The Experts below are selected from a list of 1119 Experts worldwide ranked by ideXlab platform

D. J. Sargent - One of the best experts on this subject based on the ideXlab platform.

  • A study of gene expression changes at the Bp-2 locus associated with Bitter Pit symptom expression in apple ( Malus pumila )
    Molecular Breeding, 2018
    Co-Authors: M. Buti, P. Magnago, R. Velasco, D. J. Sargent, Luca Bianco, Richard Colgan
    Abstract:

    Bitter Pit is a physiological disorder of apples that develops in the latter stages of fruit development and during storage. It is characterized by localized necrotic cells that collapse and form Pits in the epidermis and outer cortex of fruit. The disorder has been associated with low calcium concentrations, and poor calcium distribution within fruit. The mechanism that leads to individual cell necrosis, while surrounding cells remain healthy, is not fully understood. In order to ascertain the underlying process of Bitter Pit incidence in apple fruit, a mapping population of ‘Braeburn’ (susceptible to Bitter Pit) × ‘Cameo’ (resistant to Bitter Pit) was used to map the trait over two growing seasons. A subset of 96 genotypes from the mapping population representing the full range of phenotypes in the same ratio as the full population were selected for genotyping and functional characterization. RNA-Seq analysis on fruits samples of three resistant and three susceptible lines at seven developmental stages (21, 42, 63, 84, 105, 126 and 147 days post fertilization) identified a number of candidate genes displaying differential gene expression. A subset of candidate genes selected based on their position within the identified QTL interval on chromosome 16 validated by RT-qPCR, and two candidate genes displaying differential gene expression were highlighted as strong candidates for the control of Bitter Pit symptom expression at the Bp-2 locus.

  • Identification and validation of a QTL influencing Bitter Pit symptoms in apple (Malus × domestica)
    Molecular Breeding, 2015
    Co-Authors: M. Buti, R.j. Colgan, L. Poles, D. Caset, P. Magnago, F. Fernandez Fernandez, R. Velasco, D. J. Sargent
    Abstract:

    Bitter Pit is one of the most economically important physiological disorders affecting apple fruit production, causing soft discrete Pitting of the cortical flesh of the apple fruits which renders them unmarketable. The disorder is heritable; however, the environment and cultural practices play a major role in expression of symptoms. Bitter Pit has been shown to be controllable to a certain extent using calcium sprays and dips; however, their use does not entirely prevent the incidence of the disorder. Previously, Bitter Pit has been shown to be controlled by two dominant genes, and markers on linkage group 16 of the apple genome were identified that were significantly associated with the expression of Bitter Pit symptoms in a genome-wide association study. In this investigation, we identified a major QTL for Bitter Pit defined by two microsatellite (SSR) markers. The association of the SSRs with the Bitter Pit locus, and their ability to predict severe symptom expression, was confirmed through screening of individuals with stable phenotypic expression from an additional mapping progeny. The data generated in this current study suggest a two gene model could account for the control of Bitter Pit symptom expression; however, only one of the loci was detectable, most likely due to dominance of alleles carried by both parents of the mapping progeny used. The SSR markers identified are cost-effective, robust and multi-allelic and thus should prove useful for the identification of seedlings with resistance to Bitter Pit using marker-assisted selection in apple breeding programs.

  • Identification and validation of a QTL influencing Bitter Pit symptoms in apple (Malus × domestica)
    Molecular Breeding, 2015
    Co-Authors: M. Buti, L. Poles, D. Caset, P. Magnago, R. Velasco, F. Fernandez Fernandez, Richard Colgan, D. J. Sargent
    Abstract:

    Bitter Pit is one of the most economically important physiological disorders affecting apple fruit production, causing soft discrete Pitting of the cortical flesh of the apple fruits which renders them unmarketable. The disorder is heritable; however, the environment and cultural practices play a major role in expression of symptoms. Bitter Pit has been shown to be controllable to a certain extent using calcium sprays and dips; however, their use does not entirely prevent the incidence of the disorder. Previously, Bitter Pit has been shown to be controlled by two dominant genes, and markers on linkage group 16 of the apple genome were identified that were significantly associated with the expression of Bitter Pit symptoms in a genome-wide association study. In this investigation, we identified a major QTL for Bitter Pit defined by two microsatellite (SSR) markers. The association of the SSRs with the Bitter Pit locus, and their ability to predict severe symptom expression, was confirmed through screening of individuals with stable phenotypic expression from an additional mapping progeny. The data generated in this current study suggest a two gene model could account for the control of Bitter Pit symptom expression; however, only one of the loci was detectable, most likely due to dominance of alleles carried by both parents of the mapping progeny used. The SSR markers identified are cost-effective, robust and multi-allelic and thus should prove useful for the identification of seedlings with resistance to Bitter Pit using marker-assisted selection in apple breeding programs.

  • identification and validation of a qtl influencing Bitter Pit symptoms in apple malus domestica
    Molecular Breeding, 2015
    Co-Authors: M. Buti, L. Poles, D. Caset, P. Magnago, R. Velasco, F. Fernandez Fernandez, Richard Colgan, D. J. Sargent
    Abstract:

    Bitter Pit is one of the most economically important physiological disorders affecting apple fruit production, causing soft discrete Pitting of the cortical flesh of the apple fruits which renders them unmarketable. The disorder is heritable; however, the environment and cultural practices play a major role in expression of symptoms. Bitter Pit has been shown to be controllable to a certain extent using calcium sprays and dips; however, their use does not entirely prevent the incidence of the disorder. Previously, Bitter Pit has been shown to be controlled by two dominant genes, and markers on linkage group 16 of the apple genome were identified that were significantly associated with the expression of Bitter Pit symptoms in a genome-wide association study. In this investigation, we identified a major QTL for Bitter Pit defined by two microsatellite (SSR) markers. The association of the SSRs with the Bitter Pit locus, and their ability to predict severe symptom expression, was confirmed through screening of individuals with stable phenotypic expression from an additional mapping progeny. The data generated in this current study suggest a two gene model could account for the control of Bitter Pit symptom expression; however, only one of the loci was detectable, most likely due to dominance of alleles carried by both parents of the mapping progeny used. The SSR markers identified are cost-effective, robust and multi-allelic and thus should prove useful for the identification of seedlings with resistance to Bitter Pit using marker-assisted selection in apple breeding programs.

R.j. Colgan - One of the best experts on this subject based on the ideXlab platform.

  • A study of gene expression changes at the Bp-2 locus associated with Bitter Pit symptom expression in apple (Malus pumila)
    Molecular Breeding, 2018
    Co-Authors: M. Buti, P. Magnago, Luca Bianco, D. J. Sargent, R. Velasco, R.j. Colgan
    Abstract:

    Bitter Pit is a physiological disorder of apples that develops in the latter stages of fruit development and during storage. It is characterized by localized necrotic cells that collapse and form Pits in the epidermis and outer cortex of fruit. The disorder has been associated with low calcium concentrations, and poor calcium distribution within the fruit. To date, the mechanism that leads to individual cell necrosis, while surrounding cells remain healthy, is not fully understood. In order to ascertain the underlying process of Bitter Pit incidence in apple fruit, a large mapping population of “Braeburn” (susceptible to Bitter Pit) × “Cameo” (resistant to Bitter Pit) was used to map the trait over two growing seasons. A subset of 94 genotypes from the mapping population representing the full range of phenotypes in the same ratio as the full population were selected for genotyping and functional characterization. RNA-Seq analysis on fruit samples of three resistant and three susceptible lines at seven developmental stages (21, 42, 63, 84, 105, 126, and 147 days post fertilization) identified a number of candidate genes displaying differential gene expression. A subset of candidate genes selected based on their position within the identified QTL interval on linkage group 16 were validated by RT-qPCR, and two candidate genes displaying differential gene expression were highlighted as strong candidates for the control of Bitter Pit symptom expression at the Bp-2 locus.

  • Identification and validation of a QTL influencing Bitter Pit symptoms in apple (Malus × domestica)
    Molecular Breeding, 2015
    Co-Authors: M. Buti, R.j. Colgan, L. Poles, D. Caset, P. Magnago, F. Fernandez Fernandez, R. Velasco, D. J. Sargent
    Abstract:

    Bitter Pit is one of the most economically important physiological disorders affecting apple fruit production, causing soft discrete Pitting of the cortical flesh of the apple fruits which renders them unmarketable. The disorder is heritable; however, the environment and cultural practices play a major role in expression of symptoms. Bitter Pit has been shown to be controllable to a certain extent using calcium sprays and dips; however, their use does not entirely prevent the incidence of the disorder. Previously, Bitter Pit has been shown to be controlled by two dominant genes, and markers on linkage group 16 of the apple genome were identified that were significantly associated with the expression of Bitter Pit symptoms in a genome-wide association study. In this investigation, we identified a major QTL for Bitter Pit defined by two microsatellite (SSR) markers. The association of the SSRs with the Bitter Pit locus, and their ability to predict severe symptom expression, was confirmed through screening of individuals with stable phenotypic expression from an additional mapping progeny. The data generated in this current study suggest a two gene model could account for the control of Bitter Pit symptom expression; however, only one of the loci was detectable, most likely due to dominance of alleles carried by both parents of the mapping progeny used. The SSR markers identified are cost-effective, robust and multi-allelic and thus should prove useful for the identification of seedlings with resistance to Bitter Pit using marker-assisted selection in apple breeding programs.

  • Diagnosing Bitter Pit in apple during storage by chlorophyllfluorescence as a non-destructive Tool
    Acta Horticulturae, 2015
    Co-Authors: M. Mirzaee, D. Rees, R.j. Colgan, Tully
    Abstract:

    Bitter Pit is an important physiological disorder of apple that can develop on the tree but is most prevalent during storage. Delaying fruit maturation after harvest through controlled atmosphere storage and application of 1-MCP SmartFreshTM) can delay the onset of symptoms; however, significant losses may occur in long-term stored apples. It is hard to detect internal Bitter Pit using external examination alone. Current predictive methods are based on destructive internal quality assessments and mineral analysis. A non-destructive method to detect and predict the propensity of fruit to develop Bitter Pit at harvest and during the early stages of storage would improve store management practices. High risk ‘Bramley’ orchards were identified from over 100 orchards surveyed across the south east of UK in 2010/11. A subsample of susceptible orchards with fruit that consistently developed Bitter Pit in storage as well as orchards where fruit remained free from problems were selected. Trials were conducted over two consecutive seasons (2012/13 and 2013/14) to evaluate changes of chlorophyll fluorescence in SmartFreshTM treated and untreated ‘Bramley’ apples during storage. The relationship between chlorophyll fluorescence profiles and Bitter Pit incidence were similar in the presence or absence of SmartFreshTM. In the early stages of storage, the chlorophyll fluorescence profiles were able to distinguish between SmartFreshTM treated and untreated samples and correlated well with fruit maturity, rate of ethylene production and onset of Bitter Pit; however, they were less discriminatory in determining the severity of Bitter Pit in long-term storage. The most discriminant chlorophyll fluorescence characteristics correlated to Bitter Pit were identified. Models have been developed to predict the likely incidence and development of Bitter Pit during storage, although they are not capable of estimating severity of the disorder.

P. Magnago - One of the best experts on this subject based on the ideXlab platform.

  • A study of gene expression changes at the Bp-2 locus associated with Bitter Pit symptom expression in apple ( Malus pumila )
    Molecular Breeding, 2018
    Co-Authors: M. Buti, P. Magnago, R. Velasco, D. J. Sargent, Luca Bianco, Richard Colgan
    Abstract:

    Bitter Pit is a physiological disorder of apples that develops in the latter stages of fruit development and during storage. It is characterized by localized necrotic cells that collapse and form Pits in the epidermis and outer cortex of fruit. The disorder has been associated with low calcium concentrations, and poor calcium distribution within fruit. The mechanism that leads to individual cell necrosis, while surrounding cells remain healthy, is not fully understood. In order to ascertain the underlying process of Bitter Pit incidence in apple fruit, a mapping population of ‘Braeburn’ (susceptible to Bitter Pit) × ‘Cameo’ (resistant to Bitter Pit) was used to map the trait over two growing seasons. A subset of 96 genotypes from the mapping population representing the full range of phenotypes in the same ratio as the full population were selected for genotyping and functional characterization. RNA-Seq analysis on fruits samples of three resistant and three susceptible lines at seven developmental stages (21, 42, 63, 84, 105, 126 and 147 days post fertilization) identified a number of candidate genes displaying differential gene expression. A subset of candidate genes selected based on their position within the identified QTL interval on chromosome 16 validated by RT-qPCR, and two candidate genes displaying differential gene expression were highlighted as strong candidates for the control of Bitter Pit symptom expression at the Bp-2 locus.

  • A study of gene expression changes at the Bp-2 locus associated with Bitter Pit symptom expression in apple (Malus pumila)
    Molecular Breeding, 2018
    Co-Authors: M. Buti, P. Magnago, Luca Bianco, D. J. Sargent, R. Velasco, R.j. Colgan
    Abstract:

    Bitter Pit is a physiological disorder of apples that develops in the latter stages of fruit development and during storage. It is characterized by localized necrotic cells that collapse and form Pits in the epidermis and outer cortex of fruit. The disorder has been associated with low calcium concentrations, and poor calcium distribution within the fruit. To date, the mechanism that leads to individual cell necrosis, while surrounding cells remain healthy, is not fully understood. In order to ascertain the underlying process of Bitter Pit incidence in apple fruit, a large mapping population of “Braeburn” (susceptible to Bitter Pit) × “Cameo” (resistant to Bitter Pit) was used to map the trait over two growing seasons. A subset of 94 genotypes from the mapping population representing the full range of phenotypes in the same ratio as the full population were selected for genotyping and functional characterization. RNA-Seq analysis on fruit samples of three resistant and three susceptible lines at seven developmental stages (21, 42, 63, 84, 105, 126, and 147 days post fertilization) identified a number of candidate genes displaying differential gene expression. A subset of candidate genes selected based on their position within the identified QTL interval on linkage group 16 were validated by RT-qPCR, and two candidate genes displaying differential gene expression were highlighted as strong candidates for the control of Bitter Pit symptom expression at the Bp-2 locus.

  • Identification and validation of a QTL influencing Bitter Pit symptoms in apple (Malus × domestica)
    Molecular Breeding, 2015
    Co-Authors: M. Buti, R.j. Colgan, L. Poles, D. Caset, P. Magnago, F. Fernandez Fernandez, R. Velasco, D. J. Sargent
    Abstract:

    Bitter Pit is one of the most economically important physiological disorders affecting apple fruit production, causing soft discrete Pitting of the cortical flesh of the apple fruits which renders them unmarketable. The disorder is heritable; however, the environment and cultural practices play a major role in expression of symptoms. Bitter Pit has been shown to be controllable to a certain extent using calcium sprays and dips; however, their use does not entirely prevent the incidence of the disorder. Previously, Bitter Pit has been shown to be controlled by two dominant genes, and markers on linkage group 16 of the apple genome were identified that were significantly associated with the expression of Bitter Pit symptoms in a genome-wide association study. In this investigation, we identified a major QTL for Bitter Pit defined by two microsatellite (SSR) markers. The association of the SSRs with the Bitter Pit locus, and their ability to predict severe symptom expression, was confirmed through screening of individuals with stable phenotypic expression from an additional mapping progeny. The data generated in this current study suggest a two gene model could account for the control of Bitter Pit symptom expression; however, only one of the loci was detectable, most likely due to dominance of alleles carried by both parents of the mapping progeny used. The SSR markers identified are cost-effective, robust and multi-allelic and thus should prove useful for the identification of seedlings with resistance to Bitter Pit using marker-assisted selection in apple breeding programs.

  • Identification and validation of a QTL influencing Bitter Pit symptoms in apple (Malus × domestica)
    Molecular Breeding, 2015
    Co-Authors: M. Buti, L. Poles, D. Caset, P. Magnago, R. Velasco, F. Fernandez Fernandez, Richard Colgan, D. J. Sargent
    Abstract:

    Bitter Pit is one of the most economically important physiological disorders affecting apple fruit production, causing soft discrete Pitting of the cortical flesh of the apple fruits which renders them unmarketable. The disorder is heritable; however, the environment and cultural practices play a major role in expression of symptoms. Bitter Pit has been shown to be controllable to a certain extent using calcium sprays and dips; however, their use does not entirely prevent the incidence of the disorder. Previously, Bitter Pit has been shown to be controlled by two dominant genes, and markers on linkage group 16 of the apple genome were identified that were significantly associated with the expression of Bitter Pit symptoms in a genome-wide association study. In this investigation, we identified a major QTL for Bitter Pit defined by two microsatellite (SSR) markers. The association of the SSRs with the Bitter Pit locus, and their ability to predict severe symptom expression, was confirmed through screening of individuals with stable phenotypic expression from an additional mapping progeny. The data generated in this current study suggest a two gene model could account for the control of Bitter Pit symptom expression; however, only one of the loci was detectable, most likely due to dominance of alleles carried by both parents of the mapping progeny used. The SSR markers identified are cost-effective, robust and multi-allelic and thus should prove useful for the identification of seedlings with resistance to Bitter Pit using marker-assisted selection in apple breeding programs.

  • identification and validation of a qtl influencing Bitter Pit symptoms in apple malus domestica
    Molecular Breeding, 2015
    Co-Authors: M. Buti, L. Poles, D. Caset, P. Magnago, R. Velasco, F. Fernandez Fernandez, Richard Colgan, D. J. Sargent
    Abstract:

    Bitter Pit is one of the most economically important physiological disorders affecting apple fruit production, causing soft discrete Pitting of the cortical flesh of the apple fruits which renders them unmarketable. The disorder is heritable; however, the environment and cultural practices play a major role in expression of symptoms. Bitter Pit has been shown to be controllable to a certain extent using calcium sprays and dips; however, their use does not entirely prevent the incidence of the disorder. Previously, Bitter Pit has been shown to be controlled by two dominant genes, and markers on linkage group 16 of the apple genome were identified that were significantly associated with the expression of Bitter Pit symptoms in a genome-wide association study. In this investigation, we identified a major QTL for Bitter Pit defined by two microsatellite (SSR) markers. The association of the SSRs with the Bitter Pit locus, and their ability to predict severe symptom expression, was confirmed through screening of individuals with stable phenotypic expression from an additional mapping progeny. The data generated in this current study suggest a two gene model could account for the control of Bitter Pit symptom expression; however, only one of the loci was detectable, most likely due to dominance of alleles carried by both parents of the mapping progeny used. The SSR markers identified are cost-effective, robust and multi-allelic and thus should prove useful for the identification of seedlings with resistance to Bitter Pit using marker-assisted selection in apple breeding programs.

M. Buti - One of the best experts on this subject based on the ideXlab platform.

  • A study of gene expression changes at the Bp-2 locus associated with Bitter Pit symptom expression in apple ( Malus pumila )
    Molecular Breeding, 2018
    Co-Authors: M. Buti, P. Magnago, R. Velasco, D. J. Sargent, Luca Bianco, Richard Colgan
    Abstract:

    Bitter Pit is a physiological disorder of apples that develops in the latter stages of fruit development and during storage. It is characterized by localized necrotic cells that collapse and form Pits in the epidermis and outer cortex of fruit. The disorder has been associated with low calcium concentrations, and poor calcium distribution within fruit. The mechanism that leads to individual cell necrosis, while surrounding cells remain healthy, is not fully understood. In order to ascertain the underlying process of Bitter Pit incidence in apple fruit, a mapping population of ‘Braeburn’ (susceptible to Bitter Pit) × ‘Cameo’ (resistant to Bitter Pit) was used to map the trait over two growing seasons. A subset of 96 genotypes from the mapping population representing the full range of phenotypes in the same ratio as the full population were selected for genotyping and functional characterization. RNA-Seq analysis on fruits samples of three resistant and three susceptible lines at seven developmental stages (21, 42, 63, 84, 105, 126 and 147 days post fertilization) identified a number of candidate genes displaying differential gene expression. A subset of candidate genes selected based on their position within the identified QTL interval on chromosome 16 validated by RT-qPCR, and two candidate genes displaying differential gene expression were highlighted as strong candidates for the control of Bitter Pit symptom expression at the Bp-2 locus.

  • Identification and validation of a QTL influencing Bitter Pit symptoms in apple (Malus × domestica)
    Molecular Breeding, 2015
    Co-Authors: M. Buti, R.j. Colgan, L. Poles, D. Caset, P. Magnago, F. Fernandez Fernandez, R. Velasco, D. J. Sargent
    Abstract:

    Bitter Pit is one of the most economically important physiological disorders affecting apple fruit production, causing soft discrete Pitting of the cortical flesh of the apple fruits which renders them unmarketable. The disorder is heritable; however, the environment and cultural practices play a major role in expression of symptoms. Bitter Pit has been shown to be controllable to a certain extent using calcium sprays and dips; however, their use does not entirely prevent the incidence of the disorder. Previously, Bitter Pit has been shown to be controlled by two dominant genes, and markers on linkage group 16 of the apple genome were identified that were significantly associated with the expression of Bitter Pit symptoms in a genome-wide association study. In this investigation, we identified a major QTL for Bitter Pit defined by two microsatellite (SSR) markers. The association of the SSRs with the Bitter Pit locus, and their ability to predict severe symptom expression, was confirmed through screening of individuals with stable phenotypic expression from an additional mapping progeny. The data generated in this current study suggest a two gene model could account for the control of Bitter Pit symptom expression; however, only one of the loci was detectable, most likely due to dominance of alleles carried by both parents of the mapping progeny used. The SSR markers identified are cost-effective, robust and multi-allelic and thus should prove useful for the identification of seedlings with resistance to Bitter Pit using marker-assisted selection in apple breeding programs.

  • Identification and validation of a QTL influencing Bitter Pit symptoms in apple (Malus × domestica)
    Molecular Breeding, 2015
    Co-Authors: M. Buti, L. Poles, D. Caset, P. Magnago, R. Velasco, F. Fernandez Fernandez, Richard Colgan, D. J. Sargent
    Abstract:

    Bitter Pit is one of the most economically important physiological disorders affecting apple fruit production, causing soft discrete Pitting of the cortical flesh of the apple fruits which renders them unmarketable. The disorder is heritable; however, the environment and cultural practices play a major role in expression of symptoms. Bitter Pit has been shown to be controllable to a certain extent using calcium sprays and dips; however, their use does not entirely prevent the incidence of the disorder. Previously, Bitter Pit has been shown to be controlled by two dominant genes, and markers on linkage group 16 of the apple genome were identified that were significantly associated with the expression of Bitter Pit symptoms in a genome-wide association study. In this investigation, we identified a major QTL for Bitter Pit defined by two microsatellite (SSR) markers. The association of the SSRs with the Bitter Pit locus, and their ability to predict severe symptom expression, was confirmed through screening of individuals with stable phenotypic expression from an additional mapping progeny. The data generated in this current study suggest a two gene model could account for the control of Bitter Pit symptom expression; however, only one of the loci was detectable, most likely due to dominance of alleles carried by both parents of the mapping progeny used. The SSR markers identified are cost-effective, robust and multi-allelic and thus should prove useful for the identification of seedlings with resistance to Bitter Pit using marker-assisted selection in apple breeding programs.

  • identification and validation of a qtl influencing Bitter Pit symptoms in apple malus domestica
    Molecular Breeding, 2015
    Co-Authors: M. Buti, L. Poles, D. Caset, P. Magnago, R. Velasco, F. Fernandez Fernandez, Richard Colgan, D. J. Sargent
    Abstract:

    Bitter Pit is one of the most economically important physiological disorders affecting apple fruit production, causing soft discrete Pitting of the cortical flesh of the apple fruits which renders them unmarketable. The disorder is heritable; however, the environment and cultural practices play a major role in expression of symptoms. Bitter Pit has been shown to be controllable to a certain extent using calcium sprays and dips; however, their use does not entirely prevent the incidence of the disorder. Previously, Bitter Pit has been shown to be controlled by two dominant genes, and markers on linkage group 16 of the apple genome were identified that were significantly associated with the expression of Bitter Pit symptoms in a genome-wide association study. In this investigation, we identified a major QTL for Bitter Pit defined by two microsatellite (SSR) markers. The association of the SSRs with the Bitter Pit locus, and their ability to predict severe symptom expression, was confirmed through screening of individuals with stable phenotypic expression from an additional mapping progeny. The data generated in this current study suggest a two gene model could account for the control of Bitter Pit symptom expression; however, only one of the loci was detectable, most likely due to dominance of alleles carried by both parents of the mapping progeny used. The SSR markers identified are cost-effective, robust and multi-allelic and thus should prove useful for the identification of seedlings with resistance to Bitter Pit using marker-assisted selection in apple breeding programs.

Sindhuja Sankaran - One of the best experts on this subject based on the ideXlab platform.

  • Hyperspectral Imaging and Spectrometry-Derived Spectral Features for Bitter Pit Detection in Storage Apples.
    Sensors, 2018
    Co-Authors: Sanaz Jarolmasjed, Lav R. Khot, Sindhuja Sankaran
    Abstract:

    Bitter Pit is one of the most important disorders in apples. Some of the fresh market apple varieties are susceptible to Bitter Pit disorder. In this study, visible–near-infrared spectrometry-based reflectance spectral data (350–2500 nm) were acquired from 2014, 2015 and 2016 harvest produce after 63 days of storage at 5 °C. Selected spectral features from 2014 season were used to classify the healthy and Bitter Pit samples from three years. In addition, these spectral features were also validated using hyperspectral imagery data collected on 2016 harvest produce after storage in a commercial storage facility for 5 months. The hyperspectral images were captured from either sides of apples in the range of 550–1700 nm. These images were analyzed to extract additional set of spectral features that were effective in Bitter Pit detection. Based on these features, an automated spatial data analysis algorithm was developed to detect Bitter Pit points. The Pit area was extracted, and logistic regression was used to define the categorizing threshold. This method was able to classify the healthy and Bitter Pit apples with an accuracy of 85%. Finally, hyperspectral imagery derived spectral features were re-evaluated on the visible–near-infrared reflectance data acquired with spectrometer. The pertinent partial least square regression classification accuracies were in the range of 90–100%. Overall, the study identified salient spectral features based on both hyperspectral spectrometry and imaging techniques that can be used to develop a sensing solution to sort the fruit on the packaging lines.

  • Near infrared spectroscopy to predict Bitter Pit development in different varieties of apples
    Journal of Food Measurement and Characterization, 2017
    Co-Authors: Sanaz Jarolmasjed, Carlos Zúñiga Espinoza, Sindhuja Sankaran
    Abstract:

    Bitter Pit is a physiological disorder in apples. Several major apple varieties are susceptible to this disorder that poses a great challenge to growers and the associated industry as it significantly reduces the produce utilization value and marketability. The current method of Bitter Pit detection is through visual assessment of symptoms. Near infrared (NIR) spectroscopy is a non-invasive technique that can be utilized towards detecting Bitter Pit development in fruits in pre-/non-symptomatic stages. Therefore, NIR spectra (935–2500 nm) of apples were collected from healthy and Bitter Pit Honeycrisp, Golden Delicious, and Granny Smith apples from a commercial orchard. The apples were stored in a controlled environment and spectral reflectance data were acquired at days 0, 7, 14, 35, and 63 after harvest. Chemical analysis was performed at the end of the storage period to estimate calcium, magnesium, and potassium content in the fruit peel. Partial least square regression (PLSR) was used to identify the apples as healthy or Bitter Pit using NIR-based spectral features. In addition, specific spectral features were selected by implementing two feature extraction methods: PLSR and stepwise discriminant analysis (SDA) on day 63 spectral dataset. The PLSR and SDA-based selected features from day 63 in Honeycrisp apples classified the same dataset with classification accuracies of about 100% with both methods. Regression analysis indicated a strong relationship between the PLSR-based spectral features and magnesium-to-calcium ratio in fruit peel in all three (Honeycrisp, Golden Delicious, and Granny Smith) apple varieties.

  • Spectrometric techniques for elemental profile analysis associated with Bitter Pit in apples
    Postharvest Biology and Technology, 2017
    Co-Authors: Carlos Espinoza Zúñiga, Sanaz Jarolmasjed, Rajeev Sinha, Chongyuan Zhang, Lee Kalcsits, Amit Dhingra, Sindhuja Sankaran
    Abstract:

    Abstract Bitter Pit and healthy ‘Honeycrisp’, ‘Golden Delicious’, and ‘Granny Smith’ apples were collected from three commercial orchards. Apples were scanned using Fourier transform infrared (FTIR) and X-ray fluorescence (XRF) spectrometers to associate the elemental profile with Bitter Pit occurrence in apples. The FTIR spectra were acquired from apple peel and flesh; while XRF spectra were acquired from the apple surface (peel). Destructive elemental analysis was also performed to estimate calcium, magnesium, and potassium concentrations in the apples. There were significant differences between healthy and Bitter Pit affected apples in calcium, magnesium, and potassium concentrations, in addition to magnesium/calcium and potassium/calcium ratios (5% level of significance). Peak analysis of FTIR spectra of prepared standards indicated the possible spectral regions associated with calcium content as 1150–1450 cm−1. Two different classification models (support vector machine, SVM and soft independent modeling of class analogy, SIMCA) were used to classify healthy and Bitter Pit affected apples using FTIR spectral signatures. FTIR spectra were able to predict Bitter Pit incidence in apples with higher classification accuracy using peel tissue (92%) than using flesh tissue with SVM model. The XRF technique could determine Bitter Pit incidence in apples and semi-quantitative analysis using XRF data was in agreement with the elemental analysis. FTIR and XRF spectrometric techniques are rapid methods that can be used for elemental profile analysis in apples. These techniques can serve as potential prediction tools for elemental profile analysis to detect Bitter Pit in apples.

  • Computed tomography imaging-based Bitter Pit evaluation in apples
    Biosystems Engineering, 2016
    Co-Authors: Sindhuja Sankaran
    Abstract:

    Bitter Pit is an economically important physiological disorder in apples resulting in serious economic losses. Current visual assessment techniques are not completely useful in evaluating the extent of Bitter Pit development as they are limited to external symptoms. An X-ray computer tomography (CT) based imaging and associated image processing algorithm was used to assess the number of Bitter Pits inside the fruit and on the surface of apples. Samples of 40 healthy and 40 Bitter Pit affected ‘Honeycrisp’ apples were selected from two different field sites, and scanned with CT equipment on 0, 21 and 63 days after harvest. The results showed that the average number of Bitter Pits increased both on the surface and inside the fruits with increasing storage period. An average of 42–66% Pits was present inside the apple fruits in Bitter Pit-affected apples. In addition, most of the newly developed Bitter Pits in healthy apples appeared within the fruit. Therefore, the usefulness of X-ray CT imaging as an effective phenotyping tool in identifying internal Bitter Pit and on the surface in the automated manner was demonstrated in this study.

  • Postharvest Bitter Pit detection and progression evaluation in ‘Honeycrisp’ apples using computed tomography images
    Postharvest Biology and Technology, 2016
    Co-Authors: Sanaz Jarolmasjed, Sindhuja Sankaran, Carlos Zúñiga Espinoza, Lav R. Khot
    Abstract:

    Abstract Bitter Pit is a physiological disorder that is defined as brown, corky and roundish lesions, which can develop in apples before and after harvest. This disorder greatly reduces the product utilization value of the fruit, and can result in several million dollar economic loss to the apple industry. Computed Tomography (CT) imaging is a non-destructive and rapid sensing technique that can be applied to packaged apples. In this study, healthy and Bitter Pit Honeycrisp apples were harvested from two field sites and stored for 63 days. CT images of the sampled apples were collected on 0, 7, 14, 21, 35 and 63 days after harvest. Images were analyzed to estimate the total Pit area in each of the individual apples and were related to Pit incidence and progression in different stages of storage. Results showed Pit development during the storage period in Bitter Pitted apples. The rate of progression differed in samples collected from different field sites. Further analysis for Pit distribution along each of the Bitter Pit affected apples showed 54% of Pits located at the calyx-end of apples in comparison with middle and stem-end. Classification of healthy and Bitter Pitted apples using logistic regression based method resulted in false negative of 7–21%.