The relationships between leaf senescence, carbon isotope discrimination and yield performance were examined in durum wheat (
Desf.), in the high plains of Setif, eastern Algeria. Ten CIMMYT high-yielding cultivars were grown during two cropping seasons characterized by low rainfall (217 and 162 mm, respectively), freezing temperatures at heading stage and terminal heat stress. Senescence was assessed using numerical image analysis (NIA). Carbon isotope discrimination was analyzed in flag leaves at anthesis and grain at maturity. Senescence was significantly negatively correlated to grain yield in season 1, but not in season 2. There was no relationship between Δ and grain yield in both seasons. The absence of association between Δ and grain yield is likely to be due to a strong contribution of pre-anthesis assimilates to yield together with a sink limitation of yield.
Authors:Ihsanullah, J. Akhter, A. Rauf and M. Atta
A comprehensive radiochemical procedure for the measurement of gamma/beta activity of131I has been standarized by optimizing different steps. The procedure is mainly divided into three stages, i.e., (1) concentration
of iodine using anion exchange column followed by elution; (2) extraction of iodine into CCl4 and back extraction, and (3) precipitation as AgI. The percent chemical recovery and the lower limit of detection (LLD) were
found to be 75.5±5% and 0.014 mBq/ml, respectively.
Authors:M. Tufail, Sabiha-Javied, N. Akhtar and J. Akhter
Wheat is staple food of the people of Pakistan. Phosphate fertilizers, used to increase the yield of wheat, enhance the natural
radioactivity in the agricultural fields from where radionuclides are transferred to wheat grain. A study was, therefore,
carried out to investigate the uptake of radioactivity by wheat grain and to determine radiation doses received by human beings
from the intake of foodstuffs made of wheat grain. Wheat was grown in a highly fertilized agricultural research farm at the
Nuclear Institute of Agriculture and Biology (NIAB), Faisalabad, Pakistan. The activity concentration of 40K, 226Ra and 232Th was measured in soil, single superphosphate (SSP) fertilizer, and wheat grain using an HPGe-based gamma-ray spectrometer.
Soil to wheat grain transfer factors determined for 40K, 226Ra and 232Th were 0.118 ± 0.021, 0.022 ± 0.004 and 0.036 ± 0.007, respectively, and the annual effective dose received by an adult person
from the intake of wheat products was estimated to be 217 μSv.