EMBRYOGENESIS IN UNDEVELOPED OVULES OF CITRUS CULTIVARS IN RESPONSE TO GAMMA RADIATION

Immature fruits of 36 Citrus cultivars were exposed to 0 – 12 kr gamma radiation. The maximum average embryo per nucellus (EN) were recorded after 4 months of ovule culture. In control (0 kr), the EN were 6.27, 6.06, 5.62 and 4.86 in Kinnow, Jaffa, Gada dehi and Sweet lime respectively. In 3 kr, EN were 6.85, 6. 23, 5.86, 4.60 in Foster, Kinnow, Valencia and Gada dehi, respectively. In 6 kr, EN were 8.33, 8.12, 5.66 and 3.66 in Foster, Kinnow, Pine apple and Kherna Khatta respectively. In 9 kr, EN were 7.31, 6.76, 5.30 and 3.15 in Kinnow, Foster, Jaffa and Kherna Khatta respectively. In 12 kr, EN were 5.88, 3.92, 3.80 and 2.50 in Kinnow, Foster, Jaffa and Rough lemon respectively. In general, there was suppression of embryogenesis in 9 and 12 kr. The healthy embryos with normal balanced germination were ex-vitro grafted on rough lemon seedlings for growth and development