Abstract:

【Objective】 This experiment was carried out to elucidate the effects of salt stress on absorption, distribution and selective transport of Na+ and K+ in tomato plants. 【Method】 The absorption, distribution and selective transport of Na+ and K+in tomato plants under salt stress were analyzed by atomic absorption spectrometry. 【Result】 The results showed that with salt stress concentration and time increased, Na+ absorption of tomatoes increased, the fundamental order of accumulation in various organs was root＞stem＞leaf. The total accumulation of Na+ in salt-tolerant cultivar was lower than that in salt-sensitive one. Under salt stress, Na+ contents in tomato leaves, stems and roots were increased with the increase of NaCl concentration. Na+ contents in salt-tolerant cultivar were lower than that in salt-sensitive one. From the regional distribution of ions in the tomato plant, there was a higher Na+ proportion in rhizomes of salt-tolerant cultivar; the distribution of potassium was more focused in leaves. The salt-sensitive cultivar tended to allocate Na+ to the leaves. Under early salt stress, the salt concentration was 200 mmol•L-1 and more. The choice of K+ transport in tomato plants to shoot with the stress showed a downward trend. Below 200 mmol•L-1 showed a good alternative transportation, Sk/Na (transport) of salt-tolerant cultivar were higher than that of salt-sensitive cultivar. Root of salt-tolerant cultivar showed a greater K+ transport ability. 【Conclusion】 The lower Na+ content in leaves and better alternative transportation of K+ under salt stress are the most important characteristics of salt tolerant tomato varieties.

Key words: tomato, ion absorption, distribution, selective transport