Determination of the effects of anter and shed-microspore culture and polyamine applications on haploid embryo formation in pepper (Capsicum annuum L.) breeding

Pepper (Capsicum annuum L.) belongs to the Solanaceae family and has high economic value and is of great importance in the Mediterranean region in terms of climate and growing conditions. More greenhouse cultivation has made the use of hybrid (F1) seeds and pepper breeding widespread. It is important to develop new hybrid varieties that are resistant to pests and diseases, high quality and high yield in pepper, which is mostly grown in open fields and greenhouses in the Mediterranean region. Since classical breeding studies take many years, biotechnological methods are used to produce hybrid varieties. One of the biotechnological methods is plant tissue culture. Among plant tissue culture techniques, the creation of haploid plants provides significant contributions to breeding studies. Thanks to this method, which is frequently used in breeding studies, the breeding of new varieties/genotypes can be carried out more easily and quickly. In Turkey, it was aimed to obtain haploid plants using anther and shed-microspore culture with three different commercially grown kapya pepper (Capsicum annuum L.) varieties (Diyar F1, SF549 F1, and Zaruri F1). Putrescine and spermidine were added to the nutrient media to investigate the effects of polyamines on haploid plant formation. In the anther culture technique, P1 was used, while P2 solid and P3 liquid media were used in the shed-microspore culture technique. In addition to these basic nutrient media, different combinations were created by adding various doses of putrescine and spermidine. The study began with the preparation of nutrient media and the collection of flower buds. The buds were sterilized in a sterile cabinet, and their anthers were extracted. The extracted anthers were then planted in nutrient media, with 15 anthers per petri dish. After planting, the petri dishes were wrapped with stretch film and parafilm and placed in an incubator at 35°C in the dark for 2 days. The development of the anthers was monitored in a climate-controlled room. After approximately 4 weeks, embryos started to appear. The formed embryos were transferred to MS0 nutrient media. The developing embryos transformed into plantlets, resulting in the production of haploid plants. The study evaluated the number of petri dishes cultured, the number of anthers planted, the number of embryos formed, the number of normal and abnormal embryos, the number of plants obtained, and the percentage of plant yield. The effect of polyamines on haploid plant formation was demonstrated. The main objective of this study was to determine the effects of polyamines on the production of haploid plants in important kapya pepper varieties in our country and to compare the responses of these varieties to the applications. This is a significant step in plant breeding studies and can contribute to the shortening of pepper breeding efforts. Up to the writing of this thesis, polyamine applications in pepper haploid studies had not been encountered. In this respect, the study is a pioneering one. The results showed that polyamines play an important role in the process of obtaining haploid plants and that the differences among genotypes are influential in this process. Given that this type of study was conducted for the first time, its originality is high. Future studies should investigate more varieties/genotypes, different types of peppers, and different polyamine combinations.