解除欧洲花楸种子机械休眠的方法研究OA

Sorbus aucuparia is a deciduous tree belonging to the genus Crataegus in the Rosaceae fami-ly,of which seeds have dormancy characteristics.To explore the dormancy characteristics of Sorbus aucuparia seeds,establish the best method for quickly breaking the dormancy,analyze the vitality and water absorption characteristics of the seeds and set up 4 methods to treat the seeds to explore the resolving effect of the treatment.The results showed that the complete seeds and the seeds with bro-ken seed coat reached water balance after 48 hours and 32 hours of water absorption respectively.The water absorption rate of the complete seeds and the broken seed coat seeds reached 107％and 105％respectively,and there was no permeability barrier in the seed coat.The germination rate of the isola-ted embryos was as high as 90％,indicating that the embryos did not have dormancy.After removing the outer seed coat,the germination rate of the seeds was only 16.67％,while the germination rates of the seeds with the embryo root end or leaf end seed coat broken were both higher than 77％.There-fore,the dormancy of Sorbus aucuparia seeds was mainly caused by the mechanical restraint of the inner seed coat.Using sandpaper or quartz sand to scratch the seed coat,the germination rate of the seeds was only 41.33％and 28％respectively,and the decay rate was higher than 30％.The acid etch-ing the seeds with concentrated sulfuric acid for 15 minutes,the germination rate of the seeds was the highest,at 57.33％,and the decay rate was relatively low.After soaking the seeds in a 600 mg/L GA3 solution for 12 hours or 24 hours and then conducting low-temperature stratification treatment for 30 days,the germination rates of each treatment group significantly increased,and after stratification for 60 days or 75 days,the germination rates of the 600 mg/L GA3 solution soaked seeds and the 1 000 mg/L GA3 solution soaked seeds reached 92.67％,significantly higher than those of other treatment groups.The acid etching the seeds for 30 seconds and then soaking them in 600 mg/L GA3 solution for 24 hours,after 42 days of low-temperature stratification,the germination rate reached 88％,and the dormancy was basically relieved.The scanning electron microscopy observed that the surface of the Sorbus aucuparia seeds was irregular polygonal honeycomb-shaped,the outer seed coat was lignified,and the inner seed coat was membranous,tightly wrapping the embryo outside.During the process of seed dormancy release,this structure gradually broke,the thickness of the inner and outer seed coats gradually decreased,the density and stability of the seed coat structure decreased,the lignified structure of the outer seed coat gradually disintegra-ted,the inner seed coat gradually became paper-like,and the mechanical restraint force of the seed coat on the embryo decreased,allowing the embryo to break through the seed coat restraint after germination and the dormancy was gradually relieved.