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This article examines the morphological characteristics of apple varieties in northeastern Algeria, specifically focusing on the leaves, fruits, and terminal shoots of three apple varieties: Golden Delicious, Royal Gala, and Starkrimson. The study reveals limited morphological diversity among the investigated apple cultivars, with some descriptors showing insignificant differences between cultivar types. The findings emphasize the distinct physiological and morphological characteristics of each variety and highlight the need for further exploration and conservation efforts. Another document provides information on the application rate of sheep manure and urea for soil salinity levels, as well as the physical and chemical analysis of soil in an orchard. It also discusses the growth habit and length of annual shoots for different apple tree varieties, as well as the flowering characteristics and fruit characteristics such as weight, length, width, shape, color, and ripening period. The document is valuable for understanding the cultivation and quality of apple trees in the studied orchard. Lastly, a document discusses the characterization of new apple cultivars and their implications for sustainable development and consumption. The study found significant variation in vegetative growth, fruit weight, and color among the three cultivated apple tree varieties examined. The authors suggest further research and evaluation to fully understand the genetic diversity and potential uses of these cultivars, emphasizing the importance of rigorous protocols for measurement and observation. The document includes a list of references for further reading on apple diversity and characterization. [Extracted from the article]

The regulation of apple (Malus domestica) fruit texture during ripening is complex and a fundamental determinant of its commercial quality. In climacteric fruit, ripening-related processes are regulated by ethylene (ET), and jasmonate (JA) is also involved in the ethylene biosynthesis pathway, mainly through the transcription factor MYC2. However, the molecular genetic mechanism for fruit ripening processes between the JA and ET signaling pathways still needs to be elucidated. In order to explore how JA regulates apple fruit ripening through ERF4, we used 'Gala' and 'Ralls Janet' fruit at different developmental stages as experimental materials to determine the fruit firmness and related gene expression analysis. Meanwhile, we carried out different hormone treatments on 'Gala' fruit at ripening stage. Here, we show that ERF4 is a core JA signaling hub protein JASMONATE ZIM-DOMAIN (JAZ) interactor that affects ethylene signaling pathways. During fruit development, ERF4 represses the expression of ACS1 and ACO1 by interacting with JAZ, as well as with the JA-activated transcription factor MYC2. Ripening is promoted in JAZ-suppressed apples. Thus, ERF4 acts as a molecular link between ethylene and JA hormone signals, and the natural variation of the ERF4 Ethylene-responsive binding factor-associated amphiphilic repression (EAR) motif decreases repression of ethylene biosynthesis genes. [ABSTRACT FROM AUTHOR]

Though grafting in plants is in practice since ages only limited information is available on the graft-induced morphological, biochemical and molecular variations. The mechanism(s) by which rootstocks influence scion vegetative growth and development, and vice versa, are not fully understood. Therefore, in the present investigation, we studied graftinduced variations in different apple stionic combinations using scion (Scarlet Gala and Red Fuji) and rootstocks (MM111, MM106, M7, M9 and M26). Under morphological variations, significant difference was found in all the parameters viz. leaf area, shoot length, internodal length and fruit characters except petiole length and fruit firmness. Likewise, significant difference was also observed in the subjected stionic combinations based on total phenolic contents, total free amino acids and peroxidase enzyme activity. These results were further validated using DNA based molecular markers SSR. However, no polymorphism was observed in both the stionic combinations at DNA level. These results imply that rootstocks may influence morphological and biochemical parameter of the scion during graft-union but it does not influence genetic constitution of scion at DNA level. Further studies at RNA or protein level are required to unravel the reasons behind these variations. [ABSTRACT FROM AUTHOR]

Haplotypes provide useful information for genomics-based approaches, genomic prediction, and genome-wide association study. As a small number of superior founders have contributed largely to the breeding history of fruit trees, the information of founder haplotypes may be relevant for performing the genomics-based approaches in these plants. In this study, we proposed a method to estimate 14 haplotypes from 7 founders and automatically trace the haplotypes forward to apple parental (185 varieties) and breeding (659 F1 individuals from 16 full-sib families) populations based on 11,786 single-nucleotide polymorphisms, by combining multiple algorithms. Overall, 92% of the single-nucleotide polymorphisms information in the parental and breeding populations was characterized by the 14 founder haplotypes. The use of founder haplotype information improved the accuracy of genomic prediction in 7 traits and the resolution of genome-wide association study in 13 out of 27 fruit quality traits analyzed in this study. We also visualized the significant propagation of the founder haplotype with the largest genetic effect in genome-wide association study over the pedigree tree of the parental population. These results suggest that the information of founder haplotypes can be useful for not only genetic improvement of fruit quality traits in apples but also for understanding the selection history of founder haplotypes in the breeding program of Japanese apple varieties. [ABSTRACT FROM AUTHOR]

Fruit shape is the result of the interaction between genetic, epigenetic, environmental factors and stochastic processes. As a core biological descriptor both for taxonomy and horticulture, the point atwhich shape stability is reached becomes paramount in apple cultivar identification, and authentication in commerce. Twelve apple cultivars were sampled at regular intervals from anthesis to harvest over two growing seasons. Linear and geometric morphometrics were analysed to establish if and when shape stabilised and whether fruit asymmetry influenced this. Shape stability was detected in seven cultivars, four asymmetric and three symmetric. The remaining five did not stabilise. Shape stability, as defined here, is cultivar-dependent, andwhen it occurs, it is late in the growing season. Geometric morphometrics detected stability more readily than linear, especially in symmetric cultivars. Key shape features are important in apple marketing, giving the distinctness and apparent uniformity between cultivars expected at point of sale. [ABSTRACT FROM AUTHOR]

Societal Impact Statement: The English West Country is the home of cider making, providing the region with jobs and industry, as well as cultural reference points such as Laurie Lee's Cider with Rosie. Many important cider apple varieties were developed at Long Ashton Research Station (LARS), near Bristol, UK, including 29 varieties known collectively as 'The Girls'. After its closure, some of the knowledge and expertise acquired at Long Ashton was lost, including the pedigree of 'The Girls'. We sampled LARS' derived trees and, using a novel genotyping technique, rediscovered the pedigree of 'The Girls', ensuring that this important cider apple collection will be available for future generations. SummaryOur research had two objectives: (a) record the influence of Long Ashton Research Station on the introduction of new cider apple cultivars to the UK; (b) rediscover the parentage of the cider apple cultivars known collectively as 'The Girls'.For rapid, cost effective and accurate genotyping, we used the recently developed, medium density, single nucleotide polymorphism‐based genotyping procedure, SEQSNP®, to characterize the cultivars.We generated a medium density (1,500 markers), whole genome genotype for 245 apple cultivars that allowed us to determine the relationship between cultivars and, in so doing, rediscover the parentage of 'The Girls'.We show that SNP genotyping is an efficient tool for the analysis of genetic diversity in cider apples and apples in general, and that the cider apple breeding programme carried out at Long Ashton Research Station made, and continues to make, a unique contribution to UK cider production. [ABSTRACT FROM AUTHOR]

The nature and structure of genetic diversity in the Spanish apple germplasm preserved at the national level was widely unknown, since studies performed to date on this topic have been exclusively carried out at the regional scale. Here, 1453 accessions from Spanish collections of Malus × domestica were evaluated with a common set of 13 SSR (Simple Sequence Repeats) markers in order to estimate genetic diversity, to identify the underlying genetic structure and to unravel the relationships among them and among a wide set of international cultivars for reference. In total, 737 unique genotypes were identified, 581 diploids and 156 triploids. Using a model-based Bayesian clustering procedure, two reconstructed populations were obtained for diploid genotypes; one retaining only Spanish cultivars (42% of genotypes), and a second containing all foreign cultivars the latter exhibiting evidence supporting the existence of a secondary sub-structure. Similarly, analysis performed on the 156 triploid genotypes also revealed two reconstructed populations; one exclusively associated with local Spanish genotypes (44%). The Jaccard coefficient allowed clustering by UPGMA (Unweighted Pair Group Method) diploid and triploid genotypes, and remarkable differences in allelic composition among the different partitioning levels were found. AMOVA analyses showed moderate but significant differentiation among the main groups (0.08 ≤ F ST ≤ 0.12). Our results highlight an important fraction of the Spanish apple germplasm that constitutes a differentiated genepool with respect to the international and commercial apple cultivars. Moreover, the extent of the Spanish genetic diversity was spatially distributed along the northern Iberian Peninsula, suggesting an extensive migration of genotypes along the country. This study is the first valuable action for genetic conservation of apple at the national scale, and constitutes a decisive step towards the definition of a Spanish core collection that will be useful for further studies in dissecting the genetic control of important horticultural traits through genome-wide association analysis in apple. [ABSTRACT FROM AUTHOR]

The response of apple fruit to storage conditions based on low oxygen protocols depends on their genetic background. In order to elucidate common and divergent processes characterizing the metabolic changes under hypoxia, fruit of two apple ( Malus domestica ) varieties (‘Granny Smith’, GS, and ‘Red Delicious’, RD) were stored under two different low oxygen protocols (Ultra Low Oxygen, ULO, at 0.9 kPa oxygen, and Dynamic Controlled Atmosphere based on chlorophyll fluorescence, DCA-CF, between 0.2 and 0.55 kPa oxygen) for up to 200 and 214 days of storage for GS and RD samples, respectively. Through an integrated metabolomics approach ( 1 H NMR, GC–MS, HS-SPME-GC–MS analyses) a total of 130 metabolites (volatiles and non-volatiles) were identified. Most of them (117) were common to both cultivars; 95 were significantly different between both cultivars when comparing the whole set of data (ULO + DCA-CF), whereas 13 volatile compounds, identified via HS-SPME-GC–MS, were specific for either GS or RD. Multivariate analyses (PCA and PLS) of the whole dataset allowed to clearly discriminate between GS and RD samples. When storage condition was used as a categorical response variable, a lower percentage explained variance was obtained as this effect was overshadowed by the large effect of storage time. After 4 months of storage, RD underwent more pronounced metabolic compositional changes of the cortex, possibly associated with the evolution of ripening. Based on the accumulation pattern of pyruvate-derived metabolites (ethanol, acetaldehyde, lactate, alanine) it can be hypothesized that there are two main metabolic reconfiguration strategies in GS and RD to regenerate NAD + and cope with energy crisis under hypoxia. GS showed more pronounced responses through changes in the nitrogen metabolism and limited induction of the ethanol fermentation while the latter was highly induced in RD under both ULO and DCA-CF. Marked differences were detected between the VOC profiles of the two cultivars regardless storage conditions. Ethyl esters and 2-methylbutyl derivatives appeared finely modulated by the oxygen level in GS and RD apples, respectively. [ABSTRACT FROM AUTHOR]

In this study, we characterized a naturally occurring self-compatible apple cultivar, ‘CAU-1’ (S 1 S 9 ), and studied the underlying mechanism that causes its compatibility. Analyses of both fruit set rate and seed number after self-pollination or cross-pollination with ‘Fuji’ (S 1 S 9 ), and of pollen tube growth, demonstrated that ‘CAU-1’ is self-compatible. Genetic analysis by S-RNase PCR-typing of selfed progeny of ‘CAU-1’ revealed the presence of all progeny classes (S 1 S 1 , S 1 S 9 , and S 9 S 9 ). Moreover, no evidence of S-allele duplication was found. These findings support the hypothesis that loss of function of an S-locus unlinked pollen-part mutation (PPM) expressed in pollen, rather than a natural mutation in the pollen-S gene (S 1 - and S 9 - haplotype), leads to SI breakdown in ‘CAU-1’. In addition, there were no significant differences in pollen morphology or fertility between ‘Fuji’ and ‘CAU-1’. However, we found that the effect of S 1 - and S 9 -RNase on the SI behavior of pollen could not be addressed better in ‘CAU-1’ than in ‘Fuji’. Furthermore, we found that a pollen-expressed hexose transporter, MdHT1, interacted with S-RNases and showed significantly less expression in ‘CAU-1’ than in ‘Fuji’ pollen tubes. These findings support the hypothesis that MdHT1 may participate in S-RNase internalization during the SI process, and decrease of MdHT1 expression in ‘CAU-1’ hindered the release of self S-RNase into the cytoplasm of pollen tubes, thereby protecting pollen from the cytotoxicity of S-RNase, finally probably resulting in self-compatibility. Together, these findings indicate that S-locus external factors are required for gametophytic SI in the Rosaceae subtribe Pyrinae . [ABSTRACT FROM AUTHOR]

Copyright of Erwerbs-Obstbau is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Apple breeding is usually done to produce higher quality apples. We crossed two late ripening high quality apple cultivars (i.e., Golden Smoothie and Red Spur) as maternal parents with two Iranian domestic early ripening apple cultivars (i.e., Golab-e Kohanz and Shafi Abadi) as pollen parents in 2005 to breed new early ripening apple cultivars. We then measured qualitative and quantitative traits of 360 off spring during 2010 and 2011. Results of recorded traits on the 5th and 6th year of growth of the progeny showed that during two evaluation years, flowering and fruit ripening time, titrable acidity, SSC/acid ratio, and fruit weight had the highest coefficients of phenotypic variations. Progenies were classified in three groups: early, mid, and late ripening. Some of the selected progeny were better than their early ripening parental cultivars being earlier in the ripening, with larger fruit size and better texture and flavor. Genotypes A31, A32, I5, I23, and I57 were in the early ripening category, B11 and A34 were in the middle, and B77 and E21 were in the late ripening categories. These characteristics were considered to present an improvement. [ABSTRACT FROM PUBLISHER]

This study examined the factors influencing choice of different marketing channels by the apple orchardists. Further, the study aimed to find out their common marketing problems. Present study is based on primary data collected from a randomly selected sample of 110 apple orchardists in Jubbal Tehsil of District Shimla in Himachal Pradesh through a detailed and exhaustive questionnaire prepared by the researchers after reviewing the previous studies. The results indicate that pre-harvest contractors, private procurement companies, commission agents and local buyers are the predominant intermediaries of apple marketing channels in Himachal Pradesh. Findings of the study show that receipt of timely payments and lack of marketing knowledge are the factors which influence the orchardists to choose commission agents and local buyers for selling their produce whereas pre-harvest contractors and private procurement companies are mainly preferred for avoiding risk and labour problems. Empirical evidences suggest that growers are facing common marketing problem of inadequate labour and transportation, improper grading and packaging, bad condition of link roads, inadequate storage facility and absence of market information. It is suggested that the existing overall marketing channels should be updated by reducing number of intermediaries which would eventually reduce the gap between the unit income of the farmers and the market price. It is further suggested that orchardists should make their cooperative societies for remunerative returns of their produce through collective selling and direct marketing. There is a need to encourage cold storage facilities and co-operative marketing system for safe storage, quick transportation and better marketing. [ABSTRACT FROM AUTHOR]

Copyright of Erwerbs-Obstbau is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Almost all commercially grown apple cultivars in Turkey are exotic, with local varieties serving as important genetic resources for breeding and marker development purposes. Among the latter is Amasya, which has a pleasing taste and flavor, but is unsuitable for commercial use because of its small fruit size and alternate-bearing characteristics. Genetic maps of apple cultivars are important resources to facilitate marker-assisted selection. Because of its good eating quality, Amasya is a good genetic resource for marker development to enhance fruit quality, especially flavor. In this study, we constructed a simple sequence repeat (SSR) marker-based genetic map of the Amasya apple cultivar using 96 F1 progenies generated from a cross between Kaşel-41 (a selection from Amasya) and Williams' Pride cultivars. Of 187 bacterial artificial chromosome SSRs, 150 expressed sequence tag SSRs, and of 362 genomic SSR primer pairs, 400 markers were mapped, with parental and consensus maps constructed independently. A reference map was also constructed using 207 common SSR markers, thereby producing the most dense SSR-based reference map currently reported for apple. The reference genetic map was 1351 cM long, with a mean marker density of 6.5 cM. The consensus map obtained by mapping 396 markers had a length of 1476.4 cM and a 3.82-cM mean marker density. We also identified the positions of 57 SSR loci previously unmapped in apple. As a result, once additional markers have been incorporated into the maps to increase saturation, the evaluation of phenotypic traits in the mapping population should facilitate linkage between molecular markers and fruit quality traits. Additionally, the constructed apple reference genetic map, with 207 SSR markers, should also assist the construction of new genetic maps and aid integration of various apple linkage maps. [ABSTRACT FROM AUTHOR]

Apple (Malus × domestica Borkh.) is a widely-cultivated, economically important fruit crop with nutritional and medicinal value. Apple has emerged as a model horticultural crop in the post-genomic era. Apple sport resources are important, develop gradually in the apple industry, and provide genetic diversity. In this study, we have successfully developed a sequence-specific amplification polymorphism (S-SAP) marker system based on Tyl-copia retrotransposons in the apple genome. Among the 34 primer combinations used to develop the S-SAP marker system, two primer combinations produced profiles with clear and different peak patterns. Based on these primer combinations, 15 apple sport accessions (four 'Gala', six 'Fuji', and five 'Delicious') were grouped into three clusters based on a genetic variation coefficient value of 0.78. In addition, 27 'Delicious' apple sport accessions were also selected to perform S-SAP marker analysis using the same two primer combinations. The results showed that all 'Delicious' apple sport accessions tested were clearly distinguished. The S-SAP data shared many consistencies with known relationships among apple sport accessions. The available evidence showed that these S-SAP markers had a high level of polymorphism in these apple accessions, which could be applied efficiently to determine genetic diversity, systematic evolution, and for variety identification. [ABSTRACT FROM AUTHOR]

The present study is the first to compare the trait-level differentiation (Qst) and the molecular-level differentiation (Fst) between Malus× domestica and Malus sieversii. A set of 115 accessions representing M.× domestica (99) and M. sieversii (16) were genotyped using the International RosBREED SNP Consortium apple 8K SNP array and phenotyped for eight fruit quality traits in a clonally replicated experiment. A set of 3521 single nucleotide polymorphisms (SNPs) with an average call rate of 98% was retained following SNP data quality filters. About 86% of the total SNPs were polymorphic in M. sieversii, while all but three SNPs were polymorphic in M. × domestica. The patterns of linkage disequilibrium were different, especially at the longer distances, between the two species. No differentiation (Fst= 0) was observed for nearly 23% of the SNPs, but about 20% of the SNPs exhibited a high genetic differentiation (Fst≥ 0.15). A highly significant (P< 0.001) genome-level Fst= 0.12 was observed between M. × domestica and M. sieversii. The average estimated Qst value was 0.20 (range 0.08–0.40), and for three of the eight studied traits (crispness, flavour intensity and fruit weight), Qst value was more than twice the estimated genome-level Fst value. A higher Qst value than Fst value for four of the eight fruit quality traits indicated differential (or directional) selection for these traits in M. × domestica. The average posterior probability of assignment of M. × domestica accessions to the M. sieversii gene pool was 11%, supporting the hypothesis of M. sieversii being one of the progenitors of the domesticated apple. [ABSTRACT FROM AUTHOR]

The increasing availability of genomic tools improves our ability to investigate the patterns of genetic diversity and relatedness among individuals. The pedigrees of many apple cultivars are completely unknown, often reducing the efficiency of breeding programs. Using a multilocus simple sequence repeat dataset, we applied a novel multi-generation pedigree-network reconstruction procedure based on the software FRANz in a Malus × domestica collection (101 cultivated and 22 wild apples) with partially known pedigree relationships. The procedure produced 78 parent-offspring relationships organized into three networks and showed high power for detecting real pedigree links (98.5 %) and a low false-positive rate (9.0 %). The largest reconstructed pedigree network spanned four generations and involved 65 cultivars. The availability of detailed pedigree connections confirmed that recent genealogical relationships affect population genetic structure in apple. Finally, our analysis enabled us to confirm or discard several pedigrees known only anecdotically, among which the cultivar Grimes Golden was validated as a parent of the widely grown cultivar Golden Delicious. The pedigree reconstruction protocol here described will be of broad applicability to other collections and crop species. [ABSTRACT FROM AUTHOR]

Fire blight, caused by the Gram-negative bacterium Erwinia amylovora, is the most important bacterial disease affecting apple ( Malus × domestica) and pear ( Pyrus communis) production. The use of antibiotic treatment, though effective to some degree, is forbidden or strictly regulated in many European countries, and hence an alternative means of control is essential. The planting of fire blight-resistant cultivars seems to be a highly feasible strategy. In this study, we explored a segregating population derived from a cross between the wild apple species Malus fusca and the M. × domestica cultivar Idared. F1 progenies used for mapping were artificially inoculated with Erwinia amylovora strain Ea222_JKI at a concentration of 10 cfu/ml in three different years. The averages of percentage lesion length of all replicates of each genotype were used as numerical traits for statistical analysis. A Kruskal-Wallis analysis was used to determine marker-phenotype association and revealed a linkage group with Diversity Arrays Technology (DArT) markers significantly linked with fire blight. After locating the positions of the DArT markers on the Golden Delicious genome, simple sequence repeat (SSR) markers were developed from chromosome 10 to replace the DArT markers and to determine the quantitative trait locus (QTL) region. Multiple QTL mapping (MQM) revealed a strong QTL ( Mfu10) on linkage group 10 of M. fusca explaining about 65.6 % of the phenotypic variation. This is the first report on a fire blight resistance QTL of M. fusca. [ABSTRACT FROM AUTHOR]

Using resistance genes from a crossable donor to obtain cultivars resistant to diseases and the use of such cultivars in production appears an economically and environmentally advantageous approach. In apple, introgression of resistance genes by classical breeding results in new cultivars, while introducing cisgenes by biotechnological methods maintains the original cultivar characteristics. Recently, plants of the popular apple 'Gala' were genetically modified by inserting the apple scab resistance gene Rvi6 (formerly HcrVf2) under control of its own regulatory sequences. This gene is derived from the scab-resistant apple 'Florina' (originally from the wild apple accession Malus floribunda 821). The vector used for genetic modification allowed a postselection marker gene elimination to achieve cisgenesis. In this work, three cisgenic lines were analysed to assess copy number, integration site, expression level and resistance to apple scab. For two of these lines, a single insertion was observed and, despite a very low expression of 0.07- and 0.002-fold compared with the natural expression of 'Florina', this was sufficient to induce plant reaction and reduce fungal growth by 80% compared with the scab-susceptible 'Gala'. Similar results for resistance and expression analysis were obtained also for the third line, although it was impossible to determine the copy number and TDNA integration site-such molecular characterization is requested by the ( EC) Regulation No. 1829/2003, but may become unnecessary if cisgenic crops become exempt from GMO regulation. [ABSTRACT FROM AUTHOR]

Genetic variation between five apple cultivars ('Golden Delicious', 'Gala', 'Jonagold', 'Šampion', and 'Idared') and ten of their sports ('Golden Delicious Reinders', 'Goldrosio', 'Gala Must', 'Gala Schniga Schnitzer', 'Jonagored', 'Jonagold Excel', 'Szampion Arno', 'Szampion Reno Malinowy', 'Idaredest', and 'Red Idared') was investigated using five types of DNA markers: Inter-Simple Sequence Repeats (ISSR), Simple Sequence Repeats (SSR), Amplified Fragment Length Polymorphism (AFLP), Sequence-Specific Amplified Polymorphism (S-SAP), and Inter-Primer Binding Site (iPBS) amplification. In total, 941 polymorphic amplified fragments were obtained using 12 ISSR, 12 SSR, ten AFLE 19 iPBS, and 15 S-SAP primers or primer pairs. Four of the above-described techniques (except for SSRs with the primer pairs used in this study) were able to distinguish between the sports and their parental cultivar. The most effective technique to distinguish between the genotypes analysed was S-SAE which detects variations in DNA regions flanking retrotransposon insertion sites. The combined use of ISSR, AFLE iPBS, and S-SAP markers identified and distinguished all of the sports tested. [ABSTRACT FROM AUTHOR]

We have succeeded in isolating an MdMYB110a_JP gene responsible for a red-fleshed trait from a fruit of apple cultivar 'JPP35' ('Jonathan' × 'Pink Pearl'). The isolated MdMYB110a_JP gene was located on chromosome (ch.) 17, which was different from the location of known MdMYB1/ 10 gene of ch.9, and 'JPP35' and 'Pink Pearl' did not contain the known R :MdMYB10 allele responsible for the red-skin and red-fleshed trait. The MdMYB110a_JP was expressed strongly and weakly in the cortex and core of 'JPP35' fruit, respectively, at the time of coloring start in flesh, and also weakly in flower buds. Following the MdMYB110a_JP expression, the expression of the genes, MdCHS and MdLDOX, that encode the enzymes of the flavonoid pathway, was induced in flesh of 'JPP35' in accordance with anthocyanin accumulation. In contrast, the MdMYB110a_JP gene was not expressed in any tissues in red-skin and white-fleshed 'Fuji', and in red-skin and red-fleshed 'Maypole'. Instead, MdMYB1- 1 allele responsible for red-skin trait was expressed in red-skin of 'Fuji' and 'JPP35', and R :MdMYB10 allele responsible for red-skin and red-flesh trait was expressed in red-core and red-cortex in 'Maypole' as expected. Moreover, 35S: MdMYB110a_JP transgenic apple 'JM2' showed a red-foliage phenotype depending on the MdMYB110a_JP expression level. From the results, it was strongly suggested that the red-fleshed phenotype of 'JPP35' fruit was caused by up-regulation of the genes of anthocyanin pathway induced by the MdMYB110a_JP gene. [ABSTRACT FROM AUTHOR]

Consumers of whole foods, such as fruits, demand consistent high quality and seek varieties with enhanced health properties, convenience or novel taste. We have raised the polyphenolic content of apple by genetic engineering of the anthocyanin pathway using the apple transcription factor MYB10. These apples have very high concentrations of foliar, flower and fruit anthocyanins, especially in the fruit peel. Independent lines were examined for impacts on tree growth, photosynthesis and fruit characteristics. Fruit were analysed for changes in metabolite and transcript levels. Fruit were also used in taste trials to study the consumer perception of such a novel apple. No negative taste attributes were associated with the elevated anthocyanins. Modification with this one gene provides near isogenic material and allows us to examine the effects on an established cultivar, with a view to enhancing consumer appeal independently of other fruit qualities. [ABSTRACT FROM AUTHOR]

Background: Apple is a widely cultivated fruit crop for its quality properties and extended storability. Among the several quality factors, texture is the most important and appreciated, and within the apple variety panorama the cortex texture shows a broad range of variability. Anatomically these variations depend on degradation events occurring in both fruit primary cell wall and middle lamella. This physiological process is regulated by an enzymatic network generally encoded by large gene families, among which polygalacturonase is devoted to the depolymerization of pectin. In apple, Md-PG1, a key gene belonging to the polygalacturonase gene family, was mapped on chromosome 10 and co-localized within the statistical interval of a major hot spot QTL associated to several fruit texture sub-phenotypes. Results: In this work, a QTL corresponding to the position of Md-PG1 was validated and new functional alleles associated to the fruit texture properties in 77 apple cultivars were discovered. 38 SNPs genotyped by gene full length resequencing and 2 SSR markers ad hoc targeted in the gene metacontig were employed. Out of this SNP set, eleven were used to define three significant haplotypes statistically associated to several texture components. The impact of Md-PG1 in the fruit cell wall disassembly was further confirmed by the cortex structure electron microscope scanning in two apple varieties characterized by opposite texture performance, such as 'Golden Delicious' and 'Granny Smith'. Conclusions: The results here presented step forward into the genetic dissection of fruit texture in apple. This new set of haplotypes, and microsatellite alleles, can represent a valuable toolbox for a more efficient parental selection as well as the identification of new apple accessions distinguished by superior fruit quality features. [ABSTRACT FROM AUTHOR]

Anthocyanins are flavonoid pigments imparting red, blue, or purple pigmentation to fruits, flowers and foliage. These compounds are powerful antioxidants in vitro, and are widely believed to contribute to human health. The fruit of the domestic apple ( Malus x domestica) is a popular and important source of nutrients, and is considered one of the top 'functional foods'-those foods that have inherent health-promoting benefits beyond basic nutritional value. The pigmentation of typical red apple fruits results from accumulation of anthocyanin in the skin. However, numerous genotypes of Malus are known that synthesize anthocyanin in additional fruit tissues including the core and cortex (flesh). Red-fleshed apple genotypes are an attractive starting point for development of novel varieties for consumption and nutraceutical use through traditional breeding and biotechnology. However, cultivar development is limited by lack of characterization of the diversity of genetic backgrounds showing this trait. We identified and cataloged red-fleshed apple genotypes from four Malus diversity collections representing over 3,000 accessions including domestic cultivars, wild species, and named hybrids. We found a striking range of flesh color intensity and pattern among accessions, including those carrying the MYB10 R allele conferring ectopic expression of a key transcriptional regulator of anthocyanin biosynthesis. Although MYB10 R was strongly associated with red-fleshed fruit among genotypes, this allele was neither sufficient nor required for this trait in all genotypes. Nearly all red-fleshed accessions tested could be traced back to 'Niedzwetzkyana', a presumed natural form of M. sieversii native to central Asia. [ABSTRACT FROM AUTHOR]

Background: Our previous study on ripe apples from a progeny of a cross between the apple cultivars 'Prima' and 'Fiesta' showed a hotspot of mQTLs for phenolic compounds at the top of LG16, both in peel and in flesh tissues. In order to find the underlying gene(s) of this mQTL hotspot, we investigated the expression profiles of structural and putative transcription factor genes of the phenylpropanoid and flavonoid pathways during different stages of fruit development in progeny genotypes. Results: Only the structural gene leucoanthocyanidin reductase (MdLAR1) showed a significant correlation between transcript abundance and content of metabolites that mapped on the mQTL hotspot. This gene is located on LG16 in the mQTL hotspot. Progeny that had inherited one or two copies of the dominant MdLAR1 alleles (Mm, MM) showed a 4.4- and 11.8-fold higher expression level of MdLAR1 respectively, compared to the progeny that had inherited the recessive alleles (mm). This higher expression was associated with a four-fold increase of procyanidin dimer II as one representative metabolite that mapped in the mQTL hotspot. Although expression level of several structural genes were correlated with expression of other structural genes and with some MYB and bHLH transcription factor genes, only expression of MdLAR1 was correlated with metabolites that mapped at the mQTL hotspot. MdLAR1 is the only candidate gene that can explain the mQTL for procyanidins and flavan-3-ols. However, mQTLs for other phenylpropanoids such as phenolic esters, dihydrochalcones and flavonols, that appear to map at the same locus, have so far not been considered to be dependent on LAR, as their biosynthesis does not involve LAR activity. An explanation for this phenomenon is discussed. Conclusions: Transcript abundances and genomic positions indicate that the mQTL hotspot for phenolic compounds at the top of LG16 is controlled by the MdLAR1 gene. The dominant allele of the MdLAR1 gene, causing increased content of metabolites that are potentially health beneficial, could be used in marker assisted selection of current apple breeding programs and for cisgenesis. [ABSTRACT FROM AUTHOR]

Flavour is an important key factor of apple ( Malus × domestica Borkh.) fruit quality, and its improvement is an important but complex breeding goal. Acetate esters are quantitatively the most important volatile compounds in apple fruit, and only a few of them dominate the typical aroma of a cultivar. Alcohol acyl-transferase (AAT) is a key enzyme involved in the last step of ester biosynthesis. The aim of this study was to target single nucleotide polymorphisms (SNPs) in an AAT candidate gene genetically associated with ester quantitative trait loci (QTL), to enable functional marker development for marker-assisted apple breeding programs. The AAT gene inventory of apple was characterized by in-silico mining of the assembled Golden Delicious genome, and 17 putative AAT genes in total were defined. MdAAT1 located on chromosome 2 was selected as the main candidate gene associated with QTL for different acetate esters, and its allelic diversity was assessed by direct amplicon sequencing in a collection of 102 apple cultivars characterized for ester volatile profiles. Sequencing a 468 bp nucleotide sequence of the MdAAT1 coding region resulted in the detection of four SNPs. In total, 18 different SNP haplotypes/heterozygous patterns were generated from the four SNPs identified within the apple collection. Association analyses resulted in highly significant associations of both individual SNPs and distinct haplotypes with the content of four acetate esters, including hexyl acetate, butyl acetate and 2-methyl-butyl acetate. About a third (31) of the 102 apple cultivars possessed the specific MdAAT1 haplotype H1 (C-A-C-A) and were characterized by strongly decreased ester concentrations. The contrasting H8 haplotype (T-G-T-G) was found in 28 varieties but was associated with normal to elevated ester concentrations. The observed association suggests a putative causal functional relationship between MdAAT1 and production of key apple esters. [ABSTRACT FROM AUTHOR]

European populations exhibit progressive sensitisation to food allergens, and apples are one of the foods for which sensitisation is observed most frequently. Apple cultivars vary greatly in their allergenic characteristics, and a better understanding of the genetic basis of low allergenicity may therefore allow allergic individuals to increase their fruit intake. Mal d 1 is considered to be a major apple allergen, and this protein is encoded by the most complex allergen gene family. Not all Mal d 1 members are likely to be involved in allergenicity. Therefore, additional knowledge about the existence and characteristics of the different Mal d 1 genes is required. In the present study, we investigated the genomic organisation of the Mal d 1 gene cluster in linkage group 16 of apple through the sequencing of two bacterial artificial chromosome clones. The results provided new information on the composition of this family with respect to the number and orientation of functional and pseudogenes and their physical distances. The results were compared with the apple and peach genome sequences that have recently been made available. A broad analysis of the whole apple genome revealed the presence of new genes in this family, and a complete list of the observed Mal d 1 genes is supplied. Thus, this study provides an important contribution towards a better understanding of the genetics of the Mal d 1 family and establishes the basis for further research on allelic diversity among cultivars in relation to variation in allergenicity. [ABSTRACT FROM AUTHOR]

Abstract: A feature of ‘Honeycrisp’ apples [Malus sylvestris (L.) Mill var. domestica (Borkh.) Mansf.] is that they maintain flesh firmness over extended storage. The objective of this study was to elucidate molecular mechanisms that are responsible for slow softening of ‘Honeycrisp’ as compared with a rapidly softening cultivar, ‘McIntosh’. Fruit from both cultivars were picked during the normal harvest period and stored at 20°C for 10d. Internal ethylene concentrations (IECs) in ‘Honeycrisp’ fruit were lower than in ‘McIntosh’, but at climacteric levels of ethylene ‘Honeycrisp’ fruit maintained their firmness over this period, while ‘McIntosh’ softened rapidly. Concentrations of the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) were higher in ‘Honeycrisp’ than in ‘McIntosh’ apples. qRT-PCR analysis was carried out for genes involved in ethylene biosynthesis, perception and signaling [ACC synthase (MdACS); ACC oxidase (MdACO); ethylene receptors (MdETR and MdERS); constitutive triple response (MdCTR); ethylene response factor (MdERF)], as well as those involved in cell wall metabolism [polygalacturonase (MdPG); xyloglucan endotransglucosylase (MdXTH); expansin (MdEXP); β-galactosidase (Md β-GS); arabinofuranosidase (MdAFase); pectate lyase (MdPL)]. At comparable IECs, the expression of genes involved in ethylene synthesis, ethylene perception and signal transduction was generally much higher in ‘Honeycrisp’ than in ‘McIntosh’ fruit. However, the expression of MdAFase and MdEXP3 was generally lower in ‘Honeycrisp’ than in ‘McIntosh’, while that of MdPG and MdPL was extremely low in ‘Honeycrisp’. Expression of MdPG1 was very low, even though IECs were at climacteric levels. Absence of fruit softening in ‘Honeycrisp’ is probably associated with restricted cell wall enzyme activity. The lower maximum IECs found in ‘Honeycrisp’ compared with ‘McIntosh’ do not appear to be related to expression of genes involved in ethylene biosynthesis. [Copyright &y& Elsevier]

Apple cultivars and breeding lines that represent much of the diversity currently present in major European breeding programmes and are genetically related by their pedigree were examined for the trueness of their identity and parentage by consistency in marker scores using a genome-covering set of 80 microsatellite (SSR) markers and an 'identity-by-descent' approach. One hundred and twenty-five individuals were validated for the trueness-to-type of both their parents and 49 were validated for one of their parents, their second being unknown (23 individuals) or not available in this study (26 individuals). In addition, 15 individuals for which we lacked one of or both the direct parents were validated by consistency with tested parents of earlier generations. Furthermore, the identity of 28 founder cultivars was validated, their marker scores being consistent with descending cultivars and breeding lines. Four of the eight triploids identified were clearly shown to have arisen from unreduced egg cells. The assumed pedigree of 15 further individuals was found to be incorrect; fully consistent pedigrees were suggested for three of the cultivars. The pedigrees of a further eight individuals were confirmed through inference from the molecular data. [ABSTRACT FROM AUTHOR]

In ornamental apple breeding process, the vigour of the tree is an important characteristic, this trait being analyzed in selection of seminal descendants obtained by hybridization. The vigour of the apple trees was studied in 25 interspecific hybrids F1 belonging to different Malus ornamental species, used as maternal or paternal genitors, crossed with several cultivars and selections. The seedling vigour was noted when hybrids were four to seven years old, in accordance with UPOV guideline standard: 3 - weak; 5 - medium; 7 - strong. The mean of marks for tree vigour of F1 hybrids in the 25 combinations ranged between 4.00 and 6.13. Compared with the mean of experiment as control (5.20), the most vigorous seedlings were obtained in the families 'Cluj II-1-2' x M. niedzwetzkyana and 'Reinette Baumann' x M. prunifolia, both with significant differences of growth versus the mean growth of all combinations. The weakest growth was noted in progenies belonging to 'Rosu de Cluj' x M. coronaria, 'Starkrimson' x M. prunifolia, 'Frumos de Voinesti' x M. floribunda, 'Cluj II-1-2' x M. floribunda, M. zumi x 'Reinette Baumann', M. coronaria x 'Reinette Baumann'. No significant differences were found between the mean of marks for tree vigour in the group of combinations in which the Malus species were used as maternal genitors (5.18) and paternal genitors (5.20). The coefficient of variability ranged in the experiment between 2.6% and 27.4%; in ten families a lower variability for seedlings vigour (under 10%) was identified, in 13 a medium one (between 10-20%) and in two a large one (more than 20%). Even if in some combinations the variability of tree vigour was not very large, there seems to be fair possibilities to identify by selection the seedlings with a desired vigour in each family. [ABSTRACT FROM AUTHOR]

Five apple cultivars ('Florina', 'Golden Delicious', 'Idared', 'Jonathan' and Starkrimson), were tested in 2004 and 2005 in five commercial orchards located in different counties of Transylvania, Romania, with quite nonsimilar environments. In June, young shoots were harvested from each cultivar and taken to the laboratory by means of a refrigerating bag. Young leaves were harvested from the shoots and preserved in refrigerator at -70°C until the DNA extraction was performed. Twelve decamer primers were used for DNA amplification out of which ten produced polymorphic bands in each cultivar/location. A dendrograms was constructed based on DNA migration in agarose gel and analysis of formed bands and genetic distances, for revealing the intervarietal polymorphism in the five locations. As it has been expected, at the molecular level there were great differences among the tested cultivars, but the dendrogram also exhibited the existence of obvious differences, at the molecular level, within the same cultivar, depending on location. Such differences should be attributed mainly to the lack of uniformity of initial mother plants used in the process of planting material production for the five cultivars under study. It is concluded that RAPD analysis could successfully be used in checking the authenticity of planting material for apple trees produced in different nurseries, provided there are available standard forms of the interested cultivars from which DNA could be analyzed and used as control. [ABSTRACT FROM AUTHOR]

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Development of apple (Malus domestica) cultivars resistant to fire blight, a devastating bacterial disease caused by Erwinia amylovora, is a priority for apple breeding programs. Towards this goal, the inactivation of members of the HIPM and DIPM gene families with a role in fire blight susceptibility (S genes) can help achieve sustainable tolerance. We have investigated the genomic diversity of HIPM and DIPM genes in Malus germplasm collections and used a candidate gene-based association mapping approach to identify SNPs (single nucleotide polymorphisms) with significant associations to fire blight susceptibility. A total of 87 unique SNP variants were identified in HIPM and DIPM genes across 93 Malus accessions. Thirty SNPs showed significant associations (p < 0.05) with fire blight susceptibility traits, while two of these SNPs showed highly significant (p < 0.001) associations across two different years. This research has provided knowledge about genetic diversity in fire blight S genes in diverse apple accessions and identified candidate HIPM and DIPM alleles that could be used to develop apple cultivars with decreased fire blight susceptibility via marker-assisted breeding or biotechnological approaches. [ABSTRACT FROM AUTHOR]

Apple cultivars with durable resistance are needed for sustainable management of fire blight, the most destructive bacterial disease of apples. Although studies have identified genetic resistance to fire blight in both wild species and cultivated apples, more research is needed to understand the molecular mechanisms underlying host–pathogen interaction and differential genotypic responses to fire blight infection. We have analyzed phenotypic and transcriptional responses of 'Empire' and 'Gala' apple cultivars to fire blight by infecting them with a highly aggressive E. amylovora strain. Disease progress, based on the percentage of visual shoot necrosis, started showing significant (p < 0.001) differences between 'Empire' and 'Gala' 4 days after infection (dai). 'Empire' seems to slow down bacterial progress more rapidly after this point. We further compared transcriptome profiles of 'Empire' and 'Gala' at three different time points after fire blight infection. More genes showed differential expression in 'Gala' at earlier stages, but the number of differentially expressed genes increased in 'Empire' at 3 dai. Functional classes related to defense, cell cycle, response to stress, and biotic stress were identified and a few co-expression gene networks showed particular enrichment for plant defense and abiotic stress response genes. Several of these genes also co-localized in previously identified quantitative trait locus regions for fire blight resistance on linkage groups 7 and 12, and can serve as functional candidates for future research. These results highlight different molecular mechanisms for pathogen perception and control in two apple cultivars and will contribute toward better understanding of E. amylovora-Malus pathosystem. Disease resistance: How apples fight blight Different apple varieties, such as 'Gala' and 'Empire,' defend themselves against fire blight in different ways, and studying how they do it may help in breeding varieties with better resistance. Fire blight is a devastating bacterial disease that can destroy entire orchard blocks in a single season. Breeding for increased resistance is one of the most efficient ways to combat it. Some apple varieties are naturally more resistant than others, but the underlying genetics are not well understood. Awais Khan at Cornell University in New York and co-workers investigated how the 'Gala' and 'Empire' varieties defend themselves in the first 72 h after infection. 'Empire' showed stronger resistance than 'Gala,' with many distinct resistance mechanisms. The researchers identified several resistance genes in each variety, which may eventually be used in breeding more blight-resistant apple varieties. [ABSTRACT FROM AUTHOR]