Early detection of graft incompatibility in apricot (Prunus armeniaca L.) using phenol analyses

The study investigated the role of phenols in apricot graft incompatibility. Assays of phloem with cambium from 1-year-old apricot trees of cultivars Marlen, Leskora and Betinka which were grafted on the rootstocks of different genetic origin: M-LE-1, Lesiberian, MY-KL-A, Tetra, Penta, Green Gage, Julior, MRS 2/5 and Isthara were analysed with HPLC (together 23 scion/stock combinations). The phloroglucinol, catechin, p-coumaric acid and further non-identified phenols with the retention time 23–25 and 30 min were determined. The content of individual phenol compounds was related to specific cultivar/rootstock combination. The minimum number of statistical significant differences in the phenol content between tissues above and below graft union was established in homospecific combinations (P. armeniaca/P. armeniaca). Cultivars Marlen, Leskora and Betinka differ in the degree of compatibility or incompatibility with rootstocks. The pattern of non-identified phenol 23 in different graft combinations is similar to catechin and p-coumaric acid.     

Cold tolerance and short day acclimation in perennial Gaura coccinea and G. drummondii

The use of related species to integrate important traits into cultivated crops is a common practice in plant breeding. Gaura coccinea and, potentially its derived species Gaura drummondii, could be donor species for introgressing cold tolerance into non-hardy G. lindheimeri. However, cold tolerance and acclimation has not been studied in these species, so protocols for determining these traits are required. The objectives of this study were to determine the relative cold tolerance of G. coccinea, G. drummondii and whether short day photoperiod is involved in cold acclimation. G. drummondii from Texas, USA and G. coccinea from Minnesota and Texas, USA were subjected to freezing tests using whole plant or electrolyte leakage after natural acclimation or non-acclimation conditions. Minnesota genotypes were able to withstand colder temperatures (−12 °C) than Texas genotypes (−9 °C). Acclimation capacity was determined for whole plant and electrolyte leakage assays using three different plant organs—stem, crown, and rhizome. Underground rhizomes were the best predictors of cold tolerance, however they were difficult to obtain. Stem sections of G. drummondii (Texas) and G. coccinea (Minnesota and Texas) were used to determine a shift in acclimation under short days. The Minnesota G. coccinea genotypes demonstrated greater cold tolerance after 3 weeks of short days while Texas G. coccinea, G. drummondii genotypes did not change even after 5 weeks.     

Collection time,cutting age,IBA and putrescine effects on root formation in Corylus avellana L. cuttings

The effects of collection time, cutting age, indole-3-butyric acid (IBA) and putrescine application on the rooting of cuttings of Italian hazelnut cultivars ‘Tonda Gentile Romana’, ‘Tonda di Giffoni’ and ‘Nocchione’ were investigated. Samples collected during late June, late July and early September from newly formed and 1-year old part of twigs to be utilized to produce leafy cuttings, after being treated with 1000 and 2000 ppm IBA, respectively. In addition, the September cuttings were also treated, respectively, with 1000 and 2000 ppm IBA and 1600 ppm putrescine. Rooting ability was evaluated 2 months after planting for each treatment and collection time. Satisfactory rooting of hazelnut leafy cuttings was observed when collection time occurred in June and September, whereas leafy cuttings collected in July showed a limited capacity of rooting in all cultivars tested. On average, the rooting of the newly formed leafy cuttings was more than the 1-year old cuttings. Rooting was also promoted by IBA treatments, mainly in ‘Nocchione’ and ‘Tonda di Giffoni’. In contrast, young cuttings collected from ‘Tonda Gentile Romana’ in early September rooted poorly when treated with IBA alone, but showed the best rooting (∼80%) after the application of a combination of 1000 ppm IBA and 1600 ppm putrescine. The current findings confirm that putrescine can be a useful substance for increasing rooting percentage and root quality in cuttings of some hazelnut cultivars as obtained from ‘Tonda Gentile Romana’ cultivar.     

Yield and fruit quality of ‘Nova’ hybrid [Citrus clementina hort. ex Tanaka × (C. reticulata Blanco × C. paradisi Macfad)] and two Clementine varieties (C. clementina hort. ex Tanaka) as affected by self- and cross-pollination

Low yields of ‘Nova’ citrus hybrid are common in single variety plantings (plantings consisting of one variety) due to its sexual self-incompatibility. Self-incompatibility may be overcome by cross-pollination with other compatible varieties. Fruit quality and yield of ‘Nova’ citrus hybrid as well as of the ‘SRA63’ and ‘Marisol’ Clementines, when either they were self-pollinated in single variety plantings or each one of the two Clementine varieties was used as a pollenizer for ‘Nova’ in mixed plantings (plantings consisting of more than one variety), were investigated. The study was carried out for two successive years under the same environmental and cultural conditions using three single variety plantings (‘Nova’ × ‘Nova’, ‘SRA63’ × ‘SRA63’, ‘Marisol’ × ‘Marisol’) and two mixed plantings (‘Nova’ × ‘SRA63’, ‘Nova’ × ‘Marisol’).     

Auxin-dependent development and habituation of highbush blueberry (Vaccinium × covilleanum But. et Pl.) ‘Herbert’ in vitro shoot cultures

The influence of IAA (1.0 mg dm⁻³), and IBA (1.16 mg dm⁻³), on the development of highbush blueberry (Vaccinium × covilleanum But. et Pl.) ‘Herbert’ in vitro shoot cultures was examined. Depending on the kind of auxin and 2iP concentration in vitro cultures consisted of various number of axillary (AX) and adventitious (AD) shoots. Three different categories of AD shoots were found: leaf shoots (AD-L), node-adjoin shoots (AD-P), and base-adjoin shoots (AD-M, madshoots). The AX shoots were the least habituated (towards auxins, cytokinins and vitamins) whereas the AD-M shoots (madshoots) the most. In comparison to IAA, IBA caused dying or callusing higher number of initial explants. However, IBA generally suppressed development of AD shoots, especially madshoots whereas slightly weakened multiplication of AX shoots. IBA significantly enhanced elongation of AX shoots also. Axillary shoots obtained on IBA-media had relative long internodes and rigid, well-developed leaves. The adventitious shoots, especially base-adjoin (AD-M) ones, were easily distinguishable as were more thin and fragile, more or less vitrified, and had short internodes and smaller, sometimes unfolded leaves. Development of blueberry in vitro cultures on auxin-free and IAA-supplemented media was similar. AX shoots grown on such media resembled AD shoots. 2iP applied in higher doses along with IAA promoted much proliferation of AD than AX shoots. In contrast, 2iP applied in higher doses together with IBA stimulated significantly only growth of AX shoots whereas in general, development of adventitious shoots was not affected. Micropropagation carried out through routine method based on subculturing of shoot explants or shoot clumps on the medium supplemented with IAA (4 mg dm⁻³) and 2iP (10–15 mg dm⁻³) as well as stimulation of shoot elongation on the blank medium causes in fact the propagation of highbush blueberry through highly habituated adventitious madshoots. Replacement of IAA by IBA facilitates micropropagation of highbush blueberry cv. Herbert through axillary shoots.     

Study on the relationship between β-adrenoceptor and L-arginine/NO pathway in vivo

AIM and METHODS: A constant perfusion model of rabbit femoral artery was used to examine whether vasodilation induced by β-adrenoceptor(β-AR) stimulation is dependent on NOS activiation in vivo and which subtype(s) of β-AR is/are responsible for NOS activiation in order to ascertain the role of NO in vasodilation induced by β-AR stimulation. RESULTS: Isoprenaline elicited a concentration-dependent vasodilation of rabbit femoral artery, co-infusing NOS inhibitor L-NAME or β₂-AR antagonist ICI 118551 abolished the vasodilation by Isoprenaline, but β₁-AR antagonist CGP 20712A had no effect on vasodilation of rabbit femoral arterg induced by isoprenaline. CONCLUSION: Isoprenaline-induced vasodilation in this femoral vascular bed is mediated through activiation of NOS and only β₂-AR is responsible for this sort of vasodilation.     

Variation in nutrition along time and relative chlorophyll content of Leucospermum cordifolium cv. ‘High Gold’, and their relationship with chlorotic sypmptoms

Foliar samples, SPAD-502 measurements (both along the growing season), and soil samples were taken from protea plants (Leucospermum cordifolium), cultivar ‘High Gold’ cultivated in six commercial plantations of La Palma Island (Canarian Archipelago). Soil data (pH, available P, Ca, Mg, K and Na, and EC) ranged within normal levels for proteas, though O.M. was high. Drainage decreased the potential problem that could be caused by the high clay content of the soils. Leaves showed high concentrations of N, K, Mg, and Na, while Ca and Cu were normal. On the other hand, Fe and Zn presented some low foliar levels, while Mn values fluctuated depending upon the different plantations. N contents were higher in spring, and those of K, Ca, Mg, and Na increased with time. Relative chlorophyll contents (SPAD-502 measurements) were compared with macro- (N, P, Na, K, Ca, Mg) and micro- (Cu, Fe, Mn, Zn) foliar levels. Results showed no positive correlation between leaf chlorophyll and N content. Higher leaf N concentrations were observed in chlorophyll deficient than chlorophyll sufficient leaves at one site and vice versa at another site. In contrast, lower Mn, Fe and Ca concentrations, the last corresponding with higher ratios of N/Ca were observed in chlorophyll deficient than chlorophyll sufficient leaves at several sites. It is concluded that amendment of soils with Mn, Fe and Ca may prevent the development of chlorophyll deficiency symptoms, associated with diminished photosynthetic capacity, in this important commercial cultivar.     

Dormancy and germination in Rosa multibracteata Hemsl. & E. H. Wilson

Most of the achenes produced by Rosa multibracteata Hemsl. & E. H Wilson are dormant on maturity and require pretreatment to stimulate germination. To investigate the mechanism of dormancy and to develop effective methods of improving germination, roles of the pericarp, testa, and embryo of R. multibracteata in regulating dormancy were studied by investigating the effect of different pretreatments on germination. The effects of temperature and water stress were also tested with achenes treated by warm plus cold stratification. In freshly harvested achenes, pericarps are permeable and the embryo fully developed, which eliminates the possibility of physical, morphological, or morphophysiological dormancy. Germination percentage remained low (<5%) despite softening the pericarp or even removing it fully. However, fully removing the testa improved germination significantly (39%), indicating the possible presence of germination inhibitors in the testa. Dry storage, scarification with sulphuric acid (H₂SO₄), and warm stratification proved ineffective by themselves but when combined with cold stratification, improved germination and shortened the cold stratification period needed to break dormancy. Dry storage for 68 weeks followed by cold stratification for 16 or 24 weeks resulted in maximum germination (72–79%) among all the treatments. In achenes scarified with H₂SO₄, germination increased with an increase in the duration of cold stratification. Neither gibberellic acid (GA₃) nor ‘smoke water’ (water through which smoke had been bubbled for 2 h) had any positive effect on germination even on seeds that had been mechanically scarified or stratified. Both high temperature and water stress lowered germination in achenes treated with warm plus cold stratification. Our results suggest that R. multibracteata achenes have an intermediate physiological dormancy, and that dry storage for 68 weeks followed by cold stratification for 16 or 24 weeks is the best method for propagating R. multibracteata from seed.     

Application of genomic in situ hybridization for phylogenetic study between Mangifera indica L. and eight wild species of Mangifera

The phylogenetic relationship between mango (Mangifera indica L.) and eight wild species of Mangifera were analyzed by comparing signal intensity of genomic in situ hybridization (GISH) on somatic metaphase chromosomes of M. indica, using labeled DNA of eight wild Mangifera species. The eight wild species were divided into four groups based on intensity and number of hybridization signals on chromosomes of M. indica in GISH analyses. The probe of Mangifera sylvatica Roxb. gave the highest intensities on the chromosome of M. indica, indicating a close relationship between M. indica and M. sylvatica. For the other species, classification of GISH was comparable to that of the phylogenetic analysis using AFLP markers, as previously reported ( Eiadthong et al., 2000). This suggested a possibility that GISH analysis can be effectively used in the classification of Mangifera species.     

The effect of nitrate and plant size on nitrate uptake and in vitro nitrate reductase activity in strawberry (Fragaria × ananassa cv. Selva)

Nitrogen plays a major role in the growth and yield of strawberry. For optimizing nitrogen fertilizer application, it is necessary to understand the response of strawberry to nitrogen supply. The objective of this study was to determine the effect of nitrate supply and plant size on strawberry nitrate uptake and nitrate reductase activity (NRA). Strawberry plants cv. Selva were grown under growth chamber conditions in nutrient solutions containing 0, 0.1, 0.25, 0.7 or 4 mM nitrate. Cumulative nitrate uptake increased with the increase in nitrate supply. Increasing nitrate concentrations from 0 to 0.25 mM decreased leaf NRA; however, further increases to 4 mM nitrate restored NRA to activities observed at 0 mM nitrate. The activity of NADH- and NADPH-dependent NR was similar at every external nitrate concentration. Activity of NR was greater in the smallest plants and decreased as plant size increased. However, increasing external nitrate concentration increased nitrate uptake, but had not the same effect on nitrate reductase activity, showing that NRA and nitrate uptake are not necessarily correlated.     

Similarities between natural and chemically induced bud-endodormancy release in grapevine Vitis vinifera L.

Bud-break in grapevines (Vitis vinifera L) can be poor and uneven in locations that have warm winters with insufficient chilling. Growers in these regions use hydrogen cyanamide (HC), a dormancy-breaking compound, to increase and synchronise bud-break. Previous studies demonstrated that HC upregulates the expression of select genes encoding enzymes belonging to the ascorbate glutathione cycle (AGC) (glutathione reductase, VvGR) to the oxidative pentose phosphate pathway (oPPP) (glucose-6-phosphate dehydrogenase, VvG6PD) and a key enzyme for dormancy release (1,3-β-glucanase, VvβGLU). Here, the expression of these genes was studied in grapevine buds throughout the natural progression of endodormancy (ED) and under the effects of the dormancy-breaking compounds, HC and sodium azide. Although gene expression increased with the progression of ED until mid-May, in early-June they turned off transiently and reappeared in mid-July before bud-break. The upregulation of these genes under both natural and artificial conditions suggests that dormancy-breaking compounds activate the same metabolic pathways that are naturally activated during the bud-ED release process. However, in contrast with the effects of dormancy-breaking compounds, artificial chilling did not upregulate the above genes.     

Correlations between disease severity,glucosinolate profiles and total phenolics and Xanthomonas campestris pv. campestris inoculation of different Brassicaceae

Many Brassicaceae species are economically important crops and Xanthomonas campestris pv. campestris (Xcc), the causal agent of black rot, is considered one of the most important necrotrophic plant bacterial diseases occurring worldwide on these and many other crops. Therefore identifying resistance mechanisms and genes is crucial. Researchers continue to investigate the role of phytochemicals (plant secondary metabolites) in protecting plants against diseases and pathogens. Glucosinolates (GLS), and more specifically their hydrolysis products, are known to have various biological effects including antimicrobial activity. From the positive results of initial in vitro studies with Xcc and other pathogenic bacteria new experiments were designed to evaluate the possible in planta role of GLS, and also phenolics, in the interaction with Xcc. The in planta studies, with various Brassicaceae seedlings, have shown a correlation between GLS profiles, and therefore the subsequent hydrolysis products, and the inhibition of Xcc growth. There were no significant correlations between Xcc infection and total phenolics. Positive correlations were found between specific and total GLS contents and the severity of disease. Further in vitro and in planta studies need to be performed to evaluate the role of GLS and other defense mechanisms in Xcc and other important bacterial infections of Brassicaceae crops.     

Correlation between chromaticity values and major anthocyanins in seven Acer palmatum Thunb. cultivars

The correlation between the anthocyanin concentrations of seven Acer palmatum Thunb. cultivars and the chromaticity values a*, b*, a*/b* ratio, h° and L* was investigated. According to the position of leaves on the branch terminal, middle and base sample leaves were analyzed and the positional effect on the level of the major anthocyanin was estimated. Leaf color was measured with a portable colorimeter and individual anthocyanins were detected with the use of HPLC–MS. Cyanidin-3-glucoside was present in all senescing leaves of Acer cultivars and its content decreased from terminal to base position. Cyanidin-3-rutinoside was identified in lower concentrations in the leaves of all cultivars. Multiple variable analysis was calculated for each of the tristimulus values and two major anthocyanins (cyanidin-3-glucoside, cyanidin-3-rutinoside) in senescing leaves of ornamental Acer cultivars. Correlations were detected between the major anthocyanin (cyanidin-3-glucoside) in analyzed Acer cultivars and all chromaticity parameters. The highest correlation coefficient (0.94) was observed between cyanidin-3-glucoside and a*/b* ratio in cultivar ‘Bloodgood’ and lowest (0.54) between cyanidin-3-glucoside and a* in Acer palmatum Thunb. The correlation between cyanidin-3-rutinoside and chromaticity parameters was not detected in all Acer cultivars, additionally correlation coefficients and statistical significance were much lower. The expression of red color in both senescing leaves and in all-year-red cultivars can be tightly linked with the content level of cyanidin-3-glucoside; the second major anthocyanin does not contribute much to the red leaf color.     

Phenotypic variations in fruits and selection potential in Sclerocarya birrea subsp. birrea

The domestication of indigenous fruits through agroforestry is seen as one of the important issues in the transformation in the way in which land is used within rural areas. A study of the variation in fruit traits is also important as it is a prerequisite for cultivar development in the domestication process. Following an aridity gradient, phenotypic variation was assessed in fruits of Sclerocarya birrea subsp. birrea, native to West African semi-arid areas. Fruits were collected from 42 trees of various diameters in agroforestry parklands from the dry and semi-humid Sudanian zones. They were partitioned into peel, flesh and pit. Each fruit was labelled and its components were measured and weighted. The overall mean fruit mass was 18.58 ± 0.24 g (mean ± SE) but fruits from the population in the drier zone were significantly larger (19.90 ± 0.37 g vs 17.02 ± 0.24 g; P < 0.001). The results showed a strong correlation between fruits and their components (P < 0.05). Tree diameter was very weakly correlated with fruit traits. There was a high level of variation in fruit characteristics and components within and between populations. The within-population variation accounted for the greatest part (67–100%) of the total variation. Many trees, mainly from the drier zones, showed superior phenotypic traits. Five groups of trees which represented different fruit morphotypes were identified for various prospective exploitations. The results strongly support the implementation of preliminary practical conservation action and domestication of S. birrea in West Africa.     

Effects of the antiauxin PCIB on microspore embryogenesis and plant regeneration in Brassica rapa

An efficient protocol to improve microspore embryogenesis and plant regeneration in Brassica rapa was established. The antiauxin p-chlorophenoxyisobutyric acid (PCIB) was used to enhance microspore embryogenesis and plant regeneration without an intervening callus phase. All the 4 tested genotypes responded positively to PCIB. The optimum concentration of PCIB application was found to be 40 μM in NLN-13 medium, which resulted in a 3.4- to 6.2-fold increase in the number of embryos (8.27–19.2 embryos per bud) and a 9.6-fold increase (21.33%) in the plant regeneration frequency in comparison with the controls. Heat-shock treatment by incubation at 35 °C for 1 day was more efficient in inducing embryogenesis in the 2 tested genotypes. The embryos, produced in NLN medium supplemented with 40 μM PCIB and transferred at the 21-day-old followed by a treatment at 4 °C for 5 days, reached the highest direct plant regeneration rate of 58.00%.     

Antioxidant potency of white (Brassica oleracea L. var. capitata) and Chinese (Brassica rapa L. var. pekinensis (Lour.)) cabbage: The influence of development stage,cultivar choice and seed selection

The accumulation of total phenols (TP, Folin-Ciocalteu method) and total flavonoids (TF, colorimetric assay with AlCl₃) and the evolution of antioxidant capacity (FRAP assay, DPPH and ABTS radical scavenging assays) have been monitored in juices of Croatian white cabbage (Brassica oleracea var. capitata) cultivars Vara?dinski and Ogulinski, as well as Chinese cabbage (Brassica rapa var. pekinensis), at various developmental stages. Measurements were performed every four weeks, starting from planting to full maturity, throughout the course of eight months. In the first 8–12 weeks, the TP and TF contents as well as antioxidant capacity increased significantly in all analyzed juice samples and in most even doubled. This rapid increase was followed by a gradual decrease in values derived from all assays, over the course of 12–30 weeks, to the final values which were in all cases lower than the values measured at week 4. The results also point to significant variability in TP and TF contents and antioxidant capacity at the fully mature stage between white and Chinese cabbage juices and between juices extracted from cultivars Ogulinski and Vara?dinski.     

Changes in cell wall polysaccharides and cell wall degrading enzymes during ripening of Fragaria chiloensis and Fragaria ×ananassa fruits

Chilean strawberry (Fragaria chiloensis) is arising as a new fruit crop that can diversify the world supply of berries. Fruit softening is thought to be linked to an extensive modification of pectin and hemicellulosic cell wall fractions which in turn is determined to a great extent by the action of some cell wall-modifying enzymes. The objective of this work was to compare cell wall changes and the enzyme activities of pectin methylesterase (PME), polygalacturonase (PG), endoglucanase (EGase), α-arabinofuranosidase (AFase), β-galactosidase (βGal), and β-xylosidase (βXyl) between F. chiloensis and Fragaria ×ananassa (cv. Chandler) at three fruit developmental stages: large green (LG), turning (T) and ripe (R). A rapid decrease in fruit firmness between LG and T stages was observed in both species; nevertheless firmness reduction in F. chiloensis was steeper than in F. ×ananassa. This could be related to a faster loss of HCl-soluble polymers (HSP fraction) presented in F. chiloensis fruit. However, commercial F. ×ananassa showed a greater depolymerization of HSP polymers than F. chiloensis. With the exception of PME, the activity of all assayed enzymes was higher in F. chiloensis than in F. ×ananassa fruits. The role of PG and EGase seems to be central in both species: these enzymes are correlated to the decrease in the content of HSP and NaOH-soluble polymers (NSP fraction), respectively. In addition, activity levels of βGal and βXyl were significantly correlated with fruit firmness reduction in F. chiloensis and F. ×ananassa, respectively.     

Relationship between the oil and sugar content in olive oil fruits from Moraiolo and Leccino cultivars during ripening

In our previous work (Cherubini et al., 2009), sugar concentration was proposed as an accurate, reproducible index for technological ripening of olive oil fruits. During 2009 crop season, sugar and oil content of olive oil fruits from Moraiolo and Leccino cultivars were measured during ripening. The sugar content of olive oil fruits was determined both by titration and by using a portable refractometer.     

The study on the relationship between transforming growth factor-β1 and lung carcinoma

AIM: To explore the relationship between the expression of transforming growth factor-β1 (TGF-β1) and the pathogenesis of lung carcinoma, and the influence of radiotherapy on plasma TGF-β1 level of patients with lung carcinoma. METHODS: By immunohistochemical method, the expression of TGF-β1 was examined. An enzyme-linked immunoadsorbent assay (ELISA) was used to quantify the plasma TGF-β1 levels in different time as before radiotherapy, at the end of radiotherapy, and at the time of follow-up 6 months after radiotherapy, respectively. The changes of quantity of TGF-β1 in different time above were analysed statistically. RESULTS: There was a significant increase in TGF-β1 expression in the carcinoma compared with normal lung tissue. The mean TGF-β1 level in the 39 lung carcinoma patients before radiotherapy was (11.0±1.5) μg/L, which was significantly higher than control group (3.8±0.2 μg/L) (P＜0.05); but the plasma TGF-β1 level after radiotherapy was significantly lower (5.6±0.5 μg/L) compared with the level before radiotherapy (P＜0.05), and there was not significant differences compared with control group (P＞0.05). At the time of follow-up 6 months, the patients of lung carcinoma had a significantly higher plasma TGF-β1 level (11.3±1.2 μg/L) compared with the level at the end of radiotherapy (P＜0.05), but there was not significant differences compared with before radiotherapy (P＞0.05). Not significant difference was found in TGF-β1 levels among different histologic types. CONCLUSION: These data demonstrated that TGF-β1 was associated with the pathogenesis of lung carcinoma, and it may be a useful tumor marker in patients with lung carcinoma.