外源压力对甘薯生长和生理特征的影响

Effect of exogenous pressure on growth and physiological characteristics of sweetpotato

采用不同质地的黏土和砂土,利用室内可控压力的盆栽试验,对不同外源压力T_1,T_2,T_3分别为0,10,20kg的条件下,甘薯生长和生理特征的响应进行了研究.结果表明:1)甘薯地上部茎叶生物量随着压力的增大而增加,而黏土中生育后期,T_2最高,其次为T_3,说明适宜的外源压力有助于甘薯茎叶在中后期的生长.甘薯地下部生物量与地上部生物量均呈现出一致的趋势,T_2最高,其次为T_3.2)每个生育期,光合速率和内源激素最高为T_2,其次为T_3.外源压力处理和瞬时水分利用效率(P_n/T_)之间没有显著关系,而生育期和土壤类型对P_n/T_具有显著影响.3)外源压力处理和根长之间没有显著关系,而生育期和土壤类型对根长具有显著影响;生育期、外源压力处理和土壤类型对根平均直径、根表面积和根体积均具有显著影响,根平均直径、根表面积和根体积在T_2处理中最高,其次为T_3.可见,在本盆栽试验处理中,甘薯最适宜的生长条件为土壤压力为T_2,其次为T_3,而T_1处理最不利于甘薯产量的形成.即土壤外源压力对甘薯产量具有很大的影响,压力过大或过小,均不利于甘薯的高产,且黏土压力处理对甘薯根系的影响要高于砂土.

In this study,the growth and physiological characteristics of sweetpotato under different exogenous pressure conditions(T 1,T 2 and T 3 expressing 0,10 kg and 20 kg exogenous pressure treatment respectively)were studied by controlled incubation experiments in laboratory.The results showed that:1)the aboveground stem and leaf biomass of sweetpotato increased with the increase of pressure,but at the late stage in clay soil,the highest in T 2,followed by T 3,so suitable exogenous pressure was helpful to the growth of sweetpotato stem and leaf in the middle and late stage.Sweetpotato underground biomass showed a consistent trend with the aboveground biomass,the highest in T 2,followed by T 3,the lowest in T 1.2)Photosynthetic rate and endogenous hormones were the highest in T 2,followed by T 3 and the lowest in T 1.The effects of growth period,exogenous pressure treatment and soil type on P n/T were not consistent.There was no significant relationship between exogenous pressure treatment and instantaneous water use efficiency(P n/T),but growth period and soil type had significant effects on P n/T.3)There was no significant relationship between exogenous pressure treatment and root length,but growth period and soil type had significant effects on root length.Growth period,exogenous pressure treatment and soil type had significant effects on root mean diameter,root surface area and root volume,which were the highest in T 2,followed by T 3 and the lowest in T 1.The most suitable growth condition in this pot experiment for sweetpotato was soil pressure T 2,followed by T 3,and T 1 was the most unfavorable to the formation of sweetpotato yield.Soil exogenous pressure had a significant impact on the yield of sweetpotato,but if the pressure was too large or too small,they were not conducive increase the yield of sweetpotato.The effects of exogenous pressure treatment on the root of sweetpotato were greater in clay soil than that in sandy soil.