BGN 10: Evaluation of gamma-ray induced mutants and correlation studies in barley (Hordeum vulgare L.) BARLEY GENETICS NEWSLETTER, VOL. 10, II. RESEARCH NOTES
Prasad et al., pp. 58-61

II. 25. Evaluation of gamma-ray induced mutants and correlation studies in barley (Hordeum vulgare L.).

G. Prasad, S.N. Singh, D.P. Dwivedi, and Hari Pal. Department of Agricultural Botany, S.D.J. Post Graduate College Chandeshwar, Azamgarh (U.P.) 276128, India. "R"

The potential of induced mutations in genetic studies as well as in practical plant breeding is very well realized by scientists (Gustafsson 1963, Nilan 1964, Gaul 1965, Hagberg and Persson 1968, Gustafsson et al. 1971, Sigurbjörnsson 1975). Mutation breeding experiments were started in 1975 at this institution and several mutants were isolated from the mutagen treated population of barley. The present study was made with nine gamma-ray induced mutants in barley variety Jyoti, in M4 generation, to evaluate them and to study the correlations between different characters. The nine mutants CM 243, CM 244, CM 247, CM 256, CM 264, CM 277, CM 278, CM 283 and CM 329 and the parent variety Jyoti were grown in an RBD using 3 replications. Observations were made on twelve characters given in Table 1.

Table 1. Mean values of different characters.

Statistical analysis revealed that the mutants differed significantly from the parent variety Jyoti as well as among themselves. Mean values of different characters and critical differences are presented in Table 1. Eight of the mutants were smaller than Jyoti in plant height. The mean values of some characters increased in some mutants while decreased in others, as compared to Jyoti. Leaf width greatly decireased in CM 243, CM 244 and CM 247 and leaf index increased in many cases. Four of the mutants produced significantly higher grain yield per plant than the parent variety Jyoti. The increment in grain yield over Jyoti was 33% in CM 256, 48% in CM 278, 57% in CM 329 and 60% in CM 264. The Table 1 indicated that the increased grain yield in these mutants was either due to increased number of productive tillers or increased number of grains per ear or both. CM 256 and CM 278 are semidwarf mutants and therefore they may prove resistant to lodging to some extent.

Phenotypic, genotypic and environmental correlation coefficients were computed among the 12 characters in all possible combinations (Table 2). Genotypic correlation coefficients were found to be greater than phenotypic correlation coefficients (Table 2). Grain yield per plant was positively correlated with length of spike, leaf width, plant height, number of grains per ear, 100-grain weight and number of productive tillers; however, the phenotypic correlations of grain yield with the latter two characters were insignificant. Test weight (100 grain weight) was positively correlated with plant height but negatively correlated with the number of productive tillers. Number of grains per ear was found to be a more important yield component than the test weight of grains and productive tillers. There was a positive correlation of grains per ear with plant height, length of spike with and without awn, number of stem internodes and leaf width. Positive correlation of leaf width was also observed with length of spike with and without awn and number of stem internodes. Leaf index (length/width ratio) was negatively correlated with all the characters, including grain yield and its component characters, indicating that wide-leaved plants should have better yield because wide leaf provides greater photosynthetic area as compared to narrow leaf. Environmental correlation between grain yield per plant and number of productive tillers was present in an appreciable magnitude and it was positive. Very high negative environmental correlation was obtained between grain yield per plant and grains per ear, between leaf width and leaf index and between 100-grain weight and leaf width.

Table 2. Phenotypic (rph), genotypic (rg) ant environmental (re) correlation coefficients.


Gaul, H. 1965. The concept of macro- and micro-mutations and results on induced micro-mutations in barley. The use of Induced Mutations in Plant Breeding. (Report of FA0/IAEA Tech. Meet., Rome, 1964). Radiation Bot. (Suppl.):407-428.

Gustafsson, A. 1963. Productive mutations induced in barley by ionizing radiations and chemical mutagens. Hereditas, 50:211-263.

Gustafsson, A., A. Hagberg, G. Persson, and K. Wilkund. 1971. Induced mutations and barley improvement. Th. Appl. Genet., 41:239-248.

Hagberg, A. and G. Persson. 1968. Induced mutations in barley breeding. Hereditas, 59:396-412.

Nilan, R.A. 1964. The cytology and genetics of barley (1951-1962). Monographic Suppl. No. 3. Res. Studies, Washington State Univ. Press. pp. 278.

Sigurbjörnsson, B. 1965. The improvement of barley through induced mutations. Proc. 3rd Int. Barley Genet. Symp. Garching, 7-12 July, 1975. Barley Genet. III:84-95.

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