| Tomato is moderate salt-tolerant plant, which can tolerate a certain degree of salt stress. However, the scope for tomato growth is becoming narrow with the levels of salinity increasing, so it's great significance to development of tomato industry by researching salt tolerance of tomato. Six cultivated tomatoes were used in this study, these tomato seeds were treated under different Na2SO4 concentrations (0, 0.03, 0.06, 0.09, 0.12mol/L), Effect of Na2SO4 salt stress on germination of tomato seeds would be researched. In tomato seedlings, treated with another different concentrations of Na2SO4 (0, 0.1, 0.2, 0.3, 0.4mol/L), In order to observe influence of Na2SO4 salt stress on biochemical and physiological index of tomato seedling stage; in field experiments, those plants were treated with salt stress in tomato reproductive phases, and effect of salt stress on fruit yield, yield per plant and quality traits of maturity were measured during fruit maturity. The main findings are as follows:Tomato seed germination was inhibited under Na2SO4 stress.With increasing salt concentration, germination time extended, and each germination rate were shown a downward trend. Germination rate of the same or different species under different salt treatment were significantly different.The analysis of morphologic characters of tomato of Na2SO4 stress during seedling stage show that: compared with the control, the tomato plant height, stem diameter, dry weight with salt stress of Na2SO4 were constrained; but low concentrations of salt stress would favored the growth of young tomato plants, with the exception of HDL height which was lower than that of the control, the other species were higher than those of its in 0.1mol/L of Na2SO4 salt stress; It is a great influence on seedling dry weight of Na2SO4 stress, the greater the concentration, the smaller the seedling dry weight, In addition that the(WFS and HDL) two varieties were indistinctive when compared with control in 0.1mol/L, there are significant differences at the rest salt stress. There are significant differences of the dry weight of seedlings of the other species were compared with their control. EC increased with the increase of salt concentration, EC of all the six species reached a maximum at 0.4mol/L. So we can see from the test that the three varieties YPY, HDL and QF have quite strong salt tolerance.Analysis of physiological and biochemical indexes of tomato under Na2SO4 stress during tomato seedlings period shows that: total chlorophyll content had a rapid decline with increasing of concentration of Na2SO4; and MDA content was increasing and reached a maximum in 0.4mol/L; the content of proline in tomato activity change was close to the CK at low concentration of salt stress, the content of proline in all varieties respectively were increasing 50.41%, 74.88%, 461.47%, 375.11%, 497.27% and 136.41% than CK in 0.4mol/L of Na2SO4 salt treatment, HDL had the largest increase, the smallest is the FC; with an increase in salt concentration, the SOD enzyme content of FC, SJX and WFS showed second peak value, and their change had a similar trends. The other species showed a downward trend when the concentration increasing, and reached a minimum in 0.4mol/L.The analysis of maturing tomato fruit yield and quality traits on Na2SO4 stress showed that. With the concentration increased, fruit weight and yield per plant showed a decline trend; There was no difference about that of the other species except that fruit shape index of the (HDL and YPY) two tomato varieties were significantly different in the different salt stress conditions; The firmness of tomato fruit went up at high salt concentration while went down at low salt concentration ; The firmness of fruit of six tomato species were up to the minimum in 0.3mol/L Na2SO4 concentration while reached the maximum in the 0.4 mol/L Na2SO4 concentration; The content of total soluble matter of the six tomato changed with a single apex curve when treated with salinity concentration varied from 0.1 to 0.4 mol/L; Tomato fruit soluble sugar and organic acid content, as well as vitamin C, the content of lycopene showed different trends when the Na2SO4 concentration increasing. Compared with the contrast, soluble sugar and organic acid in fruit increased,the ratio of sugar to acid decreased. The yield of tomato fruit decreased under salt stress of Na2SO4, the firmness,the content of total soluble matter and organic acid in tomato fruit changed with the treatments, affected the change of vitamin C, lycopene and shape index which lead to changes of quality of tomato fruit.
|
PDF Full Text Request