Heterosis in locally adapted sorghum genotypes and potential of hybrids for increased productivity in contrasting environments in Ethiopia

Increased productivity in sorghum has been achieved in the developed world using hybrids.Despite their yield advantage,introduced hybrids have not been adopted in Ethiopia due to the lack of adaptive traits,their short plant stature and small grain size.This study was conducted to investigate hybrid performance and the magnitude of heterosis of locally adapted genotypes in addition to introduced hybrids in three contrasting environments in Ethiopia.In total,139 hybrids,derived from introduced seed parents crossed with locally adapted genotypes and introduced R lines,were evaluated.Overall,the hybrids matured earlier than the adapted parents,but had higher grain yield,plant height,grain number and grain weight in all environments.The lowland adapted hybrids displayed a mean better parent heterosis(BPH) of19%,equating to 1160 kg ha-1and a 29% mean increase in grain yield,in addition to increased plant height and grain weight,in comparison to the hybrids derived from the introduced R lines.The mean BPH for grain yield for the highland adapted hybrids was 16% in the highland and 52%in the intermediate environment equating to 698 kg ha-1and 2031 kg ha-1,respectively,in addition to increased grain weight.The magnitude of heterosis observed for each hybrid group was related to the genetic distance between the parental lines.The majority of hybrids also showed superiority over the standard check varieties.In general,hybrids from locally adapted genotypes were superior in grain yield,plant height and grain weight compared to the high parents and introduced hybrids indicating the potential for hybrids to increase productivity while addressing farmers' required traits.

Analysis on the Combining Ability and Heritability of Main Agronomic Traits of Hybrid Glutinous Sorghum

Using 3 sterile lines and 12 restorer of glutinous sorghum as experimental materials,36 hybrid combinations（3×12 NCⅡ） were designed to analyze the combining ability and heritability of six main agronomic traits,including plant height,panicle length,growth period,1 000-grain weight,per panicle grains and per panicle grain weight.The results showed that except per panicle grain number all other five agronomic traits have remarkable or extremely remarkable general combining ability and specific combining ability.Six agronomic traits were found to be control by additive genetic effect.Most of these agronomic traits are more easily influenced by restorers than sterile lines,suggesting that more attention should be paid to select restores in hybrid glutinous sorghum breeding.The narrow-sense heritability of these agronomic traits were in order growth period plant height per panicle grain weight panicle length 1 000-grain weight per panicle grains.