Analysis of the genetic behavior of some starch properties in indica rice ( Oryza sativa L.): thermal properties, gel texture, swelling volume.

Starch comprises about 90% of milled rice, so that the eating and cooking quality of rice is mainly affected by the starch properties. In the present paper, we analyzed the genetical behavior of gelatinization temperature tested by differential scanning calorimetry (DSC), gel texture, and the swelling volume (SV) of indica rice with an incomplete cross of 4x8 parents. A genetic model which can dissect the effects of triploid seed, the cytoplasm, and the maternal plant on the endosperm traits was used. The results indicated that peak temperature (T(p)), conclusion temperature (T(c)) and enthalpy (DeltaH) were controlled by three types of genetic effects: seed direct (endosperm) effects, cytoplasmic effects and maternal effects. No cytoplasmic effects for the onset temperature (T(o)), hardness and SV, and no maternal effects for cohesiveness were found. The additive variances ( V (A)+ V (Am)) were larger than the dominance variances ( V (D)+ V (Dm)) for all the traits except for T(c), which suggested that selection could be applied for the starch properties in early generations. The total narrow-sense heritability for each parameter was over 60%, indicating that selection advances were predictable in the early generations for these traits.