Effect of Irradiation of 60Co-γ on Seed Germination and Seedling Growth of Four Cultivars of Lagerstroemia indica

Seeds of Lagerstroemia indica ‘Jinwei’, L. indica ‘Shengzhouhong’, L. indica ‘Bilishi’ and L.indica ‘Hongxia’ were collected in September 2015, and irradiated in April 2016 with 60Co-γ-ray at 0, 150, 200 and 250 Gy. Observations were made on seed germination and their growth of seedlings. The results indicated that seed germination rate and their seedling growth of treated cultivars had positive relation with 60C0-γ radiation dosage at first, but negative at last. Rate of seedling with abnormal growth increased with dosage of 60Co-γ-ray except that of L indica ‘Hongxia’. The experiment concluded that the best dosage of 60C0-γ ray for L. indica ‘Jinwei’seeds was 150 Gy, 200 Gy for L. indica ‘Shengzhouhong’, L. indica ‘Bilishi’ and L. indica ‘Hongxia’.