不同耐盐高粱品种全生育期对盐胁迫的响应

Response of Different Salt Tolerant Sorghum Varieties to Salt Stress in the Whole Growth Period

为探究土壤盐胁迫对不同生育时期(拔节期、开花期、成熟期)高粱植株生长及生理特性的影响,在4个盐处理水平(CK:0 g/kg,S3:3 g/kg,S5:5 g/kg,S7:7 g/kg)种植2个耐盐性不同的高粱品种高粱蔗(耐盐)和河农16(盐敏感),比较了2个品种在不同盐处理水平下、不同生育时期植株形态、根系形态、叶片光合特性及抗氧化酶活性的差异。研究结果表明:随盐胁迫程度增加,2个品种的抗氧化酶活性和叶绿素相对含量(SPAD)先升高后降低,抗氧化酶活性在S3处理或S5处理下达到最大值,且该最大值与对照间存在显著差异。2个高粱品种的丙二醛(MDA)含量,随盐处理浓度的增大而升高,在S7处理下显著高于对照,同一处理下耐盐品种高粱蔗的抗氧化酶活性高于盐敏感品种河农16,但丙二醛含量低于盐敏感品种。2个品种的光合能力受到盐胁迫的显著影响,在拔节期,S7处理显著降低了高粱蔗的Pn值,而2个品种的胞间CO2浓度(Ci)在S7处理下均高于对照。盐胁迫下高粱地上和地下部分生长都受到影响,2个品种的基部茎粗、总根长、根面积、根尖数和分支数在S3处理下达到最大值,基部节长、株高、总根长及根体积在S7处理下达到最低值。2个高粱品种在盐胁迫下籽粒脂肪、淀粉含量下降,单宁含量在低盐处理下显著高于对照,盐胁迫使籽粒品质下降。综上,低盐(3 g/kg)能促进高粱生长,而中盐(5 g/kg)和高盐(7 g/kg)条件对高粱生长有显著的抑制作用,高粱蔗比河农16的耐盐性更强。

To study the effects of salt stress on growth and physiological characteristics of sorghum at different growth stages(elongation,flowering,and maturity),two sorghum varieties with different salt tolerances,Gaoliangzhe(salt tolerance)and Henong No.16(salt sensitive),were planted at four salt treatment levels(CK:0 g/kg,S3:3 g/kg,S5:5 g/kg,S7:7 g/kg).Moreover,the two varieties were compared under different salt treatment levels,plant morphology,root morphology,leaf photosynthetic characteristics and antioxidant enzyme activities at different growth stages.The results showed that with increasing salt treatment concentration,the antioxidant enzyme activity and relative chlorophyll content(SPAD)of the two varieties increased first and then decreased.The antioxidant enzyme activity reached the maximum value under S3 or S5 treatment,and there were significant differences between the maximum and CK.With the increase of salt treatment concentration,the malondialdehyde(MDA)of the two sorghum varieties increased significantly,which S7 treatment was significantly higher than CK.Under the same treatment,the antioxidant enzyme activity of salt-tolerant varieties(Gaoliangzhe)was higher than that of salt-sensitive varieties(Henong No.16),but the content of MDA was lower than that of salt-sensitive varieties.The photosynthetic capacity of the two varieties was significantly affected by salt stress.In elengation,S7 treatment significantly reduced the Pn of Gaoliangzhe,and Ci of the two varieties under S7 treatment was higher than that of CK.Under salt stress,the growth of the sorghum aerial portion and underground portion of sorghum were affected.The basal stem diameter,total length of root,root surface area,number of root tips,and number of root branches for two varieties reached the maximum under S3 treatment.And basal internode length,plant height,total length of root and root volume reached the lowest value under S7 treatment.In addition,grain fat content and grain starch content in two sorghum varieties decreased under salt stress.The grain tannin content was significantly higher than CK in low-salt(S3,3 g/kg).In general,low-salt can promote the growth of sorghum,while medium-salt(S5,5 g/kg)and high-salt(S7,7 g/kg)conditions have a significant inhibitory effect on sorghum growth.And Gaoliangzhe is more salt-tolerant than Henong No.16.