نوع مقاله : مقاله کامل علمی- پژوهشی
نویسندگان
1 دانشگاه علوم کشاورزی و منابع طبیعی گرگان- اصلاح نباتات و بیوتکنولوژی
2 گروه اصلاح نباتات و بیوتکنولوژی،دانشکده تولید گیاهی، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، گرگان
3 گروه اصلاح نباتات و بیوتکنولوژی، دانشکده تولید گیاهی، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، گرگان
4 بخش تحقیقات زیست‌شناسی سیستم‌ها، پژوهشگاه بیوتکنولوژی کشاورزی، سازمان تحقیقات، آموزش و ترویج کشاورزی، کرج، ایران
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Background and purpose: Salinity stress is a major limiting factor for bread wheat production and poses a significant threat to global food security. The root system, critical for water and nutrient absorption, plays an essential role in determining yield under saline conditions. Root development directly influences grain yield and biomass production in salt-affected soils. Therefore, selecting salinity-tolerant genotypes through the simultaneous evaluation of root dry weight, biomass and grain yield traits and stress tolerance indices is an effective strategy for identifying salt‐tolerant genotypes in breeding programs.
Materials and methods: This study evaluated 92 bread wheat genotypes, including commercial cultivars and native lines, in a split-plot design within a randomized complete block design (RCBD) with three replications. The experiment was conducted under both saline (16.9 dS/m) and non-saline (2.3 dS/m) soil conditions in pots at the research greenhouse of Gorgan University of Agricultural Sciences and Natural Resources during the 2022–2023 crop year. Key traits such as grain yield, biomass, and root dry weight were measured after full plant maturity to assess their relationships under salinity stress.
Results: Analysis of variance revealed statistically significant differences among genotypes for grain yield, biomass, and root dry weight under both saline and non-saline conditions. Salinity stress significantly reduced these traits, with the greatest decreases observed in grain yield (71%), biomass (65%), and root dry weight (53%) based on the sensitivity index (SI). A positive and significant correlation was found between root dry weight and grain yield (0.57**) and biomass (0.84**) under salt stress, underscoring the critical role of root traits in improving yield under saline environments. Simple linear regression analysis further demonstrated that root dry weight significantly influenced grain yield and biomass, explaining 51% and 71% of their variation, respectively. Estimates indicated that each unit increase in root dry weight contributed an additional 0.95 grams to grain yield. Additionally, correlation analyses between performance traits and various salt tolerance indices highlighted the pivotal role of root characteristics in enhancing stress tolerance. Principal component analysis (PCA) effectively played a crucial role in the more precise discrimination of genotypes based on performance traits and salinity tolerance indices, contributed to the convergence of clustering dendrograms derived from tolerance indices in genotype classification pattern. Ultimately, the consistency among these findings facilitated the identification of genotypes exhibiting superior grain yield, root dry weight, and enhanced salinity tolerance.
Conclusion: Root architecture plays a fundamental role in improving salt tolerance in bread wheat. Genotypes with higher root dry weight under salt stress not only maintained acceptable grain yields but also exhibited enhanced biomass production. Therefore, prioritizing root traits in breeding programs represents a promising strategy to enhance yield stability and improve wheat productivity under saline conditions
کلیدواژه‌ها [English]
)