著者

Maria Suzuki Kanae Masuda Hideaki Asakuma Kouki Takeshita Kohei Baba Yasutaka Kubo Koichiro Ushijima Seiichi Uchida Takashi Akagi

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.UTD-323, (Released:2022-05-25)

被引用文献数

6

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In contrast to the progress in the research on physiological disorders relating to shelf life in fruit crops, it has been difficult to non-destructively predict their occurrence. Recent high-tech instruments have gradually enabled non-destructive predictions for various disorders in some crops, while there are still issues in terms of efficiency and costs. Here, we propose application of a deep neural network (or simply deep learning) to simple RGB images to predict a severe fruit disorder in persimmon, rapid over-softening. With 1,080 RGB images of ‘Soshu’ persimmon fruits, three convolutional neural networks (CNN) were examined to predict rapid over-softened fruits with a binary classification and the date to fruit softening. All of the examined CNN models worked successfully for binary classification of the rapid over-softened fruits and the controls with > 80% accuracy using multiple criteria. Furthermore, the prediction values (or confidence) in the binary classification were correlated to the date to fruit softening. Although the features for classification by deep learning have been thought to be in a black box by conventional standards, recent feature visualization methods (or “explainable” deep learning) has allowed identification of the relevant regions in the original images. We applied Grad-CAM, Guided backpropagation, and layer-wise relevance propagation (LRP), to find early symptoms for CNNs classification of rapid over-softened fruits. The focus on the relevant regions tended to be on color unevenness on the surface of the fruit, especially in the peripheral regions. These results suggest that deep learning frameworks could potentially provide new insights into early physiological symptoms of which researchers are unaware.

著者

Mikio Shiraishi Hideaki Asakuma

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.UTD-023, (Released:2018-11-23)

被引用文献数

1

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We monitored sugar accumulation profiles and developmental changes in fruit traits during the ripening process in pollination-constant non-astringent (PCNA)-type persimmon cultivars of ‘Akiou’, ‘Fuyu’ and ‘Taishuu’. As the fruit ripened, transverse and longitudinal diameter, fruit weight, soluble solids content (SSC), and flesh juiciness increased significantly, with a constant varietal ranking throughout the ripening process. Color development of ‘Akiou’ and ‘Taishuu’ seemed to be faster than that of ‘Fuyu’ during the initial stages of fruit ripening, but there was little difference in color chart values toward the latter stage of fruit ripening. Flesh firmness decreased steadily over time, whilst varietal ranking remained constant. The varietal ranking of SSC in the latter stage of ripening was ‘Akiou’ ≥ ‘Taishuu’ > ‘Fuyu’. Significant varietal differences were observed in sucrose, glucose, and fructose contents. Based on sugar accumulation profiles, the cultivars could be classified into two types: hexose accumulators (‘Taishuu’) and sucrose accumulators (‘Akiou’ and ‘Fuyu’). The transcriptional profiles of key sugar accumulation-related genes: sucrose synthase (SuSy), vacuolar acid invertase (VAI), and sucrose phosphate synthase (SPS), were also examined. Transcriptional levels of SuSy and VAI in sucrose accumulators were lower than those in the hexose accumulator. Conversely, transcriptional levels of SPS were higher in the sucrose accumulators than in the hexose accumulator. In particular, the concomitant and rapid increase of both SPS expression and sucrose accumulation in mid-October, suggests that this period is crucial for ‘Akiou’ in terms of the SSC elevation.

著者

Takuya Tetsumura Shuji Ishimura Takashi Takita Shogo Funaki Hiroharu Uchida Takumi Hidaka Syo Haranoushiro Yasuhiro Udatsu Mitsuhiro Matsuo Chitose Honsho Hideaki Asakuma

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.UTD-020, (Released:2018-10-26)

被引用文献数

6

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The field performance of ‘Taishuu’ Japanese persimmon trees grafted onto clonally propagated rootstocks, ‘MKR1’ and FDR-1, was investigated over 10 years. These results were then compared with the performance of trees grafted onto seedling stocks (S) and own-rooted trees derived from micropropagation (O-R). ‘Taishuu’ scions on ‘MKR1’ and FDR-1 rootstocks grew well initially, but stopped growing taller at seven years after planting. Total shoot length and trunk cross-sectional area (TCSA) increased annually in all trees, while the differences in these parameters between S or O-R trees and ‘MKR1’ or FDR-1 trees continued to increase year after year. The graft union of trees grafted onto ‘MKR1’ swelled, and FDR-1 rootstock overgrew the ‘Taishuu’ scion. Trees grafted onto both ‘MKR1’ and FDR-1 bore female and male flowers soon after planting, and the percentage of shoots with female flowers relative to total shoots in ‘MKR1’- and FDR-1-grafted trees were higher than that in S and O-R trees each year. The numbers of shoots with male flowers varied from year to year in ‘MKR1’- and FDR-1-grafted trees, but did not appear to increase yearly. ‘MKR1’- and FDR-1-grafted trees almost completely inhibited secondary shoot occurrence in mid-June, and the percentages of dropped fruitlets between the middle of May and the end of July were almost always lower for ‘MKR1’- and FDR-1-grafted trees than for S and O-R trees. Cumulative yield efficiencies according to TCSA, canopy area, and canopy volume showed that ‘MKR1’- and FDR-1-grafted trees produced fruit most efficiently, although the total yields per tree were not significantly different between rootstocks. There were no significant differences in fruit quality between the rootstocks, except for the number of seeds. Concentric cracking and stylar-end cracking occurred in fruit of trees grafted onto ‘MKR1’ and FDR-1. However, the differences between the rootstock types were not large. The harvest date of ‘MKR1’ trees was significantly earlier than that of S and O-R trees. In conclusion, ‘MKR1’ and FDR-1 are both satisfactory dwarfing rootstocks for ‘Taishuu’, with high yield efficiency and inhibition of early fruit drop.