Salinity tolerant performance and genetic diversity of four rice varieties

The genetic diversity of three salinity tolerant rice varieties Pokkali, No na-Bokra and Bicol was investigated using random amplified polymorphic DNAs (RAPDs). Hi,oh yielding susceptible variety IR29 was used as check for com parison. The salinity performance of these varieties were tested by using r apid screening techniques at seedling stage. One hundred primers tested of which 42 revealed differences between Pokkali & Nonabokra, 43 between Pokka li st Bicol and 50 between Nonabokra and Bicol. Polymorphism differences be tween IR29 - Pokkali, IR29 - NonaBokra and IR29 - Bicol were 47%, 53% and 3 1%, respectively. Four primers amplified specific fragments that appeared i n all the three salt tolerant varieties but not in the salt susceptible var iety IR 29. Primer UBC 9 (5'-CCTGCGCTTA-3') produced a prominent diagnostic fragment of approximately 1600 bp; primer UBC 244 (5'-CAGCCAACCG-3') gener ated a fragment of about 800 bp in the salt-tolerant varieties; primer UBC 251 (5'-CTTGACGGGG-3') amplified one polymorphic band of 1100 bp and primer UBC 267 (5'-CCATCTTGTG-3') yielded a relatively weak polymorphic band of 1 100 bp.