Screening of bread wheat inbred lines (F۹) derived from the crossing of “Marvdasht” ˟ “Rasoul”

Introduction: The importance of bread wheat as one of the most strategic grain is clear for everyone. Estimates of the International Maize and Wheat Research Center (CYMMYT) indicate that the global demand for wheat in ۲۰۵۰ will be ۶۰% higher than the current demand (about ۶۶۳ million tons). This is while the amount of available wheat resources will decrease by ۲۰-۳۰% (Keshavarznia et al., ۲۰۲۳). The area under wheat cultivation in Iran during ۲۰۲۱-۲۰۲۲ cropping year was equal to ۶.۹ million hectares, from which ۱۳.۲ million tons of wheat were harvested (Anonymous, ۲۰۲۳). Genetic diversity is considered as one of the basic prerequisites in crop breeding programs because it helps in better selection and thus improvement and introduction of adaptable genotypes with high yield potential (Atsbeha et al., ۲۰۲۴). Selection based on traits that have a strong correlation with grain yield can be a reliable and effective method for screening available genetic resources and indirectly improving grain yield (Khoury et al., ۲۰۲۳). The current research was conducted with the aim of selecting the best bread wheat lines in terms of yield and other agronomic characteristics. Materials and methods: The number of six inbred lines (F۹ generation) obtained from the Marvdasht (M) and Rasoul (R) cross and their parents, along with Krichauff variety (KRY) and a common cultivar in the region (Torabi, T) as a control, were evaluated based on a randomized complete blocks design in four replications during ۲۰۲۱-۲۰۲۲ cropping year in the Research Farm of the Faculty of Agriculture, Razi University, Kermanshah, Iran. The spikes of ten plants were randomly selected from each plot and different traits including plant height, grain length and width, grain diameter, internal and external peduncle length, and spike length were recorded. Other investigated traits included days to booting, days to heading, days to anthesis, days to physiological maturity, period and rate of grain filling. The grain yield (g/m۲) was measured based on one square meter for each plot. Normality test was done and then, SAS software was used for analysis of variance and mean comparisons using the least significant difference (LSD) method. Pearson correlation coefficients as well as cluster analysis (Ward's method and based on Euclidean distance square) were performed on the data using SPSS software. SYSTAT software was used to draw the Pseudo-F diagram. Results and Discussion: Variance analysis of the data showed that there is a significant difference between the lines in terms of grain yield, plant height, days to booting, days to anthesis, days to physiological maturity, grain length, spike length, grain filling period, and rate (Table ۱). The results of mean comparison showed that the highest grain yield was related to Rasoul and Torabi cultivars with ۴۲۶.۸۹ and ۴۲۱.۰۱ grams per square meter. Line “۴۰” with ۱۰۴.۲۵ cm had the highest plant height and Line “۲۹” with ۱۷۳ days was identified as the earliest line in terms of phenological traits. Correlation coefficients (Table ۲) showed that grain filling rate had a negative significant correlation with days to physiological maturity and grain filling period. The length of grain filling period showed a positive significant correlation with days to physiological maturity. Dastoor & Asghari-Zakaria (۲۰۱۴) reported a similar result in their research. Based on the results of cluster analysis in this research (Fig. ۱), the genotypes were classified into three groups. The first group consisted of five lines with the parents Marvdasht and Rasoul. In the second group, only Torabi cultivar was located. The third group included one line along with Krichauff variety. The results of the pseudo-F diagram also confirmed this grouping (Fig. ۲). Conclusion: In general, according to the results obtained from this research, the lines included in the first group, which were early-matured lines, had more measured traits and high correlation with grain yield. Therefore, they could be selected and used in breeding programs to select superior genotypes in order to improve cultivars. Keywords: Analysis of variance, Bread wheat, Correlation analysis, Grain yield, Inbred line

کلیدواژه ها:

Analysis of variance ، Bread wheat ، Correlation analysis ، Grain yield ، Inbred line