Comparison of Performance and Nutritional Traits of Promising Wheat Lines with the Local Control Mehrgan under Farmers' Conditions in Darab and Fasa, Fars Province

Breeding experiments initiated with the examination of segregating generations serve as a significant source for creating genetic diversity, continuing with comparing genotypes in preliminary, advanced, and adaptability performance trials. Superior lines require further investigation under real farm conditions. Selected lines, along with common regional varieties, were assessed in performance comparison experiments, categorized as On-farm trials. These comparisons aim to evaluate new lines against traditional varieties concerning higher grain yield, disease resistance, early maturity, and lower water consumption outside of the research station areas. Additionally, conducting these trials on farmers' fields enhances the awareness of farmers, experts, and extension agents regarding the characteristics of new lines. This study aimed to compare the agronomic and quality traits of three promising bread wheat lines (S-98-7, S-98-11, and S-98-22) with the local control variety Merghan in the warm climates of Fasa and Darab during the cropping season 2022-2023. The seed rate was set at 400 seeds per square meter (equivalent to 180 kg per hectare) over 2000 square meters. Data on days to germination, spike emergence, physiological maturity, number of grains per spike, number of spikes per square meter, sensitive to shedding, plant height, lodging, grain yield, thousand-grain weight, and major plant diseases (yellow rust, stem rust, brown rust, septoria leaf blotch, and septoria strip blotch) were recorded. Quality traits related to baking (protein content, Zeleny mix volume, hardness index, wet gluten percentage, gluten index, SDS sedimentation, and hectoliter weight) were analyzed to examine the nutritional value. Results indicated no significant differences in the number of days to physiological maturity among the tested genotypes. Based on the results from Darab, Fasa, and the average of both experiments, Line S-98-22 yielded the highest grain production (10,006; 9,880; and 9,943 kg per hectare, respectively) compared to the control yield (Darab: 9,947 kg per hectare, Fasa: 8,571 kg per hectare, and average of both regions: 9,259 kg per hectare). Observations in both regions indicated no lodging or the presence of leaf blotch diseases (septoria leaf blotch, bacterial strip blotch, yellow rust, brown rust, and stem rust), with only 5% yellow rust reported in the control variety in the Fasa trial and 5% lodging in the control variety in the Darab trial. Ultimately, the Selection Index of Ideal Genotype Index (SIIG) identified Line S-98-22 as the best line based on the evaluated traits across both regions. Regarding quality traits, Line S-98-22 exhibited the highest wet gluten, gluten index, protein content, and suitable Zeleny volume, indicating the best baking quality. Other genotypes also fell within the range of desirable baking quality genotypes. Given its favorable agronomic traits, including high grain yield and drought stress tolerance at the end of the season, along with quality characteristics, Line S-98-22 can be introduced as a new bread wheat variety for warm and dry regions.