Method for promoting accumulation of carotenoid in marigold petals and application

Abstract

The invention relates to the technical field of agricultural planting, in particular to a method for promoting accumulation of carotenoids in marigold petals and application, the method comprises the following steps: Step 1: preparation of a composite solution: mixing a sodium selenite solution with the concentration of 0.5 mM with an EM microbial agent diluted by 1000 times; 2, spraying treatment, wherein when buds of the marigold grow to the S3 period, the composite solution is sprayed to the front and back faces of leaf surfaces of plants and the surfaces of the buds; 3, repeated spraying is conducted, wherein spraying is conducted once every 7 days, and spraying is conducted three times in total; and Step 4, harvesting: harvesting marigold petals in periods S6 to S7 30 days after the last time of spraying. The lutein content of the marigold is increased through exogenous spraying. The composite reagent provided by the invention can further improve the yield and economic utilization value of the marigold xanthophyll so as to reduce the production cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of agricultural planting technology, in particular to a method for promoting carotenoid accumulation in Tagetes erecta L petals and application. BACKGROUND

[0002] Tagetes erecta L. tongue-shaped flowers are rich in carotenoids, among which lutein accounts for more than 88% of the total amount of carotenoids, and is known as "soft gold". Lutein is an important medical and health care component, which is widely used in food, cosmetics, health products, medicine, tobacco and poultry feed, etc. It has high economic value and application value. The lutein content in the petals of Tagetes erecta L. planted in Yunnan is rich and relatively higher than that in other regions, making the Tagetes erecta L. industry become one of the important economic crops in Yunnan Province. However, due to the lack of Tagetes erecta L. germplasm resources in China, it is extremely difficult to breed new varieties through traditional hybridization. The introduced varieties planted in China are generally facing the problems of reduced flower yield and lutein content, which has become an important factor restricting the long-term and healthy development of the Tagetes erecta L. industry in Yunnan.

[0003] The lack of germplasm resources makes it difficult to implement traditional hybridization breeding, and the exogenous treatment technology is also in a dilemma: if a single type of treatment agent is used, the operation is simple but the improvement is limited; if a composite treatment agent is used, it faces the barriers of poor compatibility stability, unknown action mechanism and difficult cost control. More importantly, the existing technology ignores the precise intervention of the development window period and does not design the spraying process for the peak period of carotenoid synthesis, resulting in a mismatch between resource input and effect output. This technical gap forces the industry to bear the continuous losses caused by variety degradation, and it is urgent to develop a lutein regulation scheme with strong universality, standardized operation and stable effect. SUMMARY

[0004] The purpose of the present application is to provide a method for promoting carotenoid accumulation in Tagetes erecta L. petals and application, which increases the lutein content of Tagetes erecta L. by spraying a composite reagent, the composite reagent is prepared by compounding sodium selenite and EM bacterial agent in a certain proportion, and the lutein content of Tai Shan and Bo Hao varieties of Tagetes erecta L. is increased by exogenous spraying. The composite reagent of the present application can further improve the yield and economic utilization value of lutein in Tagetes erecta L. and reduce the production cost.

[0005] In order to achieve the above technical purpose and achieve the above technical effect, the present application is realized by the following technical scheme:

[0006] A method for promoting carotenoid accumulation in Tagetes erecta L. petals, comprising the following steps:

[0007] Step 1: Prepare a composite solution: mix a 0.5 mM sodium selenite solution with 1000-fold diluted EM bacterial agent;

[0008] Step2: Spraying treatment: when the flower buds of the Tagetes erecta develop to S3 stage, the complex solution is sprayed on the front and back of the plant leaves and the surface of the flower buds;

[0009] Step3: Repeated spraying: spraying once every 7 days, a total of 3 times;

[0010] Step4: Harvest: 30 days after the last spraying, the Tagetes erecta petals at S6 to S7 stage are harvested.

[0011] Further, the spraying needs to be carried out in a closed or semi-closed environment with a temperature ≤ 28℃ and a relative humidity ≥ 60%, so that the EM microbial agent forms a selenium element biological carrier.

[0012] Further, the spraying amount of the complex solution in Step2 is 500 mL per 3 plants.

[0013] Further, the spraying amount of the complex solution in Step2 is 250 mL per 3 plants.

[0014] Further, the Tagetes erecta variety is Tai Shan orange series or Bo Hao No. 1.

[0015] In another aspect, the application provides a complex solution for promoting the accumulation of lutein in Tagetes erecta petals, which is composed of 0.5 mM sodium selenite solution and 1000-fold diluted EM microbial agent, and is used for exogenous spraying on Tagetes erecta plants.

[0016] The beneficial effects of the application are:

[0017] The biosynthesis of lutein is significantly improved by the reagent of the application. The EM microbial agent is a beneficial microorganism population, which is mixed and fermented by a plurality of microorganisms in a proper ratio, and has a positive promoting effect on the overall growth environment of plants and the synthesis of secondary metabolites. Sodium selenite provides essential selenium trace elements for plants, which, combined with the physiological processes in the plant body, helps to improve the growth and development conditions and promote the accumulation of secondary metabolites. The application adopts the method of exogenous spraying, whether EM microbial agent or sodium selenite is used alone or both are sprayed together, which can effectively improve the lutein synthesis efficiency of Tagetes erecta.

[0018] The application effect of the reagent of the present application is remarkable for different varieties and cultivation environments, and the reagent shows remarkable lutein accumulation effect for two varieties of Tagetes patula, namely, Taishan and Bohao. The effect can be maintained under various cultivation conditions, and is not limited to pot experiments, field experiments or greenhouse pot experiments with light shielding agent coating. The wide adaptability indicates that the composite reagent can play a good effect under various environmental conditions, whether it is open field cultivation or planting mode in a controlled environment, which can ensure the effective improvement of secondary metabolites lutein in plants, and ensures the wide applicability and high efficiency of the technical scheme.

[0019] The treatment effect of the composite reagent of the present application is more remarkable than that of a single effective component. When the composite reagent of the present application is used to treat the Tagetes patula plant of the Bohao variety, the measured lutein content is significantly higher than that of the treatment effect of a single effective component, and the specific improvement rate reaches 26.02%. It is indicated that there may be a synergistic mechanism between the components in the composite reagent of the present application, so as to play a role beyond a single component in the synthesis and accumulation of lutein. The verification of this effect not only breaks through the technology, but also improves the economic value, which provides a more advantageous product selection for the competition of Tagetes patula market.

[0020] Of course, any product implementing the present application does not necessarily need to achieve all the advantages described above. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0022] Figure 1 The schematic diagram of the influence of different dilution multiples of EM bacterial agent treatment on lutein content of Tagetes patula is shown in the following figure:

[0023] Figure 2 The schematic diagram of the influence of different concentrations of sodium selenite treatment on lutein content of Tagetes patula is shown in the following figure:

[0024] Figure 3 The schematic diagram of the influence of different treatment methods on lutein content of Bohao Tagetes patula is shown in the following figure:

[0025] Figure 4 The schematic diagram of the influence of the composite solution and the composite solution containing Harzwood Trichoderma on pot-cultured Bohao Tagetes patula is shown in the following figure. DETAILED DESCRIPTION

[0026] With reference to the accompanying drawings on the basis of the embodiments of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0027] Embodiment 1

[0028] The method for promoting carotenoid accumulation in petals of Tagetes erecta L. described in the present embodiment comprises the following steps:

[0029] Step 1: preparation of a composite solution: mixing a 0.5 mM sodium selenite solution with 1000-fold diluted EM bacterial agent;

[0030] Step 2: spraying treatment: when the flower buds of Tagetes erecta L. develop to the S3 stage, spraying the composite solution on the front and back surfaces of the leaves and the surface of the flower buds of the plants;

[0031] Step 3: repeated spraying: spraying once every 7 days, for a total of 3 times;

[0032] Step 4: harvesting: 30 days after the last spraying, harvesting the petals of Tagetes erecta L. at the S6 to S7 stage.

[0033] In the present embodiment, the spraying amount of the composite solution in Step 2 is 500 mL per 3 plants.

[0034] In the present embodiment, the spraying amount of the composite solution in Step 2 is 250 mL per 3 plants.

[0035] In the present embodiment, the variety of Tagetes erecta L. is the Tai Shan orange series or Bo Hao No. 1.

[0036] On the other hand, the present application proposes an application of a composite solution for promoting the accumulation of lutein in petals of Tagetes erecta L., wherein the composite solution is composed of a 0.5 mM sodium selenite solution and 1000-fold diluted EM bacterial agent, and is used for exogenous spraying on plants of Tagetes erecta L.

[0037] Embodiment 2

[0038] Planting Tagetes erecta cv. Taishan Orange; configuring 4 250 ml different concentration of sodium selenite treatment solution, respectively 0.02, 0.5, 0.1, 2 mM; configuring 5 250 ml different concentration of EM bacterial agent treatment solution, respectively 250, 500, 750, 1000, 1250 times dilution. With water as control, the prepared different concentration treatment solution is respectively sprayed on the front and back of the potted Tagetes erecta cv. Taishan Orange plant, three plants are a biological repeat of one concentration, the potted plants are placed in an ordinary plastic greenhouse without controlled growth environment, spraying once every 7 days for a total of three times, and then the fully bloomed outer petals of the flowers are picked on the 30th day, and the lutein content is determined by using the acetone extraction method.

[0039] Example 3

[0040] Planting Tagetes erecta cv. Bohao No. 1; configuring 500 ml sodium selenite solution with a concentration of 0.5 mM; 500 ml EM bacterial agent with a concentration of 1000 times dilution; 500 ml compound reagent (250 ml sodium selenite solution with a concentration of 0.5 mM + 250 ml EM bacterial agent with a concentration of 1000 times dilution). Every three potted Bohao No. 1 Tagetes erecta plants are taken as 3 biological repeats of different spraying treatments. The spraying scheme, sampling time and carotenoid determination refer to Example 2. The potted plants are placed in an ordinary plastic greenhouse with a light shielding agent coating on the outer layer.

[0041] Example 4

[0042] Field planting Bohao No. 1 Tagetes erecta; the column distance between plants is 0.3 m to 0.5 m, and the reagent spraying scheme is consistent with specific Examples 2 and 3.

[0043] Example 5

[0044] The spraying treatment of the effective components of the compound solution on Tagetes erecta cv. Taishan is as follows:

[0045] The concentration gradient of the sodium selenite treatment solution is 0.02, 0.5, 0.1, 2 mM.

[0046] The dilution multiple gradient of the EM bacterial agent treatment solution is 250, 500, 750, 1000, 1250 times dilution

[0047] The control solution is water

[0048] Spraying method: the front and back of the leaf surface of the potted Tagetes erecta cv. Taishan plant and the flower bud at S3 stage are externally sprayed, three plants are a group of concentration technical repeats, water is used as a control for spraying treatment, and four concentration treatment solutions of 250 mL sodium selenite and EM bacterial agent are externally sprayed, spraying once every 7 days for a total of three times, and then the outer petals of the flowers at S6 to S7 stage are picked after 30 days, the lutein content is determined by using the acetone extraction method, and the results are as follows Figure 1 , 2 as shown in the following table;

[0049] The results show that after spraying treatment of 1000-fold diluted EM bacterial agent, the lutein content increases by 24.69% compared with the control ( Figure 1 ); after spraying 0.5 mM Se solution, the lutein content increases by 23.9% ( Figure 2 ).

[0050] The spraying treatment of the effective components of the composite solution on the Gahao variety of marigold is as follows:

[0051] According to the above concentration setting combined with Figure 1 , the concentration of sodium selenite is selected as 0.5 mM.

[0052] According to the above concentration setting combined with Figure 2 , the dilution multiple of EM bacterial agent is selected as 1000-fold dilution.

[0053] 0.5 mM sodium selenite solution is mixed with 1000-fold diluted EM bacterial agent to configure 500 mL.

[0054] Control solution: water

[0055] Spraying method: The flowers and buds of the Gahao No. 1 variety of marigold plants in the experimental field are sprayed with exogenous, the column distance between plants is 0.3-0.5 m, and every three marigold plants are a group of concentration technical repeats. Water is used as a control for spraying treatment, and 0.5 mM sodium selenite 500 mL, 1000-fold diluted EM bacterial agent 500 mL, and (0.5 mM sodium selenite + 1000-fold diluted EM bacterial agent) 1000 mL are sprayed respectively. The spraying frequency and lutein determination method are the same as above, and the detection results are shown in the following table; Figure 3

[0056] The results show that after spraying treatment of 1000-fold diluted EM bacterial agent, the lutein content increases by 32.54% compared with the control; after treatment of 0.5 mM Se, the lutein content increases by 30.85%, and after mixed spraying treatment of 0.5 mM sodium selenite and 1000-fold diluted EM bacterial agent, the lutein content increases by 23.96% ( Figure 3 ).

[0057] The exogenous spraying treatment of the composite solution on the pot-grown Gahao variety of marigold is as follows:

[0058] The pot-grown Gahao No. 1 variety of marigold planted in the greenhouse is sprayed with the composite solution SE+EM (0.5 mM x 1000-fold) and SE+EM+Hartwood (0.5 mM x 1000-fold x 1000-fold) respectively. The exogenous spraying and sampling determination of lutein are as above, and the detection results are as follows​ Figure 4 as shown in the figure;

[0059] The results show that, compared with the control group, the lutein content increases by 26.02% after SE+EM (0.5mM*1000 times) exogenous spraying, and the lutein content has no significant difference compared with the control group after SE+EM+Hartz raspberry (0.5mM*1000 times*1000 times) exogenous spraying, but the weight shows an increasing trend of 16.77%. Figure 4 ).

[0060] Through the above experimental results, it is found that after the compound solvent is exogenously sprayed on the two varieties of Tagetes of Taishan and Bohao, the lutein content is significantly increased, and for the widely planted Bohao Tagetes variety in agriculture, whether it is a greenhouse pot experiment or a field experiment, single effective component spraying or compound solvent spraying can further promote the accumulation of lutein content, and the effect is significant.

[0061] The problem to be solved by the present application is that after the single variety resource introduced from abroad is continuously planted, the variety degeneration problem of reducing flower yield and lutein content is generally faced, which is extremely unfavorable for the long-term and healthy and sustainable development of the industry. It is difficult to solve the problem of lack of germplasm resources in the short term, therefore, we focus on developing an exogenous spraying compound reagent which can effectively improve the lutein yield of Tagetes, and the compound reagent is non-toxic and harmless, and has low economic cost, and is suitable for wide application in agricultural production. The compound solvent of the present application further solves the problem of low lutein content of Tagetes petals.

[0062] The preferred embodiments of the present application disclosed above are only used to help explain the present application. The preferred embodiments do not describe all the details, nor limit the application to the specific embodiments described. Obviously, many modifications and changes can be made according to the content of the present application. The present application selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present application, so that those skilled in the art can well understand and utilize the present application. The present application is limited only by the claims and their entire scope and equivalents.

Claims

1. A method for promoting the accumulation of carotenoids in marigold petals, characterized in that: The following steps are involved: Step 1: Prepare the composite solution: Mix 0.5 mM sodium selenite solution with 1000-fold diluted EM inoculum; Step 2: spraying treatment: when the flower buds of marigolds develop to the S3 stage, spray the composite solution on the front and back surfaces of the leaves and the surface of the flower buds of the plants; Step 3: Repeat spraying: spray once every 7 days, for a total of 3 times; Step 4: Harvesting: 30 days after the last spraying, harvest marigold petals from S6 to S7.

2. The method for promoting carotenoid accumulation in marigold petals according to claim 1, wherein: The spraying amount of the composite solution in Step 2 is 500 mL for every 3 plants.

3. The method for promoting carotenoid accumulation in marigold petals according to claim 1, wherein: The spraying amount of the composite solution in Step 2 is 250 mL for every 3 plants.

4. An application of a composite solution for promoting lutein accumulation in marigold petals, characterized in that: The composite solution consists of a 0.5 mM sodium selenite solution and a 1000-fold diluted EM bacterial agent, and is used for exogenous spraying on marigold plants.

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