外源乙烯及氯化钴对磷胁迫下杉木幼苗根系生长的影响

By studying the effects of different concentrations of ethephon on the root morphology and physiological effects of Chinese fir seedlings under a low-phosphorus environment,it provides a reference for revealing the internal mechanism of Chinese fir seedlings adapting to a nutrient-stress environment.The different concentrations of ethephon(0 g/kg,0.01 g/kg,0.1g/kg,0.2g/kg,0.4 g/kg)and Cobalt chloride(0 g/kg,0.01 g/kg,0.05 g/kg,0.1 g/kg,0.2 g/kg)were used under normal and low-phosphorus environments respectively.The results showed that:1)There was significant correlation between different additives on the root length,root surface area and root volume of Chinese fir(p<0.05).The root length,root surface area and root volume reached a maximum when ethephon concentration was 0.01 g/kg under normal and low-phosphorus environments,and significantly different from 0.04 g/kg;The root length(445.60±87.42cm),root surface area(109.64±23.54cm2),and root volume(2.17±0.54cm3)reached a maximum when Cobalt chloride concentration was 0.01 g/kg,and very significant difference between 0.2 g/kg(p<0.01).Under normal phosphorus environments,with the increase of ethephon concentration,the activity of SOD showed a decreasing trend,and the activity of POD showed a increasing trend;while the addition of 0.01 g/kg cobalt chloride promotes both SOD and POD under low-phosphorus environments;There was no significant correlation between different concentrations of additives on the MDA content(p>0.05).Overall,exogenous ethephon induced endogenous ethylene production,but high concentrations of exogenous ethephon inhibited the growth of roots;The low concentration of cobalt chloride relieved the inhibition of ethylene on the root system under the low phosphorus environment,and promoted the growth of root.