Phytochemical and antioxidant properties of anthocyanin-rich Morus nigra and Morus rubra fruits

In this study, phytochemical and antioxidant properties of anthocyanin-rich mulberry species of Morus nigra L. (black mulberry) and Morus rubra L. (red mulberry) fruits harvested from across Turkey were investigated. Fruit color, total phenolics (TP), total monomeric anthocyanin (TMA), titratable acidity (TA), and individual sugar and organic acid compositions were determined. Total antioxidant capacity (TAC) of fruits was assessed by both the trolox-equivalent antioxidant capacity (TEAC) and the ferric reducing antioxidant power (FRAP) assays. Black mulberry exhibited higher TP, TMA, TAC and TA when compared to red mulberry. The average TP contents of M. nigra and M. rubra were 2737 and 1603 μg gallic acid equivalent in g fresh weight basis (GAE/g fw), respectively. M. nigra had the richest amount of anthocyanin with an average of 571 μg cy-3-glu/g fw. Overall, TAC averaged 10.5 and 12.0 mmol TE/L by the TEAC and FRAP methods, respectively. We found that FRAP, TEAC, TP and TMA were significantly correlated (r = 0.64–0.99) with each other. Fructose (5.27 g/100 mL) and glucose (5.81 g/100 mL) were determined to be the major sugars in both mulberries. M. nigra displayed a higher TA (2.05 g/100 mL) than M. rubra (0.78 g/100 mL), with citric acid as the major acid.     

Variation in total phenolics and antioxidant capacity among European plum genotypes

Our objective was to determine the amount of variation in total phenolics and antioxidants present in European plum fruits, so that it can be utilized in breeding programs to enhance the health benefits. Total antioxidant capacity and total phenolic content of the fruit, and the fruit skin color were determined in 20 genotypes, comprising of released varieties and advanced selections of European plums. Among the 20 genotypes, the total antioxidant capacity ranged from 105 to 424 mg ascorbic acid equivalents (AAE)/100 g fresh weight (FW) while the total phenolic content was 86–413 mg gallic acid equivalents (GAE)/100 g FW. The two parameters had a strong correlation of r² = 0.96. A direct correlation between skin color intensity and total phenolic content could also be observed. This study demonstrates that there is adequate variation in total phenolic compounds and antioxidants within European plums and hence there is potential for improvement towards enhancing these health-promoting phytochemicals in this fruit.     

Antioxidant capacity and phytochemical properties of cornelian cherry (Cornus mas L.) genotypes in Iran

Cornelian cherry (Cornus mas L.) is a naturally growing dogwood species in Arasbaran (East Azerbaijan, Iran). Antioxidant capacity, total anthocyanins, total phenols, ascorbic acid and total flavnoids of a number of selected cornelian cherry genotypes were investigated. The total phenolic and antioxidant activity of methanol extract of cornelian cherry fruits were determined according to Folin–Ciocalteu and DPPH method, respectively. The range of ascorbic acid content of genotypes was 183.25–299.5 mg/100 g fresh weight (FW). Genotype C24 had the highest total antioxidant capacity (82.37) and total phenolic (2695.75 mg galic acid per 100 g FW basis). The highest total anthocyanin was observed in C27 genotype (442.11 mg cyanidin-3-glucoside equivalents/100 g FW). This genotype also had the highest total flavonoid (669 mg catechin per 100 g FW basis). There are linear relationships between the antioxidant capacities with total phenols, total flavonoid and ascorbic acid. But, No statistically significant correlation was observed between antioxidant activity and total anthocyanins. According to Path analysis, the highest direct effect on antioxidant was observed in total flavonoid (0.38). The present study demonstrates the potential of certain cornelian cherry genotypes, notably C24 and C27, for improvement of nutritional value through germplasm enhancement programs.     

ISSR polymorphism in Indian wild orange (Citrus indica Tanaka,Rutaceae) and related wild species in North-east India

Inter simple sequence repeats (ISSR) polymorphism in Citrus indica Tanaka (Rutaceae), an endemic and threatened wild species, was examined along with three other closely related wild taxa (C. medica L., C. latipes (Swingle) Tanaka, and C. sp. ‘Memang athur’) by analyzing 53 representative accessions sampled from North-east India. Jaccard's similarity values among 53 accessions of Citrus ranged from 0.46 to 0.97 (average = 0.75). Genetic similarity values among all the 34 accessions of C. indica were found in the range of 0.82 to 0.97 with an average of 0.90. Heterozygosity (Ht = 0.123) and Shannon's information index (I = 0.188) values estimated for C. indica revealed significantly low level of genetic variation within the species. UPGMA dendrogram grouped all 53 accessions of Citrus into four major clusters: Cluster I – C. latipes; Cluster II – C. medica; Cluster III – ‘Memang athur’ and Cluster IV – C. indica. The dendrogram placed all the 34 accessions of C. indica in five sub-clusters under Cluster IV. The placement of C. indica accessions in various sub-clusters and groups in the dendrogram was based on molecular differentiation of individual accessions rather than their geographical origin. Very low genetic diversity and destruction of its natural habitat pose serious threat to C. indica even in the Citrus Gene Sanctuary in Nokrek Biosphere Reserve (NBR) in Meghalaya. Low genetic variability, heterozygosity and Shannon's information index in C. medica, C. latipes and ‘Memang athur’ are also concerns that need to be addressed for developing appropriate strategies to conserve the genetic diversity extant in these valuable genetic resources.     

Effects of cultivar,orchard elevation,and storage on fruit quality characters of sweet cherry (Prunus avium L.)

Fruit quality characters were analysed in the sweet cherry cultivars, Burlat, Van, Tragana and Mpakirtzeika, harvested from low (39–59 m), medium (216 m) or high (490–546 m) elevation sites. The effects of storage for 2 or 4 days at 2 °C and 1 day at 20 °C on the fruit antioxidant contents were also evaluated. Tragana and Mpakirtzeika had greater fruit fresh weight (FW) and total soluble solid content compared to Van and Burlat, the latter being the most red colored. Tragana and Burlat had greater total phenolic content and total antioxidant capacity, measured by DPPH extinction, compared to Mpakirtzeika and Van (mean values 204.4 mg vs. 103.7 mg gallic acid equivalent 100 g⁻¹ FW, and 176.1 mg vs. 79.3 mg ascorbic acid equivalent 100 g⁻¹ FW, respectively). The geographic elevation had a marked influence on the cherry antioxidant content in all studied cultivars, apart from Van, with high elevation orchards producing cherries with greater contents of antioxidant compounds compared to lower elevation orchards. Changes in the antioxidant contents during storage were depended on the cultivar and some times on the orchard elevation. Total antioxidant capacity was significantly correlated with total phenolic content in Tragana, Burlat and Mpakirtzeika, but not in Van; nevertheless this was not the case during storage.     

Effect of scale color on the antioxidant capacity of onions

The bulb onion (Allium cepa L.) has been cultivated for thousands of years and used as an important component of human diet. Recent studies suggest that onions can be used to cure, reduce, or prevent some of the health problems such as cancer, cardiovascular diseases, antidiabetic, asthma, antibiosis, and prebiotic effects due to its high antioxidant effect. In this study, we determined the antioxidant capacities of a wide range of onion cultivars; nine commercial cultivars and five advance selections differing in color. The variables tested include bulb size, scale color, total phenolic (TP), total antioxidant activity determined by both “Ferric reducing ability of plasma” (FRAP) and “Trolox equivalent antioxidant capacity” (TEAC). We found that yellow onion had the greatest TP content (3.7 mg GAE/g dw); and, the red group had higher TP mean than the white group (2.2 mg GAE/g dw vs. 1.1 mg GAE/g dw). For the antioxidant capacity measurements, the red group had the greatest means by both methods (15.4 μmol TE/g dw and 9.3 μmol TE/g dw for TEAC and FRAP). Yellow onions had higher TEAC (14.7 μmol TE/g dw vs. 8.7 μmol TE/g dw) and FRAP values (9.8 μmol TE/g dw vs. 5.6 μmol TE/g dw) than white onions. Among the cultivars tested great differences of TP, TEAC and FRAP was observed. The TP content of Me-Tan 88 (8.3 mg GAE/g dw) was two times higher than the yellow group. Yellow color Dayton had the greatest TEAC (20.5 μmol TE/g dw) and FRAP (12.3 μmol TE/g dw) means followed by yellow color Me-Tan 88 (19.4 and 11.4 μmol TE/g dw). The two antioxidant measurements were found to be highly correlated (0.99) where absolute values of FRAP were about 40% less than those of TEAC. The values of TEAC and FRAP were significantly correlated by TP with similar rs (0.74 and 0.73, respectively). TP, TEAC and FRAP were significantly and positively correlated to soluble solids (0.41, 0.43, and 0.40, respectively). Our results suggested that the red onions had higher antioxidant activities than yellow and white onions although yellow onions had the richest phenolic contents.     

CPPU application on size and quality of hardy kiwifruit

For the purpose of determining the appropriate conditions of application to increase the size of a hardy kiwifruit, Actinidia arguta ‘Mitsuko’, N₁-(2-chloro-4-pyridyl)-N₃-phenylurea (CPPU) was applied at three different growth stages of the crop: at petal fall, 10 and 25 days after petal fall (DAPF), and three different concentrations: 1, 5 and 10 mg l⁻¹. A significant increase in fruit size was obtained by treatment at the concentrations of 5–10 mg l⁻¹ and at 10 DAPF. The fruit weight doubled. Although a significant reduction in the concentrations of total soluble solids (TSS), titratable acids (TA) and ascorbic acid (AsA) in the CPPU-treated fruits was recorded, the TSS/TA ratio and AsA content per fruit increased by the treatment. CPPU application at petal fall induced abnormally protruding fruit tip.     

Use of ISSR markers to assess genetic diversity of African edible seeded Citrullus lanatus landraces

We used the twenty primers to evaluate the genetic variability of 80 individuals belonging to four accessions of edible seeded Citrullus lanatus originated from Côte d’Ivoire. Edible seeded C. lanatus, named “egusi” or “pistachio”, had a great importance in nutrition in West Africa. Nevertheless, due to its neglected status no study to our knowledge has been devoted to its genetic variability using DNA markers. The twenty ISSR primers generated 258 bands among which 252 were polymorphic (97.67%). On the whole, the bands generated revealed three types of profile sharply distinct from each other with minor differences within each type. One profile (P1) was most frequent with 65 individuals. Three accessions (NI084, NI127 and NI145) generated the three types of profile and had medium values of genetic diversity (GD = 0.246–0.275, respectively). On the opposite, the accession NI076 only contained individuals of the most represented type of profile (P1) and had the lowest genetic diversity (GD = 0.055 ± 0.017). The pairwise genetic distance between the 80 individuals varied from 0 to 0.61. The Factorial Component Analysis and the dendrogram clearly separated the 80 individuals into three clusters corresponding to the three types of profile. The results showed that clusters were well separated from each other whereas accessions were not. Our results suggest that high number of individuals should be taken into account for sampling missions and conservation strategies because accessions were not well differentiated from each other. Local agricultural practices consisting of frequent seeds exchanges between farmers and the conservation of harvested seeds for next year culture could be one explanation.     

Controlled atmosphere storage at high CO2 and low O2 levels affects stomatal conductance and influence root formation in kalanchoe cuttings

Since the response of cuttings to raised CO₂ concentration is not documented, controlled atmosphere (CA) storage of kalanchoe cuttings at combinations of high carbon dioxide and low oxygen levels was investigated to study the feasibility of using CA to sustain quality of cuttings prior to planting. During storage, stomata opening and plant fresh weight (FW) were measured, and root formation (RF) was recorded post storage. Storage atmosphere composition (10/2, 15/2, or 15/5; kPa CO₂/kPa O₂), storage duration (9 or 19 days), and cutting type (rooted or un-rooted) affected stomata conductance (G_s), and influenced FW and subsequent RF in cuttings of kalanchoe ‘Yellow Josefine’. In CA stored plants, G_s was high, 60–160 mmol m⁻² s⁻¹, indicating open stomata, whereas in control plants G_s was low, 5–14 mmol m⁻² s⁻¹, indicating closed stomata. Generally G_s values were higher for un-rooted than for rooted cuttings. Overall, cutting FW was reduced by CA storage with no significant differences in FW reduction between the CA treatments. RF of un-rooted CA stored cuttings was comparable to that of controls, whereas for rooted cuttings controls grew better than CA stored cuttings. CA at 10 kPa CO₂ and 2 kPa O₂ for 2–3 weeks could sustain un-rooted cuttings, in a pests-free state whilst retaining the ability of the cuttings RF. The results showed that stomata aperture may be altered by high CO₂ concentration combined with low O₂, and results indicated that this effect was not only caused by high CO₂ but also by low O₂ concentration. In addition, the results indicated that CA storage, stomata conductance, and water stress of kalanchoe cuttings may be correlated. Monitoring G_s of leaves of cuttings could be used as a non-destructive indicator of storability and quality status. Based on the novel positive preliminary results reported here, a protocol that focuses on minimising water loss should be developed and optimised for kalanchoe.     

Total phenolics and flavonoids and total antioxidant capacity in pistachio (Pistachia vera L.) nuts in relation to cultivars and storage conditions

The effects of cultivar, drying and storage conditions on total phenolics (TP), total flavonoids (TF) and total antioxidant capacity (TAC), measured with ferric reducing antioxidant power (FRAP) and radical scavenging capacity (2,2-diphenyl-1-picrylhydrazyl or DPPH) assays, of in-shell and unpeeled kernels of ripe pistachios were investigated. Drying was carried out at 45 °C for 34 h to approximately 5% moisture in kernels and storage of dried nuts in packaging atmosphere of dry air or N₂ at 1 °C or 20 °C for 6 or 12 months. At harvest, each cultivar showed its highest values for each measured variable and TP ranged from 16.2 to 7.9 mg gallic acid equiv. g⁻¹ d.w., TF from 7.2 to 3 mg catechin equiv. g⁻¹ d.w., FRAP from 132.5 to 58.8 μmol Trolox equiv. g⁻¹ d.w., and DPPH from 122.6 to 45.7 μmol Trolox equiv. g⁻¹ d.w. Drying resulted in losses in all cultivars that averaged approximately 14.2%, 14.1%, 11.9% and 12.2% for TP, TF, FRAP and DPPH, respectively, while during 12-month storage the corresponding losses in dried kernels averaged approximately 24.7%, 21.8%, 30.3% and 32.4%. Decreases in all measured variables were advanced by storage time, but prevented by low temperature and packaging in N₂ atmosphere. Among the studied cultivars, Pontikis, Aegina, Bronte and Cerasola showed higher values of TP, TF and TAC than Sirora, Kerman, Joley and Mumtaz in all cases, while Pontikis the highest in most cases. The effects of cultivar, time, temperature and packaging atmosphere during storage were all significant on TP, TF, FRAP and DPPH. Strong correlations were also found among the measured variables.     

Genetic assessment of apple germplasm in Bosnia and Herzegovina using microsatellite and morphologic markers

Traditional apple cultivars from Bosnia and Herzegovina (B&H), potentially diverse due to specific geographic location and history of the country, represent a possible source of valuable traits for future breeding efforts and sustainable fruit growing. A total of 39 accessions, 24 traditional B&H cultivars and 15 modern international cultivars, maintained at the ex situ apple collection “Srebrenik” in Northeast Bosnia were, investigated using 10 SSR (simple sequence repeats) markers and 23 morphologic characteristics. All the used primer pairs manage to amplify clearly distinguishable and highly polymorphic SSR alleles, in average 10.4 alleles per locus. More than two different alleles per locus were detected for seven accessions (five traditional B&H cultivars and two international cultivars). Forty one unique alleles were exclusively present within the B&H cultivars, while seven unique alleles were only detected within international cultivars. The differentiation between traditional B&H and international cultivars (Fst = 0.060; P < 0.0001) was significant, also confirmed by analyses of molecular variance (AMOVA) (f_CT = 0.092; P < 0.001). Cluster analyses of 39 apple accessions, based on 10 SSR loci, revealed that only two traditional B&H cultivars grouped tightly with international cultivars (Ljepocvjetka and Bobovec Jon), while the rest formed separate clusters. Multivariate analyses of variance (MANOVA), nonparametric multivariate analyses of variance (NPMANOVA) and analyses of similarity (ANOSIM) showed statistically significant difference in morphologic characteristics between traditional B&H cultivars and the international cultivars. Cluster analyses of 39 apple accessions, based on the morphologic data, displayed less differentiation between traditional and international accessions, in comparison to the cluster analyses based on molecular data. No correlation between the molecular and morphologic data set was detected using the Mantel test. Many of the morphologic characteristics which have been analyzed in this study have significant commercial importance, we can assume that unlike the microsatellites these traits have been under agronomic selection pressure.     

Taxonomic revision of Dendrobium moniliforme complex (Orchidaceae)

Taxonomic revision of Dendrobium moniliforme complex is presented. D. moniliforme complex is characterized by the even slim stems, bracts with brownish zone, semi-spherical anther cap and the hairy disc of lip. Dendrobium tosaense, Dendrobium officinale and Dendrobium guangxiense were excluded by having membranous bracts lacking brownish zone, anther cap conical and bifid. Two species are recognized in this complex, i.e., D. moniliforme and Dendrobium wilsonii. D. wilsonii differs from D. moniliforme by having elliptic leaves about 1.3–2 cm wide, dorsal sepal 3.0–4.0 cm long, 0.6–0.9 cm wide, petals elliptic to oblong, 3.0–4.0 cm long, 1.0–1.5 cm wide, lip elliptic to ovate–lanceolate, 2.6–3 cm long, 1.2–1.5 cm wide.     

Pome fruit viruses at the Canadian Clonal Genebank and molecular characterization of Apple chlorotic leaf spot virus isolates

A survey for apple and pear viruses was carried out at the Canadian Clonal Genebank (CCG), Harrow, Ontario, Canada, during the fall/winter of 2007 and spring of 2008. Leaves and/or dormant cuttings were randomly collected from 438 to 122 accessions of apple and pear, respectively. Samples were tested by Double Antibody Sandwich-Enzyme Linked Immunosorbent Assay (DAS-ELISA) for the presence of Apple chlorotic leaf spot virus (ACLSV), Apple stem pitting virus (ASPV), Apple stem grooving virus (ASGV) and Apple mosaic virus (ApMV). Infection rates for apples were ACLSV (48.1%), ASGV (10%), ASPV (6.6%) and ApMV (7.1%), and for pears ACLSV (42.6%). ACLSV was detected and characterization by multiplex RT-PCR with primers targeting a fragment of 677 bp corresponding to the partial coat protein (CP), movement protein (MP) and untranslated (3′UTR) region in 22 accessions of apple and pear. Multiplex RT-PCR showed a higher sensitivity over the ELISA test. The nucleotide and amino acid deduced partial CP identities ranged from 82.6–100% to 91–100%, respectively, while partial MP identities was 62.5–100% at aa level based on the amplified fragment appropriate for partial MP using a frame shift, among 22 ACLSV isolates. Phylogenetic analyses based on the partial CP region clustered CCG ACLSV isolates in two different groups, while those based on the partial MP region embraced CCG ACLSV isolates in two sub-clusters within the same group. This is the first report on the detection of ACLSV, ASPV, ASGV and ApMV at CCG, and the molecular characterization of ACLSV isolates in apple and pear plants from worldwide countries to deduce possible heterogeneity and evolution.     

Effects of a new light source (cold cathode fluorescent lamps) on the growth of tree peony plantlets in vitro

The effect of a new light source, cold cathode fluorescent lamps (CCFLs), on the growth of peony (Paeonia suffruticosa cv. ‘Wu Long Peng Sheng’) plantlets in vitro was examined in six different light quality ratios: 100% red (R), 80% R + 20% blue (B), 70% R + 30% B, 60% R + 40% B, 100% B and white CCFLs. Control illumination was provided by conventional heat-generating plant growth fluorescent lamps (PGFLs). All plantlet growth parameters were as effective under 70% R + 30% B (the best performing CCFL ratio) as they were under PGFLs. Chlorophyll content (a, b and total) was greater in the range of 60–80% R + 20–40% B, although in general there were no significant differences between the best performing R:B ratio and PGFLs. This study indicates that CCFLs can be used as effectively – if not better – than conventional PGFLs to micropropagate this woody ornamental.     

Physiological and biochemical changes with special reference to mangiferin and oxidative enzymes level in malformation resistant and susceptible cultivars of mango (Mangifera indica L.)

Changes in biophysical attributes, mangiferin and polyphenol oxidase (PPO), catalase and peroxidase activities in malformation resistant mango cultivar Elaichi were studied at various stages of flower development and compared with susceptible cvs. Amrapali, Beauty Mc-lin and Dashehari. Accumulation of mangiferin was maximum (96.0 and 108.0 mg g⁻¹ FW) in Elaichi prior to flower bud differentiation (September) and at full bloom (February), while these were minimum (59.0 and 74.0 mg g⁻¹ FW) in susceptible cv. Beauty Mc-lin. Mangiferin promoted vegetative growth and exhibited inhibitory role on the occurrence of malformation. It was also found that the resistant cultivar had highest activity of PPO as compared to susceptible ones. There was no significant difference in the enzymes catalase and peroxidase activity at early stage of flower differentiation but at flower bud burst stage the catalase activity was enhanced significantly in cv. Elaichi (25.28 unit min⁻¹ g⁻¹ FW) in comparison to Amrapali (16.20 unit min⁻¹ g⁻¹ FW), Beauty Mc-lin (18.39 unit min⁻¹ g⁻¹ FW) and Dashehari (17.50 unit min⁻¹ g⁻¹ FW). The resistant cultivar had high leaf temperature (30.30 °C) and diffusion resistance (476.14 m mol m⁻² s⁻¹) during the flowering but the rate of transpiration and relative humidity (RH) were high in susceptible cultivars. Results of the present study clearly indicate that level of mangiferin could be considered as a potential biochemical indicator for screening mango genotypes to malformation.     

Antioxidant properties of blackberry and blueberry fruits grown in the Black Sea Region of Turkey

Seven wild and ten cultivated blackberries (Arapaho, Bartin, Black Satin, Bursa 1, Bursa 2, Cherokee, Chester, Jumbo, Navaho, and Ness), and six lowbush (Vaccinium arctostaphylos) and four highbush (Vaccinium corymbosum) blueberries fruits (Ivanhoe, Jersey, Northland, and Rekord) were analyzed for total anthocyanins, total phenolics, and antioxidant activity as ferric reducing antioxidant power (FRAP) in this study. The respective ranges of total anthocyanin and total phenolic contents of the tested samples were: blackberries, 0.95–1.97 and 1.73–3.79 mg g⁻¹ and blueberries, 0.18–2.94 and 0.77–5.42 mg g⁻¹. FRAP values varied from 35.05 to 70.41 μmol g⁻¹ for blackberries, 7.41 to 57.92 μmol g⁻¹ for blueberries. Wild blackberries had the highest FRAP values while wild blueberries had the highest total phenolic and total anthocyanin contents. A linear relationship was observed between FRAP values and total phenolics for blueberries (r = 0.981). The anthocyanin pigments in samples were isolated and characterized by high-performance liquid chromatography (HPLC) with UV–visible detection. Cyn-3-glu was the predominant anthocyanin in all blackberry fruits.     

Use of ISSR,SRAP, and RAPD markers to assess genetic diversity in Turkish melons

The genetic relationships among 63 melon (Cucumis melo L.) genotypes collected from various regions of Turkey were determined by comparing their molecular ISSR, SRAP, and RAPD markers with those of 19 foreign melon genotypes to investigate the taxonomic relationships and genetic variation of Turkish melon germplasm. Total 162 polymorphic markers (69, 18, and 75 obtained from ISSR, SRAP, and RAPD primers, respectively) were used to define the genetic similarity among the melon genotypes by dendrogram or two and three dimensional scalings. The average similarity (SM coefficient) between any two pairs of accessions examined as estimated by molecular variation was 0.73 ± 0.48. Within-group genetic similarities ranged between 0.46 and 0.96. Related genotypes or genotypes collected from similar regions were partitioned to similar clusters. Southeastern Anatolian genotypes were distinctly apart from group inodorus and group cantalupensis (sweet) genotypes. This reinforced the position of Turkey in the secondary genetic diversity center of melon. The genetic diversity among Turkish genotypes (H = 0.28 and I = 0.42) was only a little less than that of the world accessions (H = 0.30 and I = 0.45). On the other hand, the percentage of polymorphic loci among Turkish melon genotypes (90.7%) was even higher than that of the world accessions (87.6%).     

Effect of phosphite fertilization on growth,yield and fruit composition of strawberries

Traditionally, phosphates (Pi, salts of phosphoric acid, H₃PO₄) have been used for plant fertilization, and phosphites (Phi, salts of phosphorous acid, H₃PO₃) have been used as fungicides. Nowadays several Phi fertilizers are available in the EU market despite the fact that in research trials Phi has often had a negative influence on plant growth. The objective of this study was to elucidate the effect of a Phi fertilizer on plant growth, yield and fruit composition of strawberries (Fragaria × ananassa Duch.). Experiments were carried out with ‘Polka’ frigo plants in South Estonia in 2005 and 2006. The number of leaves per plant, total and marketable yields, fruit size, fruit ascorbic acid content (AAC), soluble solids content (SSC), titratable acidity (TA), anthocyanins (ACY) and total antioxidant activity (TAA) were recorded.     

Effects of root inoculation of plant growth promoting rhizobacteria (PGPR) on yield,growth and nutrient element contents of leaves of apple

From 2002 to 2006, plant growth promoting effects of Bacillus M3, Bacillus OSU-142 and Microbacterium FS01 were tested alone or in combination on apple (Malus domestica L.) cv. Granny Smith in terms of yield, growth and nutrient composition of leaves in the province of Malatya, Turkey. The presence of M3 and/or OSU-142 and/or FS01 combinations stimulated plant growth and resulted in significant yield increases in Granny Smith. Root inoculation of PGPR strains significantly increased cumulative yield (26.0–88.0%), fruit weight (13.9–25.5%), shoot length (16.4–29.6%) and shoot diameter (15.9–18.4%) compared with the control. In addition, all nutrient element contents (N, P, K, Mg, Ca, Fe, Mn and Zn) investigated in Granny Smith, except Mg was significantly affected by bacterial applications compared with the control. The highest N content (3.38%) was obtained from OSU-142 + FS01 application. Phosphorus contents of leaves of Granny Smith increased from 0.29% in the control to 0.42, 0.37, 0.36, 0.36 and 0.35% by M3, M3 + FS01, M3 + OSU-142, OSU-142 and M3 + OSU-142 + FS01 application, respectively. All bacterial applications significantly increased Ca content of leaves. The highest K, Fe, Mn, Cu and Zn content of leaves were obtained from OSU-142, M3, FS01, M3 and M3 + FS01 applications, respectively. The results of this study suggest that Bacillus M3 and/or OSU-142 and/or Microbacterium FS01 in combination have the potential to increase the yield, growth and nutrition of apple trees.     

Foliar application of chlorocholine chloride improves leaf mineral nutrition,antioxidant enzyme activity,and tuber yield of potato (Solanum tuberosum L.)

In southern China, potatoes (Solanum tuberosum L.) are grown in the late season and the crops are often subjected to low temperature stress particularly during the tuber bulking stage. Exogenous chlorocholine chloride (CCC) treatment has been found to improve crop performance under suboptimal growth conditions; however, the physiological mechanisms underlying the beneficial effects have not been fully understood. The objective of this study was to investigate the effects of CCC treatment on mineral nutrition, antioxidant enzyme system, and tuber yield of potato (cv. Zhongshu 3) under field conditions. The plants were foliar sprayed twice with 1.5, 2.0 and 2.5 g l⁻¹ CCC at 24 and 28 days after emergence (DAE), respectively; and plants without CCC treatment were serviced as control. Leaf samples were collected on 56 DAE for determination of mineral nutrition contents and antioxidant enzyme activity. Results showed that 1.5 and 2.0 g l⁻¹ CCC treatments significantly increased the contents of P, K, Ca, Mg, Fe, Mn, Zn and Cu in potato leaves. These treatments also increased superoxide dismutase (SOD), peroxidases (POD) and catalase (CAT) activities in the leaves. A positive linear relationship was found between SOD activity and the content of Fe + Mn + Zn + Cu. Tuber yield was significantly increased by CCC treatment. It is concluded that treatment with certain concentration of CCC (e.g. 1.5–2.0 g l⁻¹) improves mineral nutrition and SOD, POD and CAT activities in potato leaves; which might have contributed to the higher tuber yield of the crop grown under suboptimal conditions.