摘要： 为探讨低温胁迫下不同棉花品种萌发差异成因，以强耐低温萌发品种鲁棉研37号、鲁棉研36号和低温萌发敏感品种斯字棉2B、斯字棉5A为材料，研究了不同低温下不同萌发时期的生理指标与基因表达的差异。结果显示，12℃胁迫36 h，低温萌发敏感品种MDA含量急剧上升，至胁迫48 h，低温萌发敏感品种斯字棉2B、斯字棉5A比鲁棉研37号MDA含量分别提高了48.17%，50.65%，因此，12℃胁迫36 h MDA含量的变化可以作为耐低温萌发的选择指标；SOD、POD活性在各种处理水平下鲁棉研37号、鲁棉研36号均保持较高水平；CAT活性在低温的刺激下，强耐低温萌发品种逐渐超越低温萌发敏感品种；游离脯氨酸含量在12℃胁迫48 h时，鲁棉研37号与斯字棉2B、斯字棉5A相差幅度分别为33.32%，23.27%，这些生理指标差异较好地反映了不同品种耐低温萌发差异。4个CBF基因家族成员CBF1、CBF2、CBF4、CBF6在强耐性品种中表达上调更迅速，在胁迫12 h时达到表达峰，这可能是强耐低温萌发品种应答低温胁迫时，表现更灵敏与迅速的原因。

关键词: 棉花, 低温胁迫, 生理指标, 基因表达

Abstract: To explore the causes of germination during different cotton varieties to low temperature stress,used two type materials (strong chilling resistant of SCRC37,SCRC36,and chilling sensitive of Stoneville 2B,Stoneville 5A) to study the difference of physiological indexes and gene expression to low temperature stress during different germination stages. The results showed that the MDA content of sensitive varieties increased sharply,to 12℃ stress for 36 h. The content of MDA in Stoneville 2B,Stoneville 5A respectively increased by 48.17% and 50.65%,compared with SCRC 37,to 12℃ stress for 48 h. Therefore,It was suggested to be used as a selective index for seed germination of cotton to low temperature stress,which the change of MDA content to 12℃ stress for 36 h. The SOD activity and POD activity were maintained at a high level of SCRC 37 and SCRC 36 at all levels of treatment. To low temperature stress,the CAT activity of tolerant varieties was gradually surpassing that of chilling sensitive varieties. To 12℃ stress for 48 h,the content of free proline in SCRC37 from Stoneville 2B and Stoneville 5A,respectively was 33.32% and 23.27%. These results indicate that the physiological indexes were relatively stable in response to the differences of low temperature tolerance and germination of different varieties. The gene of CBF1, CBF2, CBF4, CBF6 were up-regulated more rapidly in strong chilling varieties,and the expression was reached peak when stressed to 12 h. These may be the reason why the strong chilling varieties are more sensitive and rapid in response to low temperature stress.

Key words: Cotton, Low temperature stress, Physiological indexes, Gene expression

中图分类号: 

• S562.01