Simultaneous Improvement of Downy Mildew Resistance and Agronomic Traits in Tropical Maize uri icon

abstract

  • Downy mildew (DM) of maize (Zea mays L.), caused by Peronosclerospora spp., is a problem in lowland tropics, particularly in Southeast Asia. This study was conducted to measure progress from selection in DM resistance (DMR) and other agronomic traits in four broad-based tropical maize populations. Selection among and within S1 and S2, families was based on responses in DM nurseries at Suwan, Thailand, and at the University of Southern Philippines Agricultural Research Center (USMARC), Philippines. Bulks of C0, C1, C2, and C3 of the four populations were evaluated for reaction to DM in disease nurseries and for agronomic traits under disease-free conditions at Suwan and USMARC. Correlations for DMR between Suwan and USMARC, based on C1-S1 and C3-S1 progenies of each population, were highly significant, positive, but low. Results indicate that the selection scheme used resulted in simultaneous and highly significant improvement of levels of DMR (- 11.0% cycle-1) and grain yield (507 kg cycle-1) over the four populations.

publication date

  • 1993
  • 1993