Isozyme classification of Myanmar rice cultivars resistant to bacterial blight

The analysis of five isozyme loci ; Pgi-1. Pgi-2. Amp-1, Amp-2, and Amp-3 identified Isozyme types (Isotypes) for the cultivars resistant to bacterial blight (BB) in Myanmar. The results indicated that all the cultivars of Cas 209 group (Xa-10), TKM 6 group (Xa-4), and Mond Ba group (Xa-4 + Xa-10) belonged to Isotype I, whereas the cultivars of Java 14 group (Xa-3) were in Isotype V. The cultivars of DZ 192 group (Xa-5) were classified either into IsotypeI or intermediates. These intermediates were considered as an intermediate of IsotypeI and Isotype II. The morphological observations revealed that IsotypeI of DZ 192 group was different from IsotypeI of Cas 209 group and of TKM 6 group. The algorithm survey of Cas 209 group and TKM 6 group found that the most frequent algorithms used in the two groups were different, and that Amp-14 was specifically predominant in Cas 209 group, whilst TKM 6 group was consisted of Amp-11 only. The distribution of Amp-14 had remarkable concordance with the distribution of Cas 209 group in Asia. The cultivars of TKM 6 group tended to involve wider range of phenotypes and the distribution in Asia is also wide. These results indicated that the origin of Cas 209 group and TKM 6 group might be different