NaCl胁迫对甜高粱发芽期生理生化特性的影响

为筛选耐盐甜高粱材料,探讨NaCl胁迫对甜高粱发芽期生理生化特性的影响,研究了0、70、140、210 mmol.L-1NaCl胁迫对吉甜3、BJK156、甜132、凯勒、威利、考利、吉甜2、戴尔等8个甜高粱材料发芽率、发芽势、发芽指数、活力指数、芽长、根长、芽鲜质量、根鲜质量等8个指标盐害系数的影响,利用系统聚类分类法对甜高粱耐盐性进行聚类可分为3类：耐盐性最强的是甜132,耐盐性中等的是BJK156,耐盐性较敏感的是考利、吉甜3、吉甜2、戴尔、凯勒、威利。进一步研究了盐胁迫对甜高粱芽苗中丙二醛、可溶性蛋白含量及过氧化物酶（POD）、过氧化氢酶（CAT）、超氧化物歧化酶（SOD）活性的影响。结果得出：随着盐胁迫的加重丙二醛含量逐渐增加,可溶性蛋白含量逐渐减少。NaCl胁迫不同程度地提高了8个甜高粱材料POD、CAT、SOD活性,受3种NaCl质量浓度胁迫后8个甜高粱材料POD、CAT、SOD活性的变化趋势不同,这可能是它们耐盐差异的生理原因之一。另外,在3种NaCl浓度胁迫后甜132中的丙二醛增加量在8个材料中都是最低的,这与系统聚类分析得出甜132耐盐性最强的结论相吻合。研究认为丙二醛含量的变化可以作为筛选发芽期耐盐甜高粱品种的一个指标。

Effect of NaCl stress on physiological characteristics of sweet sorghum in sprout stages

Saline resistance at the sprouting stage is very important for sweet sorghum Sorghum bicolor（L.）Moench] production in saline region.In order to understand the biological and physiological characteristics of sweet sorghum at sprouting stage under saline stress and provide a reference for its breeding or cultivation,effect of NaCl stress with three concentrations of 70,140,210 mmol·L-1 on morphological parameters of eight sweet sorghum genotypes were investigated and water as control.Seeds were germinated under NaCl in climate incubator for 7 days.Comprehensive evaluation on salt tolerance of sweet sorghum varieties was studied by cluster analysis.The eight tested varieties were classified into three salt tolerance groups,Tian132 in salt tolerant group,BJK156 in intermediate group,Cowley,Jitian3,Jitian2,Dale,Keller,Wary in salt sensitive group.Effects of NaCl on the Malondialdehyde（MDA） and soluble protein contents and the activities of peroxidase（POD）,catalase（CAT） and superoxide-dismutase（SOD） were also investigated in sprouts of sweet sorghum.The results showed that the MDA content increased and the soluble protein content decreased after NaCl stress.The activities of POD,CAT and SOD enhanced in stressed sprouts of all genotypes as compared to the controls.Changes in the activities of POD,CAT and SOD of eight sweet sorghum genotypes in response to three NaCl concentrations were different,that might be one of the physiological causes of salt resistance difference among sweet sorghum genotypes.Moreover,the increased amount of the MDA content in Tian132 was the lowest in response to NaCl stress,as compared to their controls.This result was in accordance with cluster analysis by morphological traits.Increasing amount of MDA content after salt stress may be one of the indexes of screening sweet sorghum varieties for salt tolerance.