Frequency and spectrum of induced chlorophyll mutations in Triticum dicoccum

Manju GUPTA, M.P. SINGH¹⁾ and C.S. KALIA

Division of Genetics, Indian Agricultural Research Institute, New Delhi 12, India

Dry seeds of eight hybrid varietal selections of T. dicoccum having 10-11% moisture content, were exposed to different dosages of gamma rays (10 kr, 15 kr and 20 kr). Seeds of two selections, i.e. H.W. 85 and H.W. 84 were treated with EMS also. The studies were undertaken in order to investigate (a) the relation of radiation effects to dose rate, (b) frequency and spectrum of induced chlorophyll mutations with gamma rays and EMS treatments and (c) cytogenetical implications of lethality of chlorophyll deficient plants. The results obtained indicate that in most of the cases there is linear correlation between dose rate and chlorophyll mutation percentage (Table 1). Progenies giving higher sterility in M₁ gave maximum number of chlorophyll mutants in M₂ (Table 1). Spectrum of chlorophyll mutation is wide in gamma irradiated progeny and albina type was a pre-dominant class in all the treatments, irrespective of the varietal genotype involved (Table 2). Cytological observations confirm that the albina type (white) owe their origin to gross chromosomal rearrangement.

(Received February 4, 1969)