Relationships between Tillering, Grain Yield and Yield Components in Durum Wheat Genotypes

The grain yield of wheat is influenced by agronomic traits determined by genetic factors, such as tillering capacity, grain weight, and the number of grains per spike, as well as biotic and abiotic factors and cultivation techniques. This study examined several traits, including the number of fertile tillers, main stem height, main spike length, number of grains per main spike, main spike yield, yield from other tillers, yield per tiller, single-plant yield, and the number of days to spike formation. Additionally, relationships between the number of tillers and other traits were evaluated. Some hybrid combinations stood out with notable characteristics in the study. One prominent example is the Ç-1252/AR hybrid, which demonstrated significant potential for main spike yield, yield from other tillers, yield per tiller, and single plant yield. Another noteworthy combination is the Poyraz/Kızıltan 91 hybrid, which excelled in increasing the number of fertile tillers, reducing main stem length, enhancing grain number per main spike, and improving main spike yield, yield from other tillers, yield per tiller, single plant yield, as well as promoting earliness. As in the findings of the hybrid combinations of Ç-1252/AR14 and Poyraz/Kızıltan 91, new promising lines or varieties can be developed in terms of yield and yield components from crossbreedings of registered varieties among themselves or landraces in future studies. Significant correlations were observed between the number of fertile tillers and main spike length (0.64), yield of other tillers (0.84), and single-plant yield (0.84). Moderate correlations were found between the number of grains in the main spike (0.52) and main spike yield (0.59). Moreover, the correlation between grain yield per tiller and single-plant yield (0.80) was higher than that between main spike yield and single-plant yield (0.78). Additionally, the stability value of grain yield per tiller (0.57) exceeded that of grain yield from the main spike (0.40). These findings suggest that maintaining a balanced number of tillers through appropriate planting density, determined using the single-plant sowing method, could potentially increase grain yield.