Application of exogenous ACC in delaying flowering time and increasing flowering number of citrus

Abstract

The application relates to the field of citrus planting technology, in particular to application of exogenous ACC in delaying flowering time of citrus and increasing flowering quantity, and more particularly to a method for delaying flowering time of citrus, increasing flowering quantity, flower formation rate and fruit setting rate, which comprises the following steps: first time spraying exogenous ethylene synthesis precursor ACC on the whole plant before autumn flower bud differentiation of the citrus, and then spraying once every 12-16 days, and spraying for 5-7 times in total. The method can delay the flowering time of the citrus by 3.19 days, and the flowering quantity, flower formation efficiency and fruit setting rate are all improved, thereby providing technical support for solving the influence of extreme weather such as late spring cold on the yield and quality of the citrus.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of citrus cultivation, and particularly relates to application of exogenous ACC in delaying flowering time of citrus and increasing flowering quantity. BACKGROUND

[0002] Flowering is an important reproductive stage of citrus, and the flowering time and quantity directly affect the fruit setting rate of citrus, and have important influences on yield and quality. Extreme weather such as'spring cold' can seriously reduce the flowering quantity, quality and fruit setting rate of citrus. Relevant researches show that abnormal weather such as spring cold during the flowering period of honey orange leads to poor development and abnormal flower drop of flower organs, and further affects the yield and quality.

[0003] Ethylene is a gaseous hormone, and is an important medium for plant response to environmental stimuli. The direct precursor of ethylene synthesis is amino cyclopropyl alanine (ACC), which plays a crucial role in the growth and development of plants such as leaf and root development, fruit ripening and flower senescence. Studies have shown that different concentrations of ethylene have different effects on leaf development in different plants. Further studies have found that ethylene can reduce chlorophyll content, increase anthocyanin, sugar accumulation and biosynthesis of aromatic substances, and further regulate fruit ripening. In production, the synthesis of ethylene is often inhibited to delay the senescence of fresh-cut flowers such as roses and Chinese roses, but the technology of how ethylene affects the flowering time and quantity of large fruit trees has not been reported. SUMMARY

[0004] The present application takes potted adult citrus as experimental material, and uses the ethylene synthesis precursor ACC and the ethylene inhibitor amino oxy ethylene glycol (AVG) for treatment respectively. By observing and counting the flowering time and flowering rate of the potted plants, it is found that the ethylene synthesis precursor ACC has the effects of increasing the flowering efficiency of citrus, increasing the flowering quantity and delaying the flowering time, thereby providing technical support for solving the influences of extreme weather such as'spring cold' on the yield and quality of citrus.

[0005] One of the purposes of the present application is to protect the application of exogenous ACC in citrus cultivation, and the application at least includes one of the following:

[0006] (1) delaying the flowering time of citrus;

[0007] (2) increasing the flowering quantity of citrus;

[0008] (3) increasing the flowering efficiency of citrus, wherein the flowering efficiency refers to the ratio of flowering branches to total branches per plant.

[0009] (4) increasing the fruit setting rate of citrus, wherein the fruit setting rate refers to the ratio of fruiting quantity to flowering quantity per plant.

[0010] Further, the second object of the present application is also to protect a method for delaying the flowering time, increasing the flowering number, flowering rate and fruit setting rate of citrus, which comprises spraying the whole plant with the exogenous ethylene precursor ACC for the first time before the flower bud differentiation in autumn, and then spraying every 12-16 days for 5-7 times.

[0011] The concentration of the exogenous ACC is 150-250 μM, preferably 200 μM.

[0012] Further, the exogenous ACC solution contains Tween when sprayed.

[0013] Further, the Tween is added to the exogenous ACC solution at a volume ratio of 1 / 1000.

[0014] Further, each plant is sprayed until the leaves drip with water each time.

[0015] The method of the present application is used to treat citrus plants, and compared with the water treatment group, the ACC treatment delays the flowering time of each plant by 3.19 days, increases the flowering branch ratio of each plant by about 26.71%, increases the total flowering amount of each plant by about 88 flowers, and increases the fruit setting rate by about 11.84%, i.e. the exogenous ACC treatment has the effects of improving the flowering efficiency of citrus, increasing the flowering number, delaying the flowering time and improving the fruit setting rate, which provides technical support for the treatment of the harm of extreme weather on the citrus industry in China, and has important significance for improving the citrus yield in China. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 Fig. 1 is the flowering phenotype of different experimental groups before and after treatment;

[0017] Figure 2 Fig. 2 is the flowering branch of different experimental groups after treatment;

[0018] Figure 3 Fig. 3 is the flowering time statistical result of different experimental groups after treatment;

[0019] Figure 4 Fig. 4 is the flowering number statistical result of different experimental groups after treatment;

[0020] Figure 5 Fig. 5 is the average flowering number statistical result of different experimental groups after treatment;

[0021] Figure 6 Fig. 6 is the flowering efficiency calculation result of different experimental groups after treatment;

[0022] Figure 7 Fig. 7 is the fruit setting rate calculation result of different experimental groups after treatment. DETAILED DESCRIPTION

[0023] The application will be further described in detail below with reference to specific examples, so that those skilled in the art can more clearly understand the application. The following examples are used to illustrate the application, but not to limit the scope of the application. Based on the specific examples in the application, all other examples obtained by those skilled in the art without creative labor are within the protection scope of the application.

[0024] In the embodiments of the application, all raw material components are commercially available products well known to those skilled in the art, unless otherwise specified. In the embodiments of the application, the technical means used are conventional means well known to those skilled in the art, unless otherwise specified.

[0025] The embodiments of the application provide a method for intervention of citrus flower retention by exogenous ACC treatment, comprising the following steps:

[0026] (1) Selection of adult potted citrus:

[0027] Select 9 potted adult lemon plants (variety: Yurik) of the same age, healthy and consistent growth, with a tree height of about 1.5-2.0 meters, planted in pots with a diameter of 60 cm. These plants have the ability to flower and bear fruit. The experimental site is in the plant growth greenhouse of Huazhong Agricultural University in Wuhan, Hubei Province, with an average annual temperature of about 20℃.

[0028] (2) Management before treatment of potted citrus:

[0029] Remove all dry branches, fallen leaves, fallen fruits and weeds from the glass greenhouse and burn or bury them.

[0030] (3) Preparation of exogenous hormones:

[0031] Dissolve and prepare 200 μM ACC (CA1653, Beijing Coolabotech Electronics Co., Ltd.) and 200 μM AVG (Cas: 55720-26-8, Aldrich) in distilled water, respectively, and then add Tween (30189328, China Pharmaceutical Group) at a ratio of 1 / 1000 (v / v) and mix well for standby.

[0032] (4) Spraying of hormones:

[0033] The experiment was designed for three groups of treatment, the control group (Control) used water to spray whole plant, ACC treatment group used 200 μM ACC to spray whole plant, AVG treatment group used 200 μM AVG to spray whole plant, plant spraying until the leaves dripping water, each treatment set 3 biological replicates, before the autumn flower bud differentiation (late November) start to spray every 14 days, a total of 6 times. After spraying (end of January to February next year, spraying end, in late February to early March can see flower bud), until the spring flowering, observe and count the flowering time, flowering efficiency, count the total number of flowering, flowering time and the number of flowers per branch and fruit set rate under different treatment conditions.

[0034] Among them, the flowering time is recorded as the first spraying, and the time is counted as the standard of each flower fully blooming; Count the flowering time of all flowers on each plant, that is, count how many flowers on each plant, according to the actual number of flowers on each plant; Flowering branches are 1-2 year old branches on each plant that have bloomed; Flowering efficiency = flowering branch number / total branch number, (total branch number is the total number of 1-2 year old branches on each citrus plant that have flowering ability); Flowering number is the total number of flowers on each plant; Fruit set rate refers to the ratio of the number of fruits to the number of flowers on each plant. The results are shown in Table 1 below:

[0035] Table 1 Statistical results of each index

[0036]

[0037] From the above table, it can be seen that the use of exogenous ACC treatment can delay the flowering time of citrus, compared with the control, the average flowering time of each plant is delayed by 3.19 days after ACC treatment, while the average flowering time of each plant is advanced by 1.20 days after AVG treatment; Increase the flowering efficiency of citrus. Compared with the control, the ratio of flowering branches of each plant after ACC treatment increased by about 26.7%, while AVG decreased by 23.66%; Promote the flowering number of citrus. Compared with the control, the total number of flowers of each plant after ACC treatment increased by about 88, the AVG treatment group decreased by 15.67, the number of flowers per branch of each plant after ACC treatment increased by about 4.55, the AVG decreased by 0.12, the fruit set rate of each plant after ACC treatment increased by about 11.84%, and the AVG decreased by 2.45%. In summary, exogenous ACC treatment has the effect of improving the flowering efficiency of citrus, increasing the number of flowers, delaying the flowering time, and improving the fruit set rate. This finding will provide technical support for the treatment of citrus industry in extreme weather, and has important significance for improving the yield of citrus in China.

[0038] It is necessary to point out here that the above embodiments are only for further illustrating and describing the technical solutions of the present application, and are not for further limiting the technical solutions of the present application. The method of the present application is only a preferred embodiment, and is not used for limiting the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for delaying flowering time, increasing the number of flowers, the rate of flowering and the fruit set rate of citrus, characterized by, The method is to first spray the whole plant with an exogenous ethylene synthesis precursor ACC before the first flower bud differentiation in autumn, and then spray every 12-16 days, a total of 5-7 times; The application of the exogenous ACC in citrus planting at least includes one of the following: (1) delaying the flowering time of citrus; (2) increasing the flowering number of citrus; (3) increasing the flowering efficiency of citrus, wherein the flowering efficiency refers to the ratio of the number of flowering branches per plant to the total branches; (4) increasing the fruit setting rate of citrus, wherein the fruit setting rate refers to the ratio of the number of fruits per plant to the number of flowers.

2. The method of claim 1, wherein, The concentration of the exogenous ACC is 150-250 μM when spraying.

3. The method of claim 1, wherein, The exogenous ACC solution also contains Tween when spraying.

4. The method of claim 3, wherein, The Tween is added to the exogenous ACC solution at a volume ratio of 1 / 1000.

5. The method of claim 1, wherein, Each plant is sprayed until the leaves drip with water each time.

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