There was an accumulation of total free amino acids (calculated as the sum of the individual amino acids) in corollas from cut ‘Sonia’ roses (Rosa hybrida) stored at 2C (cold-stored flowers) but not in those kept at 20C (control flowers). In cold-stored flowers, senescence was retarded, as indicated by only a slight opening of the corolla and no subsequent petal abscission. Hence, there appeared to be no direct correlation between senescence of cut roses and accumulation of total amino acids in corollas; neither was there a relationship between individual or total free amino acids and protease activity in the corollas from either cold-stored or control flowers. Changes in the contents of all free amino acids, except alanine and lysine, were affected by cold storage. The effect on aspartic acid was statistically significant, but not spectacular. Cold storage delayed the decrease in contents of glutamic acid, asparagine, tyrosine, glycine, leucine, isoleucine and valine, and prevented accumulation of phenylalanine, proline, and histidine. We detected only one theoretically expected interconversion between two amino acids; i.e., glutamic acid to proline, that occurred in corollas from control flowers during the first 6 days of storage. We suggest that the patterns of changes in the contents of tyrosine, valine, isoleucine (or isoleucine plus leucine), and phenylalanine are not restricted to the cultivar Sonia.
Cornus sericea L. rooted cuttings were held in cold storage for 60 days and then transferred to a growth chamber in hydroponic culture. Roots and shoot tips were sampled during storage and through resumption of vegetative growth. Samples were analyzed for abscisic acid (ABA), indole-3-acetic acid (IAA), zeatin, zeatin riboside, glucose, fructose, sucrose, and starch. Budbreak was associated with increasing levels of the cytokinins and IAA, and decreasing levels of sucrose and starch in the shoot tips. Regeneration of new roots was preceded by an increase in the cytokinins and IAA, and a decrease in ABA in roots. Root sucrose increased nearly two times 1 week after budbreak and starch content generally decreased throughout the experiment. The results agree, in general, with previous reports indicating decreasing levels of ABA and increasing levels of cytokinins to be associated with root regeneration and budbreak. They also indicate that, of the four carbohydrates studied, sucrose levels changed most dramatically during the root regeneration and budbreak processes.
the entire surface of the berries to the environment during cold storage ( Fig. 1B ). The DADs were 3D-printed (PETG; 6 g) and consisted of two assembly parts, the body (parallelepiped: 86 × 63 × 2 mm) and the baskets (truncated cone: 21 × 17 mm
Mature green tomatoes (cv. Vibelco) were stored at 2°C for 2, 3, and 4 weeks. Intermittent warming treatments for 12, 24, and 36 hours at 24°C were applied at the end of every week. Control Fruit were held continuously at 2°C. All fruit were subjected to poststorage ripening at 24°C for 7 days. Fruit decay, chlorophyll and lycopene content, fruit firmness, pH, TSS and TA were detected after storage or 7 days after transfer to 24°C. Results were compared between control and intermittently warmed fruit when stored at 2°C for 2, 3, and 4 weeks. Compared to fruit kept continuously at 2°C, intermittent warming at 24°C for 12, 24, and 36 hours reduced decay, increased chlorophyll disappearance, lycopene synthesis, and fruit firmness, enhanced pH and TSS, and declined TA. Fruit intermittently warmed for 36 hours/week showed the least decay, higher chlorophyll disappearance, and lycopene synthesis; retention of fruit firmness, pH, and TSS; and lower TA than fruit intermittently warmed for 12 and 24 hours/week. Decay percentage, lycopene content, pH, and TSS were increased from 2 to 4 weeks, but chlorophyll content, fruit firmness, and TA were declined.
Kiwifruit (Actinidia chinensis Planch, cv. Hayward) shoot tip cultures were stored in the dark successfully at 8°C. After a year, their fresh weight had increased 8-fold and they produced more shoot tips than at the start of storage. Storage was less successful at 4°. Chemical names used: 1H-indole-3-butanoic acid (IBA), N 6-benzyla-minopurine (BAP).
Seeds of 25 blackberry (Rubus spp.), five red raspberry (R. idaeus L.), and two black raspberry (R. occidentalis L.) populations that had been stored for 22 to 26 years were planted in the greenhouse to evaluate their germination. Germination ranged from 0% to 84% among all populations. Thorny and thorny × thornless blackberry populations had the highest average germination; most populations had >40% germination. Thornless blackberry populations ranged from 1% to 16% germination. The seeds of two of the five red raspberry populations did not germinate and none of the black raspberry seeds germinated.
Fruit of peach (Prunus persica (L.) Batsch) exhibited rehardening when returned to low-temperature storage after softening at room temperature. Rehardening was progressively more pronounced as the temperature decreased. The process occurred in either air or nitrogen atmosphere. The softening of the fruit that occurred normally at room temperature was accompanied by a decline in protopectins and a concomitant increase in water-soluble pectic fraction. By comparison, the rehardening of the fruit at low temperatures was accompanied by little or no change in pectic substances. The results suggest that rehardening is not related to the metabolic changes associated with fruit ripening.
Hardwood cuttings from canes of highbush blueberry (Vaccinium corymbosum L.) collected in early dormancy and stored at 2°C until spring rooted better than cuttings collected in the latter part of the winter. Cuttings placed immediately in a greenhouse propagation structure rooted and grew poorly when collected before mid-December but if collected after mid-December produced plants up to two-fold larger than spring-rooted plants after 1 growing season due to the extended growing period.
`Fantasia' nectarines (Prunus persica L.Batsch) were either stored immediately at 0.5C or subjected to a 48-h delay at 20C in air or with 5% CO2 in air before storage. Samples were evaluated at harvest and after 18, 25, 32, 39 and 46 days storage in air or in 5% O2 with 0%, 4%, 8%, or 12% CO2. All samples were evaluated at optimum ripeness. A combination of delayed storage and elevated CO2 in storage effectively delayed chilling injury (CI) symptoms. Control of CI increased with increasing CO2 level in delayed and nondelayed treatments. Delayed storage was not effective without elevated levels of CO2 in the storage atmosphere. Fruit that was stored without delay did not soften normally during the ripening period and developed a dry, rubbery texture. The effect was enhanced as CI progressed, resulting in increased firmness of ripened fruit with increased storage time. The delayed storage treatments softened normally during ripening, but CI fruit had a dry, mealy texture. Internal conductivity measurements correlated well with CI development. Off-flavors were detected at the higher levels of CO2 storage.
The virulence of Mucor mucedo (L.) Fr. (the cause of mucor rot) and Botrytis cinerea Pers. (gray mold) on vegetables stored at 13C for 7 days or 1C for 70 days varied with the host and controlled atmosphere (CA). M. mucedo was severely pathogenic at 13C to cucumber (Cucumis sativus L.), eggplant (Solarium melongena L. var. esculentum Nees), pepper (Capsicum annum L.), and tomato (Lycopersicon esculentum Mill.), but not to bean (Phaseolus vulgaris L.). The fungus did not infect carrot (Daucus carota L. var. sativa DC.), celery (Apium graveolens L. var. dulce DC.), onion (Allium cepa L.), or parsnip (Pastinaca sativa L.) at 1C. B. cinerea was virulent on all of these crops at 13 or 1C. The severity of mucor rot and gray mold on eggplant stored at 13C for 14 days was suppressed most in a CA of 7.5% CO + 1.5% O2 and least in 1.5% 02, in comparison with the air control. Similarly, the growth and sporulation of each pathogen on eggplant-extract agar maintained at 13C for 4 or 14 days were suppressed most in 7.5% CO + 1.5% O2; suppression was least in 1.5% O2. The suppression of diseases on eggplant was highly correlated with the suppression of mycelial growth and sporulation of pathogens on agar.