| Objective:Cotton is an important industrial crop,and cotton seed is the basis of cotton production.The quality of cotton seed directly affects the yield and fiber quality of cotton.Therefore,high vigor seed is the basis for achieving high yield of cotton.Mechanized harvesting is currently the trend in cotton production,but through mechanized harvesting,while improving operational efficiency,it can to some extent reduce the quality of cotton seeds,resulting in inconsistent seed maturity,more red,yellow,and white seeds,significant differences in seed plumpness,and damage to some seeds.During the seed processing process,color or magnetic separation methods can effectively improve the quality of processed seeds,but at the same time,it also increases the production cost of the enterprise,causing significant seed losses and reducing the economic benefits of the enterprise.Therefore,analyze the vitality of processed seeds under different precision color or magnetic separations of different intensities;And further use different plant growth regulators to treat cotton seeds that have undergone different levels of color and magnetic separation processing,exploring ways to ensure the quality of cotton seed populations（seed index,seed breaking rate,germination potential,germination rate,etc.）while reducing seed processing losses,which is of great significance for reducing cotton seed processing costs and improving enterprise economic benefits.The research results have a positive impact on ensuring the use of high vitality cotton seeds for agricultural production and cotton seed processing,and also have practical guiding significance for further development of cotton seed coating agents.Method:1.Effect of color selection and magnetic separation on cotton seed quality:Using Xinluzao 82and 84 as experimental materials,the effects of different color selection accuracy（I,II,III levels）,different iron powder particle types（M1,M2,M3levels）,and different iron powder dosage（W1,W2,W3levels）on cotton seed quality and economic benefits were investigated using 100 seed weight,germination potential,germination rate,germination index,vigor index,and seed loss rate as evaluation indicators.2.The effect of different plant growth regulators on the quality of processed cotton seeds:Xinlu Zao82 seeds obtained through processing with different color selection accuracy（I,II,III levels）,different iron powder particle types（M1,M2,M3levels）,and different iron powder dosage（W1,W2,W3levels）were used as experimental materials,After soaking cotton seeds with different concentrations of plant growth regulators(naphthylacetic acid 20mg·L-1,30mg·L-1,40mg·L-1;pentosamine 20mg·L-1,30mg·L-1,40mg·L-1;sodium nitrite 2mg·L-1,3mg·L-1,4mg·L-1;gibberellin 10mg·L-1,30mg·L-1,50mg·L-1),analyze and compare the vitality of plant growth regulators on processed cotton seeds and the content of Malondialdehyde（MDA）in leaves The effects of Superoxide dismutase（SOD）,peroxidase（POD）,Catalase（CAT）and other enzyme activities.At the same time,under low temperature（16℃）conditions,further analysis was conducted on the effects of plant growth regulators on cotton seed vitality and related enzyme activities.Results:（1）The accuracy of color selection and magnetic separation intensity have significant effects on seed germination potential,germination rate,germination index,vitality index,etc.（P<0.01）.The various indicators of seed vitality significantly increase with the increase of color selection accuracy or magnetic separation intensity,but at the same time,the loss rate of processed seeds also significantly increases.Under the I-level color selection accuracy,the vitality index of processed cotton seeds is the highest,reaching 90.67±2.07.But at the same time,the loss rate of processed seeds is as high as 26.32%.Under the magnetic separation intensity of M3type iron powder particles,the vitality index of processed cotton seeds reaches a maximum of 92.44±0.47,and the corresponding loss rate of processed seeds is 13.65%.Under the magnetic separation intensity of W3grade iron powder,the vitality index of processed cotton seeds reaches a maximum of 89.93±4.2,and the corresponding loss rate of processed seeds is 10.74%.Based on the comprehensive seed quality and economic benefits,among the three factors of color selection accuracy,iron powder particle type,and iron powder dosage,the best choice is to use Grade II color selection accuracy,M3iron powder particle type,and W3iron powder dosage,respectively.（2）Appropriate concentrations of naphthylacetic acid,acetaminophen,sodium dinitrophenol,and gibberellin can all enhance the vitality of cotton seeds after color or magnetic separation processing to a certain extent.When germinating at 25℃,soaking the seeds with 20mg·L-1chloramphenicol had the best effect on improving the vitality of cotton seeds.Under this condition,the individual plant weight,plant height,germination potential,germination rate,germination index,and vitality index of nine processed seed materials increased by an average of 11.22%,45%,6.64%,7.27%,22.39%,and 39.07%compared to the control,respectively.When germinating at 16℃,soaking the seeds with 10mg·L-1gibberellin had the best effect on improving the vitality of cotton seeds.Under this condition,compared with the control,the nine seed materials showed an average increase of 43.05%,23.31%,20.17%,19.45%,and 71.05%in individual plant weight,plant height,germination potential,germination rate,germination index,and vitality index,respectively;The activities of SOD,POD,and CAT enzymes in cotton leaves increased by an average of 46.49%,53.52%,and 45.11%compared to the control group;Meanwhile,the MDA content in cotton leaves decreased by an average of 78.62%compared to the control group.Under low temperature,the application of plant growth regulators can reduce the damage of low temperature to membrane lipids by increasing the activity of antioxidant enzymes and reducing the content of Malondialdehyde,thus improving seed vitality.Conclusions:Choosing appropriate color selection accuracy or magnetic separation intensity for processing cotton seeds is of great significance for ensuring the supply of high vitality cotton seeds for agricultural production,reducing seed processing costs,and improving enterprise economic benefits.Using suitable plant growth regulators to treat processed cotton seeds obtained from color or magnetic separation at different levels can effectively improve the vitality of processed cotton seeds.The research results lay a certain foundation for the development of cotton seed coating agents. |
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