Persica Batsch Research Articles

Sophora flavescens Containing-QYJD Formula Activates Nrf2 Anti-Oxidant Response, Blocks Cellular Transformation and Protects Against DSS-Induced Colitis in Mouse Model.

Qu-Yu-Jie-Du decoction (QYJD) is a commercially available traditional Chinese medicine (TCM). It is an aqueous extract of a Chinese herbal formula primarily consisting of eight TCM herbs: Taraxacum campylodes G.E.Haglund, Coix lacryma-jobi L., Smilax glabra Roxb., Sanguisorba officinalis L, Styphnolobium japonicum (L.) Schott, Prunus persica (L.) Batsch, Sophora flavescens Aiton, and Eupolyphaga sinensis Walker. Matrine and oxymatrine are two of the major phytochemical constituents of QYJD.Inflammation and oxidative stress are strongly associated with colon carcinogenesis. Colorectal cancer (CRC) is the third most common type of cancer. Therefore, cancer chemopreventive agents targeting CRC are urgently needed. This study was conducted to investigate the potential anticancer effects and the underlying mechanisms of QYJD and its active constituents, matrine and oxymatrine, in human colon cancer HT29 cells and in a dextran sulfate sodium (DSS)-induced colitis mouse model. QYJD and matrine effectively inhibited the proliferation and anchorage-independent growth of HT29 cells in a dose-dependent manner. QYJD and matrine also induced an Nrf2-mediated anti-oxidant response element-luciferase activity and upregulated the Nrf2-mediated anti-oxidative stress genes HO-1 and NQO1 at both the mRNA and protein levels. In the DSS-induced colitis mouse model, QYJD reduced the disease activity index (DAI) and alleviated colonic shortening. Elevated Nrf2 and HO-1 mRNA levels were also observed in QYJD-treated mice. These findings showed that QYJD could elicit anti-inflammatory and anti-oxidative stress response in vitro in a cell line and in vivo in a DSS-induced colitis mouse model. These responses may contribute to the overall anticolon cancer effect of QYJD.

МОРФОЛОГО-БИОЛОГИЧЕСКИЕ ПРИЗНАКИ ПЕРСИКА ОБЫКНОВЕННОГО [PRUNUS PERSICA (L.) BATSCH] И ИХ ЗНАЧЕНИЕ ДЛЯ ПРОВЕДЕНИЯ ЭКСПЕРТИЗЫ СОРТОВ НА ОТЛИЧИМОСТЬ, ОДНОРОДНОСТЬ И СТАБИЛЬНОСТЬ (ООС)

МОРФОЛОГО-БИОЛОГИЧЕСКИЕ ПРИЗНАКИ ПЕРСИКА ОБЫКНОВЕННОГО [PRUNUS PERSICA (L.) BATSCH] И ИХ ЗНАЧЕНИЕ ДЛЯ ПРОВЕДЕНИЯ ЭКСПЕРТИЗЫ СОРТОВ НА ОТЛИЧИМОСТЬ, ОДНОРОДНОСТЬ И СТАБИЛЬНОСТЬ (ООС)

Effect of chemical thinning, gibberellic acid and pruning on growth and production of nectarine (Prunus persica (L.) Batsch var. nucipersica) cv. May fire

The present investigation was carried out on 12-year old trees of nectarine (Prunus persica (L.) Batsch var. nucipersica) cultivar May Fire raised on wild peach seedling rootstocks, Farmer’s orchard at Kotla- Barog in District Sirmour during the years 2014 and 2015. In this experiment, experimental trees were subjected to seventeen different treatments;T1: Pruning to retain 60 fruiting shoots tree-1 (control), T2: Pruning to retain 50 fruiting shoots tree-1, T3: Pruning to retain 40 fruiting shoots tree-1 ,T4: NAA 40 ppm, 2 WAPF (week after petal fall) ,T5: Ethrel 300 ppm, 2 WAPF, T6: GA3 100 ppm, 4 WAPF, T7: GA3 200 ppm, 4WAPF, T8: GA3 100 ppm, 6 WAPF T9: GA3 200 ppm, 6 WAPF, T10: Pruning to retain 50 fruiting shoots tree-1 + NAA 40 ppm (T4), T11: Pruning to retain 50 fruiting shoots tree-1 + Ethrel 300ppm (T5), T12: Pruning to retain 50 fruiting shoots tree-1 + GA3100 ppm (T6), T13: Pruning to retain 50 fruiting shoots tree-1 + GA3 100 ppm (T8),T14: Pruning to retain 40 fruiting shoots tree-1 + NAA 40 ppm (T4), T15: Pruning to retain 40 fruiting shoots tree -1 +Ethrel 300 ppm (T5),T16: Pruning to retain 40 fruiting shoots tree -1 + GA3 100 ppm (T6), T17: Pruning to retain 40 fruiting shoots tree -1 + GA3 100 ppm (T8), pertaining to alternative approach to chemical thinning, chemical thinner were more effective in improving the production of superior grade fruits than reducing the crop load directly by pruning or indirectly by GA 3 (Gibberellic Acid) treatments. Treatments with NAA (naphthalene acetic acid) at 40 ppm when applied two weeks after petal fall reduced the crop load to the greatest extent and improve the yield of superior grade fruits and increase the leaf to fruit ratio and decrease the fruit drop. Pruning to retain 40 fruiting shoots tree-1 + NAA 40 ppm, 2WAPF increased the shoot growth (160.80, 170.20cm), tree height (3.70,4.50 cm), tree spread (2.84,3.60), leaf area (42.71, 40.63 cm) during both the year. However, effect of chemical were less pronounced on trees subjected to severe pruning.

Effect of Oligosaccharides on Quality Characteristics and Antioxidant Activities of Prunus persica Batsch var. davidiana Max. preserved in Sugar

Effect of Oligosaccharides on Quality Characteristics and Antioxidant Activities of Prunus persica Batsch var. davidiana Max. preserved in Sugar

Peach cultivars from tropical regions: characterization and processing potential

ABSTRACT: In order to increase the availability to consumers and add even more value to peaches (Prunus persica (L.) Batsch) and to identify which cultivars grown in tropical regions are more suitable for jelly processing, the objective of this study was to characterize and evaluate the influence of different peach cultivars (‘Aurora’, ‘Biuti’, ‘Bonão’, ‘Centenário’, ‘Diamante’, ‘Douradão’, ‘Libra’, ‘Régis’ and ‘Tropical’) cultivated in tropical regions on the physicochemical characteristics, rheological properties and sensory acceptance of the resulting jelly. The evaluated cultivars presented great variability among themselves in relation to the physical and physicochemical characteristics. The jellies elaborated from these cultivars; although, presenting great variability in relation to the physicochemical and rheological parameters, presented similar, high acceptance. All cultivars studied are suitable for processing and can be used for industrialization.

Genome-wide identification and expression analysis of beta-galactosidase family members during fruit softening of peach [Prunus persica (L.) Batsch

Plant β-galactosidase (β-Gal) is an important glycosyl hydrolase, which is associated with cell wall biogenesis and modification during fruit softening. However, the roles of β-Gal family members in peach fruit softening remain unclear. In the present study, we identified 17 PpBGAL genes in peach genome, and these were investigated using bioinformatics including chromosomal locations, phylogenetic relationships, gene structure and domain and promoter analyses. Furthermore, quantitative real-time PCR analysis during fruit storage of four peach varieties with different softening characteristics suggested that PpBGAL genes, especially PpBGAL2 and PpBGAL16, may be required for peach fruit softening. These results will be useful for further functional analyses of the β-Gal gene family in plants.

English

Rootstocks influence the performance and characteristics of fruit trees. However, there is still insufficient information on the relation of rootstocks in mainly cultivars of peach trees grown in Brazil. Therefore, this study aims at evaluating the performance of eight rootstocks: Aldrighi, Capdeboscq, Flordaguard, Nemaguard, Okinawa, Umezeiro, Tsukuba and Seleção Viamão grafted by ‘Chimarrita’ peach tree, planted in 2006 and evaluated in the 2013/2014, 2014/2015 and 2015/2016 in Capão do Leão, RS, Brazil. The following dependent variables were evaluated on the field: floral phenology, affinity with rootstocks, trunk diameter, crown volume, number of fruits, fruit mass and productivity. Fruit mass, diameter, color, pulp firmness, total soluble solid content, titratable acidity, total phenolic content, total carotenoid content, L-ascorbic acid content and antioxidant activity were evaluated. The Umezeiro rootstock provided the lowest values for crown volume, trunk diameter, number of fruits and productivity. The blossoming period of peach trees can be early or delayed depending on rootstock and harvest seasons. Field compatibility constant of Chimarrita cultivar was higher with the rootstocks of Capdeboscq, Okinawa, Tsukuba and Aldrighi. Fruits of plants grafted on Capdeboscq and Okinawa rootstocks showed reddish epidermis. The Okinawa rootstock enabled ‘Chimarrita’ peaches to have higher soluble solid concentrations and L-ascorbic acid. The highest concentrations of total carotenoids were verified in the pulp of fruits obtained from the ‘Chimarrita’ cultivar grafted on Aldrighi, Okinawa, Tsukuba and Umezeiro. The antioxidant activity of the peach pulp was higher on the Capdeboscq rootstock.   Key words: Prunus persica (L.) Batsch, vegetate-productive behavior, phytochemical.

Deep sequencing reveals the first fabavirus infecting peach

A disease causing smaller and cracked fruit affects peach [Prunus persica (L.) Batsch], resulting in significant decreases in yield and quality. In this study, peach tree leaves showing typical symptoms were subjected to deep sequencing of small RNAs for a complete survey of presumed causal viral pathogens. The results revealed two known viroids (Hop stunt viroid and Peach latent mosaic viroid), two known viruses (Apple chlorotic leaf spot trichovirus and Plum bark necrosis stem pitting-associated virus) and a novel virus provisionally named Peach leaf pitting-associated virus (PLPaV). Phylogenetic analysis based on RNA-dependent RNA polymerase placed PLPaV into a separate cluster under the genus Fabavirus in the family Secoviridae. The genome consists of two positive-sense single-stranded RNAs, i.e., RNA1 [6,357 nt, with a 48-nt poly(A) tail] and RNA2 [3,862 nt, with a 25-nt poly(A) containing two cytosines]. Biological tests of GF305 peach indicator seedlings indicated a leaf-pitting symptom rather than the smaller and cracked fruit symptoms related to virus and viroid infection. To our knowledge, this is the first report of a fabavirus infecting peach. PLPaV presents several new molecular and biological features that are absent in other fabaviruses, contributing to an overall better understanding of fabaviruses.

Agro-morphological characterisation and evaluation of a Serbian vineyard peach [Prunus persica (L.) Batsch] germplasm collection

Seventy-five vineyard peach [Prunus persica (L.) Batsch] accessions, obtained by seed propagation and originating from different regions of Serbia, were characterized using a set of 39 agro-morphological traits. The evaluation was carried out over a 3-year period in a vineyard peach collection situated at the Radmilovac Experimental Station, owned by the Faculty of Agriculture, Belgrade University. To investigate diversity, descriptive statistics and multivariate analyses were used. Most studied traits showed high variability. The variability of descriptive traits was highly pronounced for fruit ground and flesh colour; regarding metric traits, the highest variation was recorded for trunk circumference, petal width, flower density, fruit set, fruit weight, sweetness index, fruit taste and fruit flavour. According to PCA, traits with high discriminating power were those related to flower type, colour and size, fruit size and presence of over colour, tree height, ripening time and fruit taste. The cluster analysis grouped accessions into three main clusters and a few sub-clusters. Agronomically-important traits allowed a clear separation between the clusters, while morphological traits had almost no impact on this. This study provided information that is important for assessing the biodiversity of vineyard peach accessions, to develop guidelines useful for the description, classification and conservation of valuable local germplasm. Moreover, the phenotypic variability in the vineyard peach collection was found to be very high, suggesting there is extensive genetic diversity available for peach cultivar and rootstock breeding programs.

Genetic analysis of the slow-melting flesh character in peach

The slow-melting flesh (SMF) trait in peach [Prunus persica (L.) Batsch] defines a slower process of postharvest fruit-softening than the prevalent melting flesh (MF) types. This gives a longer shelf life and a delayed harvest-time resulting in better fruit quality. Unlike other known fruit texture traits, SMF is difficult to measure and has a complex inheritance. We examined this character over 2 years in the offspring of two crosses, both with “Big Top,” an SMF nectarine, as the female parent, and with a melting flesh (MF) nectarine as the male parent (“Armking” and “Nectaross”). Following harvest, a texturometer was used to provide a textural profile analysis, and fruit firmness evolution was measured with a penetrometer over a period of 5 days’ storage at 20 °C. Linkage maps were constructed with a high-density SNP chip, and a phenotype-genotype analysis allowed the detection of three independent genomic regions where most QTLs (quantitative trait loci) were located. Two of these, on linkage groups 4 and 5, explained the variability for two characters—maturity date and firmness loss—that is, the QTL on linkage group 4 found in the MF parents and that on linkage group 5 in Big Top. A third region on linkage group 6, which identified a QTL for maturity date only in Armking, has no apparent association to the softening process. The relationship between maturity date and fruit-firmness loss and a hypothesis on the inheritance of the SMF character are discussed.

Molecular Cloning and Characterization of an Anthocyanidin Synthase Gene in Prunus persica (L.) Batsch

To elucidate the effect of anthocyanidin synthase (ANS) gene on anthocyanin accumulation in fruit skin of Prunus persica (L.) Batsch cv. 'Chunmei', this study cloned and characterized an ANS gene (PpANS) from peach. PpANS (GenBank accession No. KX760117) was encoded by a 1074 bp-long open reading frame (ORF) corresponding to a polypeptide consisting of 358 amino acids with a molecular mass of 40.45 kD and an isoelectric point of 5.46. PpANS contains a conserved 2-oxoglutarate- and iron-dependent dioxygenases and non-haem dioxygenase binding regions. PpANS shared high similarities to angiosperm ANS and displayed the closest genetic relationship to Prunus domestica. Real-time PCR analysis indicated that PpANS was highly expressed in fruit skin, flesh and flowers, and peach fruit skin showed the highest transcript level of PpANS. Anthocyanin accumulation analysis indicated that it was highly accumulated in fruit skin and flesh of peach. Changes in the transcript level were highly correlated with anthocyanin content in the different tissues of peach. Prokaryotic expression analysis showed PpANS that protein can be expressed correctly in E. coli, and the size of PpANS recombinant protein was consistent with its predicted size. In vitro enzyme activity assay revealed that recombinant PpANS protein could catalyze the formation the cyanidin from leucocyanidin. These results indicated that PpANS was responsible for anthocyanin accumulation in P. persica.

Natural benzaldehyde from Prunus persica (L.) Batsch

ABSTRACTBenzaldehyde is one of the most important molecules in the flavour industry. Presently, most of its industrial requirement is met through synthetic route. In this research, leaf essential oil of Prunus persica (L.) Batsch. extracted in different seasons was analysed using GC-FID, GC-MS, and NMR (1H and 13C) techniques. The oil was characterised by higher amounts of benzaldehyde (63.1%–98.3%). The yield of benzaldehyde was higher during rainy (0.45 g/100 g fresh leaves) and autumn (0.44 g/100 g fresh leaves) seasons. In conclusion, leaves of P. persica can be used as a natural source of benzaldehyde for flavour industry.

Integrated QTL detection for key breeding traits in multiple peach progenies

BackgroundPeach (Prunus persica (L.) Batsch) is a major temperate fruit crop with an intense breeding activity. Breeding is facilitated by knowledge of the inheritance of the key traits that are often of a quantitative nature. QTLs have traditionally been studied using the phenotype of a single progeny (usually a full-sib progeny) and the correlation with a set of markers covering its genome. This approach has allowed the identification of various genes and QTLs but is limited by the small numbers of individuals used and by the narrow transect of the variability analyzed. In this article we propose the use of a multi-progeny mapping strategy that used pedigree information and Bayesian approaches that supports a more precise and complete survey of the available genetic variability.ResultsSeven key agronomic characters (data from 1 to 3 years) were analyzed in 18 progenies from crosses between occidental commercial genotypes and various exotic lines including accessions of other Prunus species. A total of 1467 plants from these progenies were genotyped with a 9 k SNP array. Forty-seven QTLs were identified, 22 coinciding with major genes and QTLs that have been consistently found in the same populations when studied individually and 25 were new. A substantial part of the QTLs observed (47%) would not have been detected in crosses between only commercial materials, showing the high value of exotic lines as a source of novel alleles for the commercial gene pool. Our strategy also provided estimations on the narrow sense heritability of each character, and the estimation of the QTL genotypes of each parent for the different QTLs and their breeding value.ConclusionsThe integrated strategy used provides a broader and more accurate picture of the variability available for peach breeding with the identification of many new QTLs, information on the sources of the alleles of interest and the breeding values of the potential donors of such valuable alleles. These results are first-hand information for breeders and a step forward towards the implementation of DNA-informed strategies to facilitate selection of new cultivars with improved productivity and quality.

DNA methylation and small interference RNAs participate in the regulation of MADS-box genes involved in dormancy in sweet cherry (Prunus avium L.).

Epigenetic modifications can yield information about connections between genotype, phenotype variation and environmental conditions. Bud dormancy release in temperate perennial fruit trees depends on internal and environmental signals such as cold accumulation and photoperiod. Previous investigations have noted the participation of epigenetic mechanisms in the control of this physiological process. We examined whether epigenetic modifications were modulated in MADS-box genes, potential candidates for the regulation of bud dormancy and flowering in sweet cherry (Prunus avium L.). We identified and cloned two MADS-box genes homologous to the already-characterized dormancy regulators DORMANCY-ASSOCIATED MADS-box (DAM3 and DAM5) from Prunus persica (L.) Batsch. Bisulfite sequencing of the identified genes (PavMADS1 and PavMADS2), Methylated DNA Immunoprecipitation and small RNA deep sequencing were performed to analyze the presence of DNA methylations that could be guided by non-coding RNAs in the floral buds exposed to differential chilling hours. The results obtained reveal an increase in the level of DNA methylation and abundance of matching small interference RNAs (siRNAs) in the promoter of PavMADS1 when the chilling requirement is complete. For the first intron and 5' UTR of PavMADS1,de novo DNA methylation could be associated with the increase in the abundance of 24-nt siRNA matching the promoter area. Also, in the second large intron of PavMADS1, maintenance DNA methylation in all cytosine contexts is associated with the presence of homologous siRNAs in that zone. For PavMADS2, only maintenance methylation was present in the CG context, and no matching siRNAs were detected. Silencing of PavMADS1 and PavMADS2 coincided with an increase in Flowering Locus T expression during dormancy. In conclusion, DNA methylations and siRNAs appear to be involved in the silencing of PavMADS1 during cold accumulation and dormancy release in sweet cherry.

Response of budding methods and time on bud success and budding growth of peach (Prunus persica) on different rootstocks

A present study was undertaken, to determine the most appropriate time and method of budding of peach (Prunus persica Batsch) cv. Shan-e-Punjab on different rootstocks to achieve the maximum bud take and budding growth, by budding peach cv. Shan-e-Punjab on peach, plum and apricot rootstock by T, inverted T and patch from 15 June to 1 August at 15 days interval. The results showed that inverted 'T' budding took minimum number of days for full sprouting in plum (17.99) and apricot (18.24) rootstock. Whereas, in peach T budding took 17.58 days for same. Among different dates, plants budded on 15th July took minimum number of days to full sprouting in peach (13.88), plum (14.66) and apricot (14.21) rootstocks. Budding on 1 July recorded maximum bud take success with 93.33% in peach, 86.66% in plum and 86.66% in apricot. Maximum scion length and girth were recorded on 1 July in peach (49.23 cm and 6.29 mm), plum (48.15 cm and 6.07 mm) and apricot (38.58 cm and 6.09 mm) respectively after 120 days after budding (DAB). Inverted T budding produces maximum scion length and girth in plum (37.73 cm and 4.98 mm) and apricot (32.83 cm and 5.10 mm). Whereas, the maximum scion length and girth (41.76 cm and 5.30 mm) in peach were observed in T after 120 DAB. From the present studies, it can be concluded that budding through inverted 'T' and T on 1 July gave maximum bud take and budding growth.

Peach seedling growth with mycorrhiza and vermicompost

Sterilization of nursery substrate materials decreases the beneficial microorganisms in the surrounding root media and may result in poor seedling growth; compost and arbuscular mycorrhizal fungi (AMF) may improve the plantlet development. This experiment aimed to analyze the effect of both AMF inoculation and vermicompost for the initial peach [Prunus persica (L.) Batsch.] seedling growth in sterilized substrate. Peach seedlings germinated in sterilized perlite were distributed into four resulting treatments from the combination of two factors and two levels each: with/without vermicompost in the growing media and with/without AMF inoculation at the transplanting time. Seedlings were arranged completely randomized inside a glasshouse throughout the study. Utilization of vermicompost in the growing media and AMF inoculation, and their combination, resulted in less total chlorophyll (p < 0.05) measured at 108 days after planting (DAP). At the end of the experiment (180 DAP), AMF inoculation resulted in root colonization greater than 70 % of the total root length; however, this effect was eclipsed by adding vermicompost to the substrate. Root and shoot dry weights and also stem diameter were superior (p < 0.01) by adding vermicompost to the growing substrate, but AMF inoculation had no effect on these variables. It is concluded that vermicompost addition to the substrate is preferable to AMF inoculation in order to stimulate peach seedling growth during the initial six months in sterilized substrates. DOI: https://doi.org/10.54167/tch.v11i2.157

Morpholoical and enzymatic responses to waterlogging in three Prunus species

Anaerobic respiration is an important mechanism for plants to address energy deficiency under waterlogged (WL) conditions, when aerobic respiration is limited. Seedlings of three Prunus species—Prunus mira Koehne, Prunus persica (L.) Batsch, and Prunus amygdalus (L.)—were irrigated at 60% water (control) or waterlogged (100%) daily for 27 days, to investigate root morphological parameters and dynamics of anaerobic respiration enzymes. Both P. mira and P. persica had significantly increased the leaf number and plant height than P. amygdalus under WL. Additionally, WL decreased leaf chlorophyll content in P. mira and P. amygdalus significantly more than in P. persica. Root pyruvate carboxylase (PDC), alcohol dehydrogenase (ADH), and lactate dehydrogenase (LDH) activities first increased before decreasing under WL treatments. In P. persica, root PDC activity was significantly higher than in P. mira and P. amygdalus at 9 d and 21 d, whereas ADH activity was higher at 15 d, 21 d, and 27 d. Moreover, throughout the experiment, LDH activity was significantly higher in P. persica than in P. mira and P. amygdalus roots under WL treatments. The activities of all three measured enzymes were positively and significantly correlated. We suggest that, because of interspecific variation in root metabolic response to different environmental conditions, P. mira and P. persica may generate more energy anaerobically through EMP than through lactic-acid metabolism, whereas P. amygdalus was the reverse. We conclude that WL tolerance differed across the three Prunus, with P. persica being the most tolerant, followed by P. mira, and finally P. amygdalus.

Tongqiaozuoxue Decoction, a Traditional Korean Medicine, Improves Hypercoagulation Through Stimulating Adiponectin Expression

The efficacy and safety of traditional medicine could be proved through human trial for a long time, and now it has been required for the scientific evidence of its efficacy and identification of specific functional target. Tongqiaozuoxue Decoction (THD) is a water extract of 8 species of medicinal herb including Cnidium officinale Makino and Prunus persica Batsch, and has been used for the treatment of blood stasis and hypercoagulation in traditional Korean medicine. This study investigated the efficacy of THD and its functional target using animal model. Early vascular model was established through feeding high‐fat diet (HFD, 60% fat) for 12 weeks to C57BL/6 mice; these mice showed the phenotype of obesity, insulin resistance, chronic metabolic inflammation, hyperlipidemia, and prothrombotic state. THD was orally administered for last 4 weeks in a dose of 100mg/kg/day. THD significantly decreased plasminogen activator inhibitor‐1 (PAI‐1) level in serum and adipose tissue (AT) by 30% and 60%, respectively. Also, the plasma activity of tissue‐type plasminogen activator (tPA), the downstream target of PAI‐1, was increased by 2‐fold. Fibrin deposition was notably reduced in AT, demonstrated by immunohistochemistry. Meanwhile, adiponectin level was significantly increased both in serum and adipose tissue by 30% and 60%, respectively, although adipose tissue weight or total body weight were not changed by THD. Taken together, these results demonstrated that THD improve hypercoagulation through stimulating adiponectin expression.Support or Funding InformationThis study was supported by the grant of Korea Institute of Oriental Medicine

Accumulation of proanthocyanidin monomers in two genotypes of blood-flesh peach

ABSTRACTAccumulation of proanthocyanidin monomers (catechin and epicatechin) was revealed in flesh tissues during fruit development in two blood-flesh peach (Prunus persica (L.) Batsch) genotypes, ‘Beijingyixianhong’ (DBF-genotype) and ‘Heiyoutao’ (bfbf-genotype). The activities of two key enzymes, leucoanthocyanidin reductase (LAR) and anthocyanidin reductase (ANR), were measured, and their activities and coding genes’ expression profiles were compared at the transcription level over the fruit development period. There were different developmental profiles of catechin and epicatechin concentrations between the genotypes. In ‘Beijingyixianhong’, catechin and epicatechin concentrations remained low early in fruit development, increased gradually at the ripening stages, and reached maxima at the mature stage. In ‘Heiyoutao’, catechin and epicatechin concentrations were very low at the early stage of fruit development, with rapid accumulation to maxima at the middle development stage; however, they decreased during ripening. Activities of LAR and ANR, as well as the relative expression of their coding genes at the transcriptional level, were consistent with accumulation of proanthocyanidin monomers in each blood-flesh peach genotype. ANR activity and the quantitative expression of its coding gene were much more closely related to proanthocyanidin accumulation than was the case for LAR, which caused higher and more dramatic changes in epicatechin concentrations during fruit development in both genotypes of blood-flesh peach.

Optimizing protocols to evaluate brown rot (Monilinia laxa) susceptibility in peach and nectarine fruits

This study assessed and optimized an in vivo method to evaluate the levels of susceptibility/resistance in fruit from the EEAD-CSIC peach germplasm to an isolate of Monilinia laxa (Aderhold & Ruhland) Honey from peach. A total of four commercial cultivars and six genotypes, descendants of three families, of peach [Prunus persica (L.) Batsch] were superficially inoculated in fruits as “uninjured inoculation fruit test”. Inoculum was obtained from artificially infected peach fruit after five days of incubation under a photoperiod of 12 h supplied by fluorescent lighting system. Spores were harvested from the fruit, incubated at 20–26 °C, of 40–60% RH, being careful to avoid contamination. Production of inoculum (conidia) was rapid and adequate using these inoculation and incubation conditions (five days at 23 °C) indicating that the M. laxa used was highly pathogenic and inoculation protocol suitable to screen the peach material and commercial cultivars. Lesion diameter and colonization extent were measured on inoculated fruits to estimate disease severity (colonization severity and lesion severity) to establish levels of susceptibility/resistance to brown rot. Results from the screening test showed that although all peach genotypes and commercial cultivars screened were susceptible to the M. laxa isolate, the lack of sporulation on lesions of ‘Calante’ cultivar and the significant differences in colonization and lesion severities among the genotypes indicated the existence of genetic tolerance to M. laxa infection. The reasons for the differences in tolerance to infection and implications for breeding peach fruit in the Ebro valley are discussed.