不同育苗方式对烟苗生长及生理特性的影响OA

[Objective]To explore the effects of different seedling nursery methods on the growth and physiological characteristics of tobacco seedlings.[Method]Using Yunyan 87 as the experimental material and the traditional floating seedling nursery method as the control,two chain-type paper-pot seedling nursery methods—automatic sprinkler irrigation and manual irrigation—were established.The study analyzed their effects on seed emergence time and emergence rate of flue-cured tobacco,as well as on agronomic traits,leaf photosynthetic pigment con-tent,photosynthetic performance,and root characteristics.[Result]The emergence time of tobacco seedlings using the automatic sprinkler and manual irrigation chain-type paper-pot methods were 3 d earlier than that of the control group;the 7-day emergence rates reached 93.33%and 93.80%,respectively—representing increases of 12.79%and 13.35%over the control.From the perspective of agronomic traits,during the cross stage,the automatic sprinkler chain-type paper-pot method was superior to both the manual irrigation chain-type paper-pot method and the floating seedling nursery method.During the seedling stage,plant height,stem thickness,maximum leaf area,fresh weight,and root vol-ume of tobacco seedlings using the automatic sprinkler chain-type paper-pot seedling nursery method increased by 28.64%,18.51%,40.74%,26.22%,and 80.00%,respectively,compared with the control.Corresponding increases for the manual irrigation chain-type pa-per-pot method were 5.77%,6.27%,9.87%,23.97%,and 40.00%.Regarding leaf photosynthetic performance,during the cat-ear stage,the manual irrigation chain-type paper-pot method significantly increased leaf photosynthetic pigment content in tobacco seedlings,whereas the automatic sprinkler chain-type paper-pot method showed only a significantly higher carotenoid content than the control.During the seedling stage,the two chain-type paper-pot methods significantly enhanced photosynthetic pigment contents compared with the control;moreover,the automatic sprinkler method yielded higher photosynthetic pigment content than the manual irrigation method.In terms of root growth,during the cat ear stage and the seedling stage,the total root length,total root surface area,average root diameter,and total number of root tips of the manual irrigation chain-type paper-pot seedling nursery method and the automatic sprinkler irrigation chain-type paper-pot seedling nursery method were significantly better than those of the control.In terms of root vitality,during the cat ear stage and the seedling stage,the total ab-sorption area,active absorption area and specific surface area of the automatic sprinkler chain-type paper bowl seedling nursery method were significantly higher than those of the control.The artificial irrigation chain-type paper-pot seedling nursery method only had a significantly higher specific surface area index than the control,while there were no significant differences in the other indicators.[Conclusion]Different seedling nursery methods affect the growth of tobacco seedlings and the physiological characteristics of their leaves and roots.The chain-type paper-pot seedling nursery method is superior to the floating seedling nursery method;among them,the automatic sprinkler chain-type paper-pot method outperforms the manual irrigation chain-type paper-pot method.This study provides a theoretical foundation for automated seedling nursery and transplanting of flue-cured tobacco.