六个生长时期高粱对NaCl胁迫的响应

为了解高粱不同生长时期对NaCl胁迫的响应机制,以高粱杂交品种济粱1号为研究材料,采用自来水(CK)和0.6% NaCl溶液(T)对萌发期、苗期、拔节前期、拔节后期、孕穗期和开花期的济粱1号进行28 d处理。结果表明,与CK相比,萌发期开始NaCl胁迫,其株高、茎粗、地上部鲜重和根干重均差异显著,相对盐害率(RSR)最大,受NaCl胁迫危害最严重。拔节前期NaCl胁迫对穗鲜重影响最显著,其次是拔节后期和孕穗期。拔节前期、拔节后期和孕穗期开始NaCl胁迫对抽穗期影响均不显著。与CK相比,萌发期、拔节后期、孕穗期和开花期开始NaCl胁迫其叶片SPAD值显著降低;与CK相比,6个生长时期进行NaCl胁迫均显著提高了叶片和根中Na⁺含量;除萌发期外,NaCl胁迫后,其他5个生长时期叶中K⁺含量显著高于CK。在6个生长时期,NaCl胁迫根中K⁺含量以及叶片和根中K⁺/Na⁺显著低于CK。因此,萌发期开始NaCl胁迫对高粱幼苗形态建成影响最大,拔节前期NaCl胁迫对穗鲜重的积累影响最显著,在生产上应采取一定的抗盐胁迫措施。本研究揭示了济粱1号在6个生长时期的耐盐特点和耐盐生理机制,为盐碱地制定科学合理的抗盐栽培管理措施提供了一定的理论指导。

Response to NaCl Stress of Sorghum at Six Growth Stages

To better understand the characteristics of sorghum for NaCl stress at different growth stage, a bred salt tolerant hybrid, Jiliang No.1, was selected, and plants at germination stage (GS), seedling stage (SS), early jointing stage (EJS), later jointing stage (LJS), booting stage (BS) and flowering stage (FS), were treated with tap water (CK) and 0.6% NaCl solution (T) for 28 days. Results showed that compared with CK, NaCl stress resulted in a significant impact on plant height (PH), stem diameter (SD), fresh weight of aerial parts (FS) and dry weight of root (RDW) at the GS, and relative salt-injury rate (RSR) was the largest in the six growth stages. Spike fresh weight (SFW) was significantly impacted by NaCl stress at the EJS and followed by the LJS and BS. Heading time (HT) was less influenced when plants were subjected to NaCl stress starting at the EJS, LJS and BS. Soil and plant analyzer development (SPAD) values were significantly decreased when NaCl stress starts at the GS, EJS, LJS and BS. Na⁺ contents in leaves and roots in the six growth stages were significantly increased under NaCl stress,whereas K⁺ contents in leaves were significantly higher under NaCl stress than CK except for the GS. K⁺ content in root under NaCl stress was significantly lower than CK, and K⁺/Na⁺ in leaves and roots were all significantly decreased under NaCl stress in the six growth stages. Therefore, NaCl stress starting at the GS had the greatest effect on morphogenesis of sorghum seedlings, and salt stress starting at the EJS had the most significant effect on the accumulation of SFW. It is better to take some measures to reduce the influence of salt stress to plant in production. To some extent, the present research illustrated the characteristics and physiology mechanism for NaCl tolerance of Jiliang No.1, which provides a theoretical guidance for formulating the scientific and effective cultivation measures of sorghum in saline and alkali land.