Energy cane vs sugarcane: Watching the race in plant development

Sugarcane (Saccharum spp.) grows in all tropical and subtropical regions of the world, being cultivated in more than 100 countries. Modern cultivars are the results of interspecific crosses, having S. officinarum as the main genetic source, which results in high sucrose production. Energy cane is still a less rigorous definition, applied to cane cultivars that have higher biomass, although lower sucrose concentration. Despite the practical advance, little is known about the molecular and physiological basis of the energy cane productivity and robustness, a knowledge that can be very helpful for the development of cane varieties in general. In this work, we have explored the sprouting process, which is very irregular in sugarcane plantation and thereby a main cost factor. Our results could be summarized in three main contributions: first, we observed that energy cane has a physiological strategy very different from that one observed for sugarcane, starting with the shoot development and only thereafter beginning the root growth. After 10 days, the energy cane had a shoot height of 14.19 cm against of 4.24 cm of sugarcane. Nevertheless, we noticed the energy cane root presents a fast and vigorous development, overcoming the sugarcane root volume after 50 days, with 24.36 and 14.79 cm(3), respectively. Second, we observed that the energy cane has homogeneity in the sprouting rate of the different internodes, regardless of their age. Finally, our data allowed us to propose that the greater growth seen in energy cane might be attributed to a vigorous rate of nocturnal growth with angulation in relation to the time of 11.89 degrees, which is lower in sugarcane, with angulation of 5.47 degrees. (AU)