تاثیر سطوح مختلف شوری بر عملکرد و اجزای عملکرد ارقام اصلاح شده برنج

Mazandaran province is an important area in rice cultivation but salinity is one the biggest constraint to obtain crop potential yield in some part of the coastal line of rice cultivated area in northern Iran. In order to find tolerant varieties and study the reaction of some newly released high yielding varieties to different levels of salinity of irrigation water a Factorial experiment was conducted in a RCD in a greenhouse at the Rice Research Institute of Iran, Amol station. 8 varieties, cultivated in pots, were tested with 3 levels of salinity (2, 4 and 6 dS.m-1) along with control (S0: EC=1 dS.m-1) with 3 replications. Results showed that salinity had adverse effects on yield, number of tillers per pot, filled and unfilled spikelets, fertility, 100 grain weight, but increased number of unfilled tillering. Relative yield in salinity treatment in comparison with fresh water were 23, 63 and 85 percent, respectively. The average of rice yield loss threshold was calculated 1.3 dS.m-1. In average, number of panicle and no. of filled spikelets accounted for 80 and 59% of total variation of grain yield, but it decreased by increasing in salinity level. There was a high correlation between yield and number of panicle and grain weight per panicle. The results showed that the yield in each salinity level could be predicted by number and weight of panicle (r2= 0.85)