Classificação de mamoeiros quanto ao tipo sexual e cultivares usando a espectroscopia no infravermelho próximo, análises multivariadas e machine learning.
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Data
2021-07-28
Autores
Fernandes, Thiago Feliph Silva [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
A sexagem do mamoeiro (Carica papaya L.) é uma das práticas hortícolas mais importantes para o sucesso desta cultura, pois esta espécie apresentar flores femininas, hermafroditas e masculinas. Todavia, apenas as plantas hermafroditas produzem frutos com o formato exigido pelo mercado, ou seja, frutos mais alongados e com polpa carnosa. Desta forma, é necessário o plantio de pelo menos três mudas por cova para se garantir a presença de plantas hermafroditas, o que acarreta um maior custo para o produtor. Assim, o objetivo geral deste projeto foi verificar a possibilidade de se utilizar a espectroscopia no infravermelho próximo (NIR) como um método não destrutivo para a sexagem e identificação de cultivares de mamoeiros. Foram utilizados as cultivares ‘T2’, ‘Formosa’ e ‘Calimosa’, do grupo Formosa, e ‘THB’ e ‘Ouro’, do grupo Solo. Os espectros NIR foram coletados nas sementes e nas folhas dos respectivos seedlings. Os resultados para a classificação do tipo sexual dos mamoeiros utilizando as sementes resultou em um valor de F-score de 0,81 para o grupo de validação externa ao se utilizar a análise de componentes principais e análise discriminante quadrática (PCA-QDA). Para as folhas dos seedlings o F-score foi 0,79 usando a PCA e análise discriminante linear (PCA-LDA). Em relação aos resultados para a classificação das cultivares, ao se utilizar as sementes foi possível obter valores de F-score apenas para as cultivares ‘THB’ (0,85) e ‘Ouro’ (0,77) no grupo de validação externa com o emprego da regressão por mínimos quadrados parciais e análise discriminante (PLS-DA). Para as demais cultivares não foi possível obter modelos de classificação robustos utilizando tanto as sementes quanto as folhas. Conclui-se que é possível utilizar a espectroscopia NIR associada às técnicas multivariadas como método não destrutivo para a sexagem e classificação de cultivares de mamoeiro utilizando tanto as sementes quanto as folhas dos seedlings.
Papaya plants can have typical pistillate or female flowers, hermaphrodite flowers and typical staminate or male flowers, but hermaphrodite plants produce fruit with the shape required by the market, that is, more elongated fruit with fleshy pulp. Therefore, it is necessary to plant at least three seedlings per hole to ensure the presence of hermaphrodite plants, which entails a higher cost for the producer. Thus, the general objective of this study was to verify the possibility of using near infrared spectroscopy (NIR) as a non-destructive method for sexing and identification of papaya cultivars. The cultivars ‘T2’, ‘Formosa’ and ‘Calimosa’, from the Formosa group, and ‘THB’ and ‘Ouro’, from the Solo group, were used. NIR spectra were collected from the seeds and leaves of the respective seedlings. The results for the classification of the sexual type of papaya trees using the seeds resulted in a F-score value of 0.81 for the external validation group applying principal component analysis and quadratic discriminant analysis (PCA-QDA). For the leaves of the seedling, this value 0.79 using PCA and linear discriminant analysis (PCA-LDA). Regarding the results for the cultivar classification, when seeds were used it was possible to obtain F-score values just for the cultivars 'THB' (0.85) and 'Ouro' (0.77) in the external validation group applying partial least squares regression and discriminant analysis (PLS-DA). For the other cultivars it was not possible to obtain good classification models using both seeds and leaves. It is possible to use NIR spectroscopy associated with multivariate techniques as a non-destructive method for sexing and classification of papaya cultivars using both seeds and leaves of seedlings. However, more studies are needed to improve the performance of the developed models.
Papaya plants can have typical pistillate or female flowers, hermaphrodite flowers and typical staminate or male flowers, but hermaphrodite plants produce fruit with the shape required by the market, that is, more elongated fruit with fleshy pulp. Therefore, it is necessary to plant at least three seedlings per hole to ensure the presence of hermaphrodite plants, which entails a higher cost for the producer. Thus, the general objective of this study was to verify the possibility of using near infrared spectroscopy (NIR) as a non-destructive method for sexing and identification of papaya cultivars. The cultivars ‘T2’, ‘Formosa’ and ‘Calimosa’, from the Formosa group, and ‘THB’ and ‘Ouro’, from the Solo group, were used. NIR spectra were collected from the seeds and leaves of the respective seedlings. The results for the classification of the sexual type of papaya trees using the seeds resulted in a F-score value of 0.81 for the external validation group applying principal component analysis and quadratic discriminant analysis (PCA-QDA). For the leaves of the seedling, this value 0.79 using PCA and linear discriminant analysis (PCA-LDA). Regarding the results for the cultivar classification, when seeds were used it was possible to obtain F-score values just for the cultivars 'THB' (0.85) and 'Ouro' (0.77) in the external validation group applying partial least squares regression and discriminant analysis (PLS-DA). For the other cultivars it was not possible to obtain good classification models using both seeds and leaves. It is possible to use NIR spectroscopy associated with multivariate techniques as a non-destructive method for sexing and classification of papaya cultivars using both seeds and leaves of seedlings. However, more studies are needed to improve the performance of the developed models.
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Palavras-chave
Carica papaya L., Espectroscopia NIR, Sexagem, Quimiometria, Flores