ibclogo XVI International Botanical Congess


Abstract Number: 5588
Poster No. = 2070


CYANOGENIC POTENTIAL IN DROUGHT STRESS SORGHUM


Wang Jie, Ong Bee-Lian, Yeoh Hock-Hin, Department of Biological Sciences, National University of Singapore


Embryos of sorghum seeds contained cyanogen equal to 3.2ng HCN/g. After 36 hs germination the cyanogen content increased to 1706.5ng/g, indicating cyanogen was synthesized in embryos after the seeds imbibed water. Cyanogen is mainly synthesized in sorghum leaves, and decreased as they mature. Leaf cyanogen of seedlings decreased by 50% during the first 7 days of drought, compared to well-watered plants. Photosynthetic rate (P rate) CO-2 fixation, stomata conductance (Gs), transpiration(Evaper), chlorophyll concentration (Chl), qP and qN, however, did not change. After 11 days of drought stress no HCN was detected in leaves while in well-watered leaves the HCN was 63.5ng/g. Although Chl, qP and qN did not change, P rate, Gs and Evaper of the droughted leaves were lower than those of well-watered plants.


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