Method for promoting weight increase of saffron crocus progeny corm by enhancing illumination

Abstract

The invention provides a method for promoting weight increase of saffron crocus progeny corms by enhancing illumination, which comprises the following steps: picking filaments, transplanting mother corms into soil for vegetative growth under the illumination intensity of 20000Lux, implementing periodic maintenance management, supplementing water once every two weeks, observing morphological indexes of the progeny corms, and harvesting the progeny corms after all leaves are withered. Experimental results show that the expression level of CsCCD2L in leaves is reduced by increasing illumination intensity, so that the content of zeaxanthin is increased, photosynthesis is further facilitated, and nutrition is provided for development of filial generation corms; the increase of the corm weight of the filial generation can significantly increase the flowering number, improve the yield of saffron crocus, and hopefully solve the bottleneck problem of low yield of saffron crocus.

Description

Technical Field

[0001] The invention belongs to the technical field of traditional Chinese medicine cultivation, and relates to a method for promoting the increase of weight of saffron progeny bulbs by enhancing light. Background Art

[0002] Saffron is a widely used precious traditional Chinese medicine. Its dried stigma is used as medicine, which has the effects of promoting blood circulation and removing blood stasis, cooling blood and detoxifying, and relieving depression and calming the mind. Due to problems such as germplasm degradation and low bulb reproduction rate, the annual output of saffron is only about 3,000 kilograms, which is far from meeting the huge domestic market demand. More than 70% of saffron still relies on imports, so it is urgent to increase the output of saffron.

[0003] The introduction and cultivation method of saffron in China is a "two-stage" cultivation method: from December to May of the following year, the mother bulbs are planted outdoors for vegetative growth and reproduction of daughter bulbs; from May to November, the daughter bulbs are transferred from outdoors to indoors. After a short dormancy in summer, the flower buds begin to develop and bloom in October-November. After the flowers are picked, they are planted outdoors again. The weight of saffron bulbs is closely related to the number of flowers. Bulbs below 6g do not bloom, a single top bud of 24-28g bulbs can bloom 1-3 flowers, a single top bud of more than 40g bulbs can bloom 3-4 flowers, and a single top bud of more than 50g bulbs can bloom up to 5-6 flowers. Therefore, increasing the weight of daughter bulbs is expected to increase saffron yields. Summary of the invention

[0004] The object of the present invention is to provide a method for promoting the increase of weight of saffron progeny bulbs by enhancing light.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] The method for promoting the weight increase of saffron offspring corms by enhancing light comprises: after picking the filaments, transplanting the mother corms into the soil for vegetative growth, with a light intensity of 20,000 Lux, and implementing periodic maintenance management, replenishing water once every two weeks and observing the morphological indicators of the offspring corms, and harvesting the offspring corms after all the leaves have withered.

[0007] Preferably, the method further comprises: controlling the weight of the bulbs within the range of 25±1 g and cultivating the bulbs in a 17° C. greenhouse environment until flowering.

[0008] More preferably, saffron bulbs with a smooth surface and no lesions are selected.

[0009] Preferably, the mother bulb is transplanted into a planting container with a soil depth of 15-20 cm for vegetative growth.

[0010] Preferably, the mother bulb is placed in an adjustable light incubator and treated with a light intensity of 20,000 Lux.

[0011] Preferably, increasing the light intensity can significantly reduce the expression level of CsCCD2L in the leaves, leading to an increase in the content of zeaxanthin, which is beneficial to photosynthesis and provides nutrition for the development of offspring bulbs.

[0012] The beneficial effects of the present invention are:

[0013] The present invention provides a method for promoting the increase in weight of saffron offspring bulbs by enhancing light. Experimental results show that increasing light intensity reduces the expression level of CsCCD2L in leaves, resulting in an increase in the content of zeaxanthin, which is beneficial to photosynthesis and provides nutrition for the development of offspring bulbs. The increase in the weight of offspring bulbs can significantly increase the number of flowers and improve the yield of saffron, which is expected to solve the bottleneck problem of low saffron yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The process of enhanced light treatment of saffron plants, MC: Mother corm; DC: Daughter corm.

[0015] Figure 2 Saffron plants during reproductive and vegetative growth, saffron flower buds during floral induction (A) and floral organ differentiation (B), Bar = 0.5 mm; (C) Saffron plants on the day of flowering, leaves gradually extending out of the bud sheath; (D) Saffron plants during vegetative growth, leaves completely extending out of the bud sheath, Bar = 1 cm.

[0016] Figure 3 The expression levels of CsCCD2L during reproductive growth and vegetative growth, (A) White: white pistil stage, (B) Yellow: yellow pistil stage, (C) Orange: orange pistil stage, (D) Red: red pistil stage, (E) Blooming: flowering day, (F) Vegetative growth: vegetative growth period, (G) The expression levels of CsCCD2L during the yellow pistil stage, red pistil stage, flowering day and vegetative growth period of the reproductive growth period.

[0017] Figure 4 Effects of strong light on the expression level of CsCCD2L (A), zeaxanthin and its conversion products (B).

[0018] Figure 5 Increasing light promotes the increase in the weight of offspring bulbs. (A) Saffron plant, the red five-pointed star represents the formed offspring bulbs; (B) offspring bulbs, Bar=1cm; (C) offspring bulb weight; (D) The number of flowers of offspring bulbs of different weights. DETAILED DESCRIPTION

[0019] The present invention is described in detail below in conjunction with specific implementation methods. The following specific embodiments are helpful for those skilled in the art to further understand the present invention, but do not limit the present invention in any form.

[0020] Example

[0021] like Figure 1 As shown, the method of the present invention for promoting the increase of weight of progeny bulbs of saffron by enhancing light mainly comprises the following steps:

[0022] 1. Select saffron bulbs with smooth surface and no disease spots, control the bulb weight within the range of 25±1g, and cultivate them in a greenhouse environment at 17℃ until flowering.

[0023] 2. After picking the filaments, transplant the mother bulbs into a planting container with a soil depth of 15-20cm for vegetative growth.

[0024] 3. The mother bulbs were randomly divided into a control group and a treatment group. The treatment group was placed in an adjustable light incubator with a light intensity of 20,000 Lux, and the control group was treated with a light intensity of 3,000 Lux. Each group was treated with no less than 200 bulbs.

[0025] 4. Implement periodic maintenance management, replenish water every two weeks and observe the morphological indicators of the offspring bulbs, and continue until the leaves are completely withered, that is, the end of the vegetative growth period.

[0026] 5. Detect the changes in the expression level of CsCCD2L at different developmental stages and under different light intensity treatment conditions, and detect the content of zeaxanthin and its conversion substances under different light intensity treatment conditions.

[0027] 6. When all leaves have withered, the saffron vegetative growth period ends. Harvest the daughter bulbs, weigh them accurately, and calculate the weight and perform data analysis.

[0028] The results are as follows:

[0029] (1) Saffron growth cycle

[0030] The terminal bud of saffron is a mixed flower and leaf bud. Under normal conditions, both flower organs and leaf organs develop. After dormancy is released, the development of flower primordium and leaf primordium begins, entering the flowering induction period. During this period, the stem apical meristem changes from a vegetative state to a reproductive state, the surface area of ​​the growth cone increases, and changes from a smooth state to an oblate spherical protrusion. The development of flower primordium begins ( Figure 2 A); then undergo the differentiation process of floral organs and leaf organs ( Figure 2 B), as the flower organs and leaf organs elongate and grow, a mixed bud of flowers and leaves wrapped by a bud sheath is formed, until the flowering leaves gradually extend out of the bud sheath ( Figure 2 C) and enter the vegetative growth period ( Figure 2 D) In ​​the initial stage of the vegetative growth period, the mother bulb provides nutrients to the daughter bulbs, and as the leaves fully extend out of the bud sheath, it begins to provide nutrients to the daughter bulbs through photosynthesis.

[0031] (2) During the vegetative growth period, the expression level of CsCCD2L in leaves decreases

[0032] The reproductive growth period of saffron includes the white pistil stage, the yellow pistil stage, the orange pistil stage, the red pistil stage and the day of flowering ( Figure 3 AE). The reproductive growth period takes place indoors, when the leaves of saffron are wrapped in the sheath and the light intensity felt by the leaves is weak; the vegetative growth period takes place outdoors, when the light intensity felt by the leaves is relatively strong, and at this time the leaves are completely extended out of the sheath for photosynthesis ( Figure 3 F). qPCR technology was used to detect the expression level of CsCCD2L throughout the life cycle. It was found that the expression level of CsCCD2L gradually increased during the reproductive growth period, reached the maximum value on the day of flowering, and entered the vegetative growth period, and its expression level decreased significantly ( Figure 3 G). This result suggests that the expression level of CsCCD2L in leaves may change in response to light intensity.

[0033] (3) Enhanced light during the vegetative growth period leads to a decrease in the expression level of CsCCD2L and an increase in the content of zeaxanthin

[0034] In order to further verify whether the expression level of CsCCD2L is affected by light intensity, saffron plants in the vegetative growth period (leaves completely extended out of the bud sheath) were treated with light intensities of 3000 Lux (control group) and 20000 Lux (high light group), respectively. It was found that increasing light intensity could significantly reduce the expression level of CsCCD2L in leaves ( Figure 4 A). The CsCCD2L gene encodes a carotenoid dioxygenase that cleaves zeaxanthin at the 7' and 8' positions. Zeaxanthin participates in light absorption and photoprotection pathways, helping plants to photosynthesize efficiently. UPLC-MS / MS technology was used to detect the content of zeaxanthin in leaves under different light intensities. It was found that the content of zeaxanthin and its conversion products, antheraxanthin and violaxanthin, in leaves under strong light treatment increased significantly ( Figure 4 B). In summary, these results suggest that increasing light intensity reduces the expression level of CsCCD2L in leaves, leading to an increase in the content of zeaxanthin, which is beneficial to photosynthesis and provides nutrition for the development of daughter bulbs.

[0035] (4) Increasing light during the vegetative growth period increases the weight of offspring bulbs

[0036] About two weeks after the saffron filaments were picked, the leaves completely extended out of the bud sheaths. 200 saffron plants were transferred to the greenhouse for a light intensity treatment of 20,000 Lux, and 200 saffron plants were transferred to the greenhouse for a light intensity treatment of 3,000 Lux. When the vegetative growth period was over, that is, when the leaves withered, the daughter corms were dug out from the substrate soil, and the weight of the daughter corms under different treatments was counted. The results showed that the weight of the daughter corms under the light intensity treatment of 20,000 Lux was significantly higher than that under the light intensity treatment of 3,000 Lux ( Figure 5 A, B, C). The increase in the weight of the progeny bulbs can significantly increase the number of flowers ( Figure 5 D) Increasing saffron production is expected to solve the bottleneck problem of low saffron production.

[0037] Obviously, the above embodiments of the present invention are merely examples to more clearly illustrate the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made on the basis of the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. A method for increasing the weight of saffron progeny bulbs by enhancing light, comprising: After picking the filaments, transplant the mother bulbs into the soil for nutritional growth with a light intensity of 20,000 Lux, and implement periodic maintenance management. Replenish water every two weeks and observe the morphological indicators of the daughter bulbs. Harvest the daughter bulbs after all the leaves have withered.

2. The method according to claim 1, characterized in that Also includes: The bulb weight was controlled within the range of 25±1 g and cultivated in a 17°C greenhouse environment until flowering.

3. The method according to claim 2, characterized in that Choose saffron bulbs with smooth surfaces and no disease spots.

4. The method according to claim 1, characterized in that: Transplant the mother corm into a planting container with a soil depth of 15-20 cm for vegetative growth.

5. The method according to claim 1, characterized in that The mother bulbs were placed in an adjustable light incubator and treated with a light intensity of 20,000 Lux.

6. The method according to any one of claims 1 to 5, characterized in that: Increasing light intensity can significantly reduce the expression level of CsCCD2L in leaves, leading to an increase in the content of zeaxanthin, which is beneficial to photosynthesis and provides nutrition for the development of offspring bulbs.

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