Induced chlorophyll mutations, mutagenic effectiveness and efficiency in Lathyrus sativus L.

The spectrum and frequency of chlorophyll mutations was assessed in M2 generation in P27, an improved cultivar of Lsthyrus sstivus with a range of gamma rays (50, 100, 150, 200, 250, 300, 350 and 400 Gy) and ethyl methane sulphonate [EMS 0.5% (2h & 4h), 1% (2h & 4h)] doses. Both, gamma rays and EMS induced a wider spectrum of chlorophyll mutations. Certain chlorophyll mutations such as chlorina, followed by chlorotica and xantha were found more frequently than others, indicating preferential induction of certain type of mutations. Fairly high frequency of chlorophyll mutants was obtained with EMS than in gamma rays. Dose dependent increase in chlorophyll mutation rate was observed based on plant population and segregating progenies in M2 generation. Majority of segregating progenies yielded only one type of chlorophyll mutation and with an increase in the number of mutational events frequency of segregating families reduced. Both mutagenic effectiveness and efficiency were higher at lower doses of the mutagen. Mutagenic effectiveness, a measure of the frequency of mutations induced per unit dose of mutagen, and mutagenic efficiency, proportion of mutations in relation to undesirable effects, were higher with EMS treatments indicating EMS as more effective and efficient mutagen than gamma rays.