Responses of soilless grown tomato plants to arbuscular mycorrhizal fungal (Glomus fasciculatum) colonization in re-cycling and open systems

Mycorrhizal fungi species Glomus fasciculatum was used to determine its effects on tomato growth, yield, fruit properties, nutrient uptake and substrate ion accumulation of plants grown hydroponically under open and re-cycling (closed) perlite substrate. AM inoculation in both open and closed soilless systems did not increasingly influence the vegetative plant growing and nutrient uptake of tomato cultivar M19. However, fruit yield absolutely increased with inoculation. AM inoculated tomato plantscould effectively use photo assimilates for fruit production instead of vegetative growing. In the closed system with AM, ion accumulation and EC increases (salinity effects) were well controlled. Results indicated that mycorrhizal inoculation improved yield and fruit size, which can help alleviate deleterious effects of re-cycling soilless systems for tomato crop

Physiological root responses of iron deficiency susceptible and tolerant tomato genotypes and their reciprocal F-1 hybrids

WOS: 000176415100012By using two tomato genotypes line 227/1 (Fe chlorosis susceptible) and Roza (Fe chlorosis tolerant) and their reciprocal F(1)hybrid, some root morphological changes, pH changes of nutrient solution, reduction capacity of Fe-III and uptake and root-to-shoot translocation of Fe-59 were studied under controlled environmental conditions in nutrient solution with 3 different Fe supplies as Fe EDDHA (i.e., 10(-7) M, severe Fe deficiency; 10(-6) M, intermediate Fe deficiency; 10(-4) M, adequate Fe supply). Tolerant parent `Roza' was less affected by low Fe supply than susceptible parent `line 227/1' as judged from the severity of leaf chlorosis. Under both Fe deficient conditions there were no differences between the reciprocal hybrids concerning the appearance of chlorosis. Under intermediate Fe deficiency, reciprocal F-1 hybrids (`line 227/1 x Roza' and `Roza x line' 227/1) showed an intermediate chlorosis between tolerant and susceptible parents. However, under severe Fe deficiency the reciprocal hybrids were more chlorotic than the tolerant parent irrespective of which parent was the cytoplasm contributor. A decreased Fe supply during preculture enhanced (FeII)-I-I reduction capacities of the parents and reciprocal hybrids. Differences in the tolerance to Fe deficiency always were better correlated with (FeII)-I-I reduction capacity of the genotypes than the Fe deficiency-induced release of H+ ions. Under both Fe deficient conditions the tolerant parent Roza had a much higher (FeII)-I-I reduction capacity than the susceptible parent line 227/1. The reduction capacity of the hybrids `Roza x line 227/1' was very similar to the capacity of the parent Roza, but higher than the capacity of the hybrids `line 227/1xRoza' at both Fe-deficient conditions. Under both Fe deficient conditions tolerant parent had higher number of lateral roots than the susceptible parent. Among the reciprocal hybrids `Roza x line 227/1' possessed more lateral roots than the `line 227/1 x Roza' under both Fe deficient conditions. Low Fe nutritional status resulted in marked increase in root uptake of (5)9Fe. At adequate Fe supply, reciprocal hybrids and their parents did not differ in uptake and root-to-shoot translocation of Fe. However, under Fe-deficient conditions uptake and root-to-shoot translocation of (5)9Fe were significantly higher in the Fe chlorosis tolerant than the susceptible parent. Based on the reduction capacity of (FeII)-I-I and uptake and root-to-shoot translocation of Fe, the F-1 hybrids obtained from the cross in which the maternal genotype was Roza appeared to be more tolerant than when the maternal genotype was the susceptible line 227/1. Uptake and translocation ratio of the F-1 hybrids obtained from `Roza x line 227/1' were similar to those of the parent Roza, but higher than the F-1 hybrids obtained from `line 227/1 x Roza', particularly under intermediate Fe deficiency. The results indicate that (FeII)-I-I reduction show a better relationship to Fe efficiency than Fe deficiency induced release of H+ ions. The inheritance of Fe deficiency tolerance of Roza seems not to be simple monogenic. It might be characterised by both, nuclear and extranuclear heredity. The intermediate responses of the reciprocal hybrids of the `line 227/1 x Roza' indicates that the Fe deficiency tolerance character of Roza is transferable by nuclear heredity. The better responses of the hybrids of `Roza x line 227/1' than the hybrids of `line 227/1 x R

Genetic analysis of iron chlorosis tolerance in Prunus rootstocks

39 Pags., 4 Tabls., 4 Figs. The definitive version is available at: http://link.springer.com/journal/11295The high economic losses caused by the occurrence of iron chlorosis in Prunus orchards in the Mediterranean area justifies the implementation of breeding programs to generate high-performance rootstocks for different edaphoclimatic area conditions. For that reason, the genetic control of iron chlorosis tolerance was studied in an F1 population derived from a three-way interspecific cross between a Myrobalan plum (P 2175) and an almond × peach hybrid (Felinem). Several phenotypic measurements were assessed to guarantee an accurate data set for genetic analysis. SPAD (Soil and Plant Analyzer Development) values, chlorophyll concentration, and visual diagnostic symptoms were highly correlated with leaf chlorosis in trees. SPAD value was the most reliable measure, since it was an objective, unbiased, and non-destructive method. Two significant quantitative trait loci (QTLs) involved in SPAD and chlorophyll concentration were identified for Felinem in linkage groups 4 and 6. Both QTLs were detected in four of the six consecutive years of the experiment. For P 2175, two of the three putative QTLs identified, pspad4.1 and chl4.1, were placed in linkage group 4. These QTLs were related to the SPAD values and chlorophyll concentration, respectively, and co-localized with QTLs detected in the Felinem map affecting the same traits. Candidate gene PFIT, related to iron metabolism, was localized within the confidence interval of the QTL in linkage group 4. This research suggests an association of this chromosome region with tolerance to iron chlorosis in Prunus, and it provides a first approach to localize candidate genes involved in tolerance to this abiotic stress.This research was funded by MICINN (Spanish Ministry of Science and Innovation, AGL 2008-00283) and co-funded with a FEDER project and Gobierno de Aragón (A44). M.J. Gonzalo was the beneficiary of an I3P-PC2006 contract from the CSIC-FSE.Peer reviewe

Microbial Community Dynamics and Response to Plant Growth-Promoting Microorganisms in the Rhizosphere of Four Common Food Crops Cultivated in Hydroponics

Plant growth promoting microorganisms (PGPMs) of the plant root zone microbiome have received limited attention in hydroponic cultivation systems. In the framework of a project aimed at the development of a biological life support system for manned missions in space, we investigated the effects of PGPMs on four common food crops (durum and bread wheat, potato and soybean) cultivated in recirculating hydroponic systems for a whole life cycle. Each crop was inoculated with a commercial PGPM mixture and the composition of the microbial communities associated with their root rhizosphere, rhizoplane/endosphere and with the recirculating nutrient solution was characterised through 16S- and ITStargeted Illumina MiSeq sequencing. PGPM addition was shown to induce changes in the composition of these communities, though these changes varied both between crops and over time. Microbial communities of PGPM treated plants were shown to be more stable over time. Though additional development is required, this study highlights the potential benefits that PGPMs may confer to plants grown in hydroponic systems, particularly when cultivated in extreme environments such as space