Designer Sorghum: Combining the High Digestible and Waxy Traits for Improving the Endosperm of Sorghum.

Sorghum (Sorghum bicolor (L). Moench) is used for human consumption in parts of Africa and Asia and as an animal feed mainly in the U.S. Though sorghum grain contains higher amounts of protein than other cereal grains such as wheat and corn, it is not as readily available for enzyme degradation in humans and animals. Starch in the sorghum grain is bound by a protein body matrix, as such, it also requires more energy and time to hydrolyze into fermentable sugars for biofuel production. The sorghum line P850029 has a higher protein digestibility (HD) compared to other normal grain sorghum lines, which might be due to rearrangement of kafirins. In the HD line, the γ-kafirins are rearranged in the seed endosperm and the amount of γ-kafirin in the grain is also reduced. A population derived from P850029 X ‘Sureno', recombinant inbred lines (RILs) were developed and used in HD QTL identification. A single QTL was identified on chromosome 1 between Xtxp43 and Xtxp329. Fine mapping the identified QTL is being done using near-isogenic lines (NILs). NILs contrasting at a QTL can be developed by selection within heterogeneous inbred families (HIFs).  Moreover, the relation between endosperm traits and grain yield in sorghum has not been understood. We studied effect of different endosperms on the yield parameters in three locations across Texas in three replications at each location. HD, Waxy, HD/Waxy and wild-type line were included in the study. Waxy lines have starch completely in the form of amylopectin. The results show that there are no significant differences in the grain yield, but there are significant differences among HD, waxy, HD/waxy and wildtype lines in test weight, head weight and 100 kernel weight.