Khan Hammad Aziz, Siddique Kadambot H M, Munir Rushna, Colmer Timothy David
School of Plant Biology, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia; UWA Institute of Agriculture, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia.
UWA Institute of Agriculture, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia.
J Plant Physiol. 2015 Jun 15;182:1-12. doi: 10.1016/j.jplph.2015.05.002. Epub 2015 May 19.
Chickpea is a relatively salt sensitive species but shows genotypic variation for salt tolerance, measured as grain yield per plant in mild-to-moderately saline soil. This experiment was designed to evaluate some physiological responses to salinity in three contrasting genotypes. One tolerant (Genesis836), one moderately tolerant (JG11) and one sensitive (Rupali) genotype were grown for 108d in non-saline nutrient solution (controls) and two levels of salinity treatment (30 and 60mM NaCl). No plants survived to maturity in the 60mM NaCl treatment; however, Genesis836 survived longer (87d) than JG11 (67d) while Rupali died after 27d; only Genesis836 flowered, but no pods were filled. At 30mM NaCl, Genesis836 produced a few filled pods, whereas JG11 and Rupali did not. Genotypic differences in plant dry mass at the vegetative stage were evident only at 60mM NaCl, while at maturity differences were evident at 30mM NaCl. Photosynthesis was maintained to different degrees by the three genotypes (e.g. at 30mM NaCl, 35-81% of controls; highest in Genesis836); photosynthesis was restricted predominately due to non-stomatal limitations as the intercellular CO2 concentration was only modestly affected (94-99% of controls). Photosystem II damage was evident in the less tolerant genotypes (e.g. at 30mM NaCl, actual quantum efficiency of photosystem II values were 63-96% of controls). Across treatments, shoot dry mass was negatively correlated with both Na(+) and Cl(-) shoot concentrations. However, the sensitive genotype (Rupali) had equal or lower concentrations of these ions in green leaves, stems or roots compared to tolerant genotypes (JG11 and Genesis836); ion 'exclusion' does not explain variation for salt tolerance among these three chickpea genotypes. The large difference between Rupali (sensitive) and Genesis836 (tolerant) in the salt-induced reduction in net photosynthesis via non-stomatal limitations and the assessed damage to photosystem II, but with similar leaf ion concentrations, provides evidence that variation in 'tissue tolerance' of Na(+) and/or Cl(-) in leaves contributes to the differential salt tolerance of these chickpea genotypes.
鹰嘴豆是一种对盐分相对敏感的物种，但在轻度至中度盐渍土壤中，以单株籽粒产量衡量，其耐盐性存在基因型差异。本实验旨在评估三种不同基因型对盐分的一些生理反应。一种耐盐基因型（Genesis836）、一种中度耐盐基因型（JG11）和一种敏感基因型（Rupali）在非盐营养液（对照）和两种盐度处理水平（30和60mM NaCl）中生长108天。在60mM NaCl处理中，没有植株存活至成熟；然而，Genesis836存活时间比JG11长（87天），而JG11存活67天，Rupali在27天后死亡；只有Genesis836开花，但没有结荚。在30mM NaCl时，Genesis836结了一些饱满的豆荚，而JG11和Rupali没有。营养生长阶段植株干质量的基因型差异仅在60mM NaCl时明显，而在成熟时，差异在30mM NaCl时明显。三种基因型对光合作用的维持程度不同（例如，在30mM NaCl时，为对照的35 - 81%；Genesis836最高）；光合作用主要因非气孔限制而受到限制，因为细胞间二氧化碳浓度仅受到适度影响（为对照的94 - 99%）。在耐盐性较差的基因型中，光系统II损伤明显（例如，在30mM NaCl时，光系统II的实际量子效率值为对照的63 - 96%）。在所有处理中，地上部干质量与地上部Na(+)和Cl(-)浓度均呈负相关。然而，与耐盐基因型（JG11和Genesis836）相比，敏感基因型（Rupali）在绿叶、茎或根中的这些离子浓度相同或更低；离子“排斥”并不能解释这三种鹰嘴豆基因型之间的耐盐性差异。Rupali（敏感型）和Genesis836（耐盐型）在盐诱导的通过非气孔限制导致的净光合作用降低以及评估的光系统II损伤方面存在很大差异，但叶片离子浓度相似，这提供了证据表明叶片中Na(+)和/或Cl(-)的“组织耐受性”差异导致了这些鹰嘴豆基因型的不同耐盐性。
