盐胁迫对豆梨种子萌发及生长的影响

Effects of Salt Stress on Seed Germination and Growth of Pyrus calleryana

以豆梨(Pyrus calleryana Decne.)进口栽培品种‘红塔’种子(HT)为试材,采用6个浓度(0(对照)、50、100、200、300、400 mmol/L)的NaCl胁迫处理,测定盐胁迫后豆梨种子发芽率、发芽势、培养1~5 d的胚根长和胚芽长;以进口栽培品种‘首都’种子(SD)为对照,以7份野生豆梨种子(J_(2)、J_(8)、J_(10)、M_(6)、M_(13)、M_(15)、M_(24))为试材,采用浓度为200 mmol/L的NaCl胁迫处理,测定盐胁迫后豆梨种子发芽率、发芽势、胚根长、胚芽长。应用隶属函数法、系统聚类分析法对种子耐盐性进行综合评价,分析盐胁迫对豆梨种子萌发及生长的影响。结果表明:①不同浓度盐胁迫,对‘红塔’种子发芽势、发芽率、胚根长、胚芽长存在不同程度的抑制。随着盐浓度的增加(0~200 mmol/L),各处理间各指标均存在显著差异。当NaCl溶液浓度为300、400 mmol/L时,胚根生长2~3 d后基本停滞甚至萎蔫。在材料稀缺或进行大批量种质种子耐盐性比较时,可直接选择浓度为200 mmol/L的NaCl溶液处理,快速测定豆梨种子的耐盐萌发。②NaCl胁迫,对各豆梨种质萌发期各性状指标均有显著抑制作用。③依据豆梨种质的隶属函数及聚类分析结果,将8份豆梨种质划分为高耐盐(M_(15))、中度耐盐(J_(8)、M_(6))、盐敏感(SD、M_(24)、M_(13)、J_(10)、J_(2))3种类型。

The seeds of Pyrus calleyana‘Hongta’were treated with NaCl stress at six concentrations(0(control),50,100,200,300 and 400 mmol/L).The seed germination rate,germination potential,radicle length and germ length after 1-5-d culture were measured.With the imported cultivar‘Capital’seeds(SD)as the control and seven wild Pyrus calleryana seeds(J_(2),J_(8),J_(10),M_(6),M_(13),M_(15)and M_(24))as the test materials,the seed germination rate,germination potential,radicle length and germ length of P.calleryana were measured under NaCl stress with a concentration of 200 mmol/L.The salt tolerance of seeds was comprehensively evaluated by membership function method and systematic cluster analysis,and the effects of salt stress on seed germination and growth of P.calleryana were analyzed.The results showed that:(1)Different concentrations of salt stress inhibited the germination potential,germination rate,radicle length and germ length of‘Hongta’seeds in varying degrees.With the increase of salt concentration(0-200 mmol/L),there were significant differences in various indexes among treatments.When the contents of NaCl solution were 300 and 400 mmol/L,the radicle growth basically stagnated or even wilted after 2-3 d.When materials are scarce or salt tolerance of a large number of germplasm seeds is compared,NaCl solution with a concentration of 200 mmol/L can be directly selected for treatment to quickly determine the salt tolerance germination of P.calleryana seeds.(2)NaCl stress had a significant inhibitory effect on all character indexes of P.calleryana germplasm at germination stage.(3)According to the membership function and cluster analysis results of P.calleryana germplasm,eight P.calleryana germplasm were divided into three types:high salt tolerance(M_(15)),moderate salt tolerance(J_(8),M_(6))and salt sensitivity(SD,M_(24),M_(13),J_(10),J_(2)).