Eighty years of Brassica Cytogenetics

Abstract

Cytogenetical researches on Brassicas were initiated with the determination of chromosome number (1916-1930) and genome analysis by Morinaga and U (1928-1935) leading to unravelling the genetic archetecture of crop Brassicas. Spactacular progress has been achieved sence then. These include: 1. Characterization of somatic and pachytene chromosomes, 2. Artificial synthesis of alloploids through sexual and somatic hybridizations for enhancing the variability, 3. Extensive investigations on wild germplasm, classify into cytodemes, and synthesis of a large number of hybrids through sexual and somatic routes, 4. Synthesis of alloplasmics of crop specis for expression of male sterility based on very diverse cytoplasm, 5. Introgression of nuclear genes through chromosome manipulations for conferring agronomic advantages and fertility restoration for CMS, 6. Dissection of basic genomes for developing chromosome addition lines and identifying gene linkage groups and compairing gene synteny between related species, and, 7. Use of molecular markers for chromosome mapping and analyzing genomic relationships.