Genetic and developmental regulation of leaf senescence in grapevine rootstocks and grafted scions

Abstract

Leaf senescence in grapevines is a key developmental process influencing photosynthesis and carbon allocation from source tissues to sinks, with important implications for vineyard productivity. This study investigated the initiation and progression of leaf senescence in response to daylength changes and examined the underlying genetic regulation. Two presentations of an F1 rootstock population derived from Vitis rupestris ‘B69’ × Vitis riparia ‘HP1’ were evaluated: own-rooted individuals and individuals grafted with the common Vitis hybrid ‘Marquette’ scion. Time-series digital imaging was used to monitor leaf color change, and longitudinal phenotypic data were analyzed using functional principal component analysis. RGB pixel variation enabled identification of leaf position along the shoot and genetic associations with daylength-responsive senescence patterns. Differences between the two population presentations suggest that the scion and/or its interaction with the rootstock influences senescence dynamics in grafted plants. Basal and apical leaves showed the strongest phenotypic responses to declining daylength, potentially reflecting differences in temporal leaf age. Functional QTL analysis identified genetic loci and enriched pathways associated with senescence across leaf positions, demonstrating the value of developmental trajectory–based approaches for dissecting complex traits.

Acknowledgements

National Science Foundation (NSF) Award No. 1546859 and 2431712.