Investıgation of resıstance mechanısm and ınherıtance to downy mıldew (Pseudoperonospora cubensis) ın cucumber recombınant inbred lines

The presence of the Downy Mildew pathogen Pseudoperonopora cubensis significantly reduces the fruit yield in cucumber production. Hence, it is crucial to offer resistance against Downy Mildew. A population was established by combining the susceptible material 41311 and the resistant material A064949, both of which originated from Pakistan. The populations were derived by the process of backcrossing, and these lines advanced to the F9 and F10 generations. Based on the observations, hybrids were produced by crossing resistant and susceptible lines. The phenotypic evaluation of the materials, including resistant materials, susceptible materials, and hybrids, revealed the presence of downy mildew under controlled greenhouse settings. Furthermore, the agronomic traits of all materials were observed within the confines of the greenhouse. The DNAs obtained from all populations cultivated in a controlled greenhouse environment were analyzed using the 96 SNP marker. The phenotypic observations of Downy Mildew were used to study its associations with QTLs. The research findings indicate that the 3rd, 4th, and 5th chromosomes exert a substantial influence on resistance to downy mildew. This study utilizes markers denoted as A, F, O, Q, and R codes to facilitate marker-assisted selection. These markers enable the development of lines and hybrids that are resistant to downy mildew.