外源物质对低温胁迫条件下高粱种子萌发的影响

Effects of Exogenous Substances on Seed Germination of Sorghum under Low Temperature Stress

为筛选低温胁迫条件下促进高粱种子萌发的最佳外源物质及其浓度配比,本试验分别用不同浓度芸苔素内酯(EBR)、水杨酸(SA)、赤霉素(GA_(3))、褪黑素(MT)、硫酸锰(MnSO_(4))、硅酸钾(K_(2)SiO_(3))处理高粱种子,研究其对低温胁迫下高粱种子萌发及幼苗生长的影响。结果表明,适宜浓度的外源物质引发高粱种子可增强其萌发期及幼苗期的抗低温胁迫效应。利用隶属函数法建立的综合评价体系,可量化并较为全面地评价低温胁迫下供试外源物质不同浓度引发种子萌发、幼苗生长的抗低温胁迫效应。利用综合得分D值进行聚类分析,将6个不同浓度外源物质组成的25个处理分为3类,其中第1类处理综合分值为0.4268~0.7244,得分最高的3个处理依次是M3、E3和S3。具体表现为,0.030μmol·L^(-1)EBR处理(E3)种子相对发芽势和相对发芽指数最大,0.50 mmol·L^(-1)MT(M3)、1.0 mmol·L^(-1)SA处理(S3)均能有效促进种子萌发和幼苗生长,以0.50 mmol·L^(-1)MT处理效果最佳。

To screen out the optimal exogenous substances and their concentration proportions for promo⁃ting sorghum seed germination under low temperature stress,the sorghum seeds were treated with six exoge⁃nous substances including epibrassinolide(EBR),salicylic acid(SA),gibberellin(GA_(3)),melatonin(MT),MnSO_(4) and K_(2)SiO_(3) at different concentrations under low temperature stress,and their effects on seed germination and seedling growth were analyzed.The results showed that the exogenous substances at suitable concentrations could strengthen the resistance of sorghum seeds to low temperature at germination and seedling stages.The comprehensive evaluation system established by membership function method could be used to e⁃valuate the low⁃temperature resistance of seeds and seedlings induced by different concentrations of the exoge⁃nous substances.By cluster analysis based on the comprehensive score D value,the 25 treatments were divided into three categories.The comprehensive score of the first class of treatments was 0.4268~0.7244,and three treatments with the highest scores were M3(0.50 mmol·L^(-1) MT),E3(0.030μmol·L^(-1) EBR)and S3(1.0 mmol·L^(-1) SA)in order.Under E3 treatment,the relative germination potential and relative germination index of seeds were the highest;the M3 and S3 treatments could promote the seed germination and seedling growth,and the effect of M3 treatment was the best.