Investigation of the Possibilities for Applying Fluorescence Spectroscopy in the Qualification of Melon Seeds (Cucumis melo L.) Before Sowing

Male sterility is an important trait in heterosis breeding in a number of crops. The main advantage is low-cost seed production. Five types of male sterility have been discovered in melon, which are applied in seed production schemes. Bulgarian hybrid melon varieties were developed based on ms-4 type male sterility. The maternal parent component in nu-clear male sterility segregates into fertile to sterile plants 50%:50%. Therefore, fertile plants must be removed at the beginning of flowering period, which is a labor-intensive practice. This question provokes us to investigate for other ways to distinguish fertile from sterile plants. Fluorescence spectroscopy is a non-contact, fast-acting, selective, and non-destructive method of the sample being examined. The development of a method for evaluating melon seeds with its application is an important scientific and applied ad-vantage. To date, there is no data on a study. The aim of this study was to establish relia-ble parameters of fluorescence spectroscopy with the indicators of male sterility type ms-4. To establish the applicability of the method in primary screening for checking male steril-ity in the seed phase of melon, seeds from three breeding lines VK/1-5-5, K/15-6 and 11/9С were examined in March (sowing) and May (flowering) 2025, and June (sowing) to July (flowering) 2025. The results of the analysis reflect both a difference in signal intensity and shift in the emission maximum of the spectral distributions of the seeds from the different lines. Based on the generated clear and distinct differences in the spectral distribution in all seeds from the three breeding lines. It was established that fluorescence spectroscopy is applicable in screening melon seeds immediately before sowing to check their fertility or sterility.