2018 Volume 83 Issue 3 Pages 311-316
Chromosome counts including analyses of male meiosis and pollen fertility have been made on 36 accessions of 10 Lactuca species collected from the western Himalayas. L. orientalis (2n=18) and L. undulata (2n=18) have been counted chromosomally for the first time from India and the counts in other species confirmed previous counts. The study also adds the existence of intraspecific diploid cytotype for L. orientalis. B-chromosomes have been reported for the first time in the accession of L. hastata. Cytomixis has been detected in some accessions of L. dolicophylla, L. macrorhiza and L. scariola. Consequent to cytomixis, the accessions were depicted some pollen sterility. Based on compiled chromosomal information it is apparent that dysploidy in conjugation with polyploidy seems to play an important role in the evolution of genus the Lactuca seems to be polybasic (x=5, 8, 9, 17), and x=8 and x=9 seem to be the most common and favored base numbers.
