Effect of salt and osmotic stresses on germination in durum wheat (Triticum durum Desf.)
Effect of salt and osmotic stresses on germination in durum wheat (Triticum durum Desf.)
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DOI：
10.1023/a:1010378409663
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发表时间：
2001-04-01
期刊：
影响因子：
4.9
通讯作者：
Lutts, S
中科院分区：
文献类型：
--
作者：
Almansouri, M;Kinet, JM;Lutts, S
为了确定离子毒性与盐胁迫的渗透组分对硬粒小麦（Triticum durum Desf.）发芽的相对重要性，在NaCl、甘露醇和聚乙二醇（PEG）的各种等渗溶液（渗透势为-0.15（对照溶液）、-0.58、-1.05或-1.57MPa）中孵育三个在盐和干旱抗性方面不同的品种（Omrabi-5，干旱抗性; Belikh，盐抗性和Cando，盐敏感性）的种子。中等应力强度只延迟发芽，而最高浓度的NaCl和PEG降低最终发芽率。PEG是最有害的溶质，而甘露醇对最终发芽率没有影响。处理48 h后，所有的拟南芥胚乳淀粉和可溶性糖含量以及α-淀粉酶活性均降低，而β-淀粉酶活性则相反，在所有品种中略有刺激。NaCl和PEG对离体胚萌发到体外Linsmaier和Skoog（LS）培养基上的有害影响高于整个种子。然而，所有PEG处理的胚胎，恢复后的压力缓解，而NaCl处理的胚胎表现出较低的恢复率和一定程度的异常萌发后冲洗。它的结论是，应力抑制发芽不能归因于抑制动员储备和PEG的主要影响发生通过抑制水的吸收，而有害影响的NaCl可能与长期积累的有毒离子的影响。这三个品种在发芽过程中的行为并没有完全反映出它们在田间条件下的平均水平，因此，不推荐发芽作为育种目的的可靠选择标准。
In order to determine the relative importance of ionic toxicity versus the osmotic component of salt stress on germination in durum wheat (Triticum durum Desf.), seeds of three cultivars differing in their salt and drought resistance (Omrabi-5, drought-resistant; Belikh, salt-resistant and Cando, salt-sensitive) were incubated in various iso-osmotic solutions of NaCl, mannitol and polyethylene-glycol (PEG) (osmotic potential of -0.15 (control solution) -0.58, -1.05 or -1.57 MPa). Moderate stress intensities only delayed germination, whereas the highest concentration of NaCl and PEG reduced final germination percentages. PEG was the most detrimental solute, while mannitol had no effect on final germination percentages. All osmotica reduced endosperm starch and soluble sugars content as well as alpha -amylase activities recorded after 48 h of treatment while beta -amylase activities were, in contrast, slightly stimulated in all cultivars. Deleterious effects of NaCl and PEG were higher on isolated embryos germinated onto an in vitro Linsmaier and Skoog (LS) medium comparatively to whole seeds. All PEG-treated embryos, however, recovered after the stress relief while NaCl-treated embryos exhibited a lower rate of recovery and some extent of abnormal germination after rinsing. It was concluded that stress inhibition of germination could not be attributed to an inhibition of mobilisation of reserves and that the main effect of PEG occurred via an inhibition of water uptake while detrimental effects of NaCl may be linked to long-term effects of accumulated toxic ions. The behaviour of the three cultivars during germination did not fully reflect their mean level of putative stress resistance in field conditions and germination is, therefore, not recommended as a reliable selection criterion for breeding purposes.