Thermal Properties of Starch from 62 Exotic Maize (Zea mays L.) Lines Grown in Two Locations

Abstract

The variability in thermal properties among 62 S 3 lines derived from a high-yielding exotic corn (Zea mays) population, Antigua 1 (PI 484990), was evaluated by differential scanning calorimetry (DSC). The S 3 lines were grown in Puerto Rico (1990Rico ( -1991 and Georgia (1994). Separate single-kernel starch extractions for five kernels (five replicates) from each line grown in each location were performed, and the starch was analyzed. The DSC values reported included gelatinization onset (T oG ), range (R G ), enthalpy (ΔH G ), and peak height index (PHI) and retrogradation onset (T oR ), range (R R ), enthalpy (ΔH R ), and percent retrogradation (%R) (an indication of the stability of gelatinized starch after storing at 4°C for 7 days). Significant differences (P< 0.05) were found among the 62 lines of Antigua 1 for T oG , R G , and PHI and highly significant differences (P < 0.01) were found for ΔH G . The starches from plants grown in Georgia (1994) had significantly (P < 0.05) greater T oG , ΔH G , and PHI but a significantly lower R G than those from Puerto Rico (1990Rico ( -1991. These data suggest that the starch from plants grown in Georgia (1994) might have a greater degree of crystallinity than that from Puerto Rico (1990Rico ( -1991 The variability in thermal properties among 62 S 3 lines derived from a high-yielding exotic corn (Zea mays) population, Antigua 1 (PI 484990), was evaluated by differential scanning calorimetry (DSC). The S 3 lines were grown in Puerto Rico (1990Rico ( -1991 and Georgia (1994). Separate single-kernel starch extractions for five kernels (five replicates) from each line grown in each location were performed, and the starch was analyzed. The DSC values reported included gelatinization onset (T oG ), range (R G ), enthalpy (∆H G ), and peak height index (PHI) and retrogradation onset (T oR ), range (R R ), enthalpy (∆H R ), and percent retrogradation (%R) (an indication of the stability of gelatinized starch after storing at

Plant genetic resources: What can they contribute toward increased crop productivity?

“…The incorporation of exotic germplasm into adapted lines may give rise to additional hybrid vigor, lessening the chance for a yield plateau (26). In addition, several studies have demonstrated that exotic germplasm contains significant variation for many quality traits (27)(28)(29)(30). Because many of the genetic resources of maize have undergone extensive selection over centuries for indigenous uses such as feed, food, and beverages, it seems likely that abundant new grain qualities and characteristics remain to be discovered.…”

Resistant Starch and Starch Thermal Characteristics in Exotic Corn Lines Grown in Temperate and Tropical Environments

“…The Latin American Maize Project (LAMP) evaluated over 12,000 accessions for grain yield and agronomic data (Salhuana and Pollak 2006). Along with the agronomic evaluations, many accessions and related breeding materials have been analyzed for starch traits (White et al 1990;Campbell et al 1995Campbell et al , 1996Campbell et al , 2002Ng et al 1997;Pollak and White 1997). These studies indicated great potential for improving adapted corn for these traits by introgressing exotic materials.…”

Identification of QTL Controlling Thermal Properties of Maize Starch

“…These studies have included open pollinated populations (White et al 1990), a chemically mutagenized population (Yamin et al 1999), Corn Belt and exotic inbreds (Campbell et al 1995;Ng et al 1997a;Pollak and White 1997), and Argentinean landraces (Seetharaman et al 2001). The impact of agronomic practices on maize kernel starch properties has been examined as well (Campbell et al 1994;Ng et al 1997;Krieger et al 1998).…”

“…Many genes involved in starch biosynthesis have been isolated and characterized (reviewed by Kossmann and Lloyd 2000). Mutations in some of these genes have affected the thermal properties of starch (Wang et al 1993;Ng et al 1997a); however, there are very little data linking genes to the thermal properties of wild-type starch. Establishing these linkages is critical to breeding and biotechnology efforts directed to developing starch with improved thermal properties.…”