9. Classification of rice germplasm from Iran through isozyme analysis

Ghorban Ali NEMATZADEH and G. S. KHUSH

International Rice Research Institute, Manila, Philippines

Majority of the local varieties of Iran possess excellent cooking and eating quality (intermediate amylose content, intermediate gel consistency and gelatinization temperature) and are aromatic. Local germplasm from Iran is classified into 3 groups namely Sadri, Champa and Gerdeh based on morphological traits. We used the classification scheme of Glaszmann (1987a) based on isozyme analysis to classify Iran varieties. The material comprised of 149 Iranian rice varieties obtained from Rice Germplasm Center, IRRI. Five isozyme loci (Pgi-1, Pgi-2, Amp-1, Amp-2, Amp-3) were studied for classification.

Starch gel electrophoresis was used in isozyme analysis. Crude extracts of water soluble proteins from plumule were loaded on the starch gel (14%) and subjected to electrophoresis. The zymograms were revealed following the staining procedure as given by Glaszmann et al. (1988). The results showed that 61.1% of the varieties belong to group V, 6.0% to group 1, 6.7% to group VI (Table 1). As many as 24.8% of the varieties did not fall in any group. Glaszmann (1987b) also reported that majority of the varieties from Iran belong to Group V. The occurrence of high frequency (24.8%) of unclassified varieties indicates that these may have resulted from intergroup hybridization. Most of the varieties classified as beloning to groups I and VI have foreign names and are probably introductions from other countries.


Table 1.  Varietal grouping of rice germplasm from Iran based on
         isozyme analysis
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Varieties   Group I   Group V   Group VI   Group 0   Mixed
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No.            9        91        10         37        2
%              6.0      61.1      6.7        24.8      1.3
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References

Glaszmann, J.C., 1987a. A varietal classification of Asian cultivated rice (Oryza sativa L.) based on isozyme polymorphism. International Rice Research Newsletter 12(3): 5-7.

Glaszmann, J.C., 1987b. Isozyme and classification of Asian rice varieties. Theor. Appl. Genet. 74: 21-20.

Glaszmann, J.C., B.G. delos Reyes and G.S. Khush, 1988. Electrophoretic variation of isozymes in plumules of rice (Oryza sativa L.)- a key to the identification of 76 alleles at 24 loci. Research Paper Series No. 134, International Rice Research Institute, Manila, Philippines.