Effect of Drought Stress on Productivity of Trichomeless Pearl Millet
- Glenn W. Burton ,
- Craig S. Kvien and
- Bryan W. Maw
The trichomeless gene, tr, has been shown to modify the cuticle of pearl millet, Pennisetum glaucum (L.) R. Br., and, thus, has the potential to affect drought resistance. Near-isogenic lines, Tift 23D2B1 tr tr (trichomeless) and Tift 23D2B1 Tr Tr (trichomed), were compared in eight replications of a randomized complete block design on Tifton loamy sand (fine-loamy, siliceous, thermic Plinthic Paleudult) and Norfolk sand (fine-loamy, siliceous, thermic Typic Paleudult) in 1982, a season with good rainfall distribution. Trichomeless 23D2B1 outyielded trichomed 23D2B1 25.0% (P < 0.01) on the Norfolk sand but failed to increase forage yield on Tifton loamy sand. Near-isogenic populations 85D2B1 trichomeless and 85D2B1 trichomed were compared under a rain shelter to create drought stress. In a 2-yr comparison under the rain shelter, the trichomeless 85D2B1 population produced 13.6% (P < 0.01) more dry matter than the trichomed 85D2B1 population. In the 1986 Tifton loamy sand test that was naturally water stressed by only 290 mm rainfall during the 98-d test period (74% of the 46-yr average) the trichomeless 85D2B1 population produced 10.7% (P < 0..01) more dry matter and 23.0% (P < 0.01) more seed heads than the trichomed 85D2B1 population. Thus it appears that the recessive tr gene can be used to increase the yield of pearl millet under drought stress.
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