Effects of Light, Carbon Dioxide, and Temperature on Photosynthesis, Oxygen Inhibition of Photosynthesis, and Transpiration in Solanum tuberosum

Abstract

Individual leaves of potato (Solanum tuberosum L. W729R), a C3 plant, were subjected to various irradiances (400-700 nm), CO2 levels, and temperatures in a controUled-environment chamber. As irradiance increased, stomatal and mesophyH resistance exerted a strong and somewhat paraUeled regulation of photosynthesis as both showed a similar decrease reaching a minimum at about 85 neinsteins cm-2 sec-' (about '/2 of fuU sunlight). Also, there was a proportional hyperbolic increase in transpiration and photosynthesis with increasing irradiance up to 85 neinsteins* cm-2 sec-'. These results contrast with many C3 plants that have a near ful opening of stomata at much less light than is required for saturation of photosynthesis.Inhibition of photosynthesis by 21% 02 was nearly overcome by a 2-fold increase in atmospheric levels of CO2 (about 1,200 ng cm-3). Photosynthesis at 25 C, high irradiance, 2.5% 02 and atmospheric levels of CO2 was about 80% of the C02-saturated rate, suggesting that CO2 can be rte-limiting even without 02 inhibition of photosynthesis. With increasing CO2 concentration, mesophyll resistance decreased slightly while stomatal resistance increased markedly above 550 ng cm-3 which resulted in a significant reduction in transpiration.Although potato is a very productive C3 crop, there is substantial 02 inhibition of photosynthesis. The level of 02 inhibition was maximum around 25 C but the percentage inhibition of photosynthesis by 02 increased steadily from 38% at 16 C to 56% at 36 C. Photosynthesis and transpiration showed broad temperature optima (16-25 C). At higher temperatures, both the increased percentage inhibition of photosynthesis by 02 and the increased stomatal resistance limit photosynthesis, while increased stomatal resistance limits transpiration. Water use efficiency, when considered at a constant vapor pressure gradient, increased with increasing irradiance, CO2 concentration, and temperature.In spite of the importance of potato as a staple food crop, only limited studies (9, 24) have been done on its carbon balance and water use efficiency relative to other crops with respect to environmental factors. Potato is a C3 plant with photorespiration based on its high CO2 compensation point; yet its productivity is high (average market yield in U.S.: 4.66 metric tons dry weight of tuber/ha4) (1) and even comparable to that of some C4 crops (30). The productivity of a C3 crop depends on the carbon I

Modelling development and growth of the potato crop influenced by temperature and daylength: LINTUL-POTATO

“…Daily crop growth per unit leaf area or unit soil covered by green foliage results from photosynthesis and respiration both of which are temperature dependent. Minimum (between 0 and 7 ° C), optimum (16-25 °C) and maximum (40 °C) temperatures for photosynthesis in potato crops have been reported by Ku et al (1977), Dwelle et al (1981), Dwelle (1985), Ng and Loomis (1984), Manrique (1992), Midmore (1992) and Hammes and Jager (1990). The highest total daily crop growth is reported between ·temperatures of 15 and 23 oc (Ben Kheder and Ewing 1985;Nishibe et al 1988;Haverkort 1990).…”

Potato potential yield based on climatic elements and cultivar characteristics

“…Other workers have reported a severe reduction in the rate of assimilation at air temperatures above 30 o C under controlled experimental conditions. In such cases, reductions in CO 2 assimilation rate were shown to correlate well with reductions in growth and yield (KU et al, 1977;MIDMORE and PRANGE, 1992). These contrasting results reveal the complexity of plant responses to the combined effects of water and temperature stress, which inevitably occur in association under field conditions (PEREIRA and SHOCK, 2006).…”

“…The LINTUL-POTATO simulation model (KOOMAN and HAVERKORT, 1995) establishes potential yield of a certain cultivar for a determined growing period and plant density, and is based on: incident photosynthetically active radiation (PAR), fraction of PAR intercepted by the crop, and radiation use efficiency to produce dry matter. Phenological crop development is driven by accumulated air temperature, while development stage determines dry matter partitioning and, through haulm growth, the pattern of intercepted PAR is defined.…”

Oxygen Inhibition of Photosynthesis

“…The solubility ratio is based on calculated levels of 02 and CO2 in the intercellular spaces of leaves as derived from whole (1,5,11,12,14,15,18,22 (1, 11,12,14,15,18,22) increased with increasing temperature although the absolute rate of 02 inhibition of photosynthesis (rate of photosynthesis at 1.5% 02 -rate of photosynthesis at 21 % 02) shows an optimum temperature. Generally only atmospheric levels of CO.2 and 02 have been considered in comparative studies on 02 inhibition of photosynthesis in various species and on 02 inhibition of photosynthesis as affected by temper.ature.…”