Diurnal Patterns of Roots Growth in Grapevines

At weekly to seasonal time scales, previous studies have shown that the dynamics of grapevine root growth can be influenced by root system of genotype, developmental stage, and cultural practice and soil environmental conditions (eg. Comas et al. 2010). However, little is known about grapevine root growth characteristics over a shorter time course. In the hot grape growing regions of Australia, short term root growth responses to the soil environment are of practical interest where manageable factors such as root-zone temperature and moisture can fluctuate significantly over a period of hours and days. The possibility of genotypic variation is also relevant when the widespread use of grafted grapevines in viticulture provides an opportunity to select rootstocks based on suitability of root traits to particular environments. From a mechanistic perspective, a more detailed examination of the diurnal root growth pattern would allow links with carbon supply and the day-night 24 h (diel) cycle to be investigated. This paper summarizes the results of a series of three experiments designed to characterize the daily fine root growth pattern of several grapevine species, and with the use of controlled environment chambers, separate possible contributions of temperature and photoperiod.