Plant nuclear DNA ia an inherently unstable molecule and can be damaged metabolically or by a number of stress factors like extreme temperatures, drought and pathogen attack. In the present study, excised leaf discs harvested from two Hevea clones, RRII 430 (relatively drought tolerant) and RRII 414 (relatively) drought susceptible) were subjected to water deficit stress in vitro using PEG under low and high light conditions in a plant growth chamber and another set of leaf discs kept under sunlight in open field. The integrity of genomic DNA from the leaf discs subjected to the stress conditions indicated a fair degree of DNA fragmentation in drought susceptible clone under high light alone as well as in the combination of high light and PEG stresses. In the drought tolerant clone, DNA was comparatively intact with no visible signs of fragmentation. On the other hand, under very high light conditions in the open field, significant level of DNA fragmentation was observed in both the clones indicating that high light can inflict serious damages to DNA in both drought tolerant and susceptible clones.