Heterosis in landrace-based topcross hybrids of pearl millet across arid environments |
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Authors: | OP Yadav E Weltzien-Rattunde FR Bidinger V Mahalakshmi |
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Institution: | (1) Central Arid Zone Research Institute, Jodhpur, 342 003, India;(2) International Crops Research Institute for the Semi-Arid Tropics, Patancheru, 502 324, India |
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Abstract: | This study quantified the magnitude of heterosis in pearl millet (Pennisetum glaucum) topcross hybrids produced by crossing 16 diverse landraces and three high yielding open-pollinating varieties on two homozygous
male-sterile lines. Hybrids and pollinators were grown in 12 year ×;location combinations in India that were grouped into
three zones. Genetic components of variance quantifying the differences among these hybrids were estimated. The hybrids showed
a conspicuous heterosis for grain yield, earliness and biomass yield but not for straw yield. The level and direction of heterosis
for time to flowering depended strongly on the earliness of the male-sterile line. In the terminal drought stress zone hybrids
made on the early maturing male-sterile line 843A had the highest level of heterosis for grain yield (88%). This was partly
due to escape from terminal stress. In the other two zones the heterosis for grain yield was on average 30%. Heterosis for
biomass yield and biomass yield per day was on average also positive in all three zones. For all traits, except time to flowering
and biomass yield per day, pollinator effects were the only significant source of variation. Differences between hybrids were
mostly caused by additive genetic effects. Significant amount of heterosis observed in landrace-based topcross hybrids for
grain yield and other productivity-related traits suggested that substantial improvement in pearl millet productivity in and
environments can be obtained by topcrossing locally adapted landraces on suitable male-sterile lines.
This revised version was published online in July 2006 with corrections to the Cover Date. |
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Keywords: | genetic variance heterosis landrace Pennisetum glaucum stress environments topcross hybrids |
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