Identification and Transfer of Heterotic Chromosome Blocks for Forage Yield in Short-Day Exotic Pearl Millet Landraces
- G. W. Burton and
- J. P. Wilson
Photoperiod sensitivity of pearl millet, Pennisetum glaucum (L.) R. Br., exotic accessions has limited their use in nontropical environmerits due to excess height and late maturity problems. Objectives of this research were (i) to describe and evaluate a modification of a direct method to screen non-converted short-day Burkina Faso landraces (BFL) of pearl millet for large heterosis-creating beterotic chromosome blocks (HCBs) that can replace a small HCB in the male parent T383 of the top producing F1 hybrid Tifleaf 2 and to increase its forage yield; and (ii) to determine the variation in the size of HCBs in a single landrace. Short early T383-1ike F2 plants in (BFL × T383) F2 populations were screened for HCBs by crossing them with T23Rp1, which carries the red marker gene, crossing those Fls on T85A 1cytoplasmic male sterile (cms) green 23], growing 100 spaced plants of the cross T85 × (BFL × T383) F2, cutting and weighing 50 of the red and 50 of the green plants in each population, and analyzing the data with the SAS General Linear Model. Percent heterosis for plant forage yield in 100-plant populations of each cross ranged from 0 to 51%. The average HCB heterosis for T383 was 4%. Sister plants within a single BFL were variable enough to make it important to cross a single BFL plant with T23Rp1 to measure HCB beterosis and with T265 (T383Rp1 to start the transfer of the top HCB to T383. The modification method requires an extra year before measuring HCBs, but requires a less variable 100-plant screening population and should require fewer backcrosses to transfer the top HCB to T383.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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