Factors Affecting in Vitro Germination and Storage of Jojoba Pollen

Abstract

Abstract Conditions for in vitro germination of jojoba [Simmondsia chinensis (Link) Schneider] pollen were optimized in order to study the influence of storage temperature on viability. A medium consisting of 300 mg·liter−1 CaCl2·2H2O, 100 mg·liter−1 KNO3, 10 mg·liter−1 H3BO3, 20% sucrose, and 4% to 5% Difco Bacto-agar was optimal for germinating both fresh and stored pollen. Pollen germinated readily in media with a pH range of 4 to 8. The optimum incubation temperature range for pollen germination was 25° to 30°C. When stored at room temperature (22° to 25°), the initial pollen viability was decreased to 50% in 3 weeks and to 0% after 10 weeks, as determined by in vitro germination. Pollen stored at 4° maintained its initial viability for 10 weeks, followed by a gradual decrease in germination to 70% in 17 weeks and 0% after 22 weeks. Pollen stored at −196° in liquid nitrogen for 2 years retained a germination percentage as high as that of fresh pollen. The eryogenieally stored pollen, when used in controlled pollinations, produced normal fruit set comparable to that with fresh pollen.