Heterosis in crosses between landraces and elite exotic populations of pearl millet [Pennisetum glaucum (L.) R. Sr.] in arid zone environments

Abstract

Stress-adapted landraces of pearl millet [Pennisetum glaucum (L) R. Sr.] are prevalently grown in the drought prone regions of northwestern India. This study evaluated 12 crosses between selected landraces and elite composites along with 7 parental populations for two years in arid zone environments. There was significant genetic variation among test entries which was due to variation due to parental populations, crosses and 'parent VB. cross'. Landraces and elite exotic composites represented two contrasting, but complementary, groups of genetic material. Landraces produced the greatest amount of biomass and stover yield with lowest harvest index while elite composites had the lowest biomass and stover yield with highest harvest index. Crosses produced almost as high biomass as landraces but their better partitioning resulted into highest grain yield in them. Manifestation of heterosis in crosses varied for different characters. Grain yield was the most heterotic trait with mean heterosis of 17% and other traits viz., days to flowering, plant height, panicle length and harvest index were far less heterotic with mean heterosis ranging between 2-4%. Data indicated that significant heterosis for total biomass is very critical in order to obtain simultaneously improvement in both grain and stover yields. The expression of grain yield heterosis in the best crosses was realized through differential expression of heterosis in various yield-contributing traits.