Tolerance to Lime - Induced Chlorosis and Drought in Grapevine Rootstocks - Abiotic Stress: Plant Responses and Applications in Agriculture - page 283

used in vineyards established on calcareous soils. A. Ruggeri, an Italian breeder and selec‐
tionist, was the author of the rootstock 140 Ru ( Vitis berlandieri x Vitis rupestris ), which also
showed tolerance to lime chlorosis (Fregoni & Bavaresco, 1986). The rootstock Fercal, selected
in France by Pouget and Ottenwaeter (1978) is one of the most modern rootstocks showing a
very high degree of tolerance to calcium.
3.1. Deficiency symptoms of lime-induced chlorosis
A correct identification of symptoms of lime-induced chlorosis is one of the first presumptions
of a successful fight against this deficiency. Iron deficiency chlorosis is one of the major
problems affecting a variety of crop species grown in calcareous soils (Gruben & Kosegarten,
2002). Iron deficiency causes various morphological and physiological changes in plants
(Bertamini & Nedunchezhian, 2005).
Although the symptoms of lime-induced chlorosis are visible on the whole grapevine plant,
the most important ones can be probably observed on leaves.
Iron-deficient plants are characterized by the development of a pronounced intervenial
chlorosis similar to that caused by magnesium (Mg) deficiency but occurring first on the
youngest leaves. Intervenial chlorosis is sometimes followed by chlorosis of the veins, causing
the whole leaf to become yellow. In severe cases, the leaves become white with necrotic lesions
(Abadia, 1992).
Typical symptoms of lime-induced chlorosis are the inter-vein yellowing of leaves and a
decrease in plant biomass because, under conditions of iron (Fe) deficiency, a decreased
photosynthetic performance of plants is induced by a lower content of chlorophyll in leaves
(Bavaresco & Poni, 2003). Chlorosis is a disease manifesting itself by yellowing of young leaves,
whereas more mature leaves are frequently green. Plant growth is often considerably de‐
pressed, independent of whether young leaves are chlorotic or green (Mengel, Bübl, Scherer,
1984). The impaired formation of new leaves and restricted leaf growth is a typical and more
sensitive symptom of Fe-deficiency than is leaf chlorosis (Kosegarten et al .,1998)
Chlorotic symptoms also vary from year to year as a result of environmental variables, like
yields, temperature, rains. In soils where shallow layers are less rich in CaCO 3 than deeper
layers, it is likely that vines develops chlorosis only when the age and roots explore layers with
poor conditions for Fe uptake (Tagliavini & Rombola, 2001).
As the lime-induced chlorosis is the result of the relationship existing between soil conditions
and grapevine root system, it is manifested also in growth characteristics of grapevines. The
lime-induced chlorosis of grapevine was characterized by a dramatic reduction of shoot
growth, grape production and leaf Fe content, and a distribution of dry matter towards roots
more than to the clusters (Bavaresco, Giachino, Pezzutto, 2003).
Vines growing on high-bicarbonate soil significantly reduced the dry matter production of
individual organs and the total plant weight. Lime stress conditions increased the percent
distribution of dry matter in the stem and roots and decreased that one in the fruit (berries and
cluster stems) (Bavaresco & Poni, 2003).