A method for cultivating lily with excellent traits and early flowering

Abstract

The present invention discloses a method for cultivating lilies with excellent traits and early flowering. In the present invention, lily bulbs are induced to bolt under dark and low-temperature conditions with the help of a light substrate, and then the lilies are planted in the field and managed under field temperature control. Compared with the control group, the lily flowering period of the present invention is advanced by about 2 months, and the obtained cut lilies have no (or little) pollen pollution, and the papillae are significantly reduced. It can be seen that the present invention achieves the triple effects of cultivating cut lilies with early flowering period, no pollen pollution, and reduced papillae through simple and effective technical control. This method is an important method for cultivating cut lilies. It not only solves the problem of difficulty in regulating the flowering period of lilies in the open field, but also avoids the cost and labor of cultivating varieties with no (or little) pollen through molecular breeding, and obtains more excellent ornamental traits. It has important theoretical research value and good promotion and application prospects.

Description

Technical Field

[0001] The present invention belongs to the technical field of new plant variety breeding, and particularly relates to a method for cultivating lilies with excellent traits and early flowering. Background Art

[0002] Lilies (Lilium spp.) are perennial bulbous flowers in the Liliaceae family, known for their large, colorful, graceful blooms and pleasant fragrance. Known as the "king of bulbous flowers," lilies are widely used as cut flowers, potted plants, and even in landscape gardening, possessing exceptionally high ornamental value. Some lilies are also used medicinally and edible, possessing both high ornamental and economic value. Lilies are diverse in variety and widespread, occupying a significant position in the domestic and international cut flower markets (Yang Liping and Fu Yongyao, Research on Lily Resource Utilization in China [M], Northeast Forestry University Press, November 2018).

[0003] However, most existing lily varieties have a high pollen content. During the flowering process, a large amount of pollen will be shed, which will cause pollen pollution. It is inconvenient to clean after being contaminated, and it is also easy to cause adverse reactions such as pollen allergies in some people. Cut flowers and potted lilies sold on the market are generally artificially emasculated, which is a cumbersome process and wastes a lot of manpower and material resources. Therefore, the cultivation of lilies with no (or little) pollen has always been the focus of lily breeding (Wu Meijiao, Zhang Yaming, Wang Xueqian, etc., Research on hybrid breeding of lilies without pollen pollution, Journal of Nanjing Agricultural University, 2019, 42(06): 1030-1039). At the same time, by adjusting the flowering period, the plants can bloom in advance, which significantly extends the viewing period of lilies, improves the ornamental quality of their flowering period and the commercial value of lilies, and has huge market prospects. Papilles are common protrusions on the lower middle portion of lily petals, often brightly colored. However, lilies with numerous papillae, such as the Nanchuan lily and the Hubei lily, significantly reduce their ornamental value (Yang Liping and Fu Yongyao, Research on the Utilization of Lily Resources in China [M], Northeast Forestry University Press, 2018.11). To date, there are few reports on the regulation of lily papillae. Therefore, research on cultivating lily varieties that flower early and have no (or minimal) pollen or fewer papillae is of great significance.

[0004] Research has found that the primary principle of flowering control is to regulate plant vegetative growth, flower bud differentiation, and the flowering environment. This regulation is primarily achieved through temperature manipulation, light treatment, chemical treatment, and cultural practices. Low-temperature storage of lily bulbs is a particularly effective method for controlling the flowering period. Combined with artificial lighting, it can promote seedling growth and accelerate flower bud differentiation (Tian Chunyuan, Zhang Weiying. Research on Flowering Period Control Techniques for Cyclamen and Lily, 2015, 17, Forestry Science, Modern Agricultural Science and Technology, 2015, 17:192-193). Furthermore, different low-temperature treatments and the duration of low-temperature treatment are closely correlated with flowering period. Currently, in practical production, low-temperature treatment at 0-8°C followed by storage for 4-12 weeks is used to break dormancy in lily bulbs. Lower temperatures lead to later flowering, while longer low-temperature treatments lead to earlier flowering, with the impact on flowering occurring as little as 3-4 days and as much as 15-20 days. During lily production, for bulbs that have been treated with low temperatures, higher temperatures lead to earlier flower bud differentiation, but fewer leaves and flowers, and shorter flower stems. Cultivating at low temperatures can shorten internodes and delay flowering. Furthermore, regulating the flowering period of open-field lilies is difficult; simply adjusting the planting time or fertilizing often yields ineffective results. Regulating the flowering period of cut lilies in greenhouses is often costly.

[0005] Studies have found that pollen abortion is closely related to abnormal mitochondrial respiration, membrane lipid peroxidation, material metabolism disorders and abnormal small RNA function (Zhang Pengfei, Zhang Daorong, Ling Dong, et al. Research progress on plant pollen abortion, Hubei Agricultural Sciences, 2019, 58(23): 10-15). Among them, high temperature often causes pollen abortion, while low temperature has no obvious effect on pollen formation or activity (Quan Dongxing, Zhou Guangchun, Hou Ligang, Effect of flowering temperature on pollen abortion and fertility of BT-type sterile lines of northern hybrid japonica rice, Hubei Agricultural Sciences, 2011, 50(1): 30-32). So far, no researchers have found that low temperature can have a significant effect on pollen. At present, there are some preliminary basic studies on male sterile pollen-free lilies at home and abroad, but most of them involve gene editing methods. For example, the Department of Ornamental Horticulture and Landscape Architecture of China Agricultural University used Lilium fusca as a test material. On the basis of establishing a sterile small scale multi-frequency regeneration system, they established an efficient genetic transformation system. Through Agrobacterium-mediated method, the corn anther development-related gene Zm401 was introduced into Lilium fusca. Preliminary molecular level detection proved that the exogenous gene Zm401 had been successfully integrated into the genome, thus obtaining positive plants (Li Qiuhua et al., Establishment of genetic transformation system of Lilium fusca and introduction of Zm401 gene, Journal of Agricultural Biotechnology, 2008, 16(1):96-102). However, this method is difficult to screen genes, difficult to operate, and has high cost. Invention patent CN106417000B discloses a method for breeding pollen-free lily varieties. It uses a special lily hybrid breeding combination, combined with bottle sowing, lily tissue culture propagation, lily small seed bulb cold storage vernalization, lily bulb cultivation, pollen-free lily screening and propagation technology to breed pollen-free lilies. Zhao Xiangyun et al. obtained male sterile mutant plants through radiation breeding (Zhao Xiangyun, Research on Radiation-Induced Male Sterility in Lily. Chinese Horticulture, 2003, 2:25-2). However, the above method is cumbersome and requires a long breeding cycle.

[0006] Currently, there is no effective method for simultaneously regulating the flowering period, pollen formation, and fertility of lilies. Therefore, it is crucial to find a simple, practical, and widely applicable technology for regulating the flowering period, pollen formation, and papillae of lilies. Summary of the Invention

[0007] In response to the problems existing in the prior art, the present invention aims to provide a method for cultivating lilies with excellent traits and early flowering, which solves the problems of difficult flowering period control of outdoor cut lilies, large amount of pollen and easy contamination, and low ornamental quality caused by many papillae, and provides a new method for cultivating lilies with better ornamental traits.

[0008] To achieve the above-mentioned object, the present invention adopts the following technical solution: a method for cultivating lilies with excellent traits and early flowering, comprising the following steps:

[0009] 1) Place the lily bulbs in a lightweight substrate, seal it, and place it in a cool, dark environment until the bulbs grow to about 12-15 cm.

[0010] 2) Planting the bolting lilies obtained in step 1) in a field;

[0011] 3) Performing field management on the lilies cultivated in step 2), wherein the temperature during the management process is 0-15°C, and preferably, a periodic temperature change treatment is selected during the day and night, such as 10-15°C during the day and 0-5°C at night.

[0012] Preferably, the lightweight substrate in step 1) is one or more of peat, wood shavings and sawdust.

[0013] Preferably, the low temperature in step 1) is 8-12°C.

[0014] Preferably, the dark-proof culture time in step 1) is 2 to 3 weeks.

[0015] Preferably, in step 2), the plants are planted on raised ridges with a height of 20 to 30 cm and a width of 1.5 m, and a planting density of 4 to 5 plants / m 2 .

[0016] Preferably, in step 2), the bolting lily is placed vertically in the planting hole, with the lily base with the fleshy roots facing downward, and the thickness of the covering soil is 4 to 6 cm.

[0017] Preferably, in step 2), outdoor cultivation can be carried out in late autumn in a location with an outdoor temperature of 0-15°C in winter, such as a subtropical region with a minimum winter temperature of around 0°C. In this way, the lily buds are subjected to a periodic cold stress treatment (0-5°C at night and approximately 10-15°C during the day) for approximately two and a half months in their natural winter state, which is more conducive to the lily cut flowers being free of pollen or having less pollen, and having significantly fewer papillae. This also enables open-air cultivation of lilies, generally without the need for temperature control.

[0018] Preferably, in step 3), when the field temperature is below -2°C, it is necessary to cover the field with an appropriate amount of film to control the temperature.

[0019] Preferably, the field management in step 3) includes water management, fertilizer management or pest and disease management.

[0020] Another object of the present invention is to provide a lily variety cultivated by the above method.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The present invention induces bolting of lily bulbs with the aid of a light substrate under dark and low-temperature conditions, and then plants the lily bulbs in the field and manages the temperature under field control. The present invention can significantly shorten the flowering time of lilies, bringing the flowering period forward by about 2 months, with significant effects. The obtained lily cut flowers are free of pollen or have little pollen contamination and are sterile. The inner whorl of red papillae is significantly reduced, and the outer whorl of papillae disappears, resulting in better ornamental quality. The present invention provides new ideas and new options for cultivating excellent lily traits through cultivation management.

[0023] 2. The present invention achieves the triple effects of cultivating cut lilies by simple and effective technical control, namely, early flowering, no pollen pollution, and reduced petal papillae. It is an important method for cultivating cut lilies. The method is simple and easy to operate, has a short processing cycle, and has potential market application prospects.

[0024] 3. The cultivation method of the present invention is suitable for open-air cultivation and promotion in subtropical areas (where the lowest temperature in winter is around 0°C). It is planted in the field in late autumn, avoiding the usual practice of regulating the flowering period of lilies through greenhouses, solving the problem of difficulty in regulating the flowering period of open-field lilies, and does not require gene editing to cultivate varieties with no or little pollen. The time is greatly shortened, the cost is significantly reduced, and it has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a diagram of the inducing bolting of lily 'Sorbonne' bulbs.

[0026] Figure 2 This is a diagram showing the growth and development process of the bolting cut flower lily 'Sorbonne' in field cultivation. A is one week after field planting, B is one month after field planting, and C is the flowering period of the 'Sorbonne' lily more than four months after planting.

[0027] Figure 3 This is a picture of the flower parts of the cut lily 'Sorbonne' during the flowering period. A is the experimental group, B is the control group, and the scale bar represents 2.5 cm.

[0028] Figure 4 The petals and filaments of the experimental group lily 'Sorbonne' are shown. A is the outer petals, B is the inner petals, the scale bar is 1 cm, and C is the filament.

[0029] Figure 5 These are pictures of anthers of the cut lily 'Sorbonne'. A shows six anthers from a single flower in the early stage of pollen shedding in the experimental group. The scale bar represents 1 cm. B shows six anthers from a single flower in the late stage of pollen shedding in the experimental group (including the scale bar).

[0030] Figure 6 This is an enlarged picture of the anthers of the cut lily 'Sorbonne'. A is the anther without pollen in the experimental group, B and C are the anthers with very little pollen in the experimental group, and D is the anther with loose pollen in the control group. The scale bar represents 1 mm.

[0031] Figure 7 Pollen tube germination of pollen, A and B are experimental groups, C is the control group, and the scale bar represents 100 μm. DETAILED DESCRIPTION

[0032] The present invention will be further described in detail below with reference to specific examples and accompanying drawings, but the scope of protection of the present invention is not limited to the contents described above. Unless otherwise specified, the raw materials described in the examples are all common commercially available products. Unless otherwise specified, the experimental methods described in the examples are performed according to conventional biological experimental methods.

[0033] The material used in this example is the cut flower lily 'Sorbonne', purchased from Sichuan Yishang Agricultural Tourism Ecology Co., Ltd., and the bulb size is 14 to 16 cm in circumference.

[0034] Example 1

[0035] A method for cultivating lilies with excellent traits and early flowering, comprising the following steps:

[0036] 1) Lily bulb bolting induction

[0037] 60 normal 'Sorbonne' lily bulbs were selected and randomly divided into two groups, one for the experimental group and the other for the control group. The experimental group was placed in a white plastic box filled with pure sawdust, sealed, and placed in a low temperature environment (about 10°C) and away from light. After 2 to 3 weeks, the bulbs were observed for their bolting development. When they grew to about 12-15 cm (such as Figure 1 The control group received no treatment.

[0038] 2) Field planting of lilies

[0039] The experimental group and the control group in step 1) were planted in the outdoor field of Yangtze Normal University in Fuling District, Chongqing in late autumn (early November 2020) (according to observations since 2017, the lowest temperature in winter at the lily planting base of Yangtze Normal University in Fuling District, Chongqing is around 0 degrees Celsius; the average daily temperature in winter is around 10 degrees Celsius, which is suitable for the experiment). Select an area with moderate light, good drainage and ventilation, and other soils except heavy clay soils, and plant them in raised beds with a height of 20 to 30 cm and a width of about 1.5 m, with a planting density of 4 to 5 plants / m 2 Place the bolting lily vertically into the planting hole, making sure the fleshy roots at the base of the lily face downwards, and cover the soil with a thickness of about 5 cm to protect the bolting lily stems.

[0040] 3) Field management

[0041] The control group and the experimental group were managed in the field according to the needs and the two were kept consistent. Figure 2As shown in A, the stems and leaves of the lilies in the experimental group turned green, and appropriate amount of farmyard manure was applied. One month after planting, the leaves and stems of the lilies in the experimental group grew normally, the stem height increased, the leaves became wider and greener, and the number of leaves increased (as shown in Figure 2 B). Two months after planting (January 2021), flower buds began to appear in the experimental group. In the control group, buds sprouted in mid-February 2021, and flower buds began to appear in early April. During field management, please note that in special circumstances, when the field temperature drops below -2°C, appropriate film should be applied to properly control the temperature. During field growth, pay attention to the prevention and control of leaf gray mold and underground pests. If diseased plants are found, remove them immediately.

[0042] 1. The flowering period of the experimental group and the control group was observed. The results showed that from January to late March 2021, the lily buds in the experimental group gradually developed, became longer and larger, and the color gradually changed from green to purple, and then gradually to white, and turned to light pink before flowering. Some pictures of lilies during flowering are as follows: Figure 2 C and Figure 3 As shown in A, the lilies in the control group began to bloom gradually in late May. This shows that the flowering period of the experimental group was nearly 2 months earlier than that of the control group.

[0043] 2. Observe the phenotypes of the experimental and control groups. The results are as follows: Figure 3 and Figure 4 shown.

[0044] As can be seen from the figure: the average flower diameter of the experimental group can reach 16cm, and no obvious pollen is seen ( Figure 3 A), the papillae on the outer petals disappear ( Figure 4 A), the red papillae on the inner petals are significantly reduced ( Figure 4 B), the filaments show a slight bend ( Figure 4 C). The anthers of the lilies in the control group have clearly lost their pollen, and the flower diameter is similar to that of the experimental group. There are more red papillae in the middle and lower parts of the inner and outer petals (such as Figure 3 B) Both the experimental and control 'Sorbonne' lilies retained their floral fragrance.

[0045] 3. Observe the anthers of the experimental and control groups directly or dissect them under a stereo microscope (OLYMPUS SZ61 JAPAN). Figure 5 and Figure 6 shown.

[0046] from Figure 5 It can be seen that the anthers of the experimental group before pollination ( Figure 5 A) and anthers after pollination ( Figure 5 In B), no pollen was found or the pollen content was very low. From the enlarged anther image, it can be seen that some anthers in the experimental group had no pollen at all (e.g. Figure 6A), some anthers contain very small amounts of pollen (e.g. Figure 6 B and Figure 6 C). The lily anthers in the control group contained a large amount of pollen (such as Figure 6 D).

[0047] 4. The pollen liquid culture method (Gou Hui et al., Screening of the best culture medium for lily pollen germination and its activity determination, Agricultural Science and Information (Modern Garden), 2015, 12(4): 299-303) was used to detect the activity of pollen in the experimental group and the control group. The results are as follows: Figure 7 shown.

[0048] As can be seen from the figure, no pollen tube germination was found in the lilies of the experimental group (e.g. Figure 7 A and Figure 7 B), indicating that the pollen is sterile and the pollen grains are oval or irregular in shape. Figure 7 C), indicating that the pollen is fertile and most of the pollen grains are oval.

[0049] Example 2

[0050] The experiment was conducted from October 2021 to June 2022. The experimental steps were the same as in Example 1, and the results were the same. To avoid repetition, the specific drawings are omitted here.

[0051] In summary, it is shown that the cultivation method of the present invention can indeed simultaneously regulate the flowering period, pollen and petal papillary traits of lily, and the present invention is feasible.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for cultivating lilies with excellent traits and early flowering, characterized in that: The following steps are involved: 1) Place the lily bulbs in a lightweight substrate, seal it, and place it in a cool environment of 8-12°C. Keep it away from light and cultivate it until the bulbs grow to 12-15 cm. 2) Planting the bolting lilies obtained in step 1) in the field; 3) Field management is performed on the lilies cultivated in step 2), wherein the temperature during the management process is 0-15°C, and a periodic temperature change treatment is selected during the day and night, 10-15°C during the day and 0-5°C at night; the cultivated lilies have an earlier flowering period, the lily cut flowers have no or little pollen, and the papillae are reduced or disappeared.

2. The method for cultivating lily with excellent traits and early flowering according to claim 1, characterized in that: The light substrate in step 1) is one or more of peat, wood shavings and sawdust.

3. The method for cultivating lily with excellent traits and early flowering according to claim 1, characterized in that: The dark-proof culture time in step 1) is 2 to 3 weeks.

4. The method for cultivating lily with excellent traits and early flowering according to claim 1, characterized in that: In step 2), the plants are planted in raised beds with a height of 20 to 30 cm and a width of 1.5 m, and a planting density of 4 to 5 plants / m 2 .

5. The method for cultivating lily with excellent traits and early flowering according to claim 1, characterized in that: In step 2), the bolting lily is placed vertically in the planting hole, with the part of the lily base with the fleshy roots facing downward, and the thickness of the covering soil is 4 to 6 cm.

6. The method for cultivating lily with excellent traits and early flowering according to claim 1, characterized in that: In step 2), select a place where the outdoor temperature is 0-15°C in winter and perform open-air cultivation in late autumn.

7. The method for cultivating lily with excellent traits and early flowering according to claim 1, characterized in that: In step 3), when the field temperature is lower than -2°C, it is necessary to cover the field with an appropriate amount of film to control the temperature.

8. The method for cultivating lily with excellent traits and early flowering according to claim 1, characterized in that: The field management described in step 3) includes water management, fertilizer management or pest and disease management.

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