Stand establishment in processing carrots – Effects of various temperature regimes on germination and the role of salicylates in promoting germination at low temperatures

Abstract

Rajasekaran, L. R., Stiles, A. and Caldwell, C. D. 2002. Stand establishment in processing carrots -Effects of various temperature regimes on germination and the role of salicylates in promoting germination at low temperatures. Can J. Plant Sci. 82: 443-450. The effects of various temperature regimes on carrot seed germination and the possibility of hastening germination at a low temperature using salicylates were studied. Seeds were incubated at various temperatures viz., 25, 20, 15, 10, 5 and 2°C. Salicylates such as, 2,6-dihydoxybenzoic acid (DHBA), acetylsalicylic acid (ASA), salicylic acid (SA) were supplied at 0, 1, 10, 100 and 1000 mg L -1 continually to the seeds incubated at 25 and 5°C until germination. Data on germination percentage were collected, and vigor value was calculated. Incubating seeds at various low temperature regimes significantly and proportionately reduced germination percentage and vigor value. The highest cumulative germination and vigor value was observed at 25°C. Critical threshold temperature for germination (GT 50 ) was 5°C. Seed treatment using salicylates hastened germination at 5°C. 2,6-dihydoxybenzoic acid 1, ASA 100 and SA 1 mg L -1 all were effective in hastening germination at 5°C. Among all the salicylates, ASA 100 mg L -1 was the most effective in advancing germination at 5°C. Salicylates at the highest concentration of 1000 mg L -1 inhibited germination significantly both at 25 and 5°C.

Response of barley grains to the interactive e.ect of salinity and salicylic acid

“…In addition, the germination percentage of seeds under salinity stress was markedly higher with SA application than without, especially at the highest stress level of 200 mM NaCl (Figure 1). These results are consistent with those of Rajasekaran et al (2002) and Shakirova et al (2003) who showed a promotion in seed germination with SA application.…”

Effect of salicylic acid and salt on wheat seed germination

“…The exogenous application of SA may influence a range of diverse processes in plants, including seed germination, ion uptake and transport, and membrane permeability. These results are consistent with those of Rajasekaran et al (2002) and Shakirova et al (2003), who showed that seed germination is promoted by the application of SA. Gutierrez-Coronado et al (1998) have also reported a similar increase in the growth of shoot and roots of soybean plants under normal conditions in response to SA treatment.…”

Role of salicylic acid in acclimation to low temperature

“…Further studies proved that not only SA, but also its putative precursors, benzoic acid (BA) and ortho-hydroxy-cinnamic acid (oHCA), and other related compounds such as aspirin or 2,6-dihydroxy BA may have a protective role against chilling stress in young maize plants Horváth et al, 2002). Similarly, not only SA, but other related compounds, such as 2,6-dihydroxy BA or aspirin (acetyl-SA), hastened the germination of carrot seeds at 5°C (Rajasekaran et al, 2002). It should also be mentioned, however, that these compounds, like SA, may cause severe damage to the plants when applied above a certain concentration at normal growth temperature: a significant decrease was detected in the photosynthetic capacity and the growth rate.…”