Method for efficiently screening waterlogging-resistant cassava germplasm

Abstract

The invention discloses a method for efficiently screening waterlogging-resistant cassava germplasm, and belongs to the technical field of cassava germplasm screening. The method comprises the following steps: S1, selecting mature and healthy cassava seed stems which are free of plant diseases and insect pests and have the same specification, uniformly cutting the cassava seed stems into sections, respectively planting the sections of cassava seed stems in different observation pots 1, and performing open-air management; s2, when the cassava seedlings are higher than 40cm, selecting the cassava seedlings with similar heights and immersing the cassava seedlings in water together with the observation pot 1; s3, soaking the cassava in an observation basin 1 for 7-20 days, and observing and recording changes of leaves and tuberous roots of each group of cassava; and S4, when the test is finished, selecting the screened waterlogging-resistant cassava germplasm with most of green leaves and non-rotten tuberous roots as the germplasm of the waterlogging-resistant cassava. According to the method, two batches of cassava seedlings are planted at the interval of three months, when a soaking test is carried out, waterlogging-resistant planting in different growth stages such as a cassava root forming stage and a mature stage can be screened at the same time, the screening period is shortened, and the efficiency is improved. The inner pot is arranged in the outer pot, and the soaking water change of the root tuber can be observed through the mesh holes and the observation holes, so that more comprehensive and accurate data can be obtained.

Description

Technical Field

[0001] The present invention belongs to the technical field of cassava germplasm screening, and particularly relates to a method for efficiently screening waterlogging-tolerant cassava germplasm. Background Art

[0002] Cassava is a plant of the Euphorbiaceae family and the Manihot genus, also known as tapioca and tree potato. It is one of the three major tuber crops in the world and is distributed between 30° north and south latitudes. It has now been widely cultivated in more than 100 countries or regions in Africa, Asia, and the Americas, becoming an important tropical crop for solving hunger and providing the necessary heat energy source and basic living guarantee for 1 billion people. Currently, the cultivated area of cassava in China is about 290,000 hectares, mainly distributed in tropical and subtropical regions such as Guangxi, Guangdong, Yunnan, and Hainan, and is mainly used for starch and alcohol production.

[0003] Due to the characteristics of heavy rainfall and long rainy seasons in tropical and subtropical regions, after cassava tuber formation, it is extremely easy for the root tubers to rot due to blocked respiration caused by excessive soaking time, which has become one of the main reasons for cassava yield reduction. Screening waterlogging-tolerant germplasm, obtaining the quality that cassava root tubers will not rot even when soaked for a relatively long time, and promoting its cultivation, play an important role in increasing the yield of cassava.

[0004] Screening waterlogging-tolerant cassava germplasm is one of the methods to obtain waterlogging-tolerant cassava varieties. During screening, multiple groups of potted cassavas are soaked in a container filled with water, and the changes in cassava leaves and root tubers after soaking are observed and recorded every day. Since the cassava root tubers are planted in pots, when observing the root tubers, the pot needs to be taken out of the water first, and then some of the soil in the pot needs to be dug out to observe the rot situation of the cassava root tubers. For those that can continue the soaking test, continue the soaking test, and pick up the pot again when observing the root tubers next time, and repeat the above operation to observe the rot situation of the root tubers. Since it is necessary to observe 1 - 2 times every day during the test period, the above operations need to be repeated repeatedly.

[0005] Therefore, during the screening test, the following operations need to be repeated repeatedly: soaking the cassava seedlings, taking the pot out of the water, digging out the soil to observe the rot situation of the root tubers, soaking the cassava again, taking it out of the water again to observe, etc. There are problems of many and cumbersome operation steps. Moreover, when observing the root tubers, the soil may block the view and the observation may not be comprehensive. Digging the soil is likely to cut the cassava root tubers, and the root hairs may cause or accelerate their rot, resulting in inaccurate data. Summary of the Invention

[0006] The present invention provides a method for efficiently screening waterlogging-tolerant cassava germplasm to solve the above technical problems.

[0007] To solve the above technical problems, the present invention adopts the following technical solutions:

[0008] A method for efficiently screening waterlogging-tolerant cassava germplasm includes:

[0009] S1. Select mature, healthy, pest- and disease-free cassava stem cuttings of the same size, cut them into uniform segments, and plant each segment of cassava seedlings in different observation pots respectively, and manage them outdoors.

[0010] S2. When the cassava seedlings are over 40 cm tall, select cassava seedlings of similar height together with the observation pots and immerse them in water.

[0011] S3. Immerse the observation pots for 7 - 20 days, and observe and record the changes in the leaves and tuberous roots of each group of cassava.

[0012] S4. At the end of the experiment, the cassava germplasms with most leaves still green and no rotted tuberous roots are the selected waterlogging-tolerant cassava germplasms.

[0013] In step S1, in addition to using soil in the observation pots, peat soil is also added; the weight ratio of soil to peat soil is 3:1.

[0014] In step S1, the length of the cut cassava seedlings is 18 - 23 cm.

[0015] In step S2, when the observation pots are immersed in water, the height of the water submerging the soil is 1.5 - 2.5 cm.

[0016] Further, the cassava seedlings are planted in two batches with a time interval between the two batches; when the later batch of cassava seedlings are over 40 cm tall, the cassava seedlings of similar height in the two batches together with the observation pots are put into water.

[0017] Further, the time interval between the plantings of the two batches of cassava seedlings is 3 months.

[0018] Further, the observation pot includes an inner pot and an outer pot; the inner pot is arranged inside the outer pot, and its outer side contacts with the inner side of the outer pot; during the waterlogging tolerance test, the inner pot can be lifted out of the water surface according to the observation needs to observe the changes in the tuberous roots after being immersed in water.

[0019] Further, the inner pot includes side plates, and a number of mesh holes are distributed on the side plates.

[0020] Further, the inner pot further includes: an upper ring arranged at the top of the inner pot; a lower ring arranged at the bottom of the inner pot; an observation area arranged on the side surface of the side plate, and the aperture of the observation hole opened on the observation area is larger than the aperture of the mesh hole; the upper and lower ends of the side plate are respectively movably connected to the upper ring and the lower ring, so that when the side plate rotates horizontally relative to the upper ring and the lower ring, the position of the observation area can be adjusted.

[0021] Further, the usage method of the inner pot is as follows:

[0022] S5, placing the inner pot inside the outer pot, and then planting the cassava seedlings in different inner pots respectively, and managing them in the open air;

[0023] S6. When the cassava seedlings grow to a suitable height, the observation basin is placed in water and soaked for 7-20 days, and the height of the water submerging the soil is 1.5-2.5 cm;

[0024] S7, when observing the waterlogging resistance of each group of cassava seedlings, the inner basin is lifted out of the water surface to observe the rot of the cassava tubers therein, and the side plate can be rotated to rotate horizontally along the upper ring and the lower ring, so that the observation area corresponds to different positions of the inner basin to observe the rot of the cassava tubers in the area;

[0025] S8. After each observation and recording is completed, the inner basin is placed into the outer basin to continue soaking.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. The present invention arranges two batches of cassava seedlings, and the planting time interval of the two batches is 3 months. In this way, when the observation basin is soaked in water, the changes of cassava tubers during soaking in water at different growth stages such as the tuber formation stage and the maturity stage can be observed at the same time, thereby shortening the screening period of waterlogging-resistant cassava planting and improving efficiency.

[0028] 2. The observation pot is divided into an inner pot and an outer pot. When in use, the inner pot is placed inside the outer pot, and the mesh holes arranged around the inner pot can be used to observe the changes in the water soaking of the tubers in the pot, thus avoiding the existing screening method that requires digging out the soil in the pot to observe the tubers, and the situation that some tubers at the bottom of the pot are difficult to observe, so that the data obtained are more comprehensive and accurate, and the observation is more intuitive and quick.

[0029] 2. The side panels of the inner pot can rotate along the lower ring and the upper ring, so that the position of the observation area can be adjusted according to actual needs. By digging up the nearby soil through the observation hole, the changes in the root tubers in different areas after soaking in water can be observed, which can better understand whether the root tubers are rotten and the degree of rot, so as to obtain more accurate screening data. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0031] Figure 1 It is a longitudinal cross-sectional view of the present invention.

[0032] Figure 2 It is a schematic structural diagram of the inner basin.

[0033] Figure 3 It is a top view of the present invention.

[0034] Reference numerals: 1 - observation basin, 2 - inner basin, 21 - side plate, 22 - mesh hole, 23 - upper ring, 24 - lower ring, 25 - observation area, 26 - observation hole, 3 - outer basin. Specific embodiments

[0035] For better understanding of the present invention, it is illustrated by the following examples in conjunction with the accompanying drawings. These examples belong to the protection scope of the present invention, but do not limit the protection scope of the present invention.

[0036] Example

[0037] A method for efficiently screening waterlogging - tolerant cassava germplasms, comprising:

[0038] S1. Select mature, healthy, pest - and - disease - free cassava seed stems with the same stem specifications, cut them into uniform segments, and then plant each segment of cassava seedlings in different observation basins 1 respectively, and manage them in the open air;

[0039] S2. When the cassava seedlings are over 40 cm tall, select cassava seedlings with similar heights together with the observation basins 1 and immerse them in water;

[0040] S3. Immerse the observation basins 1 in water for 10 d, and respectively observe and record the changes in the leaves and tuberous roots of each group of cassava;

[0041] S4. At the end of the experiment, those with most leaves still being green and tuberous roots without rot are the screened waterlogging - tolerant cassava germplasms.

[0042] In step S1, in addition to using soil in the observation basin 1, peat soil is also added; the weight ratio of soil to peat soil is 3:1.

[0043] In step S1, the length of the cut cassava seed stems is 20 cm.

[0044] In step S2, when the observation basin 1 is immersed in water, the height of the water submerging the soil is 2 cm.

[0045] The cassava seedlings are planted in two batches with a time interval between the two batches; when the later - batch cassava seedlings are over 40 cm tall, the cassava seedlings with similar heights in the two batches together with the observation basins 1 are put into the water.

[0046] The time interval between the plantings of the two batches of cassava seedlings is 3 months.

[0047] A gauze can be placed at the bottom of the observation basin to prevent the cassava roots from extending out of the holes at the bottom of the basin.

[0048] When soaking in water, it is necessary to ensure that the water surface is at a certain height to ensure that all the soil is submerged by water. At this time, the respiration of the cassava tuberous roots will be blocked, ensuring the smooth progress of the experiment.

[0049] Cassava is planted in different batches, so that when conducting the water soaking experiment, the growth states of cassava in different batches are different. For example, in this batch of cassava, the tuberous roots may start to form, while in another batch, the tuberous roots may start to mature, etc. By using different batches of cassava to conduct the water soaking experiment simultaneously, not only can the change data of leaves and tuberous roots during the water soaking experiment under different growth conditions be obtained, but also the growth conditions of different batches of cassava are different, and their abilities to cope with water soaking are also different, which helps to screen out waterlogging-tolerant cassava germplasms. Compared with the existing screening method that uses the same batch of cassava with the same growth state for the water soaking experiment, it can shorten the experiment time and improve the efficiency.

[0050] As Figures 1 - 3 shown, the observation pot 1 includes an inner pot 2 and an outer pot 3; the inner pot 2 is arranged inside the outer pot 3, and its outer side contacts the inner side of the outer pot 3; during the waterlogging tolerance experiment, the inner pot 2 can be lifted out of the water surface according to the observation needs to observe the changes of the tuberous roots after immersion in water.

[0051] As Figures 1 - 3 shown, the inner pot 2 includes side plates 21, and a number of mesh holes 22 are distributed on the side plates 21.

[0052] As Figures 1 - 3 shown, the inner pot 2 further includes: an upper ring 23 arranged at the top of the inner pot 2; a lower ring 24 arranged at the bottom of the inner pot 2; an observation area 25 arranged on the side surface of the side plate 21, and the aperture of the observation hole 26 opened on the observation area 25 is larger than the aperture of the mesh hole 22; the upper and lower ends of the side plate 21 are respectively movably connected to the upper ring 23 and the lower ring 24, so that when the side plate 21 rotates horizontally relative to the upper ring 23 and the lower ring 24, the position of the observation area 25 can be adjusted.

[0053] The screening of waterlogging-tolerant cassava germplasms requires a long-term water soaking experiment, and the existing experiment for planting cassava uses conventional flower pots. When observing and recording, the leaves on the rhizome can be directly observed for whether they turn yellow or fall off, but the tuberous roots buried in the soil are not easy to observe and need to dig out the soil to see. And the cassava water soaking experiment lasts for at least 7 days, and it is observed 1-2 times a day. In this way, it is necessary to repeatedly pick up the pot from the water and then dig out the soil to observe whether the tuberous roots are rotten and the degree of rot, resulting in cumbersome operation and low efficiency. By dividing the observation pot into an inner pot and an outer pot, during observation, the inner pot can be lifted out of the water, and the situation of the tuberous roots inside can be directly observed through the mesh holes or observation holes, greatly improving the convenience of the experiment and making the operation more convenient.

[0054] Combined with Figures 1 - 3 shown, the usage method of the inner pot 2 is as follows:

[0055] S5. Place the inner pot into the outer pot, and then plant the cassava seedlings in different inner pots respectively, and manage them outdoors;

[0056] S6. When the cassava seedlings grow to an appropriate height, immerse the observation pot 1 in water for 7 - 20 days, and the height of the water submerging the soil is 2 cm;

[0057] S7. When observing the waterlogging tolerance of each group of cassava seedlings, lift the inner pot 2 out of the water surface, and observe the rot situation of the cassava tuberous roots therein. The side plate 21 can be rotated to rotate horizontally along the upper ring 23 and the lower ring 24, so that the observation area 25 corresponds to different positions of the inner pot 2 to observe the rot situation of the cassava tuberous roots in this area;

[0058] S8. After each observation and record, put the inner pot 2 back into the outer pot 3 and continue to soak.

[0059] During the water immersion test of cassava, the side plate can rotate horizontally relative to the upper ring and the lower ring, so that the position of the observation area can be adjusted, which is convenient for observing the changes of cassava tuberous roots in different areas after soaking through the observation holes with larger apertures; during the test, only lift the inner pot out of the water surface, the operation is simple and easy to observe; after the observation, put the inner pot back into the outer pot to continue the water immersion test until the test time is completed or the target waterlogging - tolerant cassava germplasm is screened out.

[0060] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non - exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising a..." does not exclude the existence of additional identical elements in the process, method, article or device comprising the said element.

[0061] The above are only the preferred embodiments of the present invention, and are not used to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for efficiently screening waterlogging-resistant cassava germplasm, characterized in that: include: S1, selecting mature, healthy, disease-free and insect-free cassava stems of the same stem size, cutting them into even sections, and then planting each section of the cassava stem in different observation pots (1) for outdoor management; S2. When the cassava seedlings are more than 40 cm tall, select cassava seedlings of similar height and immerse them in water together with the observation basin (1); S3, soak the observation pot (1) for 7-20 days, and observe and record the changes of the leaves and tubers of cassava in each group; S4. At the end of the experiment, most of the leaves are still green and the tubers are not rotten, which is the selected waterlogging-resistant cassava germplasm.

2. The method for efficiently screening waterlogging-resistant cassava germplasm according to claim 1, characterized in that, In step S1, in addition to soil, peat soil was also added to the observation pot (1); the weight ratio of soil to peat soil was 3:

1.

3. The method for efficiently screening waterlogging-resistant cassava germplasm according to claim 2, characterized in that, In step S1, the length of the cassava seedlings cut into segments is 18-23 cm.

4. The method for efficiently screening waterlogging-resistant cassava germplasm according to claim 3, characterized in that, In step S2, when the basin (1) is immersed in water, the height of the water covering the soil is 1.5-2.5 cm.

5. The method for efficiently screening waterlogging-resistant cassava germplasm according to claim 4, characterized in that, The cassava seedlings are planted in two batches with a time interval between the two batches; when the height of the latter batch of cassava seedlings is above 40 cm, the cassava seedlings of similar height in the two batches are placed in water together with the observation basin (1).

6. The method for efficiently screening waterlogging-resistant cassava germplasm according to claim 5, characterized in that, The planting time interval between two batches of cassava seedlings was 3 months.

7. The method for efficiently screening waterlogging-resistant cassava germplasm according to any one of claims 1 to 6, characterized in that: The observation basin (1) comprises an inner basin (2) and an outer basin (3); The inner basin (2) is arranged inside the outer basin (3), and the outer side surface is in contact with the inner side surface of the outer basin (3); During the waterlogging resistance test, the inner pot (2) can be lifted out of the water surface according to observation needs to observe changes in the tuberous roots after being immersed in water.

8. The method for efficiently screening waterlogging-resistant cassava germplasm according to claim 7, characterized in that: The inner basin (2) comprises a side plate (21), and a plurality of mesh holes (22) are distributed on the side plate (21).

9. The method for efficiently screening waterlogging-resistant cassava germplasm according to claim 8, characterized in that, The inner basin (2) also includes: An upper ring (23) is arranged on the top of the inner basin (2); A lower ring (24) is arranged at the bottom of the inner basin (2); An observation area (25) is provided on the side of the side plate (21), and the diameter of the observation hole (26) provided on the observation area (25) is larger than the diameter of the mesh hole (22); The upper and lower ends of the side plate (21) are movably connected to the upper ring (23) and the lower ring (24) respectively, so that when the side plate (21) is horizontally rotated relative to the upper ring (23) and the lower ring (24), the position of the observation area (25) can be adjusted.

10. The method for efficiently screening waterlogging-resistant cassava germplasm according to claim 9, characterized in that: The method of using the inner basin (2) is as follows: S5, placing the inner pot inside the outer pot, and then planting the cassava seedlings in different inner pots respectively, and managing them in the open air; S6. When the cassava seedlings grow to a suitable height, the observation basin (1) is placed in water and soaked for 7-20 days, with the height of the water covering the soil being 1.5-2.5 cm; S7, when observing the waterlogging resistance of each group of cassava seedlings, the inner basin (2) is lifted out of the water surface to observe the rotting of the cassava tubers therein, and the side plate (21) can be rotated to rotate horizontally along the upper ring (23) and the lower ring (24), so that the observation area (25) corresponds to different positions of the inner basin (2) to observe the rotting of the cassava tubers in the area; S8. After each observation and recording is completed, the inner basin (2) is placed into the outer basin (3) to continue soaking.

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