A method for breeding zinc-iron composite nutrition rice

Abstract

The present invention provides a method for breeding zinc-iron composite nutrition rice, the method comprising: using Zhejiang University zinc rice as the male parent and Zhejiang University black treasure as the female parent, hybridizing to obtain F1 and backcrossing with Zhejiang University zinc rice as the female parent, obtaining BC1F1 and self-pollinating, obtaining BC1F2 for planting, transplanting zinc-rich nutrient solution for growth within 12 days, selecting plants higher than Zhejiang University black treasure within 30 days of transplanting for continued planting and harvesting, determining polished rice to select high zinc strains, obtaining BC1F3 and planting, selecting strains with purple-black seed coats of husks and grains, determining polished rice to select high iron strains; obtaining BC1F4 and planting, determining polished rice to select low cadmium strains, obtaining BC1F5 and planting, determining brown rice to select high anthocyanin strains, obtaining BC1F6 and planting, determining and selecting high zinc, high iron, high anthocyanin, low cadmium, high yield varieties, and obtaining zinc-iron composite nutrition rice. The varieties bred by the present invention contain high zinc and iron elements and low cadmium, and are suitable for developing nutritionally safe infant and child products.

Description

Technical Field

[0001] The invention relates to the technical field of rice breeding, and in particular to a method for breeding zinc-iron composite nutrition type rice. Background Art

[0002] Zinc and iron are essential trace nutrients for human growth and development, and are known as the "flower of life" and "elements of wisdom." It is reported that about 38% of pregnant women and 43% of preschool children worldwide have zinc and iron deficiencies to varying degrees, among which children are particularly deficient in zinc and iron, with symptoms such as decreased appetite or poor concentration, which have an impact on physical and intellectual development.

[0003] The human body mainly relies on food to supplement zinc and iron. Seafood products and animal offal are rich in zinc, while rice and flour staple foods, milk, eggs and snacks that children love to eat are almost not rich in zinc and iron. There are also few vegetables and fruits rich in zinc and iron. Rice is the staple food in daily life. There are genotypic differences in the zinc and iron content in the grains of rice varieties. The zinc and iron content in each kilogram of rice ranges from a few milligrams to tens of milligrams. The zinc and iron content of traditional red rice and black rice varieties is higher than that of ordinary rice.

[0004] Therefore, it is necessary to provide a method for breeding zinc-iron composite nutrition rice, which can not only meet the daily consumption, but also provide trace elements such as zinc and iron needed in life. Summary of the invention

[0005] The present invention provides a method for breeding zinc-iron composite nutrition type rice. The method can not only obtain rice varieties with high zinc, high iron, high anthocyanin, low cadmium and high yield, but also significantly reduce the breeding population, has the technical advantages of saving labor and cost, and realizes the advantages of better and more efficient breeding. The bred rice has a moderate soft and glutinous taste, the cooked rice grains are just the right hardness and softness after cooling, the recovery characteristics are excellent, the taste quality is better, and the rice is suitable as dietary nutritious rice.

[0006] The specific technical solutions are as follows:

[0007] A method for breeding zinc-iron composite nutrition rice comprises the following steps:

[0008] (1) Using ZJU Zinc Rice as the male parent and ZJU Black Rice as the female parent, hybridization was performed to obtain F1 generation seeds;

[0009] (2) Planting F1 seeds, using the F1 generation as the female parent and Zhejiang University zinc rice as the male parent, and backcrossing to obtain BC1F1 seeds;

[0010] (3) Planting BC1F1 seeds and self-pollinating to obtain BC1F2 seeds;

[0011] (4) sowing and germinating the BC1F2 seeds, transplanting the seedlings within 12 days after germination to a zinc-rich nutrient solution for hydroponics, selecting plants with a plant height significantly higher than that of Zhejiang University Black Pearl within 30 days after transplanting and continuing to plant, harvesting the individual plants after maturity, determining and selecting the high zinc strains in the polished rice, and obtaining BC1F3 seeds;

[0012] (5) Planting BC1F3 seeds, selecting strains with purple-black husks and black seed coats, measuring and selecting strains with high iron content in polished rice, and obtaining BC1F4 seeds;

[0013] (6) Planting BC1F4 seeds, determining and selecting the strains with low cadmium in polished rice, and obtaining BC1F5 seeds;

[0014] (7) Planting BC1F5 seeds, determining and selecting the strains with high anthocyanin content in brown rice, and obtaining BC1F6 seeds;

[0015] (8) Plant BC1F6 seeds, test and select varieties with high zinc, high iron, high anthocyanin, low cadmium and high yield, and finally breed zinc-iron complex nutrition rice.

[0016] Among them, Zhejiang University Black Treasure is a new japonica glutinous rice variety bred by Zhejiang University for both ornamental and edible purposes. Its leaves, lemmas, and seed coat are all purple-black. It has applied for protection of new plant variety rights (announcement number CNA031479E). For details, please see the Variety Rights Application Announcement of July 1, 2020 (No. 126 in total) and the New Variety Rights Protection Announcement.

[0017] Among them, Zhejiang University Zinc Rice is a new japonica rice variety with high zinc content and first-class rice quality bred by Zhejiang University. It has been approved by the Zhejiang Provincial Crop Approval Committee (Approval No.: Zhejiang Approval Rice 2020021). For details, please see Announcement No. 3 of 2020 of the Zhejiang Provincial Department of Agriculture and Rural Affairs.

[0018] Furthermore, in step (4), the zinc-rich nutrient solution is a basic rice nutrient solution to which ZnSO4·7H2O is added; wherein the nutrient elements and their concentrations of the basic rice nutrient solution are N (NH4NO3, 2.9mM), P (NaH2PO4·2H2O, 0.32mM), K (K2SO4, 1.0mM), Ca (CaCl2, 1.0mM), Mg (MgSO4·7H2O, 1.7mM), Mn (MnCl2·64H2O, 9.1μM), Mo ((NH4)6MoO 24·4H2O, 0.52μM), B (H3BO3, 18μM), Cu (CuSO4·5H2O, 0.16μM), Fe (FeCl3·6H2O, 36μM), Zn (NH4NO3, 0.15μM); the zinc concentration of ZnSO4·7H2O in the zinc-rich nutrient solution after addition is 10-14μM, and the time for transplanting the seedlings to the zinc-rich nutrient solution is 8-12 days after the seeds are sown and germinated.

[0019] Furthermore, in step (4), the plant height is measured 26-30 days after the seedlings are transplanted into the zinc-rich nutrient solution hydroponics; the judgment standard for the plant height being higher than that of Zhejiang University Black Treasure is that the plant height is significantly higher than that of Zhejiang University Black Treasure at the 0.05 level.

[0020] Furthermore, in step (4), the zinc content in the polished rice ≥ 30 mg / kg is used as a criterion for selecting high-zinc strains.

[0021] Furthermore, in step (5), the iron content in the polished rice ≥ 20 mg / / kg is used as the criterion for selecting high iron strains.

[0022] Furthermore, in step (6), the cadmium content in the polished rice ≤ 0.06 mg / kg is used as the criterion for selecting low-cadmium strains.

[0023] Furthermore, in step (7), the anthocyanin content in brown rice ≥ 2.0 mg / g is used as a criterion for selecting high anthocyanin strains.

[0024] Furthermore, in step (8), the zinc content in polished rice ≥30 mg / kg, the iron content ≥20 mg / kg, the cadmium content ≤0.06 mg / kg, the anthocyanin content in brown rice ≥2.0 mg / g, and the yield ≥400 / kg / mu are used as the criteria for selecting high zinc, high iron, high anthocyanin, low cadmium, and high yield varieties.

[0025] Furthermore, the method for determining the zinc content can be found in GB / T5009.14-2003; the method for determining the iron content can be found in GB / T5009.90-2003; the method for determining the cadmium content can be found in DB43 / T 2354-2022; the method for determining the anthocyanin content can be found in GB / T 22244-2008; the method for determining the yield can be found in National Rice Variety Experiment Observation Recording Items, Methods and Standards (Trial).

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] (1) The offspring bred with ZJU Zinc Rice as the male parent and ZJU Black Rice as the female parent not only have the characteristics of high zinc, high iron, and high anthocyanin, but also have the characteristics of low cadmium by utilizing the antagonistic effect of zinc.

[0028] (2) Zhejiang University Black Pearl was selected as the female parent based on maternal genetics. The purple-black color of the glume was used as the primary appearance marker for the significant correlation between the glume and the seed coat to reduce the population size and improve efficiency. In addition, plant height was used for the initial screening of zinc-rich materials in the breeding process, which greatly reduced the breeding population and achieved the advantage of high breeding efficiency.

[0029] (3) Compared with the parent rice, the zinc-iron composite nutritional rice obtained by the present invention has a moderate content of amylose and gelatin consistency in the rice, a moderately soft and glutinous taste, a just-right hardness after the cooked rice cools, excellent recovery characteristics, and better taste quality. It is suitable as a dietary nutritious rice and is suitable for the development of high-zinc infant and children's products. DETAILED DESCRIPTION

[0030] The present invention will be further described below in conjunction with specific embodiments. The following are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto.

[0031] Example 1

[0032] Study on plant response of rice varieties to different zinc concentrations

[0033] Two varieties of rice with significantly different zinc content, Zheda Heizhen and Zheda Zinc Rice, were used as materials. Ten days after sowing and germination, rice nutrient solution with different zinc gradients of ZnSO4·7H2O was added. The zinc concentrations were 0μM, 1μM, 4μM, 8μM, 12μM, and 16μM, respectively.

[0034] The results of the plant height survey after 20 days showed that the two varieties had significantly different sensitivities to exogenous zinc nutrition due to their own zinc-rich characteristics.

[0035] When the zinc concentration was ≤1μM, the growth of both high- and low-zinc rice was inhibited. There was no significant difference between the low-zinc variety Zhejiang University Black Pearl at 4μM and 8μM, and the height of the plant was significantly inhibited at 12μM.

[0036] The zinc-rich variety Zhejiang University Zinc Rice stimulated growth at 8μM, still performed normally at 12μM, and its growth was significantly inhibited at 16μM.

[0037] Therefore, the sensitivity of rice materials to zinc can be used to carry out initial screening of early zinc-rich rice, improve breeding efficiency, and save labor and costs.

[0038] Table 1 Plant height responses of Zheda Heizhen and Zheda Zinc Rice to different zinc concentrations

[0039]

[0040] Note: * indicates significant difference compared with the untreated control at the 0.05 level

[0041] Example 2

[0042] Study on the inheritance and correlation of purple-black leaves, husks and seed coats carried by Zhejiang University Heizhen

[0043] The forward and reverse hybridization experiments of Zhejiang University Black Rice with purple-black leaves, glume and seed coat and normal Zhejiang University Zinc Rice showed that the leaves, glume and seed coat of the orthogonal hybrid F1 were all purple, which had a maternal genetic effect, indicating that the breeding efficiency of the hybrid maternal offspring was higher; in the hybrid F2 segregating population, there was no obvious correlation between the purple-black leaves and the purple-black traits of the glume and seed coat, and the purple-black colors of the glume and seed coat were significantly correlated, indicating that the purple-black color of the glume can be used as a primary appearance marker, which can significantly improve the breeding efficiency of the purple-black seed coat and reduce the population size to improve efficiency.

[0044] Example 3

[0045] A method for breeding zinc-iron composite nutrition rice, the specific steps are as follows:

[0046] (1) Using ZJU Zinc Rice as the male parent and ZJU Black Rice as the female parent, hybridization was performed to obtain F1 generation seeds;

[0047] (2) Planting F1 seeds, using the F1 generation as the female parent and Zhejiang University zinc rice as the male parent, and backcrossing to obtain BC1F1 seeds;

[0048] (3) Planting BC1F1 seeds and self-pollinating to obtain BC1F2 seeds;

[0049] (4) sowing and germinating the BC1F2 seeds, transplanting the seedlings within 12 days after germination to a zinc-rich nutrient solution for hydroponics, selecting plants with a plant height significantly higher than that of Zhejiang University Black Pearl within 30 days after transplanting and continuing to plant, harvesting the individual plants after maturity, determining and selecting the high zinc strains in the polished rice, and obtaining BC1F3 seeds;

[0050] The zinc-rich nutrient solution contains ZnSO4·7H2O, in which the zinc concentration is 12μM. The seedlings are transplanted into the zinc-rich nutrient solution 8 to 12 days after the seeds are sown and germinated. The criterion for judging whether the plant height is higher than that of Zhejiang University Black Treasure is that the plant height is significantly higher than that of Zhejiang University Black Treasure at the 0.05 level. The zinc content in polished rice ≥30mg / kg is used as the criterion for selecting high-zinc strains.

[0051] (5) Planting BC1F3 seeds, selecting strains with purple-black husks and black seed coats, measuring and selecting strains with high iron content in polished rice, and obtaining BC1F4 seeds;

[0052] The iron content in polished rice ≥20mg / / kg was used as the criterion for selecting high iron strains;

[0053] (6) Planting BC1F4 seeds, determining and selecting the strains with low cadmium in polished rice, and obtaining BC1F5 seeds;

[0054] The cadmium content in polished rice ≤ 0.06 mg / kg was used as the criterion for selecting low-cadmium strains;

[0055] (7) Planting BC1F5 seeds, determining and selecting the strains with high anthocyanin content in brown rice, and obtaining BC1F6 seeds;

[0056] The anthocyanin content in brown rice ≥2.0 mg / g was used as the criterion for selecting high anthocyanin strains;

[0057] (8) Planting BC1F6 seeds, testing and selecting varieties with high zinc, high iron, high anthocyanin, low cadmium and high yield, and finally breeding zinc-iron composite nutrition rice; initially named "Duozigu";

[0058] The zinc content in polished rice ≥30 mg / kg, iron content ≥20 mg / kg, cadmium content ≤0.06 mg / kg, anthocyanin content in brown rice ≥2.0 mg / g, and yield ≥400 / kg / mu are used as the evaluation criteria for selecting high zinc, high iron, high anthocyanin, low cadmium and high yield varieties.

[0059] The comparison of zinc, iron, heavy metal cadmium, anthocyanin and amylose content of each variety is shown in Table 2. The determination methods of each index in Table 2 are as follows: zinc see: GB / T5009.14-2003; iron see: GB / T5009.90-2003; cadmium see: DB43 / T2354-2022; anthocyanin see: GB / T 22244-2008; amylose see GB / T 15683; yield see: National Rice Variety Experiment Observation Recording Items, Methods and Standards (Trial).

[0060] According to variety comparison tests, the selected "Duozigu" has a zinc content of 32.6 mg / kg, iron content of 24.6 mg / kg, cadmium content of 0.02 mg / kg, anthocyanin content of 2.87 mg / g, amylose content of 8.9%, and a yield of 412 kg / mu; the zinc and iron contents possess the excellent traits of both parents, among which the parent with a high zinc ratio, Zhejiang University Zinc Rice, is slightly lower, but there is no significant difference, and the parent with a high iron ratio, Zhejiang University Heizhen, is slightly higher, but there is no significant difference; the cadmium and anthocyanin contents are significantly lower and higher than those of the parents, respectively.

[0061] Cadmium is a typical heavy metal pollutant, which has a significant impact on human health and food safety. Whether the cadmium content in rice exceeds the standard is an important aspect of public concern about rice safety. The newly bred variety "Duozigu" combines the advantages of its parents. While being rich in zinc and iron, the cadmium content in rice is only 0.02 mg / kg, which is significantly lower and safer. The reason for the low cadmium content may be related to its high levels of zinc and anthocyanins, especially the antagonistic effect of zinc. Therefore, "Duozigu" has the characteristics of nutritional safety, which helps to meet the high-end needs of nutritional health, green and high quality.

[0062] Table 2 Comparison of various traits of hybrid rice “Duozigu” bred from Zhejiang University Heizhen and Zhejiang University Zinc Rice

[0063]

[0064]

[0065] Note: *, ** are significantly different from Zhejiang University Heizhen at 0.05 and 0.01 levels respectively

[0066] Anthocyanin is one of the bioflavonoids and is currently recognized as the most effective natural antioxidant for removing free radicals from the human body. It has the function of detoxification and beauty care. The selected "Duozigu" has an anthocyanin content of 2.87 mg / g, which is significantly higher than that of its parents. This may be related to the fact that its seed coat color is similar to Zhejiang University Black Pearl, but the grain size (thousand-grain weight) is smaller than that of Zhejiang University Zinc Rice.

[0067] The content of amylose is an important factor influencing the taste quality of rice; the parent Zhejiang University Black Treasure has an amylose content of 0.6%, which is a typical glutinous rice with a gel consistency of 100mm. It is too sticky and eating too much can easily cause gastrointestinal discomfort. It is not suitable for daily consumption, but has good recovery characteristics; the parent Zhejiang University Zinc Rice has an amylose content of 14.6% and a gel consistency of 73mm. It is not soft and sticky enough when eaten as nutritious brown rice, and the cold rice is hard and has poor recovery characteristics; the selected "Duozigu" has an amylose content of 8.9% and a gel consistency of 91mm. The rice has a moderately soft and glutinous taste. The cooked rice is just the right hardness after cooling. It has excellent recovery characteristics and better taste quality, making it suitable as dietary nutritious rice.

[0068] Therefore, the varieties bred by the present invention not only have the nutritional and complex safety characteristics of high beneficial elements zinc and iron and low heavy metal cadmium, and are suitable for developing nutritional and safe infant and children's products; but the new rice varieties bred have the characteristics of moderate soft and sticky taste, excellent recovery characteristics, and better taste quality, and are suitable as dietary nutritious rice, and are also particularly suitable for making foods such as sushi.

Claims

1. A method for breeding rice with zinc-iron composite nutrition, characterized in that: The following steps are involved: (1) Using ZJU Zinc Rice as the male parent and ZJU Black Rice as the female parent, hybridization was performed to obtain F1 generation seeds; (2) Planting F1 seeds, using the F1 generation as the female parent and Zhejiang University zinc rice as the male parent, and backcrossing to obtain BC1F1 seeds; (3) Planting BC1F1 seeds and self-pollinating to obtain BC1F2 seeds; (4) Sowing and germinating BC1F2 seeds, transplanting seedlings within 12 days after germination to zinc-rich nutrient solution for hydroponics, selecting plants with significantly higher plant height than Zhejiang University Black Pearl within 30 days after transplanting and continuing to plant, harvesting individual plants after maturity, determining and selecting high zinc strains in polished rice, and obtaining BC1F3 seeds; Among them, the plant height was measured 26-30 days after the seedlings were transplanted into the zinc-rich nutrient solution hydroponics; the criterion for the plant height to be higher than that of Zhejiang University Black Treasure was that the plant height was significantly higher than that of Zhejiang University Black Treasure at the 0.05 level; The zinc-rich nutrient solution contains ZnSO4·7H2O, wherein the zinc concentration is 10-14 μM, and the seedlings are transplanted into the zinc-rich nutrient solution 8-12 days after the seeds are sown and germinated; The zinc content in polished rice ≥30 mg / kg was used as the criterion for selecting high-zinc strains; (5) Planting BC1F3 seeds, selecting strains with purple-black husks and black seed coats, measuring and selecting strains with high iron content in polished rice, and obtaining BC1F4 seeds; the iron content in polished rice ≥ 20 mg / kg was used as the criterion for selecting strains with high iron content; (6) Planting BC1F4 seeds, determining and selecting the strains with low cadmium in polished rice, and obtaining BC1F5 seeds; the cadmium content in polished rice ≤ 0.06 mg / kg was used as the criterion for selecting the strains with low cadmium; (7) Planting BC1F5 seeds, determining and selecting high anthocyanin strains in brown rice, and obtaining BC1F6 seeds; using the anthocyanin content of brown rice ≥ 2.0 mg / g as the criterion for selecting high anthocyanin strains; (8) Plant BC1F6 seeds, test and select varieties with high zinc, high iron, high anthocyanin, low cadmium and high yield, and finally breed zinc-iron complex nutrition rice; the zinc content in polished rice ≥30 mg / kg, iron content ≥20 mg / kg, cadmium content ≤0.06 mg / kg, anthocyanin content in brown rice ≥2.0 mg / g, and yield ≥400 / kg / mu were used as the evaluation criteria for selecting varieties with high zinc, high iron, high anthocyanin, low cadmium and high yield.

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