Immature Tomato Research Articles

Sorption of Some14C-Herbicides by Isolated Plant Cells and Protoplasts

Isolated plant cells (Zinnia elegansJacq. leaf tissue) and protoplasts (immature tomato fruit,Lycopersicon esculentumMill.) were obtained by hydrolysis of pectic substances in the middle lamella and the primary cell wall, respectively. Both types of cells were stabilized in an inorganic salt solution and used to study absorption and distribution of four14C-herbicides. Intracellular distribution within the protoplast was determined by ultracentrifugation in a discontinuous Ficoll gradient. Marked absorption ofp-nitrophenyl-α,α,α-trifluoro-2-nitro-p-tolyl ether (fluorodifen) and α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine (trifluralin) by the isolated cells was observed; absorption increased with time. Trifluralin was retained within the cell more strongly than fluorodifen. Similar absorption patterns of fluorodifen and trifluralin by protoplasts were observed. Trifluralin was incorporated to a greater extent than fluorodifen by the cells and protoplasts. Trifluralin was distributed evenly between the mitochondrial and the chloroplasts-nuclei fractions; whereas fluorodifen was concentrated in the chloroplast-nuclei fraction. No significant absorption of 1,1-dimethyl-3-(α,α,α-trifluoro-m-tolyl)urea fluometuron) or 3-(4-bromo-3-chlorophenyl)-1-methoxy-1-methylurea (chlorbromuron) was detected by either the isolated cells or protoplasts.

Ethrel-induced ripening of immature and mature-green tomato fruits

Ethrel accelerated the ripening of both immature and mature-green ‘2029’ tomato fruits. The best concentrations and time of dipping used were 2500 to 10,000 ppm and 5 minutes, respectively. Addition of surfactants and DMSO did not markedly influence the effectivity of Ethrel. Ethrel-treated fruits harvested 21 and 28 days after fruit set ripened normally but 14 day old fruits did not.

Effects of Selected Herbicides on Plant Protoplasts

AbstractPlant protoplasts were released from immature tomato fruits by incubation with a 20% solution of polygalacturonase (Pectinol R‐10, Rhom & Haas) dissolved in 0.1 M KCl + 0.1 M MgCl2. In this salt solution the protoplasts remained stabilized for up to 8 h and were used as a source of exposed plasma membrane. Gross responses of protoplasts to selected chemicals and herbicides were recorded photomicroscopically.Paraquat (1,1′‐dimethyl‐4,4′‐bipyridinium ion) treatments resulted in a characteristic response which was different from that of general denaturants (trichloroacetic acid, ethanol, and detergents) and of osmotic shock. Initial phases of the paraquat response were characterized by a segregation of the cytoplasm into isolated areas on the inner membrane surface. The final phase was a rupture of the plasma membrane and collapse of the cell.The herbicides, 2,4′‐dinitro‐4‐trifluoromethyl‐diphenylether (preforan); 1,1‐dimethyl‐3‐(α,α,α‐trifluoro‐m‐tolyl)urea (fluometuron); 3‐(3‐chloro‐4‐bromophenyl)‐1‐methoxy‐1‐methylurea (chlorbromuron); and α,α,α‐trifluoro‐2,6‐dinitro‐N‐N‐dipropyl‐p‐toluidine (trifluralin) produced no apparent structural effect on the protoplasts.

Damage and repair of protein in gamma irradiated tomato fruit

Changes in the ratio of Trichloroacetic acid (TCA) soluble N/Total N were measured in pericarp tissue of tomato fruit of two stages of development, during the first 4 days following treatment with 200 krads. Immediately following irradiation there was a large increase in the ratio. Two days after irradiation the ratio for irradiated immature fruit had returned almost to that of the control fruit, whereas the ratio in nearly mature fruit remained unchanged between 1 and 4 days. The changes in the proportions of nitrogenous compounds soluble in TCA were interpreted in terms of change in protein and were related to previous observations on the age-dependent recovery of immature tomato fruit from the effects of irradiation.

The Effect of Crimson and High Pigment Genes on Color Development in Detached Immature Tomato Fruits

Abstract Harvesting mature-green tomatoesis common practice where they are grown commercially for the fresh market. Usually, the tomato fields are picked 4 to 6 times in a season, as the most mature fruits on the vine reach the mature-green stage. If mechanical harvesting becomes a reality for fresh market tomatoes, a once-over harvest will probably be used instead of the usual multiple pick. Yields will then be limited by the number of fruits mature enough at a given time to ripen off-vine and meet market standards for color. It will be imperative to grow a variety that has a concentrated set and whose fruits have good ripening ability when harvested prematurely.

The Effect of Crimson and High Pigment Genes on Color Development in Detached Immature Tomato Fruits

Abstract Harvesting mature-green tomatoesis common practice where they are grown commercially for the fresh market. Usually, the tomato fields are picked 4 to 6 times in a season, as the most mature fruits on the vine reach the mature-green stage. If mechanical harvesting becomes a reality for fresh market tomatoes, a once-over harvest will probably be used instead of the usual multiple pick. Yields will then be limited by the number of fruits mature enough at a given time to ripen off-vine and meet market standards for color. It will be imperative to grow a variety that has a concentrated set and whose fruits have good ripening ability when harvested prematurely.