טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
Ph.D Thesis
Ph.D StudentBen-Simhon Zohar
SubjectStudying the Genetic-Molecular Components that are
Responsible for Anthocyanin Biosynthesis in
Pomegranate (Punica granatum L.)
DepartmentDepartment of Biology
Supervisors Professor Oded Beja
Dr. Doron Holland
Full Thesis text - in Hebrew Full thesis text - Hebrew Version


Abstract


Color in Pomegranate is one of the most important features within the framework of the pomegranate breeding program, conducted at the Newe-yaar Research Center. Pomegranate color has significant influence on the demand and consumption of pomegranate as an edible product and as a gardening and ornamental plant. In addition, color influences the ability of the fruit and plant to cope with abiotic environmental stress, such as UV radiation. The molecules that contribute to color in pomegranate have also antioxidant activity that is beneficial for human health. Anthocyanins are the molecules that contribute most of the color in pomegranate and are responsible for typical color variations among different pomegranate accessions; these include the red, pink, orange and even dark purple color.

Three accessions that represent the color variation in the Israeli pomegranate collection were studied for the purpose of identifying the molecular and genetic components which are responsible for color variation (anthocyanin) in the skin, arils and flowers of pomegranate.

The findings of this study include the identification of genes involved in pomegranate anthocyanin biosynthesis pathway, and identification and usage of genetic markers for the "white", "orange" and purple color. These markers might shorten and improve the breeding process of new pomegranate cultivars. The results of this study may also elucidate the anthocyanin metabolic flux, and  show how flavonoid compounds which are upstream to anthocyanins  and known to be highly beneficial to the human diet could be over accumulated. In addition, understanding the genetic basis for the variation of color in pomegranate might improve our understanding concerning the influence of the composition of anthocyanin and other flavonoids on the protection against environmental stress such as heat and UV radiation, as well as extending shelf life and light signal transduction. This study proved for the first time in pomegranate that the genetic approach which combines molecular markers and breeding populations can be efficiently used in order to identify genes, which determine important phenotypes. Moreover, these findings demonstrate that the pomegranate, beyond its commercial and cultural importance, can be utilized as an efficient genetic model system for identifying genes that are involved in important features of deciduous fruit trees.