Varietal Differences in the Salinity Tolerance of Forage Rice in the Early Growth Stage

Abstract

We investigated varietal differences in the salinity tolerance among four forage rice varieties, ‘Nishiaoba', ‘Hoshiaoba',‘Tachiaoba', and ‘Mohretsu', for 35 days after transplanting by pot-culture experiment. Seedlings at 16 days after sowing were transplanted in saline and paddy field soils detecting EC at 0.98 and 0.21 mS/cm, respectively. In saline soil conditions,all varieties except for ‘Mohretsu' showed growth disorder at 100% in both ‘Hoshiaoba' and ‘Nishiaoba', followed by 50% in ‘Tachiaoba', while no visible phenomenon for the disorder appeared in ‘Mohretsu'.In saline soil conditions, shoot dry weights for all varieties also decreased compared with paddy field soil conditions, in the order from the lowest at 7% in ‘Tachiaoba', followed by 11% in ‘Nishiaoba' and 19% in ‘Hoshiaoba', while ‘Mohretsu' decreased by only less than 50%. These results suggest that ‘Mohretsu' should have highest salinity tolerance at least in the early growth stage among the examined varieties.