alterations and observed that although ‘Oroval’ mandarin is enormously sensitive to calyx abscission, ‘Satsuma’ mandarin is to calyx browning. Color evolution. ‘Oronules’ fruits were harvested with a higher CI than the other cultivars: −1.81 and 4
Catarina P. Carvalho, Alejandra Salvador, Pilar Navarro, Adela Monterde, and Jose M. Martínez-Jávega
Valéria Santos Cavalcante, Renato de Mello Prado, Ricardo de Lima Vasconcelos, Hilário Júnior de Almeida, and Thais Ramos da Silva
them to nutrient accumulation at the end of their cultivation ( Costa et al., 2017 ). However, there is a need to link macronutrient deficiency with alterations in plant biological processes, such as those that affect nutrient absorption efficiency and
Julio G. Loaiza-Velarde, Francisco A. Tomás-Barberá, and Mikal E. Saltveit
Wounding during minimal processing of lettuce (Lactuca sativa, L.) induces alterations in phenolic metabolism that promote browning and the loss of quality. The activity of phenylalanine ammonia-lyase (PAL; the first committed enzyme in phenylpropanoid metabolism) and the concentration of phenolic compounds (e.g., chlorogenic acid, dicaffeoyl tartaric acid, and isochlorogenic acid) increase in excised iceberg lettuce midrib segments after wounding. The effect of short heat-shock treatments on browning and phenolic metabolism in excised midrib segments of iceberg lettuce was studied. As the heat-shock temperature increased from 20 to 70 °C, there was a decrease in the subsequent increase in PAL activity and the accumulation of phenolic compounds in excised midrib segments. Treatments of 45 °C for 120 s, 50 °C for 60 s, or 55 °C for 30 s significantly reduced the increase in PAL activity and subsequent browning seen in control tissue after wounding. Exposure to 45 °C for 480 s, 50 °C for 60 s, or 55 °C for 45 s prevented PAL activity from rising above initial levels. Phenolic compounds remained at initial levels for 3 days in excised midribs exposed to 50 °C for 90 s or to 55 °C for 60 s. However, 55 °C damaged the tissue, as indicated by a* and L* Hunter color values. The synthesis of chlorogenic acid, dicaffeoyl tartaric acid, and isochlorogenic acid was greatly reduced by these heat-shock treatments. These treatments also decreased polyphenol oxidase activity and, to a lesser extent, peroxidase activity.
Celso L. Moretti, Elizabeth A. Baldwin, Steven A. Sargent, and Donald J. Huber
Tomato (Lycopersicon esculentum Mill.) fruit, cv. Solar Set, were harvested at the mature-green stage and treated with 50 μL·L-1 ethylene at 20 °C. Individual fruits at the breaker stage (<10% red color) were dropped onto a solid surface to induce internal bruising. Dropped and undropped fruit were stored at 20 °C until red-ripe, at which time pericarp, placental, and locule tissues were excised. Tissues from dropped tomatoes were examined for evidence of internal bruising and all tissues were analyzed for selected volatile profiles via headspace analysis. Individual volatile profiles of the three tissues in bruised fruit were significantly different from those of corresponding tissues in undropped, control fruit, notably: trans-2-hexenal from pericarp tissue; 1-penten-3-one, cis-3-hexenal, 6-methyl-5-hepten-2-one, cis-3-hexenol and 2-isobutylthiazole from locule tissue; and 1-penten-3-one and β-ionone from placental tissue. Alteration of volatile profiles was most pronounced in the locule tissue, which was more sensitive to internal bruising than the other tissues. Changes observed in the volatile profiles appear to be related to disruption of cellular structures.
Jennifer K. Boldt and James E. Barrett
A daminozide plus chlormequat chloride tank mix spray was applied to six Coleus cultivars or breeding lines at different times during propagation. For UF 03-8-10 and `Coco Loco', plants sprayed on day 7 or day 10 were shorter than control plants at transplant, but plants sprayed on day 13 were not. Other cultivars did not respond to single applications. Five of the six cultivars responded to application on days 7 and 13. Plants of UF 03-8-3 and `Coco Loco' were significantly shorter than control plants at transplant. Plants of UF 03-8-10, UF 03-6-1, and UF 03-17-8 were shorter than control plants at 3 weeks after transplant. `Hurricane Louise' did not respond to the tank mix. A second study found a cultivar specific response to three chemical treatments applied as a spray on day 10 of propagation. At transplant, UF 03-8-10, UF 03-8-3, UF 03-6-1, and `Coco Loco' plants sprayed with the tank mix at 2500 plus 1500 mg·L-1, respectively, were significantly shorter than the control plants. A uniconazole spray at 2 mg·L-1 reduced elongation in UF 03-8-10, UF 03-8-3, and UF 03-6-1, compared to control plants. Ethephon at 250 mg·L-1 reduced elongation in UF 03-8-10, UF 03-8-3, and `Coco Loco' plants. None of the chemical sprays reduced elongation in `Hurricane Louise' at the concentrations applied. Ethephon increased axillary branching in all cultivars, and induced lower leaf abscission in UF 03-17-8 and `Hurricane Louise'; leaf malformation in UF 03-6-1 and `Coco Loco'; and color alteration in UF 03-6-1, UF 03-8-3, and `Coco Loco'.
Matthew W. Fidelibus, Karen E. Koch, and Frederick S. Davies
these were evident at or before differences in fruit color, and that GA 3 -based alterations in sugar levels persisted throughout the 54- or 58-d study. A longer-term involvement of flavedo hexoses (although not flavedo sucrose) was also indicated by
Alejandra A. Salgado and John R. Clark
structure at the end of the ripening process ( Brummell, 2006 ; Winkler et al., 2015 ). Alterations in the bonding between polymers along with degradation of polysaccharides can cause an increase in cell separation, softening, and swelling of the cell wall
Baniekal Hiremath Gangadhar, Raghvendra Kumar Mishra, Gobinath Pandian, and Se Won Park
blue) on plant growth and development, metabolites (total sugar, reducing sugar, starch, protein, and free amino acid), color, and pungency of fruit in chili pepper. Materials and Methods Plant material. Seeds of commercial chili pepper ( Capsicum
Hisayo Yamane, Megumi Ichiki, Ryutaro Tao, Tomoya Esumi, Keizo Yonemori, Takeshi Niikawa, and Hino Motosugi
for the analysis of tannin contents. Three fruits were used for this analysis. A fruit skin-color index that indicates similar developmental stages of the fruits has been developed for HTN (National Agricultural Research Station, Tsukuba, Japan
Aneta K. Studzinska, David S. Gardner, James D. Metzger, David Shetlar, Robert Harriman, and T. Karl Danneberger
( Allard et al., 1991 ; Wherley et al., 2005 ; Wilkinson and Beard, 1974 ). Alteration in spectral composition and specifically reduced R:FR further contribute to aforementioned morphological changes ( Casal et al., 1990 ; Dudeck and Peacock, 1992