COMBINING ABILITY AND HETEROSIS STUDIES FOR YIELD AND WATER USE EFFICIENCY IN FORAGE SORGHUM [SORGHUM BICOLOR (L.) MOENCH] TOPCROSSES UNDER NORMAL AND WATER STRESS ENVIRONMENTS
MINAL GOYAL, R.K. BAJAJ, B.S.GILL AND R.S. SOHU
Department of Plant Breeding and Genetics,
Punjab Agricultural University, Ludhiana, India.
(email: minalgoyal@rediffmail.com)
(Received: 16 December 2013; Accepted: 27 December 2013)
SUMMARY
Sorghum is an important fodder crop of Punjab during Kharif season. There is deficiency of fodder during this season and increase in productivity through hybrid breeding is an effective solution. As water stress is one of the major causes for crop losses worldwide therefore there is a need to breed for more water use efficient genotypes. To achieve the objective 15 male sterile lines were crossed to four random mating populations to generate 60 topcrosses to study combining ability and heterosis for forage yield and physiological traits affecting water use efficiency (WUE) under two environments viz., normal (N) and water stress (S). Based on general combining ability (gca) effects, male sterile lines viz., 2077A, NSS1007A, NSS1008A and population RSSV-9 were good general combiner parents for green fodder yield and WUE under both the environments. Two top cross hybrids 94002A x RSSV-9 and NSS1007A x Ramkel had high sca effects and significant heterosis over commercial check Punjab Sudax Chari (PSC-1) for green fodder yield and WUE traits in both the environments. As the released interspecific hybrid PSC-1 faces seed production problems under Punjab conditions, these two high yielding and water use efficient, intraspecific hybrids will help to overcome the problem of hybrid seed production.
Keywords: Forage sorghum, environments, combining ability, heterosis