In India, approximately 350 species of hardwoods provide leaf fodder that is almost as nutritious as fodder crops. Tree leaf fodder constitutes about one tenth of the total fodder consumption in the Indian hill country and is equally valuable in other areas during periodic scarcity of fodder crops. The nutritive value and fodder characteristics of most species are known, but detailed cytogenetic analyses have been limited. Cytogenetical screening of these species is desirable prior initiation of breeding programs, as chromosomal variation can exist within species.
Some tree fodder species have been subjected to cytogenetic investigations. Intraspecific chromosomal variation involving polyploidy occurs in 33 species, and dysploidy occurs in 40 species. Accessory chromosomes are known to exist in some populations of approximately 12 species. Polyploidy is important to fodder quality in some species. Triploids of Growia hainesiana, Morus alba and Populus alba exhibit good potential as leaf fodder. Polyploids of Aegle marmelos, Syzygium cumini and Terminalia chebula are superior as fodder to their respective diploid cytotypes. As natural polyploidy can associated with good fodder characteristics, artificial induction needs to be explored in taxa that are cytogenetically conservative.
Key words: cytogenetics, fodder, hardwoods, polyploidy.