• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.4
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• pp.371-376
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• 1993

This experiment was conducted to elucidate the salt tolerance mechanism of crop plants. Plants used in this experiment were rye, barley, Italian ryegrass. Seeds were treated at saline condition and the saline conditions were controlled by NaCl. The results were summerized as follows. In rye, germination ratio and speed were above 90% and 80% at NaCl concentrations below 0.5% but germination ratio was seriously decreased at NaCl concentration above 0.6%. In barley germination ratio was not less than 80% at NaCl concentration below 0.8%. In italian rye grass germination ratio was decreased gradually by increasing NaCl concentration but germination speed was seriously decreased at NaCl concentration above 0.6% as not more than 7.5%. Water absorption rate was low in barley than rye and it was decreased by increasing NaCl concentration and duration of absorption. In barley, carbohydrate content was decreased slightly in response to increased NaCl concentration and content of reducing sugar was independent of NaCl concentration. In rye, reducing sugar content was increased until 0.3% of NaCl and increased seriously after 20 hours. $\beta-Amylase activity was high at control and 0.6% lot of NaCl, but it was not general tendency.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.4
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• pp.413-419
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• 1995

This study was conducted to find out the suitable NaCl concentration and temperature for investigating the varietal difference of salinity tolerance in Italian ryegrass. Seeds of 20 cultivars including 9 diploid and 11 tetraploid were exposed to eight levels of NaCl concentration ranging from 0 to 350mM under three temperature levels of 15, 20 and $25^{\circ}C$. The NaCl concentration(C50%) inhibited germination of 50% of the viable seeds for the cultivars at 15$^{\circ}C$ was 354mM, and those at 2$0^{\circ}C$ and $25^{\circ}C$ were 342mM and 325mM, respectively. There were significant correlations among C50% at three levels of temperature, and correlation coefficient for C50% between 2$0^{\circ}C$ and 15$^{\circ}C$ was higher than that between $25^{\circ}C$ and 15$^{\circ}C$ or 2$0^{\circ}C$. C50% was positively correlated only with germination speed at 10 days after sowing when the plants were exposed to 350mM NaCl at 2$0^{\circ}C$. For the germination speed at 10 days after sowing in 350mM NaCl at 2$0^{\circ}C$, the cultivars used could be classified into three groups. Wase Aoba, Bettina, E. K -11, Tetrone, Lira Sand, Tetra Florum and Billiken belonged to the tolerant group, and Tuchi Was, Wase Yutaka, Sakura Wase, Magnolia, Limella and Delita were as the semi-susceptible group, and Atalja, Barmultra, Ajax, Liberta, LM-16, Elving and Wilo were as the susceptible group.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.3
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• pp.365-370
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• 1995

This study was conducted to obtain the basic information on salinity tolerance in Italian Ryegrass. Seeds of 20 cultivars that contained diploid(9 cultivars) and tetraploid(l1 cultivars) types were exposed to eight levels of NaCl concentration ranging from 0 to 350 mM under three levels (15$^{\circ}C$, 2$0^{\circ}C$ and $25^{\circ}C$) of temperature. There were highly significant differences in germination percentage among the levels of NaCl concentration, levels of temperature and cultivars, respectively. Average germination percentage of cultivars in control(no NaCl was higher at 2$0^{\circ}C$(90.1%) than that of $25^{\circ}C$(87.8%) or 15$^{\circ}C$(87.5%). Average germination percentage of cultivars began to decrease over 200mM of NaCl concentration. The degree of decrease in germination was higher at $25^{\circ}C$ than that of 15$^{\circ}C$ or 2$0^{\circ}C$. At 2$0^{\circ}C$, the germination percentage and gemination speed were gradually decreased as NaCl concentration increased. The average germination day was lengthened by the increase of NaCl concentration and temperature. The germination percentage in diploid types were higher than that of tetraploid types but the average germination day in diploid types was shortened more than that of tetraploid types, regardless of temperature and NaCl concentration.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.3
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• pp.340-350
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• 1995

This study was conducted to obtain the basic information for the salt stress of Italian Ryegrass. Fourteen cultivars including 7 diploid and 7 tetraploid were subjected to eight levels of NaCl treatments during germination and early seedling stages. Germination percentage decreased remarkably over 300mM of NaCl concentration. The NaCl concentration that inhibited germination of 50% of the viable seeds in the cultivars was 344mM. The decreasing degree of germination percentage was higher in tetraploid type than in diploid type. The varietal difference of germination percentage was shown to be very conspicuous as the NaCl concentration increased. Top dry weight in 166 mM NaCl was decreased by 50% compared with that of control. Inhibition of NaCl appeared to be more in early seedling stage than in germination stage. Top dry weight of cultivars in NaCl stress was not related with germination capacity. Root dry weight in 148mM NaCl decreased by 50% compared with that of control. Root dry weight of cultivars was significantly correlated with top dry weight in NaCl treatment. Top dry weight and root dry weight was higher in diploid type than in tetraploid type at each 8 levels of NaCl concentration. Total chlorophyll content increased with the increase of NaCl concentration and the degree of increase in chlorophyll a was higher than that in chlorophyll b. Chlorophyll a was higher in tetraploid type than in diploid type. But chlorophyll b was higher in diploid type than in tetraploid type. There were significant correlation between chlorophyll a and top dry weight of cultivars over 150mM of NaCl concentration. Free proline content accumulated remarkably in NaCl treatment compared with control and was not difference between diploid type and tetraploid type. Free proline content of cultivars was not related with top dry weight in NaCl treatment.