Soil salinity has become a serious environmental abiotic stress limiting crop productivity and quality. The root system is the first organ sensing the changes in salinity. Root development under elevated salinity is therefore an important indicator for saline tolerance in plants. Previous studies focused on varietal differences in morphological traits of quinoa under saline stresses; however, variation in root development responses to salinity remains largely unknown. To understand the genetic variation in root development responses to salt stress of quinoa, we conducted a preliminary screening for salinity response at two salinity levels of a diverse set of 52 quinoa genotypes and microsatellite markers were used to link molecular variation to that in root development responses to salt stresses of represented genotypes. The frequency distribution of saline tolerance index showed continuous variation in the quinoa collection. Cluster analysis of salinity responses divided the 52 quinoa genotypes into six major groups. Based on these results, six genotypes representative of groups I to VI including Black quinoa, 2‐Want, Atlas, Riobamba, NL‐6 and Sayaña, respectively, were selected to evaluate root development under four saline stress levels: 0, 100, 200 and 300 mM NaCl. Contrasts in root development responses to saline stress levels were observed in the six genotypes. At 100 mM NaCl, significant differences were not observed in root length development (RLD) and root surface development (RSAD) of most genotypes except Black quinoa; a significant reduction was observed in this genotype as compared to controls. At 200 mM NaCl, significant reduction was detected in RLD and RSAD in all genotypes showing this as the best concentration to discriminate among genotypes. The strongest inhibition of root development was found for all genotypes at 300 mM NaCl as compared to lower saline levels. Among genotypes, Atlas of group III shows as a saline‐tolerant genotype confirming previous reports. Variation in root responses to salinity stresses is also discussed in relation to climate conditions of origins of the genotypes and reveal interesting guidelines for further studies exploring the mechanisms behind this aspect of saline adaptation.

中文翻译：

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藜对盐胁迫根发育响应的遗传变异

土壤盐分已经成为严重的环境非生物胁迫，限制了作物的生产力和质量。根系统是第一个感知盐度变化的器官。因此，盐分升高下的根系发育是植物耐盐性的重要指标。以前的研究集中在盐胁迫下藜麦的形态特征上的品种差异。然而，根系发育对盐度反应的变化仍然未知。为了了解藜麦对盐胁迫的根系发育响应的遗传变异，我们对52种藜麦基因型的不同盐度水平下的盐度响应进行了初步筛选，并使用微卫星标记将分子变异与根系发育响应的分子变异联系起来。代表基因型的盐胁迫。耐盐指数的频率分布显示藜麦收集物中的连续变化。盐度响应的聚类分析将52种藜麦基因型分为六个主要组。根据这些结果，分别选择了代表I至VI组的六种基因型，分别包括黑藜麦，2-Want，Atlas，Riobamba，NL-6和Sayaña，以评估四种盐胁迫水平下的根系发育：0、100、200和300 mM NaCl。在六种基因型中观察到根部发育对盐胁迫水平的响应的差异。在100 mM NaCl中，除黑藜麦外，大多数基因型的根长发育（RLD）和根表面发育（RSAD）均未观察到显着差异。与对照相比，该基因型观察到显着降低。在200 mM NaCl下，在所有基因型中检测到RLD和RSAD的显着降低，表明这是区分基因型的最佳浓度。与较低的盐水平相比，在300 mM NaCl的所有基因型中，根发育的抑制作用最强。在基因型中，第三组图集显示为耐盐基因型，证实了先前的报道。还讨论了根系对盐分胁迫的响应变化与基因型起源气候条件的关系，并揭示了有趣的指导方针，供进一步研究探索盐分适应这一方面的机制。第三组地图集显示为耐盐基因型，证实了先前的报道。还讨论了根系对盐分胁迫的响应变化与基因型起源气候条件的关系，并揭示了有趣的指导方针，供进一步研究探索盐分适应这一方面的机制。第三组地图集显示为耐盐基因型，证实了先前的报道。还讨论了根系对盐分胁迫的响应变化与基因型起源气候条件的关系，并揭示了有趣的指导方针，供进一步研究探索盐分适应这一方面的机制。