Carbon isotope discrimination (') is used to determine differences in apparent transpiration efficiency amongst genotypes of many C3 plant species. In this present study the possible influence of certain commercially-available rootstocks on apparent transpiration efficiency in grapevines was investigated. Variation in ' was studied for Shiraz and each of six rootstock varieties when grown either (1) on their own roots, (2) with Shiraz grafted as a scion onto different rootstocks (conventional graft) or (3) with rootstock varieties grafted onto Shiraz roots (reciprocal graft). When grown on own roots or as a reciprocal graft, there was significant variation in '. In contrast, there was no significant variation in ' for Shiraz (as a scion variety) when grafted onto different rootstock varieties (conventional graft). These results imply a predominance by the scion genotype in determining variation in the leaf-level physiological characteristics that determine apparent transpiration efficiency under well-watered (and non-saline) conditions.
|Number of pages||3|
|Journal||Australian Journal of Grape and Wine Research|
|Publication status||Published - 2003|