Method for measuring fruit stalk length of citrus fruit, evaluation method and application thereof

Abstract

The present invention belongs to the technical field of research on fruit traits of the citrus genus, and particularly relates to a method for measuring the fruit stalk length of citrus fruits, an evaluation method thereof, and applications thereof. The method for measuring the fruit stalk length of the citrus fruits according to the present invention comprises the following steps: measuring the measured value of the fruit stalk length and the measured value of the pericarp thickness of the citrus fruits; and obtaining the fruit stalk length of the citrus fruits according to the measured value of the fruit stalk length, the measured value of the pericarp thickness, and a predetermined relational expression that the fruit length = the measured value of the fruit stalk length / the measured value of the pericarp thickness. The present invention quantifies the ratio of the measured value of the fruit stalk length to the measured value of the pericarp thickness as the fruit stalk length of the citrus fruits, can more accurately and objectively reflect and evaluate the phenotypic traits of the fruit stalk length of citrus fruits including pomelo fruits, and has important value for breaking through the bottleneck of scientific research on the fruit stalk length of citrus fruits.

Description

Technical Field

[0001] The present invention belongs to the technical field of research on fruit traits of citrus fruits, and specifically relates to a method for measuring, evaluating and applying the length of the fruit base of citrus fruits. Background Art

[0002] Pomelo is a perennial horticultural plant of the genus Citrus in the Rutaceae family and is one of the three basic species of the genus Citrus. At present, pomelo is mainly planted in the tropical and subtropical regions of southern Asia.

[0003] Fruit shape, also known as fruit form, is one of the most important appearance qualities of horticultural crop fruits and significantly affects the commercial value of fruits. The fruit base, also known as the "fruit neck" or "fruit stalk", is the part or tissue from the fruit stalk to the fruit cavity of a mature pomelo fruit and is an important part of the pomelo fruit. Its length directly affects the fruit shape and edible rate of horticultural crops. At the same time, the fruit base part is easily damaged during picking, resulting in a reduction in the commerciality of the fruit.

[0004] Through years of research on the fruit base length of pomelo germplasm resources, it has been found that the fruit base length trait of pomelo fruits belongs to a quantitative trait and is easily affected by factors such as fruit shape and fruit size. In the research on the statistical method of fruit base length in horticultural plants, only similar research on cucumbers has been found, but the statistical method of fruit base length on cucumbers is not applicable to the statistical description of the fruit base length of pomelo fruits. In cucumbers, the fruit base length only affects the appearance quality of the fruit and belongs to the edible part, while the fruit base of pomelo belongs to the pericarp tissue and is an inedible part; secondly, through the statistical analysis of the fruit base length and pericarp thickness of more than 100 pomelo germplasm resources fruits, it has been found that the pericarp thickness of pomelo fruits with long fruit bases may be very thin or very thick, and the pericarp of pomelo fruits with short fruit bases may also be very thick or very thin. This leads to the fact that the direct measurement method cannot truly and objectively reflect the fruit base length of pomelo fruits, which has a great obstructive effect on the basic research of the fruit base length trait of the genus Citrus. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for measuring, evaluating and applying the length of the fruit base of citrus fruits. The method for measuring the length of the fruit base of citrus fruits can objectively reflect the fruit base length trait of citrus fruits and has important value for the research on the fruit base length trait of the genus Citrus.

[0006] The present invention provides a method for measuring the length of the fruit base of citrus fruits, including the following steps:

[0007] Measuring the measured value of the fruit base length and the measured value of the pericarp thickness of citrus fruits;

[0008] According to the measured value of the fruit base length and the measured value of the pericarp thickness, and a predetermined relational formula, obtaining the fruit base length of citrus fruits;

[0009]

[0010] Preferably, the measurement of the fruit base length of the citrus fruit includes: longitudinally cutting the citrus fruit along the middle, measuring the vertical distance from the fruit stalk to the pulp, and obtaining the measurement value of the fruit base length.

[0011] Preferably, the measurement of the peel thickness of the citrus fruit includes: longitudinally cutting the citrus fruit along the middle, measuring the vertical distance from the outer peel to the pulp at the equatorial plate of the fruit, and obtaining the measurement value of the peel thickness.

[0012] Preferably, the citrus fruits include pomelo fruits, loose-skin citrus fruits or citron lemon fruits.

[0013] The present invention also provides an application of the above-mentioned measurement method in evaluating the fruit base length trait of citrus fruits.

[0014] The present invention also provides a method for evaluating the fruit base length trait of citrus fruits, including the following steps:

[0015] Measuring the fruit base length of the citrus fruit to be evaluated by using the measurement method described in the above technical solution;

[0016] When the fruit base length ≥ 3.0, it is determined that the fruit base part of the citrus fruit to be evaluated is significantly protruded, which is a long fruit base; when 2.0 ≤ fruit base length < 3.0, it is determined that there is a protrusion in the fruit base part of the citrus fruit to be evaluated, which is a short fruit base; when the fruit base length < 2.0, it is determined that there is no protrusion in the fruit base part of the citrus fruit to be evaluated, which is a fruitless base.

[0017] Preferably, the citrus fruits include pomelo fruits, loose-skin citrus fruits or citron lemon fruits.

[0018] The present invention also provides the above-mentioned measurement method or the above-mentioned evaluation method in gene mining and / or gene function verification of citrus fruits.

[0019] Beneficial effects:

[0020] The present invention provides a method for measuring the fruit base length of citrus fruits, including the following steps: measuring the measurement value of the fruit base length and the peel thickness of the citrus fruit; according to the measurement value of the fruit base length and the peel thickness, and the relational formula of the predetermined fruit base length = fruit base length measurement value / peel thickness measurement value, obtaining the fruit base length of the citrus fruit. The present invention quantifies the ratio of the fruit base length measurement value to the peel thickness measurement value as the fruit base length of the citrus fruit, which can more correctly and objectively reflect and evaluate the fruit base length of the citrus fruit, and has important value for breaking through the bottleneck of scientific research on the fruit base length of citrus fruits. Description of the drawings

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required in the embodiments.

[0022] Figure 1 It is a determination diagram of the fruit stalk length measurement value and the pericarp thickness measurement value of the pomelo fruit in Example 1;

[0023] Figure 2 It is the evaluation of the fruit stalk length (RL) of the pomelo fruit in Example 1 and the comparison result of the fruit stalk traits of the pomelo fruit;

[0024] Figure 3 It is the BSA mapping result of the candidate gene region of the fruit stalk length of the pomelo fruit by different statistical methods in Example 2. Detailed implementation manners

[0025] The present invention provides a method for determining the fruit stalk length of citrus fruits, comprising the following steps:

[0026] Measure the fruit stalk length measurement value (L) and the pericarp thickness measurement value (T) of the citrus fruit;

[0027] According to the fruit stalk length measurement value, the pericarp thickness measurement value, and a predetermined relational formula, obtain the fruit stalk length of the citrus fruit;

[0028]

[0029] In the present invention, the citrus fruits preferably include pomelo fruits, loose-skinned citrus fruits, or citron lemon fruits, and more preferably include pomelo fruits. The citrus fruits of the present invention preferably include mature and normally growing citrus fruits, and the mature and normally growing citrus fruits have the function of showing the typical appearance shape of the variety.

[0030] In the present invention, the measurement of the fruit stalk length measurement value (L) of the citrus fruit preferably includes: longitudinally cutting the citrus fruit along the middle, and measuring the vertical distance from the fruit stalk to the pulp to obtain the fruit stalk length measurement value (L).

[0031] The present invention preferably longitudinally cuts the citrus fruit along the middle to obtain a longitudinal section of the citrus fruit. The present invention preferably ensures that the longitudinal section of the citrus fruit is located in the middle of the fruit to ensure the accuracy of subsequent measurements.

[0032] After obtaining the longitudinal section of the citrus fruit, the present invention preferably measures the vertical distance from the fruit stalk to the pulp on the longitudinal section of the citrus fruit to obtain the fruit stalk length measurement value (L).

[0033] The present invention preferably measures the vertical distance from the outer peel to the pulp at the equatorial plane of the citrus fruit on the longitudinal section of the citrus fruit to obtain the measured value (T) of the peel thickness. Measuring the measured value (T) of the peel thickness at the equatorial plane of the fruit in the present invention can ensure the fixity of the measurement position to reduce the deviation caused by manual measurement.

[0034] The present invention preferably uses a vernier caliper to measure the measured value (L) of the fruit stalk length and the measured value (T) of the peel thickness to ensure the accuracy of the measurement.

[0035] Quantifying the fruit stalk length of citrus fruits by the measurement method described in the present invention can more accurately and objectively reflect the fruit stalk length of citrus fruits, and thus can correctly evaluate the fruit stalk length trait of citrus fruits.

[0036] Based on the above advantages, the present invention also provides the application of the measurement method described in the above technical solution in evaluating the fruit stalk length trait of citrus fruits.

[0037] The present invention also provides a method for evaluating the fruit stalk length trait of citrus fruits, comprising the following steps:

[0038] Measuring the fruit stalk length (RL) of the citrus fruit to be evaluated by the measurement method described in the above technical solution;

[0039] When RL≥3.0, it is determined that the fruit stalk part of the citrus fruit to be evaluated is significantly protruded, being a long fruit stalk; when 2.0≤RL<3.0, it is determined that there is a protrusion in the fruit stalk part of the citrus fruit to be evaluated, being a short fruit stalk; when RL<2.0, it is determined that there is no protrusion in the fruit stalk part of the citrus fruit to be evaluated, being a fruit stalkless.

[0040] In the present invention, the citrus fruit preferably includes pomelo fruit, loose-skin citrus fruit or citron lemon fruit, more preferably includes pomelo fruit. The step of measuring the fruit stalk length (RL) of the citrus fruit to be evaluated in the present invention is the same as the above technical solution and will not be elaborated herein.

[0041] The present invention also provides the application of the measurement method described in the above technical solution or the evaluation method described in the above technical solution in citrus fruit gene mining and / or gene function verification, further preferably including pomelo fruit gene mining and / or gene function verification, more preferably including pomelo fruit gene mining and gene function verification, and most preferably being pomelo fruit fruit stalk length gene mining and gene function verification.

[0042] In order to further illustrate the present invention, the technical solution provided by the present invention will be described in detail below with reference to the drawings and embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0043] Example 1

[0044] 1. A method for measuring the fruit base length of citrus fruits, the steps are as follows:

[0045] 1) Picking of mature pomelo fruits: Select mature and normally growing pomelo fruits for picking;

[0046] 2) Measurement of fruit base length: Cut the picked pomelo fruit longitudinally along the middle, ensure that the longitudinal section is in the middle of the fruit, and use a vernier caliper to measure the vertical distance from the fruit stalk to the pulp. The measured value is recorded as the fruit base length measurement value (L), as Figure 1 shown;

[0047] 3) Measurement of pericarp thickness: Cut the picked pomelo fruit longitudinally along the middle, ensure that the longitudinal section is in the middle of the fruit, and use a vernier caliper to measure the vertical distance from the outer pericarp to the pulp at the equatorial plate of the fruit. The measured value is recorded as the pericarp thickness measurement value (T), as Figure 1 shown;

[0048] 4) Quantitative statistical formula:

[0049] Using the above measurement method, measure the relative fruit base length value (RL), fruit base length measurement value (referred to as fruit base length in Table 1), and pericarp thickness measurement value (referred to as pericarp thickness in Table 1) of 114 pomelo fruits. The results are shown in Table 1.

[0050] Table 1 Statistical results of fruit base length traits of 114 pomelo resources

[0051]

[0052]

[0053]

[0054] As can be seen from Table 1, there are certain differences between the directly measured fruit base length and the relative fruit base length value. 2. A method for evaluating the fruit base length trait of citrus fruits, the steps are as follows:

[0055] Use the measurement method in step 1 to measure the fruit base length of 39 pomelo fruits to be evaluated. The numbers and measurement results of the 39 pomelo fruits to be evaluated are shown in Table 2; Judgment criteria: When RL≥3.0, it is determined that the fruit base part of the citrus fruit to be evaluated is significantly protruded, and it is a long fruit base; when 2.0≤RL<3.0, it is determined that there is a protrusion in the fruit base part of the citrus fruit to be evaluated, and it is a short fruit base; when RL<2.0, it is determined that there is no protrusion in the fruit base part of the citrus fruit to be evaluated, and it is a fruitless base. The measurement results are shown in Table 2;

[0056] Among them, the physical pictures of the pomelo fruits numbered 534, 43, 335, 1, 424, and 108 are as Figure 2As shown in the figure; in A, the pomelo fruits are No. 534 and No. 43, which are pomelo fruits with long fruit stalks; in B, the pomelo fruits are No. 335 and No. 1, which are pomelo fruits with medium fruit stalks; in C, the pomelo fruits are No. 424 and No. 108, which are pomelo fruits with short fruit stalks; this is consistent with the measurement results in Table 2, and further indicates that the measurement method and evaluation method in the present invention are relatively accurate and objective.

[0057] Table 2 Measurement and evaluation results of the fruit stalk length of pomelo fruits

[0058]

[0059] Example 2

[0060] In order to verify the reliability of the measurement method in Example 1, the present invention carried out the mapping of candidate gene regions for the fruit stalk length of pomelo fruits based on 115 materials of the F1 generation sexual segregation population of Guanxi pomelo × Pingtan pomelo, and the genotype data was entrusted to Novogene Co., Ltd. in Beijing for determination;

[0061] The phenotypic data was statistically analyzed in three ways, which are as follows:

[0062] Group A: The absolute value of the fruit stalk length of pomelo fruits was directly measured according to the method in step 1) of Example 1, and this was used as the phenotypic data of the fruit stalk length of pomelo fruits;

[0063] Group B: According to the methods in steps 1) and 2) of Example 1, the absolute value of the fruit stalk length and the peel thickness of pomelo fruits were measured respectively, and the value of the absolute fruit stalk length - peel thickness was obtained, and this was used as the phenotypic data of the fruit stalk length of pomelo fruits;

[0064] Group C: The relative value RL of the fruit stalk length obtained according to the measurement method in step 1 of Example 1 was used as the phenotypic data of the fruit stalk length of pomelo fruits.

[0065] The phenotypic data of groups A to C were respectively subjected to BSA analysis with the genotype data to map the candidate gene regions. The BSA results of the three statistical methods for the fruit stalk length of pomelo fruits are as Figure 3 shown, where Figure 3 A, B, and C in it respectively correspond to the BSA mapping results obtained using the phenotypic data of group A, group B, and group C.

[0066] It can be obtained from Figure 3 that: Group A shows an obvious peak on chromosome 3 (chr3) (ΔSNP > 0.4), group B does not show an obvious peak, and group C shows an obvious peak on chromosome 1 (chr1) (ΔSNP > 0.4).

[0067] By comprehensively analyzing the candidate segment genes of Group A and Group C using more than 40 sexually segregating population offspring and more than 50 natural population genome re-sequencings, it was found that there were no linked variations in the genes within the candidate gene segment of Group A, while there were linked variations in the genes within the candidate segment of Group C. Combining with the transcriptome data of fruit base development, the present invention locked the key candidate genes for pomelo fruit base development within Group C.

[0068] From the results in Example 2, it can be concluded that the fruit base length trait obtained by using the pomelo fruit base length measurement method in Example 1 is more accurate and objective, can better reflect the fruit base length of pomelo fruits, and has high value for gene mining and mapping research on the fruit base length of pomelo fruits.

[0069] From the above examples, it can be concluded that the measurement method and evaluation method for the fruit base length of citrus fruits described in the present invention are more accurate and objective, and can assist in the basic research of citrus fruits.

[0070] Although the above embodiments have described the present invention in detail, they are only a part of the embodiments of the present invention, not all embodiments. People can also obtain other embodiments without creative efforts based on these embodiments, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for determining the relative value of the fruit stalk length of citrus fruits, comprising the following steps: Measure the fruit stalk length measurement value and the peel thickness measurement value of citrus fruits; Obtain the relative value of the fruit stalk length of citrus fruits according to the fruit stalk length measurement value, the peel thickness measurement value, and a predetermined fruit stalk length relationship formula; 。 2. The measurement method according to claim 1, characterized in that, The measurement of the fruit stalk length measurement value of citrus fruits includes: longitudinally cutting the citrus fruit along the middle, and measuring the vertical distance from the fruit stalk to the pulp to obtain the fruit stalk length measurement value.

3. The measurement method according to claim 1, characterized in that The measurement of the peel thickness measurement value of citrus fruits includes: longitudinally cutting the citrus fruit along the middle, and measuring the vertical distance from the outer peel at the equatorial plate of the fruit to the pulp to obtain the peel thickness measurement value.

4. The measurement method according to any one of claims 1 to 3, characterized in that, The citrus fruits include pomelo fruits, loose-skin citrus fruits or citron lemon fruits.

5. The application of the determination method according to any one of claims 1 to 4 in evaluating the fruit stalk length trait of citrus fruits.

6. A method for evaluating the fruit stalk length trait of citrus fruits, comprising the following steps: using the determination method according to any one of claims 1 to 4 to measure the relative value of the fruit stalk length of the citrus fruits to be evaluated; When the relative value of the fruit stalk length ≥ 3.0, it is determined that the fruit stalk part of the citrus fruit to be evaluated is significantly protruded, and it is a long fruit stalk; when 2.0 ≤ the relative value of the fruit stalk length < 3.0, it is determined that there is a protrusion in the fruit stalk part of the citrus fruit to be evaluated, and it is a short fruit stalk; when the relative value of the fruit stalk length < 2.0, it is determined that there is no protrusion in the fruit stalk part of the citrus fruit to be evaluated, and it is a fruit stalkless.

7. The evaluation method according to claim 6, wherein The citrus fruits include pomelo fruits, loose-skin citrus fruits or citron lemon fruits.

8. The application of the determination method according to any one of claims 1 to 3 or the evaluation method according to claim 6 or 7 in gene mining and / or gene function verification of citrus fruits.

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