SO2 Tolerance Research Articles

Photosynthesis and respiration of feather mosses fumigated at different hydration levels with SO2

Fumigation with SO2 of the three feather mosses Pleurozium schreberi, Hylocomium splendens, and Ptilium crista-castrensis results in an immediate decline in their rate of photosynthesis but has no effect upon respiration. Pleurozium schreberi is the most sensitive of the three species, even though they all take up the same amount of SO2. Thus, the feather moss species appear to have similar degrees of SO2 avoidance (uptake) but dissimilar degrees of SO2 tolerance. With increasing desiccation, respiration declines equally in all three species, but photosynthesis declines most rapidly for P. schreberi. The immediate effects of SO2 upon photosynthesis of water-limited and of fully hydrated feather mosses are similar, but after a 24-h recovery period in an SO2-free environment photosynthesis remains impaired only in those mosses fumigated in the fully hydrated state. This probably is related to the larger amounts of SO2 absorbed by hydrated mosses.

Quality of Muscadine Grapes after Storage with Sulfur Dioxide Generators1

Abstract Nine cultivars/selections of muscadine grapes (Vitis rotundifolia Michx.) were stored for 49 days at O°C in 6 liter telescoping, corrugated-cardboard shipping containers with polyethylene liners, and 3 types of commercially available SO2 generators. Susceptibility to decay during storage varied greatly among selections (7 to 82% decay without SO2). The SO2 generators produced up to 29 ppm SO2 and all 3 types reduced decay. The genotypes also varied widely in their tolerance of SO2. Placement of newspaper in the shipping containers reduced the concentrations of SO2, reduced SO2 damage to the fruit by up to 74%, and had an inconsistent influence on the development of decay. Fruit of selection NC 67A015-17 appeared to be the best suited for long-term storage.

Studies ON THE TOLERANCE TO SULPHUR DIOXIDE OF GRASS POPULATIONS IN POLLUTED AREAS

SUMMARY Dactylis glomerata, Festuca rubra, Holcus lanatus, Lolium perenne and Phleum bertolonii were collected from one or more of three sites with differing pollution characteristics in the north of England, and screened for tolerance to both acute and chronic sulphur dioxide injury in comparison with either bred cultivars or individuals of the same species collected from clean areas. Selection for tolerance was detected in all species and at all sites, suggesting that this is widespread in the field.Differential response to chronic injury was manifested as effects on senescence, dry matter production, and/or partition of assimilate between roots and shoots. No correlation was found between the degree of acute and chronic injury at either the intraspecific or interspecific levels, which may indicate independent physiological mechanisms for these. Tolerance may evolve within 17 to 25 years. The significance of the evolution of SO2 tolerance for grasslands at polluted sites is discussed.

Effect of SO2on Sexual Reproduction in Lepidium virginicum L. Originating from Regions with Different SO2Concentrations

Tolerance of SO2 with respect to sexual reproduction is reported for populations of Lepidium virginicum from the Copper Basin of Tennessee, a region subjected to SO2 pollution for the past 75 yr. The offspring of plants from inside and outside the Copper Basin were fumigated with 2,130 μg/m3 SO2 for 9 h at high relative humidity in replicated experiments. As a result of SO2 stress, plants from outside the Copper Basin were less fertile than plants from inside the Copper Basin.

Evolution of sulphur dioxide tolerance in perennial ryegrass

THE combustion of fossil fuels for domestic and industrial purposes, coupled with rapid industrial growth over the past 150 years, has resulted in sulphur dioxide becoming an integral part of the environment. Extensive research into the effects of sulphur dioxide on vegetation began in the 1920s, but the possibility of evolution of tolerance has only recently received attention, in spite of the implications of this for the overall effect of SO2 in the field. We present here data that provide strong evidence for the evolution of SO2 tolerance in a perennial ryegrass population from an urban area of Merseyside, UK.