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CN-121970680-A - Method for identifying low cadmium accumulation characteristic of rice sterile line and application thereof

CN121970680ACN 121970680 ACN121970680 ACN 121970680ACN-121970680-A

Abstract

The invention belongs to the technical fields of crop heavy metal accumulation phenotype identification and crop breeding, and particularly relates to a method for identifying low cadmium accumulation characteristics of a rice sterile line and application thereof. According to the method, through standardized identification environment and diversified and easily obtained detection samples, such as a small amount of self-bred or outbred matured rice, unfired empty grains or rice spikes or leaves, simplification, standardization and high efficiency of the identification of the low-accumulation characteristic phenotype of the sterile line cadmium are realized, and important support is provided for cultivation and official approval and identification of the low-cadmium sterile line, so that breeding and large-area popularization and application of the low-cadmium hybrid rice variety are improved.

Inventors

  • FANG BAOHUA
  • DAI LI
  • ZHAO YANG
  • KUANG WEI
  • LIANG YUGANG

Assignees

  • 湖南杂交水稻研究中心

Dates

Publication Date
20260505
Application Date
20260209

Claims (10)

  1. 1. The method for identifying the low cadmium accumulation characteristic of the rice sterile line is characterized by comprising the following steps of: 1) Raising rice seedlings of the sterile line of the rice to be identified to obtain rice seedlings; 2) Transplanting the rice seedlings into a rain-proof and light-transmitting identification pool, and then performing field management until the rice seedlings reach a mature period; The soil in the identification pond is natural soil excavated from a paddy field cultivation layer, the total cadmium content of the soil in the identification pond is 1.0-2.0 mg/kg or 1.0-1.7 mg/kg, and the thickness of the soil in the identification pond is 0.15-0.4 m; The field management comprises irrigation management; The irrigation management comprises the steps of keeping the height of a water layer in an identification pond to be 1-3 cm before the rice seedlings are planted to a field at the end of tillering, and keeping the height of the water layer in the identification pond to be 1-3 cm after the rice seedlings are planted to the field at the end of tillering for 7-9 days, carrying out cyclic management of watering, draining and sunning, re-watering and then draining and sunning until the rice is harvested at the end of tillering, and keeping the height of the water layer of 2-3 cm in the identification pond to be 6-24 h when each watering, wherein each time the water layer is drained and sunned until the foot is not sticky; 3) Sampling and detecting cadmium content in a mature period, and judging that the rice sterile line to be identified has low cadmium accumulation characteristic when the cadmium content of a rice sample is less than or equal to 0.2mg/kg, otherwise, judging that the rice sterile line to be identified does not have low cadmium accumulation characteristic; The rice sample comprises one or more of self-maturing solid rice, outcrossing solid rice, uncorrupted empty shrunken rice, rice ears and leaves.
  2. 2. The method according to claim 1, wherein the leaf in the rice sample in step 3) comprises a leaf at any position or a mixed leaf of a plurality of leaves at positions other than the axillary bud regeneration seedling.
  3. 3. The method according to claim 1, wherein a sunlight plate with a rain shielding function is arranged above the rain-proof and light-transmitting identification tank, and the identification tank is provided with water filling and/or drainage facilities.
  4. 4. The method according to claim 1 or 3, wherein the width of the identification pool is 1.5-3.0 m, the length is 5-50 m, an upper row of water seepage holes and a lower row of water seepage holes are arranged on the long-side pool wall of the identification pool, the heights of the lower row of water seepage holes are flush with the bottom of the identification pool, the heights of the upper row of water seepage holes are flush with the upper surface of soil in the identification pool, the distance between adjacent water seepage holes of the same row of water seepage holes is 0.15-0.3 m, and the diameter of each water seepage hole is 2-3 cm; a row of water inlet holes are formed in the long-side tank wall of the identification tank, the height of each water inlet hole is 0-20 cm higher than that of the upper row of water inlet holes, the distance between adjacent water inlet holes of the same row of water inlet holes is 0.15-0.3 m, and the diameter of each water inlet hole is 2-3 cm.
  5. 5. The method according to claim 1, wherein the cadmium content detection comprises the steps of drying the rice sample and pulverizing the dried rice sample to obtain a rice powder sample; and detecting the cadmium content in the rice powder sample by adopting a graphite furnace atomic absorption spectrophotometry.
  6. 6. The method according to claim 1 or 5, wherein the same rice sample is provided with not less than three biological replicates when sampling and detecting cadmium content, and the replicate with the greatest cadmium content is taken to determine the low cadmium accumulation characteristic.
  7. 7. The method according to claim 1, wherein the seedling raising means in step 1) comprises a floppy disk seedling throwing and/or water seedling raising.
  8. 8. The method according to claim 1, wherein the method comprises identifying the cadmium low accumulation characteristic of a plurality of rice sterile lines simultaneously, and when the cadmium low accumulation characteristic of the plurality of rice sterile lines is identified simultaneously, planting not less than three biological repeats of each rice sterile line to be identified, each biological repeat being not less than 10 holes, and transplanting one rice seedling in each hole.
  9. 9. The method of claim 1, further comprising planting a non-low cadmium rice sterile line as a control.
  10. 10. Use of the method according to any one of claims 1 to 9 in the breeding of low cadmium rice varieties.

Description

Method for identifying low cadmium accumulation characteristic of rice sterile line and application thereof Technical Field The invention belongs to the technical fields of crop heavy metal accumulation phenotype identification and crop breeding, and particularly relates to a method for identifying low cadmium accumulation characteristics of a rice sterile line and application thereof. Background The hybrid rice variety has the advantages of remarkable high yield, stress tolerance and the like, is the key for improving the unit yield and the total yield of rice in China, and is bred without sterile line. The low-cadmium rice is the most economical and effective way for solving the heavy metal cadmium pollution of the rice at present, and the breeding of the low-cadmium hybrid rice variety is a key measure for realizing the improvement of the yield of the low-cadmium rice. The breeding of the low-cadmium hybrid rice variety requires that both male parent and female parent (sterile line) have the characteristic of low accumulation of cadmium, so that the breeding and identification of the low-cadmium sterile line becomes an essential part of the low-cadmium hybrid rice breeding. Currently, low cadmium rice varieties have developed and matured in technology for identifying the low cadmium accumulation characteristics, and the characteristics of the varieties are generally characterized by utilizing the phenotype of the low cadmium accumulation characteristics of rice or brown rice. However, the sterile line cannot obtain sufficient rice samples due to the fact that the sterile line cannot be self-matured naturally or the maturing rate is too low, or the low-cadmium sterile line has high difficulty in phenotype identification of low-cadmium accumulation characteristics due to the fact that the fertility recovery condition of the sterile line is severe, the operation is complex, and the like, and the rice samples stay on the level of genotype indirect identification in most cases. However, genotyping cannot be used as a direct basis for official identification of sterile lines, since it does not directly and completely characterize the cultivar itself. On the other hand, the existing method for restoring fertility of sterile line and evaluating phenotype of low accumulation characteristic of cadmium by complex measures in field environment is easy to be influenced by natural precipitation, soil moisture, cadmium content, poor uniformity of pH value and the like, so that the annual and inter-region repeatability of the identification result is poor, the identification efficiency is low, and the supporting effect on the cultivation and identification of sterile line is not strong. Disclosure of Invention In order to solve the technical problems, the invention provides a method for identifying the low cadmium accumulation characteristic of a rice sterile line and application thereof, and the method realizes the phenotype simplification, standardization and high-efficiency identification of the low cadmium accumulation characteristic of the rice sterile line through standardized identification environment and diversification and easy acquisition of detection samples. The invention provides a method for identifying low cadmium accumulation characteristics of a rice sterile line, which comprises the following steps: 1) Raising rice seedlings of the sterile line of the rice to be identified to obtain rice seedlings; 2) Transplanting the rice seedlings into a rain-proof and light-transmitting identification pool, and then performing field management until the rice seedlings reach a mature period; The soil in the identification pond is natural soil excavated from a paddy field cultivation layer, the total cadmium content of the soil in the identification pond is 1.0-2.0 mg/kg or 1.0-1.7 mg/kg, and the thickness of the soil in the identification pond is 0.15-0.4 m; The field management comprises irrigation management; The irrigation management comprises the steps of keeping the height of a water layer in an identification pond to be 1-3 cm before the rice seedlings are planted to a field at the end of tillering, and keeping the height of the water layer in the identification pond to be 1-3 cm after the rice seedlings are planted to the field at the end of tillering for 7-9 days, carrying out cyclic management of watering, draining and sunning, re-watering and then draining and sunning until the rice is harvested at the end of tillering, and keeping the height of the water layer of 2-3 cm in the identification pond to be 6-24 h when each watering, wherein each time the water layer is drained and sunned until the foot is not sticky; 3) Sampling and detecting cadmium content in a mature period, and judging that the rice sterile line to be identified has low cadmium accumulation characteristic when the cadmium content of a rice sample is less than or equal to 0.2mg/kg, otherwise, judging that the rice sterile line to be ident