Department of Agronomy and Plant Breeding, College of Agriculture, Isfahan University of Technology, Isfahan, Iran.
PLoS One. 2024 Sep 12;19(9):e0310061. doi: 10.1371/journal.pone.0310061. eCollection 2024.
The effects of salinity memory and its interaction with genetic diversity for drought tolerance and pollination system in terms of morphological, physiological, root characteristics and spectral reflectance indices (SRIs) in tall fescue is still unknown.
Four tall fescue genotypes (two drought-sensitive and two drought-tolerant) were manually controlled to produce four selfed (S1) and four open-pollinated (OP) progeny genotypes (finally eight progeny genotypes). Then all genotypes were assessed for two years in greenhouse under five salinity treatments including control treatment (C), twice salinity stress treatment (primary mild salinity stress in two different stages and secondary at the end stage) (S1t1S2 and S1t2S2), once severe salinity stress treatment (secondary only, S2), and foliar spray of salicylic acid (SA) simultaneously with secondary salinity stress (H2S2).
Results indicated that obligate selfing (S1) caused to inbreeding depression in RWC, plant growth, catalase activity, root length and the ratio of root/shoot (R/S). Once salinity stress treatment (S2) led to depression in most measured traits, while pre-exposure to salinity (salinity memory) (S1t1S2 and S1t2S2) improved photosynthetic pigments, proline, antioxidant enzymes and R/S.
Salinity memory was more pronounced in drought-sensitive genotypes, while it was more evident in OP than S1 population. Foliar spray of salicylic acid (SA) was almost equally effective in reducing the effects of salinity stress in both populations. The efficacy of application was more pronounced in tolerant genotypes compared to sensitive ones. The possibility of modeling correlated spectral reflectance indices (SRIs) for prediction of different morphological, physiological and root characteristics will be discussed.
盐分记忆的影响及其与耐旱性和授粉系统的遗传多样性的相互作用，就羊茅的形态、生理、根系特征和光谱反射率指数（SRIs）而言，在羊茅中仍然未知。
人为控制四种羊茅基因型（两个耐旱敏感型和两个耐旱型），产生四个自交（S1）和四个开放授粉（OP）后代基因型（最终得到八个后代基因型）。然后，所有基因型在温室中进行了两年的评估，共进行了五个盐分处理，包括对照处理（C）、两次盐分胁迫处理（两次不同阶段的初级轻度盐分胁迫和第二次在末期）（S1t1S2 和 S1t2S2）、一次严重盐分胁迫处理（仅第二次，S2），以及同时进行二次盐分胁迫的水杨酸叶面喷雾（H2S2）。
结果表明，强制自交（S1）导致 RWC、植物生长、过氧化氢酶活性、根长和根/茎比（R/S）的近交衰退。一旦盐分胁迫处理（S2）导致大多数测量性状的衰退，而盐分预暴露（盐分记忆）（S1t1S2 和 S1t2S2）提高了光合色素、脯氨酸、抗氧化酶和 R/S。
盐分记忆在耐旱敏感型基因型中更为明显，而在 OP 中比 S1 群体中更为明显。水杨酸叶面喷雾（SA）在两个群体中几乎同样有效地减轻盐分胁迫的影响。与敏感基因型相比，在耐受基因型中应用效果更为明显。将讨论建立相关光谱反射率指数（SRIs）模型以预测不同形态、生理和根系特征的可能性。
