Raising yield potential of wheat. II. Increasing photosynthetic capacity and efficiency

Abstract

Past increases in yield potential of wheat have largely resulted from improvements in harvest index rather than increased biomass. Further large increases in harvest index are unlikely, but an opportunity exists for increasing productive biomass and harvestable grain. Photosynthetic capacity and efficiency are bottlenecks to raising productivity and there is strong evidence that increasing photosynthesis will increase crop yields provided that other constraints do not become limiting. Even small increases in the rate of net photosynthesis can translate into large increases in biomass and hence yield, since carbon assimilation is integrated over the entire growing season and crop canopy. This review discusses the strategies to increase photosynthesis that are being proposed by the wheat yield consortium in order to increase wheat yields. These include: selection for photosynthetic capacity and efficiency, increasing ear photosynthesis, optimizing canopy photosynthesis, introducing chloroplast CO(2) pumps, increasing RuBP regeneration, improving the thermal stability of Rubisco activase, and replacing wheat Rubisco with that from other species with different kinetic properties.

Comparative behavior of wheat and barley associated with field release and grain weight determination

“…In fact the main outcome of breeding in different countries was an improved sink capacity without a corresponding increase in storage reserves or post-anthesis assimilation (source) (Rharrabti et al, 2010;Parry et al, 2011;Foulkes et al, 2011). Thus, if breeding programs continue improving sink capacity, without a corresponding increase in storage reserves or post-anthesis assimilation (source), grain weight responses in both species, but mainly in barley, will continue increasing over the years.…”

Physiology and transcriptomics of water-deficit stress responses in wheat cultivars TAM 111 and TAM 112

“…3). The increase in final grain yield could be the result of a combination of several phenotypes and processes including spike number (Xue et al, 2013), dry weight of the spike at anthesis, efficient resource partitioning (Fischer, 2011;Foulkes et al, 2011), sink strength (Ji et al, 2010;Marcelis, 1996), radiation use efficiency (Parry et al, 2011), ear photosynthesis (Maydup et al, 2010), and overall photosynthetic capacity and efficiency (Fischer, 2011;Parry et al, 2011;Sreenivasulu and Schnurbusch, 2012). However, details about the specific processes remain unknown.…”

A eficiência na produção de biomassa e grãos de aveia pelo uso do nitrogênio

“…As mudanças climáticas no planeta têm proporcionado novo desafio na produção agrícola de vez que, afora a obtenção de cultivares mais produtivas e tolerantes a fatores bióticos e abióticos (Araus et al, 2008;Oliveira et al, 2011), existe a necessidade de que sejam mais eficientes no aproveitamento de luz e nutrientes, condição-chave para uma agricultura cada vez mais sustentável (Parry et al, 2011). Desta forma, estudos da eficiência de uso do N sobre novos genótipos disponíveis são fundamentais para atualizar as recomendações técnicas e disponibilizar tecnologias mais ajustadas trazendo produções economicamente satisfatórias e com menor risco de poluição ambiental (Teixeira Filho et al, 2010;Prando et al, 2013).…”