Physiological responses to soil lime in wild grapevine (Vitis vinifera ssp. sylvestris)

Abstract

Lime-induced chlorosis is a widespread nutritional disorder affecting grapevines cultivated in calcareous soils. A greenhouse experiment was conducted to investigate the response of Vitis vinifera ssp. sylvestris to soil lime by evaluating the effects of a range of soil CaCO3 contents (0-60%) on plant growth, nutrient content (iron, potassium, nitrogen and phosphorus) and photosynthetic performance (gas exchange, chlorophyll fluorescence parameters and photosynthetic pigments). The highest soil CaCO3 concentration induced nutrient imbalances and significantly inhibited photosynthetic function, causing a reduction in carbon gain and consequently, a drastic growth reduction and high mortality. However, all the plants survived external CaCO3 contents of up to 40%, and reduction in growth at 20% CaCO3 was slightly lower than that recorded in several previously studied lime-tolerant varieties of grapevine. Plants grown at 20% CaCO3 maintained net photosynthesis values of around 6μmolm-2s-1, a similar chlorophyll content to that of the control plants and dawn Fv/Fm values close to the optimal values for unstressed plants. Up to the 40% CaCO3 treatment, the study species was capable of maintaining Fe uptake by the roots and translocation to leaves, while controlling the nutritional status of N and P. Our study indicates that the studied population of V. vinifera ssp. sylvestris could provide a source of genetic diversity for lime tolerance improvement in grapevine.