Nostoc muscorum cells showed metal-induced decrease in the relative growth, pigment contents, O2 evolution, and Hill activity in response to lead (Pb2+) and cadmium (Cd2+) treatment, which was further accentuated with increase in metal exposure time and metal concentration. I50 concentrations (50% growth inhibitory concentrations) of Pb2+ and Cd2+ for growth of N. muscorum were 55 and 21 μg mL-1, respectively. These results indicated that the cells of N. muscorum were more susceptible to Cd2+ in comparison to Pb2+. The O2 production was relatively more sensitive to both heavy metals (I50: 16 and 10 μg mL-1 of Pb2+ and Cd2+, respectively) than the Hill activity (I50: 61 and 39 μg mL-1 of Pb2+ and Cd2+, respectively). Further, measurement of Hill activity in the presence of metals and electron donors showed that inhibition sites of both Pb2+ and Cd2+ were located on the oxidizing site of PSII. The chlorophyll a (Chl a) and phycobilisome (PB) fluorescence emission spectra showed that energy transfer from Chl a and PB to PSII reaction center was more susceptible to Cd2+ than Pb2+., S. Dixit, D. P. Singh., and Obsahuje bibliografii
Diurnal patterns of leaf water potential (ΨW), canopy net photosynthetic rate (PN), evapotranspiration rate (E), canopy temperature (Tc), and water use efficiency (WUE) of clusterbean [Cyamopsis tetragonoloba (L.) Taub., cv. Desi] were studied at six phenological stages of plant development under field conditions at CCS Haryana Agricultural University, Hisar. The highest PN, E, and WUE were observed at pod initiation stage (61 DAS). Daily maxima of PN were usually between 11:00 to 14:00 h while those of E and WUE between 12:30 and 16:00 h. PN was mainly dependent on photosynthetically active radiation and E on air temperature (Ta) but the relationships varied at different growth stages. WUE declined with the increase in Ta. At mid-day, ΨW was highest during pod initiation. and A. Kumar ... [et al.].
Diurnal patterns of canopy net photosynthetic rates (jPií), evapotranspiration (£) and
water use efBciency (WŤJE = P^^E) of field grown irrigated wheat (Triticum
aestivum L. cv. WH 147) were studied fi'om tillering to maturity at Haryana
Agricultural University Farm, Hisar, India. Hie maximum photosynthetic rates
(^N, max) increased fi'om tillering to anthesis and declined at a rapid rate thereaňer till
maturity. Relatively high £'mav but low WUE„ax were recorded at tillering, milk ripe
and dough stages of growth. Diumally foUowed die course of photosynthetícaUy
active radiation (PAR) fiom tillering to wateiy ripeness but it declined at high PAR at
latter reproductive stages of growth. E was curvilinearly related to air temperature.
There was a lag of about 2 h between ^N, „lax (12.00 h) and E„,ax (14.00 h) during
the day. WUE was high fi-om 07.30 to 10.00 h, depressed during midday and a
slightly increased fi^om 15.00 to 16.00 h.Diurnal patterns of canopy net photosynthetic rates (jPií), evapotranspiration (£) and water use efBciency (WŤJE = P^^E) of field grown irrigated wheat (Triticum aestivum L. cv. WH 147) were studied fi'om tillering to maturity at Haryana Agricultural University Farm, Hisar, India. Hie maximum photosynthetic rates (^N, max) increased fi'om tillering to anthesis and declined at a rapid rate thereaňer till maturity. Relatively high £'mav but low WUE„ax were recorded at tillering, milk ripe and dough stages of growth. Diumally foUowed die course of photosynthetícaUy active radiation (PAR) fiom tillering to wateiy ripeness but it declined at high PAR at latter reproductive stages of growth. E was curvilinearly related to air temperature. There was a lag of about 2 h between ^N, „lax (12.00 h) and E„,ax (14.00 h) during the day. WUE was high fi-om 07.30 to 10.00 h, depressed during midday and a slightly increased fi^om 15.00 to 16.00 h.