نوع مقاله : مقاله پژوهشی
نویسندگان
1 استادیار، مؤسسه تحقیقات اصلاح و تهیه نهال و بذر، سازمان تحقیقات، آموزش و ترویج کشاورزی، کرج، ایران.
2 استاد، مؤسسه تحقیقات اصلاح و تهیه نهال و بذر، سازمان تحقیقات، آموزش و ترویج کشاورزی، کرج، ایران.
3 کارشناس، مؤسسه تحقیقات اصلاح و تهیه نهال و بذر، سازمان تحقیقات، آموزش و ترویج کشاورزی، کرج، ایران.
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
This research was carried out to evaluate morpho-physiological and root-related traits of 20 bread and durum wheat genotypes of southern warm and dry, northern warm and humid, temperate, and cold agro-climatic zones in Iran, under non-stress and moisture stress conditions in grain filling stage. The experiment was conducted using factorial arrangements in randomized complete block design with three replicationsin glasshouses of Cereal Research Department, Seed and Plant Improvement Institute, Karaj, Iran, in 2023-24. The results showed significant differences among genotypes for all measured traits. The highest reductions in traits due to moisture stress were related to specific root length (SRA), grain yield plant-1, shoot dry weight plant-1 (SDW), and photosynthetic capacity (Fv/Fo). The highest increases due to moisture stress were observed to root volume density (RTD), root: top ratio (RTS), root dry weight plant-1 (RDW) and root volume (RV). Using PCA-based biplot, genotypes G9 (Barat), G17 (CD-96-10), G18 (C-96-10), G12 (Araz), G14 (Taktaz) and G7 (D-400-18) were identified as moisture stress tolerant with desirable morpho-physiological and
root-related traits. These bread and durum wheat genotypes can be using in the national wheat breeding programs for development of moisture stress tolerance in grain filling stage of new cultivars.
Keywords: Wheat, physiological traits, specific root length, root dry weight, root volume, grain yield plant-1.
Introduction
Wheat is the world’s most important cereal, which has the largest cultivated area and plays a central role in global food supply and security (OECD/FAO, 2020). The world's wheat cultivated area was 220 million hectares, and the total production was about 805 million tons in 2023. Iran, with a cultivated area of 6.2 million hectares and a total production of 13.5 million tons, ranked 13th among other major wheat producer countries (FAO, 2023).
Drought is one of the limiting factors for wheat production worldwide, and is a serious threat to food security. About one-third of the world's cultivated land is in arid and semi-arid regions (Blum, 2011). It seems that in improving new wheat cultivars, it is necessary to study the characteristics of the root system because the roots play key role in water and nutrients uptakes from the soil. In fact, the root structure determines the plant's ability to absorb resources from the soil) Pirnajmedin et al., 2015).
The present study, therefore, aimed to evaluate the morpho-physiological and root related traits of bread and durum wheat genotypes under non-stress and moisture stress conditions in graing filling stage.
Materials and Methods
This research was conducted in the glasshouses of the Seed and Plant Improving Institute as factorial arrangements in randomized complete block design with three replications in 2023-24. The main factor was: non- stress (optimal irrigation based on soil field capacity) and moisture stress (irrigation was ceased from the flowering stage), and the second factor included 20 bread and durum wheat genotypes developed by the national wheat breeding programs for temperate, southern warm and dry, northern warm and humid, and cold agro-climatic zones in Iran.
After seed germination, the seedlings were sown in small plastic pots and were transferred to freezer and kept at 4°C for two weeks, to statisfy their low temperature requirements. Then the seedlings were transferred to the glasshouse and grown in plastic tubes (130 cm high and 12 cm in diameter) containing soil and sand (3:1 ratio).
The traits measured in this experiment were day to heading (DH), day to physiological maturity (DM), plant height (PH), spike number plant-1(NS), grain number spike-1 (NG), grain yield plant-1 (Yield) and shoot dry weight plant-1 (SDW), chlorophyll index (SPAD), chlorophyll fluorescence parameters, root length (RL), root volume (RV), root dry weight plant-1 (RDW), specific root length (SRL), root volume density (RTD: root volume multiply by root dry biomass), and root: top ratio (RTS).
Analysis of variance was performed using SPSS software. Principal component analysis (PCA) was performed using XLSTAT software to interpret the relationships between measured traits.
Results and Discussion
The results revealed significant differences among genotypes for all measured traits. Also, the effect of moisture stress on all measured traits, except plant height, was significant. The results showed significant changes in the morpho-physiological and root related traits, which can be attributed to the differences in the genetic backgrounds of the studied bread and durum wheat genotypes. This result was confirmed by comparing responses of wheat genotypes of different agro-climatic zones to moisture stress in grain filling stage.
The greatest effect of moisture stress in grain filling stage was on specific root length, root volume density, root: top ratio, root and shoot dry weight plant-1 as well as grain yield plant-1, which led to increases or decreases in these traits compared to non-stress conditions. This finding is in accordance with the results reported by other researchers (Pirnajmedin et al., 2015)
In general, the results of PCA-based biplot showed that wheat genotypes; G9 (cv. Barat), G17 (CD-96-10), G18 (C-96-10), G12 (cv. Araz), G14 (cv. Taktaz) and G7 (D-400-18) were tolerant genotypes to moisture stress in grain filling stage with a more desirable morpho-physiological and root-realted traits. These genotypes can be used as parental genotypes in the national wheat breeding programs to develop and improve moisture stress tolerance in graing filling stage in new cultivars.
References
Anonymous. 2023. FAO statistical data. Available on: www.faostat.org
Blum, A. 2011. Plant breeding for water limited environments. Springer. New York, USA. 255 pp.
OECD/FAO. 2020. OECD-FAO Agricultural Outlook 2020-2029. FAO, Rome/OECD Publishing, Paris. 330 pp. DOI: 10.1787/1112c23b-en.
Pirnajmedin, F., Majidi, M. and Gheysari, M. 2015. Root and physiological characteristics associated with drought tolerance in Iranian tall fescue. Euphytica, 202(1), pp.141–155. DOI: 10.1007/s10681-014-1239-5
کلیدواژهها [English]
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