaming are used as evaluation criteria for breeding, so as to obtain high zinc and high resistant starch potatoes.

[0024] Furthermore, in step (7), the specific method of phased planting is: sowing once every 5 days, and sowing 3 times or more cumulatively.

[0025] Therefore, the present invention has the following beneficial effects:

[0026] (1) The high-zinc and high-resistant starch potatoes obtained by the present invention serve seed agriculture, are oriented towards food and health, and can meet current healthy living needs.

[0027] (2) The present invention specifically selects parents and formulates breeding strategies in a targeted manner, selects high-resistant starch Zhejiang University resistant starch potato as the female parent for hybridization and backcrossing, and uses high-zinc potato MG56-42 as the male parent, which can ensure that the expected high-zinc and high-resistant starch potatoes are bred and have high efficiency.

[0028] (3) The potatoes bred by the present invention are rich in RS3, zinc and iron, and have more abundant and comprehensive nutrients, which is of great significance for patients with gestational diabetes and people with specific health needs such as zinc deficiency. DETAILED DESCRIPTION

[0029] The present invention is further described below in conjunction with specific embodiments. Those of ordinary skill in the art will be able to implement the present invention based on these descriptions. In addition, the embodiments of the present invention involved in the following description are generally only embodiments of a part of the present invention, rather than all embodiments. Therefore, based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work should fall within the scope of protection of the present invention.

[0030] The determination methods of various indicators in this section are as follows: for the determination method of apparent amylose content, see: Bao J et al., Analysis of genotypic and environmental effects on rice starch.1.Apparentamylose content, pasting viscosity, and gel texture.J Agric Food Chem 52:6010-6016 (2004); for the determination method of resistant starch (RS3) in cooked potatoes, see: DB23 / T 1245-2008; for the determination method of zinc, see: GB / T5009.14-2003; for the determination method of iron, see: GB / T5009.14-2003; for the determination method of cadmium, see: GB 5009.15-2023; for the determination method of fat, see: GB / T5009.6-2003.

[0031] Example 1

[0032] Study on hybrid complementation using potato parents Zheda Anti-Fenshu, MG56-42 and other similar varieties as parents

[0033] Using the potato varieties Zhejiang University resistant to powder potato, MG56-42 and similar varieties as materials, hybrid complementary breeding studies were conducted as shown in Table 1. The results showed that: (1) Using the high RS3 Zhejiang University resistant to powder potato with many flowers and easy to produce eggplant fruits as the female parent, it is easy to produce eggplant fruits and obtain a large number of F1 seedlings, while using the high zinc potato MG56-42 with few flowers and basically no eggplant fruits as the female parent, it is difficult to obtain a large number of F1 seeds. Therefore, it is necessary to select Zhejiang University resistant to powder potato as the female parent when formulating breeding strategies. (2) Using Zhejiang University resistant to powder potato as the female parent and MG56-42 as the male parent, targeted hybridization has complementary advantages and is easy to obtain potatoes with high RS3 and high zinc complex nutrition. However, using Zhejiang University resistant to powder potato as the male parent and MG56-42 as the female parent, the breeding effect is poor and the material with high RS3 and high zinc complex nutrition is not selected as expected. (3) Similarly, when the Zhejiang University double-resistant powder potato with similar properties to the Zhejiang University powder potato was used as the female parent and MG56-42 was used as the male parent, the breeding effect was also very poor, and it was not expected to breed materials with high RS3 and high zinc complex nutrition. (4) In the in-depth parent selection and breeding population, the Zhejiang University double-resistant powder potato with similar properties to the Zhejiang University powder potato was used as the female parent and the Dongnong 303 with similar properties to MG56-42 was used as the male parent. The breeding effect was also poor, and it was not expected to breed materials with high RS3 and high zinc complex nutrition. (5) In the in-depth selection of parents and breeding populations, the Dongnong 303 with similar properties to MG56-42 was used as the female parent and the Zhejiang University double-resistant powder potato with similar properties to the Zhejiang University powder potato was used as the male parent. The breeding effect was still poor, and it was not expected to breed materials with high RS3 and high zinc complex nutrition. A series of parallel examples show that in order to obtain potatoes with high RS3 and high zinc complex nutrition, it is particularly necessary to specifically select parents and hybridize them.

[0034] Table 1 The trait indexes of the best strains selected from the hybridization of Zhejiang University resistant potato with MG56-42 and other varieties *

[0035] Hybrid combination RS3(%) Zinc (mg / kg) Example 1-1 Zhejiang University Anti-Fen Potato / MG56-42 5.3±0.25 40.3±0.37 Example 1-2 MG56-42 / Zhejiang University Anti-Fermented Potato 4.5±0.18 36.3±0.38 Examples 1-3 Zhejiang University Double Resistance Sweet Potato / MG56-42 4.8±0.17 23.2±0.59 Examples 1-4 Zhejiang University Double Resistance Sweet Potato / Dongnong 303 4.7±0.22 24.1±0.36 Examples 1-5 Dongnong 303 / Zheda Double Resistance Sweet Potato 4.3±0.31 37.2±0.48 Zhejiang University Anti-Fen Potato 5.1±0.17 23.1±0.39 MG56-42 4.5±0.18 36.5±0.83 Zhejiang University Double Resistance Sweet Potato 4.8±0.15 22.9±0.31 Dongnong 303 4.7±0.24 36.9±0.37

[0036] *: The characteristic nutritional traits of potato mother plants are the primary breeding targets, and the trait indicators of the best strains are selected and bred.

[0037] Example 2

[0038] A method for breeding high-zinc and high-resistant starch potatoes, the specific steps are as follows:

[0039] (1) In the spring of 2021, the high-resistant starch Zheda Anti-Fenshu, which blooms a lot and easily bears eggplants, was used as the female parent, and the MG56-42, which blooms less and basically does not bear eggplants, was used as the male parent. A hybrid was performed to obtain 69 F1 generation seeds;

[0040] (2) F1 generation seedlings were raised in the greenhouse. In the autumn of 2021, when the seeds were flowering, the F1 generation was used as the male parent and the Zhejiang University resistant pink potato was used as the female parent. 319 BC1F1 generation seedlings were obtained through backcrossing;

[0041] (3) BC1F1 generation seedlings were raised in the greenhouse and harvested in the field in the winter and spring of 2022. Tubers with apparent amylose content ≥ 30.0% were measured and selected to obtain 47 asexual S1 generation seed potatoes;

[0042] (4) Planting S1: In the autumn of 2022, tubers with RS3 ≥ 5.0% were measured and selected to obtain 32 asexual S2 seed potatoes;

[0043] (5) Planting S2: In the winter and spring of 2023, measure and select tubers with zinc ≥ 30 mg / kg to obtain 5 asexual S3 generation seed potatoes;

[0044] (6) Planting S3: In the autumn of 2023, plant in Yuhang, Hangzhou, Kaihua, Quzhou, and Changxing, Huzhou. Test and select tubers with RS3 ≥ 5.0% and zinc ≥ 30 mg / kg to obtain three S4-generation seed potatoes;

[0045] (7) Planting S4: In the winter and spring of 2024, the sowing will be carried out in four phases in Kaihua, Quzhou. The second phase will be sown 5 days after the first phase, the third phase will be sown 10 days after the first phase, and the fourth phase will be sown 15 days after the first phase. Finally, one high zinc and high resistant starch potato with RS3 ≥ 5.0%, zinc ≥ 30 mg / kg was selected and initially named "Excellent Anti-starch Potato".

[0046] The comparison of potato peel, potato flesh, RS3, iron, zinc, cadmium and fat contents of each variety is shown in Table 2.

[0047] Table 2 Comparison of main agronomic and functional nutritional traits of Zhejiang University resistant potato, MG56-42 and excellent resistant potato

[0048]

[0049] Note: Different lowercase letters after the values ​​represent significant differences between varieties at the 0.05 level.

[0050] According to the variety comparison test, the bred "Youkangshu" has light red potato skin, yellow potato flesh, RS3 content of 5.4%, amylose content of 31.2%, zinc content of 40.6mg / kg, iron content of 56.5mg / kg, cadmium content of 0.043mg / kg, and fat content of 0.19%. Among them, the micronutrient zinc and iron content of "Youkangshu" are significantly higher than those of its parents, which may be related to the high efficiency polymerization of the two traits of the parent MG56-42 high zinc and the light sweet potato skin of Zhejiang University Kangfenshu, which leads to super-parent. The cadmium content of "Youkangshu" is significantly lower than that of its parents, and the cadmium content of the high zinc parent variety MG56-42 is also significantly lower than that of the low zinc parent variety Zhejiang University Kangfenshu. This result is directly related to the significantly high zinc content; because zinc is a typical antagonistic element, the selective competition of high zinc varieties for metal zinc cations will naturally lead to a significant reduction in the binding opportunity of cadmium cations, which are also heavy metals. The fat content of 'Youkangshu' is slightly higher than that of its parents, which is related to its slightly higher amylose content, which makes it easier for 'Youkangshu' to form amylose-fat composite resistant starch complexes, ultimately leading to a moderate increase in RS3. Therefore, 'Youkangshu' has better functional nutritional quality.

[0051] In order to test the stability of four super-parent composite nutritional traits, RS3, iron, zinc and cadmium content, 'Youkangshu' was planted in Yuhang, Hangzhou, Zhejiang, Kaihua, Quzhou and Changxing, Huzhou. The test results showed that these functional nutritional traits can be stably expressed (see Table 3). This result proves that the RS3, iron, zinc and cadmium content obtained by hybrid backcrossing with Zhejiang University Anti-Fenshu as the female parent and MG56-42 as the male parent has a significantly better effect than both parents and is a super-parent trait.

[0052] Table 3 Multi-point stability of resistant starch, zinc and iron properties in 'Youkangshu'

[0053]

[0054]

[0055] Therefore, the new potato variety 'Youkangshu' with high zinc and high resistant starch bred by the present invention can provide a variety of nutrients, and its functional characteristics are of great significance to patients with gestational diabetes and people with specific health needs.

Claims

1. A method for breeding high zinc and high resistant starch potatoes, characterized in that: The following steps are involved: (1) Using Zhejiang University resistant powder potato as the female parent and MG56-42 as the male parent, hybridization was performed to obtain F1 generation seedlings; (2) F1 generation seedlings were grown in greenhouses. When flowering, the F1 generation was used as the male parent and the Zhejiang University resistant pink potato was used as the female parent for backcrossing to obtain BC1F1 generation seedlings; (3) Cultivating BC1F1 generation seedlings in a greenhouse, measuring and selecting tubers with high apparent amylose content, and obtaining asexual S1 generation seed potatoes; (4) Planting the S1 generation, measuring and selecting tubers with high RS3 content, and obtaining asexual S2 generation seed potatoes; (5) Planting the S2 generation, measuring and selecting tubers with high zinc content, and obtaining the asexual S3 generation seed potatoes; (6) Planting the S3 generation in multiple locations, measuring and selecting tubers with high RS3 and zinc content, and obtaining asexual S4 generation seed potatoes; (7) The S4 generation was planted in stages to select and breed potatoes with high zinc and high resistant starch.

2. The breeding method according to claim 1, characterized in that: In the step (3), the high apparent amylose content is evaluated by an amylose content ≥ 30.0%.

3. The breeding method according to claim 1, characterized in that: In the step (4), the high RS3 content is evaluated by the RS3 content in the cooked potatoes after the cooking process being ≥5.0%.

4. The breeding method according to claim 1, characterized in that: In the step (5), the high zinc content is evaluated by a zinc content ≥ 30 mg / kg.

5. The breeding method according to claim 1, characterized in that: In the step (6), the high RS3 content is evaluated by the RS3 content of the cooked potatoes after steaming and cooking being ≥5.0%, and the high zinc content is evaluated by the zinc content being ≥30 mg / kg.

6. The breeding method according to claim 1 or 5, characterized in that: In step (6), multi-location planting refers to planting in three or more different counties and cities.

7. The breeding method according to claim 1, characterized in that: In the step (7), the breeding method is: RS3 content ≥ 5.0% and zinc content ≥ 30 mg / kg in cooked potatoes after steaming are used as evaluation criteria for breeding, so as to obtain high zinc and high resistant starch potatoes.

8. The breeding method according to claim 1 or 7, characterized in that: In step (7), the specific method of staged planting is: sowing once every 5 days, and sowing 3 times or more cumulatively.

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