The determination of agronomic characteristics of pea lines in F4 generation

Peas, the fourth most produced legume globally, suffer from yield losses due to diseases. Developing disease-tolerant varieties can contribute to sustainable agriculture by meeting the protein needs through pea cultivation. For this reason, 24 pea lines, advanced to the F4 generation through hybridization and single-seed descent selection, along with 6 control varieties, were evaluated in 2016 under field conditions in Konya using an Augmented Experimental Design with three replications. Among the genotypes, the highest number of pods per plant (11.35 pods) was observed in the line coded as G1 (10-1). The line coded as G11 (12-1) demonstrated the highest seed yield (229.93 kg da⁻¹). Additionally, plants exhibiting natural symptoms of viral infection and powdery mildew under field conditions were scored as 1 (diseased), while those without symptoms were scored as 3 (healthy). To evaluate the tolerance of genotypes under these biotic stress conditions, a path analysis was conducted. The path model revealed that plant height, pod width, and pod height were associated with the presence of viral and powdery mildew pathogens. Furthermore, a cluster analysis based on these five traits grouped the 24 lines and 6 control varieties into four clusters. In the first group, comprising susceptible genotypes, G11 (12-1) and G9 (4) emerged as the most tolerant lines. The second group included genotypes tolerant to both pathogens, with G10 (208) standing out. The third group consisted of genotypes tolerant to powdery mildew, with G1 (10-1), G2 (15), and G18 (10-1 Ozel S) being prominent. The fourth and final group, composed of the most tolerant genotypes, identified G12 (10-1 Ozel) as the most productive type. Based on the findings, we conclude that these seven genotypes, characterized by high tolerance to diseases and superior seed yield, hold potential as genetic resources for developing high-yielding, disease-resistant pea varieties. Keywords: Augmented trial design, plant breeding, Pisum sativum ssp. arvense, selection, yield