Publicaciones 2025. Fotosíntesis en los órganos verdes de la espiga de trigo: aspectos fisiológicos y su contribución al llenado de granos

 BACKGROUND AND AIMS

 The green reproductive organs are photosynthetically active and, in the case of cereals can contribute to crop yield. In wheat and other cereals, this contribution has received greater attention in recent decades. The green parts of the ear possess some advantages over leaves, such as a lower decrease in photosynthetic rate under drought conditions. This improved performance appears to be based on maintaining a better water status, possibly linked to a greater capacity for osmoregulation (osmotic adjustment) and probably due to a lower susceptibility to cavitation in the peduncle. Other attributes (still speculative) could contribute to this strategy of avoiding dehydration in the ear, such as its upright posture (lower energy load during periods of high irradiance). Furthermore, the ear shows greater efficiency in instantaneous water use (photosynthesis/transpiration ratio) compared to leaves. On the other hand, several morphophysiological traits impact the thermal balance of the ear and have implications for yield. The contribution of ear photosynthesis varies depending on the methodology used, germplasm, and experimental conditions, although it is relevant in all cases, and it seems to have increased due to breeding. This review analyzes these aspects of ear physiology and discusses the contributions reported in the scientific literature. Finally, we propose potential outstanding issues and aspects that require further study.