Evaluation of Heterotic Patterns among Caribbean and Tropical ✕ Temperate Maize Populations

Abstract

The integration of tropical maize (Zea mays L.) germplasm into template breeding programs has been difficult and slow. More information on performance of temperate ✕ tropical populations and their heterotic combinations is needed. This study was conducted to compare heterotic patterns among four populations. Two, a Caribbean flint and a Caribbean dent, are useful in the tropics and have potential for temperate areas; the other two are temperate ✕ tropical populations adapted to the tropics. The four populations, their diallel crosses and reciprocals, and a commercial hybrid check were grown in two locations in Puerto Rico during two winter‐season environments. The best heterotic combination among the four populations was between the Caribbean flint and dent. The best‐yielding population per se was the temperate ✕ tropical population of Reid (Group B) heterotic pattern. The Caribbean flint population had highly significant negative maternal effects for yield. Both reciprocal crosses of the temperate ✕ tropical populations were low yielding. The results indicated that, for temperature breeding programs, both Caribbean populations should be useful for improving Corn Belt maize.

Incorporating different proportions of exotic maize germplasm into two adapted populations

“…Michelini and Hallauer (1993) showed a midparent heterosis of 89.6% with Suwan-1 (BR 105) in the Corn Belt when crossed with the improved BS13(S)C4 derived from BSSS. BR 105 is primarily Caribbean germplasm that has been exploited in Brazil as one half of the common heterotic pattern with BR 106 (Tuxpeño), but there are results showing the potential of Suwan as a Corn Belt heterotic group (Goodman, 1985;Pollak et al, 1991).…”

“…Most results relate to the usefulness of crosses between exotic x adapted germplasm (Eberhart, 1971;Gerrish, 1983;Oyervides-Garcia et al, 1985;Holland and Goodman, 1995), the estimates of genetic parameters (Goodman, 1965;Hallauer and Sears, 1972;Sheata and Dhawan, 1975;Santos and Miranda Filho, 1992), and the determination of heterotic patterns (Holley and Goodman, 1988;Mungoma and Pollak, 1988;Pollak et al, 1991;Godshalk and Kauffmann, 1995;Uhr and Goodman, 1995;Eschandi and Hallauer, 1996).…”

Conversion of elite subtropical maize germplasm to temperate environments

“…The utilization of exotic maize germplasm has been difficult and slow because of a lack of information on the performance of temperate by exotic populations and their heterotic patterns . Attempts have been made to identify temperate by adapted exotic combinations that exhibit heterosis (Gerrish, 1983;Mungoma and Pollak, 1988;Pollak et al, 1991;Echandi and Hallauer, 1996).…”

“…Diallel analysis has been used in adapted environments to investigate the heterotic potential of adapted exotic material crossed to U. S. Com Belt material (Gerrish, 1983;Mungoma and Pollak, 1988;Echandi and Hallauer, 1991;Pollak et al, 1991), and, in exotic environments, to identify the heterotic potential of exotic crosses for use in tropical and temperate breeding programs (Crossa et al, 1990;Beck et al, 1991). Gerrish (1983) indicated the use of temperate-adapted exotic germplasm would allow direct evaluation of F1 racial combinations under temperate zone conditions.…”

Heterosis and heterotic patterns among maize landraces for forage

“…According to Crossa et al (1990), in the Americas there is a tremendous genetic diversity in maize, as a result of thousands of years of evolution under domestication and hybridization, which has not been effectively exploited. Many authors have suggested the usefulness of incorporating exotic germplasm into breeding programs (Eberhart 1971, Hallauer and Miranda 1981, Oyerbides-Garcia et al 1985, Holley and Goodman 1988, Mungoma and Pollak 1988, Iglesias and Hallauer 1989, Pollak et al 1991, Michelini and Hallauer 1993, Rodrigues and Chaves 2002, Carena 2005, Soengas et al 2006. Thompson (1968) found that a group of exotic and semi-exotic populations yielded on average 28% more digestible dry matter than adapted hybrids, and Stuber LC Gabriel et al (1986) suggested that some semi-exotic materials might be suitable for silage, given their good grain production and great vegetative development.…”