Indian Journal of Genetics and Plant Breeding (The)
SCOPUSWeb of Science
  • Year: 1978
  • Volume: 38
  • Issue: 3

Genetic Analysis of some Exotic x Indian Crosses in Sorghum XX. Genotypic Differences for Root Activity

  • Author:
  • R. Damodar, I.V. Subba Rao, N.G.P. Rao
  • Total Page Count: 10
  • Page Number: 421 to 430

National Research Centre for Sorghum and All India Coordinated Sorghum Improvement Project IARI-Regional Station, Rajendranagar, Hyderabad, 500 030 (A.P.)

1Present Address: Agricultural Research Station, Adilabad (Andhra Pradesh).

2Present Address: Andhra Pradesh Agricultural University, Rajendranagar, Hyderabad 500 030 (Andhra Pradesh).

Abstract

The studies reported comprised varietal differences in relation to root activity using radio-active tracer 32p.

1. Improved dwarf varieties of sorghum, which are mostly derived from exotic x Indian crosses, two commercial hybrids and their parents, and the tall Indian variety ‘Aispuri’ exhibited distnct patterns of root activity at knee-high and flowering stages. The differences were pronounced at the knee-high stage, the root activity of dwarfs being more at the surface at 5 cm lateral distance (L1) and in deeper layers at 10 cm (L2) and 20 cm (L3) lateral distances. In case of the tall parent, while the root activity was relatively deeper at L1, at L2 and L3 the activity was relatively superficial.

At flowering the genotypic differences for root activity were not significant. The interactions E × V, L × V and E × L × V were highly significant at both stages. In the selection of genotypes, seedling vigour for root activity, differences due to vertical depths and the interactions E × V, L × V and E × L × V should be given weightage.

2. The patterns of root activity of hybrids and high yielding varieties exhibited similarities in certain respects. The improved variety ‘302’ appears to be most tolerant to drought followed by ‘CSH-1’ and ‘Swarna’. The root activity correlated well with varietal performance in All India Trials.

3. Phosphorus accumulation in hybrids and high yielding varieties followed a similar trend. While there was a decreae in leaf phosphorus in parents and the Indian variety ‘Aispuri’ at flowering, the P content in the flag leaf increased in the high yielding hybrids and varieties. Increasing accumulation of leaf P at flowering compared to knee-high stage may be used as a criteria for selection of high yielding varieties.