Study on the response of diploid, tetraploid and hexaploid species of wheat to the elevated CO2

Abstract

Study was done to compare the response of Triticum aestivum (hexaploid), Triticum durum (tetraploid) and Triticum monococcum (diploid) wheat species to the elevated CO2 using Free Air CO2 Enrichment (FACE) facility. It was demonstrated that the modern cultivar of wheat Triticum aestivum (hexaploid) was largely sink limited. It appeared to have less photosynthesis per unit leaf area than Triticum monococcum (diploid wheat). While leaf size, grain weight and amylase activity increased with the ploidy level from diploid to hexaploid wheat forms, the photosynthetic rate was reduced significantly. These wheat species responded differentially to the elevated CO2. The larger leaf area and greater seed weight and presence of 38 KDa protein band caused by elevated CO2 had additive effect in improving the productivity of hexaploid wheat by changing the source sink ratio. Whereas, such a source sink balance was not induced by elevated CO2 in diploid wheat. The increasing CO2 may present opportunities to breeders and possibly allow them to select for cultivars responsive to the elevated CO2 with better sink potential.

Rising atmospheric carbon dioxide on grain quality in crop plants

“…The changes in lipid composition such as increase in palmate with corresponding decrease in linoliate, have been identified in plants, exposed to elevated CO 2 (Williams et al 1994). Uprety et al (2009) observed significantly greater CO 2 induced increase in mass, length and breadth of grains of hexaploid compared to tetraploid and diploid wheat species in a FACE study (Table 1). They have attributed this variation to the enhanced flow of carbohydrates in hexaploids due to their greater sink capacity.…”

“…Model projections also suggest an increase of 1.4 to 4.5°C in earth's temperature by 2100. A significant amount of literature is available on the response of crop plants to elevated CO 2 for their growth, productivity, physiological and biochemical processes and the impact assessment analysis of CO 2 and temperature on these processes in crop plants indicates possibilities of considerable changes in biochemical composition of grains and their nutritional quality (Stafford 2007;Uprety and Reddy 2008;Uprety et al 2009). This review will describe the impact of rising atmospheric CO 2 on the grain characters of wheat, rice, brassica, mungbean and soybean, which are significantly responsive to the elevated CO 2 for their growth and productivity (Kimball 1983).…”

“…The reallocation of nitrogen away from Rubisco to light harvesting and sucrose synthesis will increase nitrogen use efficiency (Conroy and Hocking 1993) and grain protein concentration is generally decreased (Lawlor and Mitchell 2001;Jablonski et al 2002;Kimball 2004). A striking feature of CO 2 enrichment experiments is that the nitrogen concentration of the foliage is reduced by up to 50% (Conroy 1992;Conroy and Hocking 1993 (Uprety et al 2009) the size of amino acid export pool in the leaves, resulting in the lower levels of nitrogen and protein in the grains (Hocking and Meyer 1991). Conroy et al (1994) observed the reduction in nitrogen and protein in flour produced from grains of high CO 2 grown plants.…”

Impact of Elevated CO<sub>2</sub> on Wheat Growth and Yield under Free Air CO<sub>2</sub> Enrichment

“…Uprety et al (2009) [15] observed increases in growth and yield with increase in grain starch and decrease in protein concentration in grain as ploidy level increased in Triticum species under mid-FACE system. However there is hardly any information conditions.…”

Cultivar Specific Response of CO2 Fertilization on Two Tropical Mung Bean (Vigna radiata L.) Cultivars: ROS Generation, Antioxidant Status, Physiology, Growth, Yield and Seed Quality

“…The primary effects of rising CO 2 on plants have been well documented and include higher rates of photosynthesis (Garcia et al 1998). Variability in crop responses to the elevated CO 2 (EC) made the agricultural productivity and food security vulnerable to the climate change (Uprety et al 2009). In view of the irreversible rise of atmospheric CO 2 concentration, there is an urgent need for developing crop varieties with the potential of increased utilization of CO 2 to feed the growing population (Kant et al 2012).…”