The effect of maturity,sunburn and the application of sunscreens on the internal and external qualities of pomegranate fruit grown in Australia

Consumer interest in pomegranate fruit (Punica granatum L.) is increasing in Australia as a result of its unique external and internal qualities. This work looked at the effect of applying sunscreen treatments to pomegranate fruit on the degree of sunburn damage and the effect of maturity and sunburn on the internal antioxidant concentration of the juice. The pomegranates, cultivar ‘Wonderful’ were grown in Condobolin, New South Wales, Australia.     

Characterization of progenies derived from pollination of pomegranate cv. Malase-Tourshe-Saveh using fruit traits and RAPD molecular marker

Fruit traits and molecular markers (RAPD) were used to survey genetic similarities and inheritance pattern of offspring, derived from self- and open pollination of pomegranate cv. Malase-Tourshe-Saveh (MTS) as well as progenies derived from cross between ‘MTS’ and ‘Narm-Daneh’ (ND) a soft-seed cultivar in the present study. Clustering based on fruit traits, divided the accessions firstly into two major groups, sweets and sour or sweet–sours. Members of sub-clusters were different in fruit characters, and seed softness also was affecting the grouping of individuals. Offspring of ‘MTS’ × ’ND’ showed somehow seed softness with varying degrees compared to other individuals. In RAPD analysis, by using 26 polymorphic primers, 325 fragments were produced from 39 individuals, among which 70 reproducible, polymorphic bands were scored for data analysis. NTsys and Bootstrap software were used for RAPD data analysis and respective dendrogram depicted by Jaccard's similarity coefficients using UPGMA method. The similarity coefficients were ranging from 0.2 to 0.94 and the lowest was obtained between pollen parent (ND cv.) and a genotype from open pollination of MTS cultivar. The highest similarity coefficient (0.94) was observed between two offspring both from self-pollination of MTS cultivar. In corresponding dendrogram, pollen parent was separated from other genotypes and laid individually in a sub-cluster, while the mother plant clustered with its progenies. In addition, some marker–trait associations were observed, especially for seed softness.     

Characterization of Tunisian pomegranate (Punica granatum L.) cultivars using amplified fragment length polymorphism analysis

The amplified fragment length polymorphism (AFLP) analysis of DNA was used to characterize 34 pomegranate cultivars. By using a combination of six primers, a total of 327 markers were scored with a mean of 57.5. The high percentage of polymorphic bands (ppb) of 94.7 and the resolving power (R_p) collective rate value of 129.14 were scored. Data proved that the tested primers were informative to discriminate among cultivars and to survey the genetic diversity in this fruit crop. It has been assumed that the local pomegranate germplasm is characterized by a typically continuous genetic diversity. The derived dendrogram proved that cultivars are clustered independently from their geographical origin and their denomination. In addition, AFLP permitted the generation of a nearly unlimited number of molecular markers that are reliable in differentiating the cultivars and/or the polyclonal varieties.     

Seed characterisation of five new pomegranate (Punica granatum L.) varieties

This study evaluated the production of five new pomegranate varieties (ME14, ME15, PTO2, PTO7 and CRO1), being all indigenous to Southeastern Spain where the species shows high variability. A morphological and organoleptic characterisation of the edible portion of the seeds were investigated. Some chemical characteristics of the juice, including total soluble solids, pH, acidity and maturity index, were assessed. Morphological characteristics of both the edible and the woody portions of the seed were evaluated. Also productive and organoleptic characteristics of all varieties were considered, being ME14 and ME15 the highest yielders. Furthermore, PTO2 and CRO1 showed the heaviest seeds (both showing an average weight of 0.61 g) while ME15 the lightest one (0.37 g). Regarding seed juice content, there were significant differences among the evaluated varieties; whereas PTO2 and CRO1 showed the highest juice contents, PTO7 yielded the lowest one. However, the cultivar PTO7 showed a significantly higher acidity content than the others, along with the lowest maturity index at all. Finally, ME14 and ME 15 were very interesting because of their high production, large fruit size and excellent seed organoleptic characteristics.     

Transformation of Brassica oleracea var. capitata with bacterial betA gene enhances tolerance to salt stress

The bacterial betA gene for biosynthesis of glycinebetaine was transferred to cabbage (Brassica oleracea var. capitata) cultivar ‘Golden Acre’ through Agrobacterium-mediated transformation of hypocotyl explants. Transgenic status was established through Southern hybridization and mRNA expression in the shoots. The transformants exhibited higher tolerance to NaCl stress compared to untransformed parent plants. In physiological assessment of salinity tolerance, transgenics showed better growth response and greater stability in maintaining plant water relations at increasing levels of salinity. These results demonstrate that engineering glycinebetaine biosynthetic pathway into cabbage can lead to enhanced salt tolerance.     

Auxins increase the occurrence of leaf-colour variants in Caladium regenerated from leaf explants

Leaf explants of Caladium ‘Pink Cloud’ were cultured in vitro on MS medium containing various auxins (NAA, IBA, IAA, 2,4,5-T and 2,4-D) in combination with cytokinin (BA). NAA gave the most vigorous in vitro propagation of this plant, and only 15% of the plants were leaf-colour variants on the medium containing 0.5 μmol NAA. Leaf colour variation was observed in all plants regenerated on the medium containing 2,4-D at 0.5–4.5 μmol. In hormone-free medium, only a few leaf-colour variants (6%) occurred, but the rate of plant regeneration was very low. Application of 0.5 μmol NAA together with 4.5 μmol BA seemed to be the most appropriate for in vitro propagation of Caladium ‘Pink Cloud’ with only a few leaf-colour variants.     

Role of bioinoculants in development of salt-resistant saplings of Morus alba (var. sujanpuri) in vivo

Pot experiments were conducted for the development of salt-resistant saplings of Morus alba (var. sujanpuri) involving bioinoculants, namely arbuscular mycorrhizal (AM) fungi, Azotobacter and indole butyric acid (IBA). The IBA and sodium chloride (NaCl) concentrations were optimized prior to the experiments. By using both low and high concentrations, 15 ppm IBA and 0.05% NaCl (w/v) were found to be optimum in acting synergistically with AM fungi and Azotobacter and also for increasing all the growth parameters and microbial count in the rhizosphere. For in vivo development of salt-resistant saplings, the optimal concentration of IBA, along with AM fungi and Azotobacter in different combinations, was applied. The saplings were irrigated regularly with 0.05% NaCl water. Although growth parameters such as AM infection percentage, AM spores per 100 g soil and Azotobacter cells/g soil were affected by NaCl watering, the inoculation of both bioinoculants significantly enhanced survival percentage of saplings from 25 to 50% under salt stress. Maximum survival (55%) of saplings was found with IBA (15 ppm)+AM fungi+Azotobacter.     

Response of young hydroponically grown tomato plants to phenolic acids

Phenolic acids—excreted both as root exudates and by microorganisms—are of interest in cultivation systems of different horticultural crops since they have been claimed to accumulate in closed hydroponic growing systems. The aim of the present investigation was to assess the phytotoxic effects when hydroponically grown tomato plants are exposed to phenolic acids in the root environment. The tomato plants were grown in static aerated culture and exposed to benzoic, caffeic, chlorogenic, ferulic, p-hydroxybenzoic, salicylic and vanillic acid at concentrations of 50, 100, 150, 200 and 400 μM in the fresh nutrient solution. The highest concentration of all tested compounds significantly reduced fresh and dry weights. Salicylic and ferulic acid affected plants already at 150 and 200 μM while effects were less pronounced for p-hydroxybenzoic and chlorogenic acid. Chlorophyll fluorescence analysis did not result in any significant difference between any of the tested acids or concentrations. No clear dose-related pattern was obtained with respect to number of leaves and plant length. Visual assessment showed that the most deleterious effects appeared on the roots, which were discoloured and/or had slimy coatings when exposed to the phenolic acids. The uptake of several mineral nutrients was influenced at the highest concentration of all studied compounds. Significantly more bacteria were enumerated in the nutrient solution treated with phenolic acids compared to the controls. Most of the phenolic acids were degraded after 2 days during the start of the trial and within 1 day at the end of the trial. Concentrations phytotoxic to small tomato plants were 1000-fold higher than the natural concentrations measured before. Instead of potentially harmful, the relevance of certain phenolic acids as antimicrobial substances should be considered.     

Influence of medium composition and vessel ventilation on in vitro propagation of Phillyrea latifolia L.

Micropropagation of Phillyrea latifolia L. a wild species present in Mediterranean coastal areas having drought and salt tolerance was performed using explants from adult plants. Shoots were induced from nodal explants on the Rugini’s initial medium (IM). Then these were proliferated on either Rugini olive medium (OM) or Linsmaier and Skoog (LS) medium, each supplemented with 2.22 μM 6-benzylaminopurine (BA) or 4.56 μM zeatin (Z). Rooting (66.1±11%) was induced on shoots grown in perlite soaked with half-strength Rugini olive proliferation medium (OMr) containing 2.69 μM α-naphthaleneacetic acid (NAA) and 160 mg l⁻¹ putrescine. Both shoot multiplication and rooting were performed using Magenta^® GA-7 (Sigma) vessels either non-permeable or permeable to gas exchanges. Contamination (about 40%) was observed during the first five passages notwithstanding the addition of cefotaxime to the culture medium, but a high proliferation rate (90%) of explants provided enough healthy plant material. The highest shoot proliferation was observed on LS medium and zeatin whereas the presence of the ventilated filters reduced fresh weight of explants growing on LS media and did not affect shoot growth on OM media. During rooting, the use of ventilated vessels in comparison with the closed ones enhanced development of roots, and doubled the dry weight of plantlets. The vessel ventilation combined with the artificial substrate (perlite) was beneficial for in vitro acclimatization of rooted Phillyrea plantlets.     

Morpho-pomological and chemical characterization of pomegranate (Punica granatum L.) genotypes in Apulia region,Southeastern Italy

A recent increasing demand in Western countries for pomegranate products by consumers is especially supported for the nutritional and medicinal characteristics, due to the antioxidant properties of this fruit. Some studies have been published on the morphological and biochemical characteristics of pomegranate fruits in some Mediterranean countries, but little information is available about the genotypes present in Italy and in particular in Apulia (Southeastern region of Italy). This study (2008–2009) evaluated morpho-pomological and chemical parameters of eight pomegranate genotypes localized in private small orchards. Significant differences were observed among the pomegranate genotypes for many of the parameters investigated. In particular, fruit weight ranged from 168.9 g (SouMol) to 574.9 g (SouOst), °Brix from 14.7 (ComTri) to 18.0 (SouMol), titratable acidity from 5.4 (ComMol) to 25.0 (SouTri) g/L. SouMol showed the highest polyphenols (97.1 mg/L) and vitamin C (236.3 mg/L) contents. Oil content of the seeds was between 5.90% and 10.30%, no differences have been observed for the fatty acid composition with conjugated linoleic acid (CLA) isomers as the most abundant fraction (81.23%). Considering all the evaluated parameters, and especially those referring to the organoleptic characteristics and antioxidants content, it must be stated that the best genotypes worthy to be considered from agricultural and industrial points of view were AdeSgi for fresh market and SouOst for the juice industry.     

Effects of thermoperiodicity and plant population density on stem and flower elongation, leaf development, and specific fresh weight in single stemmed rose (Rosa hybrida L.) plants

Thermoperiodicity, i.e. growth in the alternating temperature regime with the same diurnal mean compared with growth at the constant temperature at which optimal growth occurs, was studied at three plant population densities in four cultivars of Rosa hybrida L. Single-node cuttings with five-leaflet leaves were excised and grown as single-stemmed rose plants at an average photosynthetic photon flux density of about 260 μmol m⁻² s⁻¹ and supplied with carbon dioxide at about 1000 μmol mol⁻¹. The optimal constant temperature regime was 22 °C day (20 h)/22 °C night (4 h); alternating temperatures were 23 °C day (20 h)/18 °C night (4 h). The plant population densities were 100, 131 and 178 plants m⁻² of bench area. Thermoperiodicity was absent, or could not be detected, in the parameters related to the growth period, the formation of fresh biomass, the bloom quality, and most parameters related to shoot elongation. However, classic thermoperiodic effects of alternating regime were significant in the cultivars Red Velvet and Sonia, with shoot elongation promoted (7.1 and 10.5%, respectively) in the growth phase from onset of axillary bud growth until the flower bud became visible. Compared with the other two cultivars, plants of Red Velvet and Sonia tended to develop longer internodes. The results, obtained concurrently at three different plant population densities, suggest that thermoperiodicity can affect (single-stemmed) plant growth and development in R. hybrida. Increased plant population density also increased plant height at visible flower bud, but the bloom quality, expressed as specific fresh weight, and the flower height at anthesis was decreased at the highest density. Increased plant population density increased the number of five-leaflet leaves developed in Red Velvet, but had no effect on leaf number in Texas and Sonia, while, in Lambada the leaf number was decreased at the highest density.     

Clone identification and genetic relationship among vine cacti from the genera Hylocereus and Selenicereus based on RAPD analysis

Clones of Hylocereus and of Selenicereus species were distinguished from each other by the banding pattern generated by one to nine 10-mer oligonucleotide primers in the random amplified polymorphic DNA (RAPD) reaction. RAPD analysis was also applied to estimate the genetic relationship among five Hylocereus and nine Selenicereus species. A dendrogram was constructed based on a data matrix of 173 polymorphic bands originated by nine primers. Two groups were identified, one consisting of Hylocereus species and the other consisting of Selenicereus species. These results are consistent with the accepted taxonomic classification of the genera studied. The principal coordinate analysis (PCO), i.e. the plot drawn on the basis of the RAPD data, clearly distinguished between three groups, namely, Hylocereus species, S. megalanthus and the rest of the Selenicereus species studied. PCO thus strongly support the notion that the tetraploid S. megalanthus is an exception among the Selenicereus group. The RAPD results support our hypothesis regarding the allopolyploid (rather than autopolyploid) origin of this species.     

Analysis of genetic diversity among wild pomegranates in Western Himalayas,using PCR methods

The genus Punica (Punicaceae) is distributed in Iran, Afghanistan, India and Mediterranean countries. Iran is considered to be its primary center of origin. In India Punica granatum is found in wild only in Western Himalayan regions comprising, Jammu and Kashmir, Himachal Pradesh and Uttarakhand states. However, there is little information available about the genetic variation present in pomegranates in the regions. In this paper we describe the use of DAMD and RAPD methods that generate the profiles, to study genetic diversity in wild genotypes of the P. granatum in India. Forty-nine accessions representing two regions of Western Himalaya were analyzed. Similarity coefficient value varied from 0.08 to 0.79 across different accessions. The results indicate that DAMD (97.08%) revealed more polymorphism in comparison to RAPD (93.72%). The results show that these methods are sufficiently informative to unravel the genetic variations in wild pomegranates in Western Himalayas.     

Aptitude for mycorrhizal root colonization in Prunus rootstocks

Eighteen Prunus rootstock cultivars were inoculated with three arbuscular mycorrhizal fungi under greenhouse conditions in order to evaluate their affinity for mycorrhizal colonization. The rootstocks were peach–almond hybrids, peaches, plums and cherries of Spanish, French and Italian origin. Mycorrhizal colonization was low in plants inoculated with Glomus mosseae (Nicol. and Gerd.) Gerdemann and Trappe, and Glomus etunicatum Becker and Gerdemann. In contrast, Glomus intraradices Schenck and Smith, proved to be the most infective endophyte, achieving the highest mycorrhizal colonization rate in most of the rootstocks evaluated. Species of Prunus insititia L. were the only botanical group to show a consistently high affinity for mycorrhizal colonization with G. intraradices.     

Seasonal changes of mineral nutrients and phenolics in pomegranate (Punica granatum L.) fruit

Pomegranate fruit is an important source of potentially healthy bioactive compounds and mineral nutrients. Changes in total phenolic compound, concentrations, and levels of macronutrients (P, K, N, Mg, Ca and Na) and micronutrients (Zn, Cu, Mn, Fe and B) in arils and peel of pomegranate fruit were recorded from 10 days after full bloom until harvest. Total phenolics levels increased at early stage of growth both in peel and arils of fruit, but thereafter generally decreased during maturation and reached to 3.70 and 50.22 mg g⁻¹ of dry weight in arils and peel, respectively, at harvest. The amount of total phenolics in peel was markedly higher than arils of pomegranate fruit. The concentration of most elements in arils and peel decreased during fruit growth and development. At harvest the relative order of concentration of macronutrients both in arils and peel was K > N > Ca > P > Mg > Na. The concentration of most micronutrients was greater in the arils than in the peel especially in early season. The relative order of concentration of micronutrients in arils was B > Fe > Zn > Cu > Mn. The accumulation of all the macro- and microelement within the fruit also increased during fruit growth and development. These results provide important data on total phenolics and macro- and micronutrient changes during fruit growth and development, emphasizing that pomegranate fruit can be a good source of bioactive compounds and minerals.     

Micropropagation and accumulation of essential oils in wild sage (Salvia fruticosa Mill.)

A protocol for in vitro propagation of the wild three-lobed sage (Salvia fruticosa Mill.) (Synonym, Salvia triloba L.) was developed. Shoot tips were excised from in vitro seedlings and established on MS, Nitch and Nitch (NN), or B5 medium. For shoot proliferation, in vitro nodal and apical explants were cultured on MS medium containing 0.25–2 μM 6-benzylaminopurine (BA), 6-furfurylaminopurine (kinetin), or thidiazuron (TDZ). Proliferated microshoots were rooted on MS medium supplemented with 2.7–11.4 μM indole-3-butyric acid (IBA), indole-3-acetic acid (IAA), or α-naphthaleneacetic acid (NAA). Results indicated that shoots established at 100% regardless of media type, however, shoot height, nodes per shoot, and leaf number were highest for explants established on MS medium compared to NN or B5. Number and height of proliferated shoots, nodes per shoot, and leaf number were highest for nodal explants cultured on a medium containing 0.75 μM BA. Microshoots cultured on a medium supplemented with 2.7 μM IBA exhibited the highest rooting percentage compared to those cultured with IAA or NAA. Essential oil composition in microshoots and shoots of greenhouse-grown plants was determined by gas chromatography/mass spectrometry. The major essential oils detected in both plant materials were α-pinene, 1,8-cineole, camphor, and borneol. No α-thujone or β-thujone was detected. The content of essential oils, camphor, and borneol were higher in the microshoots than in shoots of greenhouse-grown plants.     

Callus induction and plant regeneration from cotyledonary explants of ash gourd (Benincasa hispida L.)

A protocol for the production of complete plantlets through multiple shoots from the cotyledon-derived calli of ash gourd (Benincasa hispida L.) is described. The embryos were excised from mature seeds and cultured on Murashige and Skoog (MS) medium supplemented with 6-benzylaminopurin (BAP, 1–5 μM). After 10 days the well-developed green cotyledons from the growing embryos were isolated and cultured on MS medium fortified with 2,4-D (1–6 μM). The cultured cotyledons gave rise to luxuriantly growing calli after 6 weeks. These calli were subcultured on MS medium supplemented with various concentrations of BAP (1–6 μM) alone or in combination with naphthalene acetic acid (NAA, 0.2 and 0.5 μM) for regeneration. The regenerated shoots were multiplied and rooted on quarter strength MS medium supplemented with indole-3-butyric acid or NAA (1–5 μM). The rooted shoots were transplanted to soil with 90% success.     

Glutamine and glutamate levels and related metabolizing enzymes in tomato fruits with different shelf-life

Free amino acids composition and glutamate dehydrogenase (GDH) and glutamine synthetase (GS) levels were evaluated in fruits of Lycopersicon esculentum var. esculentum genotypes having standard (cv. Caimanta) and altered (nor and rin mutants) ripening characteristics. Two accessions of the wild L. esculentum var. cerasiforme (LA1385 and LA1673) were also assayed. Shelf-life (SL) of these fruits ranged from 12 (cv. Caimanta) to 36 (nor mutant) days. The relative glutamate content (as percentage of total free amino acid content) of ripe mature fruits differed considerably among lines, having cv. Caimanta and the nor mutant the highest and the lowest values, respectively. A negative correlation between the relative glutamate content and fruit SL was also found. In the standard ripening cv. Caimanta, GS was principally present in green mature fruits while GDH was found in ripe mature fruits. In the other lines, GS and GDH were detected at both maturation stages. Summarizing, standard SL correlates with higher relative glutamate content and reciprocal induction pattern of GS and GDH, while long SL is associated with lower relative glutamate content and simultaneous presence of both enzymes in the pericarp of tomato fruits. These data suggest that the regulation of the level of glutamate, GS and GDH during fruit ripening is related to the final SL of fruits.     

Yield stability of peach germplasm differing in dormancy and blooming season in the Mexican subtropics

Peach cultivation in Mexico has recently extended to subtropical climates to reduce drought, but in many areas winter frosts are a strong limiting factor. Information about the behavior of a wide range of peach accessions during dormancy and bud-break was collected over a 4-year period in the most important peach growing region in the subtropical highlands of central Mexico where winter frosts are common. Observations were made on 33 peach accessions (local, introduced and hybrids between both groups). Differences in fruit set among peach genotypes which were related to sensitivity to enter rest (SER), time of blooming, duration of blooming, bud density (BD) and flower density (FD). The latter were generally related, however, bud to flower ratios and yields were low for materials that were very late blooming. Selections such as San Juan, Fred, 17-1, and 24-1, were based on mid to late-bloom, high and stable yielding. SER, BD and FD values and BD:FD ratios, should be included as important breeding goals to provide more stability of peach production in the subtropical highlands.     

Agrobacterium tumefaciens mediated genetic transformation and regeneration of Morus alba L.

An efficient method was established for genetic transformation of Morus alba clone M5 using Agrobacterium tumefaciens mediated gene transfer. Cotyledon explants from in vitro grown seedlings were co-cultivated with disarmed strain LBA 4404 harbouring the binary vector p^BI121 carrying chimeric β-glucuronidase (GUS) and neomycin phosphotransferase (npt II) genes. Maximum transformation frequency of 18.60% was recorded with 48 h of pre-conditioning followed by co-cultivation for the same duration. Expression and presence of transgene was confirmed by histochemical test and polymerase chain reaction. The transgenic plants were micropropagated and successfully acclimatised.