Discriminant analysis is an important method in multivariable statistic analysis to show what type an individual should belong to. Based on actual field photosynthetic value set obtained from our research platform, North East China Transect (NECT), a new approach, developed from the concept and principle of discriminant analysts, was proposed to distinguish C3 and C4 plants. Indices related to plant photosynthetic capacity measured by an LCA4 photosynthesis system were selected to build the discriminant model which is based on four related parameters: net photosynthetic rate, transpiration rate, stomatal conductance, and difference in temperature between leaf surface and atmosphere. Compared with other approaches, the present one is fast, straightforward, and efficient. and H. P. Tang, X. S. Zhang.
High altitude profoundly influenced plant diversity and distribution on mountains of southern Sinai (Egypt). Plants exhibiting the C3-mode of photosynthesis were widely distributed along the altitudinal transect. Plants exhibiting the C4-mode were restricted below an altitude of about 1400 m above sea level. The transition from C3-dominated areas to C4-dominated areas occurred between 1200 and 1400 m a.s.l. and O. H. Sayed, M. K. Mohamed.
C3 photosynthesis at high light is often modeled by assuming limitation by the maximum capacity of Rubisco carboxylation (VCmax) at low CO2 concentrations, by electron transport capacity (Jmax) at higher CO2 concentrations, and sometimes by
triose-phosphate utilization rate at the highest CO2 concentrations. Net photosynthetic rate (PN) at lower light is often modeled simply by assuming that it becomes limited by electron transport (J). However, it is known that Rubisco can become deactivated at less than saturating light, and it is possible that PN at low light could be limited by the rate of Rubisco carboxylation (VC) rather than J. This could have important consequences for responses of PN to CO2 and temperature at low light. In this work, PN responses to CO2 concentration of common bean, quinoa, and soybean leaves measured over a wide range of temperatures and PPFDs were compared with rates modeled assuming either VC or J limitation at limiting light. In all cases, observed rates of PN were better predicted by assuming limitation by VC rather than J at limiting light both below and above the current ambient CO2. One manifestation of this plant response was that the relative stimulation of PN with increasing the ambient CO2 concentration from 380 to 570 µmol mol-1 did not decrease at less than saturating PPFDs. The ratio of VC to VCmax at each lower PPFD varied linearly with the ratio of PN at low PPFD to PN at high PPFD measured at 380 µmol(CO2) mol-1 in all cases. This modification of the standard C3 biochemical model was much better at reproducing observed responses of light-limited PN to CO2 concentrations from
pre-industrial to projected future atmospheric concentrations., J. A. Bunce., and Obsahuje bibliografii
Photosynthetic pathway type, based on 5*^C measurements, was determined for 48 species in 39 genera and 15 families of flowering plants from the grassiand region of Northeast China. Of this total, 10 species in 10 genera from 4 families were found to háve C4 photosynthesis; 38 species in 29 genera from 13 families had C3 photosynthesis. One C4 species in the Chenopodiaceae and three in the Gramineae had not been previously docnmented in the literatuře. The C4 species were most frequent in disturbed habitats, meadow steppe and šalině grassiand; C3 species dominated the other habitats sampled.