Development of aneuploids of pennisetum glauhum (l)r. br as a base for high density chromosome mapping

Abstract

Pennisetum glaucum (L) R.Br commonly known as pearl millet is a very important grain and fodder crop in the semi-arid tropics of the world. It is grown on 37.8 M ha in the world yielding annually 28.5 M mt of grain. It tolerates drought, low soil fertility, low soil pH and responds well to water and favourable soil conditions (Anand Kumar, 1989). Inspite of the importance of the crop and availability of large number of genetic markers (>145 mutants) linkage relationships are known for only 18 loci in seven linkage groups. These are (i) yn\ (yellow mutant) - lgni (light green mutant) - fs (female sterile) loci (Hanna et al. 1978), (ii) hi (hairy lamina) - hst (hairy stem) - hs (hairy sheath) - Hm (hairy leaf margin) loci (Krishna Rao and Koduru 1979), (iii) bl (bleached leaf) - gl (glossy trait) and (iv) ws (white sheath) - (y) yellow leaf (Appa Rao et al. 199.0), Manga et al. (1988) observed linkage (v) Pnj Pn2 (purple node) - Par] Par2 (purple auricle) (vi) purple midrib, margin and sheath with purple internode and purple apicule and (vii) 62 (dwarf) - Skdh A (Shikimate dehydrogenase) (Tostain 1985). Minocha and Sidhu (1979a and 1979b) determined the chromosomal location of 10 genes using a primary trisomic series. Of these two genes hi (hairy leaf) and Pg] (purple glume) on chromosome 1; three genes Br (bristled earhead), yst (yellow foliage striping), and Pp] (purple pigmented foliage) on chromosome 2; Pp2 (purple pigmented foliage) on chromosome 4; two loci Beb (branched earbase) and Rn] (purple node) on chromosome 5; and two other loci Bet (branched eartip) and Pg2 (purple glumes) on chromosome 6. Chromosome specific mapping of markers has been achieved by extensively using aneuploids in different crop plants.