RADIO-SENSITIVITY OF <em>BAMBUSA</em> <em>ARUNDINACEA</em> TO GAMMA RAYS

Abstract

The radio-sensitivity of Bambusa arundinacea was assessed by exposing the seeds collected from a deciduous forest following a mast flowering, to gamma rays with 10 to 150 kR doses at 10 kR interval. Observations on seed germination, seedling mortality, shoot and root lengths, number of leaves and internodes were recorded. Lethal dose-50 (LD-50) was assessed by using linear regression analysis. Gamma rays enhanced seed germination in 10 kR treatment compared to the control, drastically reduced and delayed germination in 20 and 30 kR treatments respectively and completely inhibited germination above 30 kR Seedling mortality was highest in 30 kR dose. Surprisingly, the control recorded comparatively higher mortality of emerged seedlings than the 10 and 20 kR treatments which is thought to be due to the death of weak seedlings originating from seeds with partial endosperms. Stimulatory effect was seen for shoot length, number of nodes and leaves. Root length decreased linearly with increase in dose. 'Albino' was the most frequently observed chlorophyll mutation type. LD-50 for seed germination was 19.37 kR, 26.30 kR for shoot length and 22.04 kR for root length indicating the high radio-sensitivity of B. arundinacea. Possible biological reasons are discussed.