Yerli mandarin x Carrizo sitranjı melezlerinde, embriyo kurtarma tekniğinde embriyo gelişim aşaması ve GA3 dozlarının optimizasyonu

Abstract

Many difficulties are exist in citrus breeding due to incompatibility, long juvenility, sterility and nucellar embryo. Zygotic embryo in the seeds of polyembryonic citrus cultivar is degenerated by nucellar embryos during embryo development. Accordingly, in vitro embryo culture is a useful tool in citrus breeding, since it assures embryo germination and development. In this study, Common mandarin x Carrizo citrange were crossed in order to produce new rootstock genotypes. Immature embryos were taken from fruit after 80, 100 and 120 pollination days to determine the suitable embryo rescue stage. Then, the embryos were germinated in Murashige and Tucker (MT) culture medium including 0, 0.5 and 1 mg l-1 GA3. According to the results, high germination rates were materialized as 100% and on 95% to taken embryos from 120 days after pollination (DAP) in supplemented with 1 mg l-1 GA3 and 0.5 mg l-1 GA3 in MT culture medium respectively. The embryos taken from 80 days after pollination did not germinate on MT medium without GA3 (control) and including with 0.5 mg l-1. Generally, the existence of GA3 on medium increased the ratio of germination compared to the control. The highest trifoliate ratio was determined as 33.33% at the embryos taken from 100 and 120 days after pollination and medium including 0.5 and 1 mg l-1 GA3 consecutively. The results have revealed that the optimal time for embryo rescue at citrus is 120 DAP and including GA3 in the medium increased embryo germination.