Micropropagated one-year old plants of ten clonal plum rootstocks (eight of the ‘S. Julien’ hybrid series, named I.S.G., and two of the myrobalan series, named Mr.S.) were grown in a modified Hoagland nutrient solution supplemented or not with 10 mM NaHCO3 plus 0.5 mg L-1 CaCO3. Trials were repeated for two years: during the culture month in greenhouse iron deficiency occurred and rootstocks showed different symptomatology. In Fe deficient leaves the total chlorophyll content (mg g-1 F.W.), decreased from 30% to 60% respect to control plants; the same trend was observed when the content was expressed as milligrams per square centimetres, but with a higher decrement, due to different susceptibility of rootstocks and leaf thickness. Chlorophyll content correlated strictly with visual appearance. A general increment of Chl a/ Chl b ratio was showed in stress conditions, except from ‘Mr.S.2/8’, ‘I.S.G.1/2’, ‘I.S.G.1/4’, ‘I.S.G.1/6’ and ‘I.S.G.2/10’ clones. Fe2+ iron content was analysed in leaves and roots by Ferrozine® chelate. Results showed that the control conditions determined uniform contents, while bicarbonate influenced them in different way. The leaf mineral content changed relative to treatments, nutrient type and clone susceptibility. Generally N and P macronutrient content decreased in all rootstocks under iron deficiency, while K content increased in some of them. As already remarked in other species, calcium content decreased in the chlorotic leaves and they presented a high K/Ca ratio, but without statistically significant differences. Other mineral content ratios were discussed. Iron, manganese and zinc contents were significantly lower in the yellow leaves, even if the most tolerant plum rootstocks showed similar or, however, high contents.
|Autori interni:||CINELLI, FABRIZIO|
|Autori:||CINELLI F; TAMANTINI I|
|Titolo:||Iron deficiency in plum rootstocks: effects on leaf chlorophyll content and mineral composition|
|Anno del prodotto:||2005|
|Appare nelle tipologie:||1.1 Articolo in rivista|