Cd2+ + Cr6+ causes toxic effects on chromosomal development of microspore in Carthamus tinctorius

Abstract Intra-category hybrids of Carthamus tinctorius were analyzed for the genetic toxicity in detail for effect of Cd2+ + Cr6+ on reproductive biology of Carthamus tinctorius. Five partially tolerant and five non-tolerant accessions of Carthamus tinctorius after screening were crossed to produce intra-category hybrid. These two heavy metals in combination influenced antagonistically first as well as second meiotic divisions inducing various kinds of anomalies and reduced the number of pollen grains per anther and significantly increased pollen sterility. A differential response for the amount of meiotic irregularity was recorded between different treated sets of hybrids in (Cd + Cr) treated sets. This could be due to differential response of the genotypes for the same concentration of (Cd + Cr). These two heavy metals in combination reduced the number of pollen grains per anther and significantly increased pollen sterility.