虉草幼苗对盐胁迫的生理与生长响应

Physiological and Growth Response of Phalaris Arundinacea Seeding to Salt Stress

采用不同浓度的NaCl(A)和NaCl+NaHCO3(B)盐溶液对当地选育出的虉草新品系(Phalaris arundinacea)进行3周盐胁迫处理,通过测定茎叶生物量、根系生物量、茎叶相对含水率、叶片电导率以及丙二醛、叶绿素、脯氨酸含量等,探讨2种盐胁迫对草苗期生理与生长的影响.结果表明,随着盐浓度的升高虉草茎叶生物量、根系生物量、茎叶相对含水率、叶绿素含量逐渐降低,茎叶生物量下降幅度大于根系生物量;叶片电导率、丙二醛含量和脯氨酸含量随盐浓度升高而上升.当盐浓度为100mmol/L时,A、B组处理叶片电导率、游离脯氨酸含量分别比对照高34.5%、25.16%和56.85%、45.34%,差异显著(P<0.05),而茎叶生物量和叶绿素含量分别比对照低13.2%、19.01%和24.43%、23.9%,差异极显著(P<0.01).NaCl+NaHCO3混合盐处理对虉草苗期生长的影响大于NaCl处理,表明草对碱性盐胁迫较敏感.

Conducting three-week-long salt stress treatment with NaCl and NaCl＋NaHCO3 salt solution of different concentration for phalaris arundinacea newly selected locally. Through determining stem-leaf biomass, root biomass, stem-leaf relative water content, leaf conductance and content of malonaldehyde, chlorophyll and proline, we can study the influence of two types of salt stress on physiology and growth of phalaris arundinacea seeding. The result shows that stem-leaf biomass, root biomass, stem-leaf relative water content and chlorophyll content reduce as salt concentration increases, among which stem-leaf biomass reduces more than root biomass; while leaf conductance, malonaldehyde content and proline content increase as salt concentration rises. When salt concentration reaches 100mmol/L, leaf con-ductance and free proline content in A and B groups are 34.5%, 25.16%and 56.85%and 45.34%higher than those in the blank group respectively, with great difference（P〈0.05）, while stem-leaf biomass and chlorophyll content in A and B groups are 13.2%, 19.01%and 24.43%and 23.9%lower than those in the blank group respectively, with tremen-dous difference（P〈0.01）. NaCl＋NaHCO3salt mixture has greater influence on the growth of phalaris arundinacea seeding than NaCl, which indicates that phalaris arundinacea is sensi-tive to alkaline salt stress.