Gibberellic Acid Protection against EMS and MMS Induced Damage to Chromosomes in Pisum sativum L

Abstract

Meiotic studies indicated that EMS (0.25%) and MMS (0.025%) induced a large number of aberrations such as reciprocal translocations comprising rings and chains of 4, 6 and 8 chromosomes; inversions consisting of chromosomal and chromatid bridges and fragements, laggards; and unequal distribution of chromosomes. In a few cases rings of 6 and 8 chromosomes were found in the same PMC, indicating that all the 7 pairs of chromosomes were labile to the action of these mutagens. Reduction in chromosome aberrations in M₂ and M₃ and a slight increase in M₃ over M₂ was observed in all treatments. Post treatment with gibberellic acid at 1000ppm effectively reduced the chromosomal damage in M₁ and was more effective in the case of MMS than EMS. The aberrations in M₂ and M₃ in gibberellic acid post-treated plants were decreased as compared to M₁ generation.