Research on Breeding by Seeds of Rhododendrons Species at the Botanical Garden of Jibou

Abstract

SUMMARY In nature rhododendrons multiply almost exclusively through seeds. It is a method widely used in improvement works of species and rootstocks (Iliescu, 2002). The paper presents the results of various seeding techniques on different culture substrates to identify an optimal method of obtaining rootstocks and plant required for hybridization. All seeds were received from botanical gardens and arboretum which have exchange relations with the Botanical Garden of Jibou. Rhododendron species were chosen from previous experiments that proved resistant to low temperatures and adapted to the climatic conditions in the area. All seeds were sown in March, in the greenhouse on a substrate made of 70% peat moss and 30% perlite in pots and kept at a temperature of 21-24C (Railey, 2004). Pots were covered with plastic foil (Tataranu, 1960). Germination lasted from 12 days to 4 weeks, depending on the species and the freshness of seeds. When seedlings have two to four true leaves, transplant them into pots with different substrates. The following were pursued in the experiment:  seedling growth and development on different soil substrates using six variants;  establishing an optimal pH for plant development.