Fabrizio Cinelli

Physiological responses of clonal quince rootstocks to iron-deficiency induced by addition of bicarbonate to nutrient solution

Abstract “MA”; quince clonal rootstock is more susceptible to lime‐induced chlorosis than clone “Ct.S.212”;. Trials were performed in order to determine whether differences observed between the two clones in calcareous soil were maintained when iron (Fe)‐deficiency was induced by addition of bicarbonate (HCO3) to a modified Hoagland nutrient solution No 1. In addition, trials were aimed to verify whether the rootstocks showed differing physiological responses. Results confirmed that total leaf Fe content was not a suitable tool to screen rootstocks for chlorosis tolerance. In contrast, “active”; Fe and chlorophyll content (well correlated with chlorotic symptom levels), together with fresh and dry matter production, were found to be good parameters for genotype evaluation. Total Fe content increased in the root system of stress‐grown “MA”; plants more than in “Ct.S.212”; root systems. Root Fe3+‐reductase activity increased in “MA”; and “Ct.S.212”; under Fe‐deficiency conditions obtained by using an Fe‐fre...

Physiological characterization of two peach seedling rootstocks in bicarbonate nutrient solution. I. Root iron reduction and iron uptake

Investigations were conducted on two peach seedling rootstocks, Nemaguard and TXR4989-2 (hybrid Titan × Nemared’), grown in bicarbonate-containing nutrient solution with 50 μM Fe-DTPA. Root-associated Fe(III)-reductase activity and iron absorption were determined to elucidate the physiological differences which cause the different tolerance of the two rootstocks in calcareous soils. Reductase activity was detectable in intact plants after several weeks and visualized on excised roots in gelrite medium. The physiological responses of NMG and TXR rootstocks suggest that stress conditions increase the Fe-reduction capacity and the iron uptake enormously. Both assays indicated interesting differences in behaviour between rootstocks.

Lime‐induced chlorosis in quince rootstocks: Methodological and physiological aspects

Abstract Two quince rootstocks for pear, clone MA and Ct.S.306, were screened to evaluate their threshold tolerance rate to lime‐induced chlorosis. Another important objective was to correlate the results of a chlorophyll analysis with observed chlorosis symptoms. The ron content in leaves was insufficient to determine the amount of iron available to the plant. The use of sodium bicarbonate (NaHCO3) in the hydroponic culture of pear was found to be the preferable over calcium carbonate (CaCO3) because of its higher solubility.

Application of tissue culture on quince rootstock in iron‐limiting conditions 1

Abstract Two quince rootstocks for pear, clones “MA”; and “Ct.S.212”;, were screened under iron (Fe)‐limiting conditions in in vitro culture. The most important objectives of this work were: first, to develop use of the tissue culture technique as a rapid screening methodology for evaluation of Fe efficiency in quince, and second, to identify morphophysiological characters associated with variation in response. Iron content of the MS medium (200 meq FeEDTA) was reduced to 80%, 65%, 50%, 25%, and 15% of standard content in order to induce chlorosis symptoms. Results showed that “Ct.S.212”; presented a higher proliferation rate and greater growth than clone “MA”; in the 15 and 25% Fe treatments, but clear symptoms of chlorosis were observed in both clones at the two lowest Fe concentrations. Parameters of vegetative development commonly used in in vitro culture proved to be difficult to interpret for this type of screening, and further tests will be necessary. In contrast, type and content of chlorophyll we...

Morpho-physiological approaches to investigate lime-induced chlorosis in deciduous fruit tree species

Abstract Several deciduous fruit tree species are affected by iron chlorosis when grown in calcareous soils and worldwide research on rootstock breeding and screening in relation to iron deficiency is carried out. For many years the goal of our department has been to investigate morphological and physiological aspects related to lime‐induced chlorosis, and to identify markers usable as tools for tolerance screening of clonal rootstocks. Experimental strategies using pot, hydroponic and in vitro culture have been used to understand if they are able to originate suitable indicators on developmental and biochemical changes resulting from iron deficiency. Results risen up from in vitro trials suggest that iron deficiency sensitive system should work in a divergent way from that of bicarbonate system. Physiological and morphological data highlight diverse syndromes and behaviors among the genotypes, probably reflecting properly perception, regulation, and activation of biological answer system to iron deficiency and bicarbonate. Recently, quince (Cydonia oblonga Mill.) minus‐ and plus‐variants have been obtained by in vitro somaclonal variation to clarify the agonistic relationship between bicarbonate and iron deficiency sensitive systems, that in turn can induce the activation of two specific gene expression pathways.

Characterization of salt tolerant plants derived from a Lycopersicon esculentum Mill. somaclone

Summary Plants were regenerated from cotyledon explants of Lycopersicon esculentum Mill., placed on a control medium and on medium added with a glucose derived, non trophic compound: 3-O-methyl-D-glucose, used as an osmotic agent. A preliminary test conducted in vitro , allowed us to identify a somaclone (named C4) which showed three times higher germination rates compared to wild type, in a salt enriched medium. To confirm the tolerance character in vivo and during the different life phases of the plant, young R1 plantlets from this somadone and wild type plantlets, have been tested with increasing concentrations of salt (0, 75, 150, 300 mmol/L sodium chloride). At the end of the treatment, consistent necrosis of leaf and flower organs were evident only in wild type plants. Moreover, we observed a strong drop of leaf turgor in wild type leaves under salt treatment, instead, line C4 plants retaining the turgor. A highest concentration of sodium was detected in leaf tissues in wild type plants, compared to line C4 ones, attesting the capacity of C4 line plants to regulate the amount of this toxic ion in leaves. The synthesis of organic compounds, proline and total amino acids, was lower in line C4 plants. Polymorphic RAPD fragments in C4 line were identified. Taking together all the data, line C4 plants show the ability to tolerate high salinity conditions, compared to wild type, in particular we suggest that these plants are able to regulate differently the amount of sodium in tissues.

Practical use of root cation exchange capacity as a predictive marker of lime‐induced chlorosis tolerance in prunus cerasifera L. rootstocks 1

Abstract Lime‐induced chlorosis still today places limits on cultivation and optimum production of many fruit tree species, even in only slightly calcareous soil. Research must, therefore, be directed towards new selections of rootstocks and/or cultivars tolerant of this abnormal soil condition. In addition, it is necessary to evaluate the possibility of adopting physiological parameters, such as root cation exchange capacity (CEC) for a rapid screening of new selections. This physiological indicator, when used together with other evaluation parameters, such as vigor, clorophyll and mineral content, allowed to obtain a reliable identification of the most tolerant rootstocks. The aim of the present work was, therefore, to assess whether this parameter can discriminate among Myrobalan clones and GF 677 rootstock as regards iron (Fe) efficiency. This method is based on the assumption that the root system is the plant component playing the most fundamental role in allowing Fe utilization.

Effects of recycled materials added to the substrate on nursery trees

Transplant can be a shock for plants, especially when they are moved from the nursery, where the environmental conditions are very favourable, to urbanised areas, where resources and maintenance are scarce. Moreover, some characteristics of urban soils, such as alkaline pH and compaction, make it difficult for trees to adapt. Recycled organic material (compost) added as mulch to trees plantings is effective in contrasting compaction in urban soils.