Test matching method in hybrid japonica rice breeding process

Abstract

The invention discloses a test mating method in a hybrid japonica rice breeding process. The test mating method comprises the steps of rice sterile line plant selection, rice sterile line panicle treatment, rice sterile line glumous flower treatment, rice restorer line panicle treatment and rice restorer line pollination hybridization. Aiming at the problems of late flowering time, low stigma exsertion rate and the like of the japonica rice sterile line, the physiological characteristics of long activity time of pistil of rice, low-temperature delay of flowering of rice and the like are utilized to postpone the test-mating pollination time and improve the test-mating hybridization setting rate, so that the test-mating efficiency and quality in breeding work can be greatly improved, the test-mating work intensity can be greatly reduced, and the breeding cost is reduced. Therefore, the breeding speed of a new variety of hybrid japonica rice is improved.

Description

Technical Field

[0001] The invention relates to the technical field of hybrid matching methods, and in particular to a matching method in the hybrid japonica rice breeding process. Background Art

[0002] The breeding of new japonica hybrid rice varieties requires a lot of testing and pairing work between sterile lines and restorer lines. Figure 1-3 As shown, the technical steps of the currently used measurement and matching method are as follows:

[0003] 1. Treatment of the mother plant: First, remove the opened spikelets of the entire sterile line, then cut off the unopened spikelets, and then remove the leaves above the ear.

[0004] 2. Treatment of the male parent: First, dig out the selected male parent with soil and transplant it next to the female parent, then remove the leaves below the ear that affect pollen scattering.

[0005] 3. Adjustment of posture: In order to ensure that the female plant is lower than the male plant to receive pollen, during the transplanting of the male plant, choose to raise it or dig deep to lower the height according to the height of the parent plants.

[0006] 4. Pollination: Use a large paper bag to put the parent plants together. In the following week, every day when the rice blooms, manually knock the pollen to drive out the pollen.

[0007] 5. To harvest, you need to cut off all the sterile rice ears and then pick out the strong grains.

[0008] The above-mentioned matching method has the following disadvantages:

[0009] The traditional method of matching requires the entire male parent to be leaf-cut and the entire female parent to be trimmed and trimmed, which is a huge workload. Therefore, a single person can only match 20 hybrid rice combinations per day at most. At the same time, each male parent can weigh up to 5 kilograms, and the work of transplanting and transporting the male parents is also extremely heavy.

[0010] Traditional matching methods are used because the hybrid rice parents are sterile during flowering, and the sterile lines have low fruit set rates. The daily flowering time of the japonica rice sterile lines is later than that of the restorer lines. When the sterile lines bloom in large quantities, only a small amount of pollen remains in the restorer lines, and the sterile lines have low fruit set rates.

[0011] In the traditional matching method, the entire parent plant is placed in an isolation bag. The space inside the paper bag is small, the air is not circulated, and the humidity is high, which is not conducive to the dispersion of pollen and the later filling.

[0012] Therefore, a test and matching method in the hybrid japonica rice breeding process was proposed to address the above problems. Summary of the invention

[0013] The object of the present invention is to provide a method for testing and matching in the process of hybrid japonica rice breeding, the testing and matching steps comprising:

[0014] Step 1: Selection of sterile rice plants: Selecting sterile rice plants with more than 50% heading and identifying their fertility;

[0015] Step 2: Treatment of sterile rice panicles: After selecting sterile rice plants, bag them in the morning before the rice flowers and pollinates. Select the panicles that have not bloomed or have bloomed very little, and cut off all the bloomed spikelets. Use a self-pollination bag with one end sealed to bag the panicles, mark the bagging date, and fix the self-pollination bag on the second leaf with a paper clip;

[0016] Step 3: Treatment of spikelets of sterile rice lines: 3-4 days after bagging, when more than 50% of the spikelets in the rice ears in the bag have bloomed, remove the selfing bag and cut the spikelets. Cut the spikelets in the morning before the rice blooms or in the afternoon after the rice blooms and sheds pollen. Cut off half of the husks of all spikelets at the flat ends, and put a kraft paper hybrid bag with unsealed ends on the cut spikelets. Put 1-2 spikes in each hybrid bag, adjust the height of the rice ears in the hybrid bag, fix the hybrid bag with a stapler, and fold the upper mouth of the hybrid bag to prevent contamination by foreign pollen before pollination;

[0017] Step 4: Treatment of rice restorer lines: Take the rice ears from 1-2 hours before flowering on the day of pollination to when the restorer lines bloom a little. Select the rice ears whose spikelets have bloomed 1 / 3-2 / 3. Take 1-2 ears and cut them at the second stem node. Cut off the spikelets that have bloomed on the upper part of the rice ears. Wet the rice ears with water, and then beat them on clothes and boots to remove excess water, so that the rice ears remain moist and fluffy. Put the rice ears in unsealed kraft paper bags with restorer line information marked in advance at both ends. Each group of 20 paper bags is tied with rubber bands, leaving 5-10 cm of stems outside the paper bags, cutting off the excess parts, trimming the lower ends of the remaining stems neatly, and placing the bundles of rice ears with stems facing down in a covered bucket for hydroponics. The water depth is 3-5 cm, and the bucket is more than 60 cm high. The bucket is placed in a shaded and windproof place;

[0018] Step 5: Hybridization pollination: Start pollination after the peak flowering period of the sterile rice line on the same day, take out the rice ears of the restorer line from the covered bucket, put them in an apron or bucket, handle them with care, try to avoid shaking and wind to prevent pollen from flying, take the rice ears of the restorer line to pollinate the sterile line in sequence, the restorer line spikelets open, the anthers extend out, the anthers turn white after pollination, and pollen can be seen floating in the self-pollination bag in the form of smoke, which means the pollination is successful. After pollination is successful, bend the upper mouth of the hybridization bag and then fix it with a stapler.

[0019] Preferably, the identification of the fertility of the rice plants includes: identification of anther size, where the anthers of sterile plants are thin and small, and the anthers of fertile plants are fat and large;

[0020] Identification of anther color: the anthers of sterile plants are yellow, light yellow or colorless, and in a water-soaked state; the anthers of fertile plants are yellow before they shed pollen after flowering, and turn white after they shed pollen.

[0021] Regarding the anther shape, the anthers of sterile plants remained in the shape of thin rods, while the anthers of fertile plants had broken tips and were in the shape of empty bags.

[0022] Preferably, in the step 2, in order to ensure the continuity of the subsequent testing and matching work, a large number of self-pollination bags are required, and in order to distinguish different bagging dates, self-pollination bags of various colors can be prepared.

[0023] Preferably, in step three, the planned hybrid combination needs to be written on the hybrid bag, and the matching plan, male parent area code, and pollination date information need to be noted on the hybrid bag, which should be clear and easy to identify.

[0024] Preferably, during pollination in step 5, if the pollen state of the restorer line is not good, immediately return to the male parent plot to re-pollinate or postpone the time of re-pollinating the ears the next day, and re-pollinate each bag of sterile lines. It is sufficient to successfully pollinate once.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The new method of the present invention does not require panicle pruning for both parents. For each combination, only 1-2 panicles of the female parent need to be cut, which saves a lot of workload and time. Pollination by shaking pollination no longer requires transplanting the male parent, which greatly reduces heavy physical labor. In addition, the new method can assemble an average of 60 hybrid rice combinations per day by one person, compared with a maximum of 20 hybrid rice combinations per day by the traditional method, thereby improving efficiency, which is 3 times the efficiency of the traditional method.

[0027] The present invention places the restorer line plants in a cool place for hydroponics, which will delay the flowering time of the restorer line. At the same time, the restorer line rice ears are sealed and stored in paper bags. The rice pollen will not be scattered but will be stored in the pollen sac. The pollen has a longer life after flowering, and pollination can be carried out after the sterile line blooms. Compared with the traditional matching method, the sterile line has a high fruit setting rate, it is easy to obtain sufficient hybrid grains, and the work efficiency is high.

[0028] There are only two female parent ears in the hybrid bag of the present invention, and air can circulate at the upper and lower openings of the hybrid bag. Compared with the traditional matching method in which the parent plants are completely covered in an isolation bag, the space in the paper bag is small, the air is not circulated, and the humidity is high, which is not conducive to the dispersion of pollen and the later filling. The present method provides excellent environmental conditions for the stigma to accept pollen and the later filling.

[0029] The invention can greatly improve the testing and matching efficiency and quality in breeding work, and can greatly reduce the testing and matching work intensity, thereby increasing the breeding speed of new hybrid japonica rice varieties. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of plant pruning using the traditional test matching method;

[0031] Figure 2 It is a schematic diagram of the pollination posture adjustment of the traditional test matching method;

[0032] Figure 3 It is a schematic diagram of bagging in the traditional test and matching method;

[0033] Figure 4 This is a schematic diagram of the self-pollination bag-encased ear of the present invention;

[0034] Figure 5 It is a schematic diagram of a hybridization bag of the present invention;

[0035] Figure 6 is a schematic diagram of pollination of the present invention;

[0036] Figure 7 is a schematic diagram of a large number of hybridization experiments of the present invention;

[0037] Figure 8 It is a schematic diagram of the hybrid rice seed of the present invention. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] The present invention provides a method for testing and matching in a hybrid japonica rice breeding process, wherein the testing and matching step comprises:

[0040] Step 1: Selection of sterile rice plants: Selecting sterile rice plants with more than 50% heading and identifying their fertility;

[0041] Step 2: As attached Figure 4 As shown, rice sterile line panicle treatment: after selecting rice sterile plants, bagging is carried out in the morning before rice blooms and pollination, and the panicles that have not bloomed or have bloomed very little are selected. All the bloomed spikelets are cut off, and a self-pollination bag with one end sealed is used to bag the panicles, and the bagging date is marked. The self-pollination bag is fixed on the second leaf with a paper clip. In order to ensure the continuity of subsequent measurement and matching work, a large number of self-pollination bags are needed. In order to distinguish different bagging dates, self-pollination bags of various colors can be prepared;

[0042] Step 3: Treatment of spikelets of sterile rice lines: 3-4 days after bagging, when more than 50% of the spikelets in the bag have bloomed, remove the selfing bag and cut the spikelets. Cut the spikelets in the morning before the rice blooms or in the afternoon after the rice blooms and sheds pollen. Cut all the spikelets flat and remove half of the husk. Figure 5As shown, put the unsealed kraft paper hybridization bag on the cut ear of rice, cover 1-2 ears in each hybridization bag, adjust the height of the rice ear in the hybridization bag, fix the hybridization bag with a stapler, fold the upper mouth of the hybridization bag to prevent foreign pollen contamination before pollination, write the planned hybrid combination on the hybridization bag, and indicate the test and matching plan, restorer area code, and pollination date information on the hybridization bag, which should be clear and easy to identify;

[0043] Step 4: Treatment of rice restorer lines: Take the ears from 1-2 hours before flowering on the day of pollination to when the restorer lines bloom a little, select the ears of rice whose spikelets have bloomed 1 / 3-2 / 3, take 1-2 ears and cut them at the second stem node, cut off the spikelets that have bloomed on the upper part of the rice ears, wet the rice ears with water, and then beat them on clothes and boots to remove excess water, so that the rice ears remain moist and fluffy, put the rice ears in unsealed kraft paper bags at both ends marked with restorer line information in advance, and tie them with rubber bands for every 20 paper bags, leaving 5-10 cm of stems outside the paper bags, cutting off the excess parts, trimming the lower ends of the remaining stems neatly, and placing the stems of the bundled rice ears downward in a covered bucket for hydroponics, with a water depth of 3-5 cm and a bucket height of more than 60 cm, and placing the bucket in a shaded and windproof place;

[0044] Step 5: As attached Figure 6 As shown, hybrid pollination: start pollination after the peak flowering period of the sterile rice line on the same day, take out the rice ears of the restorer line from the covered bucket, put them in an apron or bucket, handle them with care, try to avoid shaking and wind blowing to prevent pollen from flying, take the rice ears of the restorer line in sequence to pollinate the sterile line, the restorer line spikelets open, the anthers extend out, and the anthers turn white after pollination. Pollen can be seen floating in the form of smoke in the self-pollination bag, which means the pollination is successful. After successful pollination, bend the upper mouth of the hybrid bag and then fix it with a stapler. During pollination, if the pollen state of the restorer line is not good, immediately return to the male parent plot to re-take the ears for pollination or postpone the time of taking the ears the next day and re-take the ears for pollination. Each bag of sterile line can be successfully pollinated once.

[0045] As attached Figure 7 As shown, a large number of hybridization experiments can be performed using the matching method of the present invention;

[0046] As attached Figure 8 As shown, a large number of grains can be obtained with 1-2 ears using the matching method of the present invention.

[0047] Specifically, the identification of the fertility of the rice plants includes: identification of anther size, where the anthers of sterile plants are thin and small, and the anthers of fertile plants are fat and large;

[0048] Identification of anther color: the anthers of sterile plants are yellow, light yellow or colorless, and in a water-soaked state; the anthers of fertile plants are yellow before they shed pollen after flowering, and turn white after they shed pollen.

[0049] Regarding the anther shape, the anthers of sterile plants remained in the shape of thin rods, while the anthers of fertile plants had broken tips and were in the shape of empty bags.

[0050] In the traditional method of matching, the workload is huge, because the male parent needs to be pruned of leaves and the female parent needs to be pruned of ears and glumes, so a single person can only match 20 hybrid rice combinations per day at most. At the same time, each male parent weighs up to 5 kilograms, and the work of transplanting and transporting the male parents is also extremely heavy. However, the new method no longer requires the pruning of ears for both parents, and only 1-2 ears of the female parent need to be pruned for each combination, which saves a lot of workload and time. The use of shaking pollination no longer requires the transplanting of male parents, which greatly reduces heavy physical labor. The new method can match an average of 60 hybrid rice combinations per day by a single person, which is three times more efficient than the traditional method.

[0051] The traditional matching method has a low fruit set rate due to the sterility of the hybrid rice parents during flowering. The sterile japonica rice blooms later than the restorer line every day. When the sterile line blooms in large quantities, only a small amount of pollen is left in the restorer line, and the sterile line has a low fruit set rate. The new method places the restorer line in a cool place for hydroponics, which will delay the flowering time of the restorer line. At the same time, the rice ears of the restorer line are sealed in paper bags. The rice pollen will not scatter but be preserved in the pollen sacs. The pollen has a longer lifespan after flowering, and pollination can wait until the sterile line blooms. The sterile line has a high fruit set rate. The new method can easily obtain sufficient hybrid grains and has high work efficiency.

[0052] Due to the use of shaking pollination, there is no need to consider the problem of poor pollination posture caused by differences in plant height. In the traditional matching method, the parent plants are completely covered in an isolation bag. The space in the paper bag is small, the air is not circulated, and the humidity is high, which is not conducive to the dispersion of pollen and later filling. However, in the new method, there are only two female ears in the hybrid bag, and air can circulate at the upper and lower openings of the hybrid bag, providing excellent environmental conditions for the stigma to accept pollen and later filling.

[0053] In summary, the new method can greatly improve the efficiency and quality of testing and matching in breeding work, and can significantly reduce the intensity of testing and matching work, thereby increasing the speed of breeding new hybrid japonica rice varieties.

[0054] Utilizing the technical solution described in the present invention, or those skilled in the art designing a similar technical solution inspired by the technical solution of the present invention to achieve the above-mentioned technical effects, all fall within the protection scope of the present invention.

Claims

1. A method for testing and matching in the process of hybrid japonica rice breeding, characterized in that: The matching steps include: Step 1: Selection of sterile rice plants: Selecting sterile rice plants with more than 50% heading and identifying their fertility; Step 2: Treatment of sterile rice panicles: After selecting sterile rice plants, bag them in the morning before the rice flowers and pollinates. Select the panicles that have not bloomed or have bloomed very little, and cut off all the bloomed spikelets. Use a self-pollination bag with one end sealed to bag the panicles, mark the bagging date, and fix the self-pollination bag on the second leaf with a paper clip; Step 3: Treatment of spikelets of sterile rice lines: 3-4 days after bagging, when more than 50% of the spikelets in the rice ears in the bag have bloomed, remove the selfing bag for spikelet cutting. The spikelets are cut in the morning before the rice blooms or in the afternoon after the rice blooms and sheds pollen. Cut off half of the husks of all spikelets at the flat ends, put a kraft paper hybrid bag with unsealed ends on the rice ears, and put 1-2 ears in each hybrid bag. Adjust the height of the rice ears in the hybrid bag, fix the hybrid bag with a stapler, and fold the upper mouth of the hybrid bag to prevent foreign pollen contamination before pollination; Step 4: Treatment of rice restorer lines: Take the rice ears from 1-2 hours before flowering on the day of pollination to when the restorer lines bloom a little. Select the rice ears whose spikelets have bloomed 1 / 3-2 / 3. Take 1-2 ears and cut them at the second stem node. Cut off the spikelets that have bloomed on the upper part of the rice ears. Wet the rice ears with water, and then beat them on clothes and boots to remove excess water, so that the rice ears remain moist and fluffy. Put the rice ears in unsealed kraft paper bags with restorer line information marked in advance at both ends. Each group of 20 paper bags is tied with rubber bands, leaving 5-10 cm of stems outside the paper bags, cutting off the excess parts, trimming the lower ends of the remaining stems neatly, and placing the bundles of rice ears with stems facing down in a covered bucket for hydroponics. The water depth is 3-5 cm, and the bucket is more than 60 cm high. The bucket is placed in a shaded and windproof place; Step 5: Hybridization pollination: Start pollination after the peak flowering period of the sterile rice line on the same day, take out the rice ears of the restorer line from the covered bucket, put them in an apron or bucket, handle them with care, try to avoid shaking and wind to prevent pollen from flying, take the rice ears of the restorer line to pollinate the sterile line in sequence, the restorer line spikelets open, the anthers extend out, the anthers turn white after pollination, and pollen can be seen floating in the self-pollination bag in the form of smoke, which means the pollination is successful. After pollination is successful, bend the upper mouth of the hybridization bag and then fix it with a stapler.

2. The method for testing and matching in the hybrid japonica rice breeding process according to claim 1, characterized in that: The identification of rice plant fertility includes: identification of anther size, where the anthers of sterile plants are thin and small, and the anthers of fertile plants are fat and large; Identification of anther color: the anthers of sterile plants are yellow, light yellow or colorless, and in a water-soaked state; the anthers of fertile plants are yellow before they shed pollen after flowering, and turn white after they shed pollen. Regarding the anther shape, the anthers of sterile plants remained in the shape of thin rods, while the anthers of fertile plants had broken tips and were in the shape of empty bags.

3. The method for testing and matching in the hybrid japonica rice breeding process according to claim 1, characterized in that: In order to ensure the continuity of the subsequent testing and matching work in the step 2, a large number of self-pollination bags are required. In order to distinguish different bagging dates, self-pollination bags of various colors can be prepared.

4. The method for testing and matching in the hybrid japonica rice breeding process according to claim 1, characterized in that: In step three, the planned hybrid combination needs to be written on the hybrid bag, and the matching plan, restorer area code, and pollination date information need to be noted on the hybrid bag, which should be clear and easy to identify.

5. The method for testing and matching in the hybrid japonica rice breeding process according to claim 1, characterized in that: During the pollination in step 5, if the pollen state of the restored line is not good, immediately return to the male parent plot to re-pollinate or postpone the time of re-pollinating the ears the next day, and re-pollinate each bag of sterile lines.

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