Breeding Potential of European Flint and U.S. Corn Belt Dent Maize Populations for Forage Use

摘要

Information about appropriate breeding populations and the type of forage maize (Zea mays L.) hybrids that should be developed for cooler regions of Europe is scarce. Our objectives were to determine the potential, performance, and heterosis of flint (F) and dent (D) populations as base germplasm for developing silage maize hybrids. Four U.S. Corn Belt dent populations which had been selected for early maturity and four European flint populations were included in our study. The eight populations, the 28 possible crosses among them, and topcrosses to inbreds A632 and EC18 were evaluated for stover, ear, and whole plant dry matter yield (DMY), as well as stover and whole plant dry matter content (DMC), digestible organic matter (DOM), and acid detergent fiber (ADF) content in northwest Spain. Means of F ?— D population crosses for stover and ear DMY (6.98 and 8.71 Mg haa?’1, respectively) were greater than those of D ?— D crosses (6.12 and 8.05 Mg haa?’1, respectively) and F ?— F crosses (6.03 and 7.64 Mg haa?’1, respectively). Average heterosis of whole plant DMY was greater for the F ?— D crosses (2.16 Mg haa?’1) than for the D ?— D and F ?— F crosses (0.23 and 0.56 Mg haa?’1, respectively). No significant heterosis was found for DOM and ADF of the stover and whole plant fractions. The only exception was a negative average heterosis of population BSSS-M for stover DOM. Results suggest that forage maize hybrids should be developed from the F ?— D heterotic pattern. Breeding strategies should include selection for stover DOM for both parent lines and hybrids because favorable recessive genes may be involved in this trait.