烟草耐旱突变体生理特性分析

Physiological Characteristics Analysis of Tobacco Drought Tolerant Mutant

干旱是影响植物生长发育和产量的重要制约因素,选育耐旱烟草品种对农业生产实践具有重要意义。为了探究前期筛选的烟草耐旱突变体M28耐旱生理机制,本研究对5~6叶期的K326和M28进行了自然干旱胁迫处理。表型鉴定结果显示,经干旱胁迫31 d及复水3 d后,M28的生长状态优于对照K326。相对应地,生理生化指标显示,在干旱处理7 d(或14 d)后,突变体M28叶片相对含水量(RWC)、过氧化物酶(POD)活性、净光合速率(Pn)显著高于K326;超氧化物歧化酶(SOD)、过氧化氢(H2O2)含量、超氧阴离子(O2-)含量、相对电导率(EL)、丙二醛(MDA)含量、气孔导度(Gs)及蒸腾速率(Tr)显著低于K326,以上结果表明突变体M28的耐旱性强于K326。该研究不仅解析了突变体M28的耐旱生理机制,也为烟草抗逆改良提供了育种素材。

Drought is an important factor that affects the growth,development and yield of plants,thus it is of great significance to breed drought-tolerant tobacco varieties for agricultural production practice.To explore the physiological mechanism of tobacco drought tolerant mutant M28 screened earlier,natural drought treatment was performed on K326 and M28 at 5~6 leaf stage in this study.The phenotypic result showed that the growth state of M28 was better than that of K326,after 31 days of drought stress and 3 days of rehydration.Correspondingly,physiological and biochemical indicators showed that the values of relative water content(RWC),peroxidase(POD)activity and net photosynthetic rate(Pn)of M28 were significantly higher than those of K326 after 7 days(or 14days)of drought treatment.But,the levels of superoxide dismutase(SOD)activity,hydrogen peroxide(H_2O_2)superoxide anion(O_2~-),relative conductivity(EL),malondialdehyde(MDA),stomatal conductance(Gs)and transpiration rate(Tr)were significantly lower than those of K326.These results showed that the drought resistance of M28 is stronger than that of K326.This study not only elucidates the physiological mechanism of drought tolerance of mutant M28,but also provides breeding materials for the improvement of tobacco stress resistance.