محاصيل الغلال
MANIFESTATIONS OF HETEROSIS IN GRAIN
SORGHUM
By A. E. KAMBAL and E. H. ABU-EL-GASIM*
Faculty of Agriculture, Sliambat, Sudan
(Accepted 9 May 1975)
SUMMARY
The magnitude of heterosis for 15 characters was studied in ten sorghum hybrids, produced by crossing ten restorer varieties with male-sterile Combine Kafir 60 as a common female parent. The most evident expressions of heterosis were higher yield and increased vegetative growth, often assoc-iated with delay in owering. The increase in yield oi" the hybrids over their superior parents, ranging from 35 to ^3*1%, resulted mainly from an increase in number of grains per head, rather than from an increase in the weight of individual grains. The regressions of hybrids on male parents, and the correlations of yield with other characters were studied, and the prospects ot producing adapted hybrids for the Sudan are brielly discussed. Several workers have reported on heterosis in sorghum (e.g. Bartel, 1949; Qjiinby et al.y 1958; Kambal and Webster, 1966; Blum, 1970). The higher productivity of the hybrids compared to jheir parents was often associated with increased vegetative growth and late maturity, although in some cases the hybrids were more productive and at the same time earlier than their parents.^
The commercial exploitation of heterosis in sorghum has resulted in substantial yield increases in U.S.A., India and elsewhere, but in the Sudan, where sorghum
is the main food crop, work on hybrid sorghum has been very limited. None of the American hybrids tested in the Sudan out-yielded improved local varieties
(Tahir, 1964; Mahmoud, 1970), and it was thought logical to probe the possibilities of producing higher-yielding hybrids from local material. The present investi-
gation was therefore undertaken to study the manifestations and magnitude of heterosis in a set often sorghum hybrids, produced by crossing ten restorer varieties (seven local and three exotic) with male-sterile Combine Kafir 60 as a common female parent.
