Starch, mainly composed of amylose and amylopectin, is the major nutrient in grain sorghum. Amylose and amylopectin composition affects the starch properties of sorghum flour which in turn determine the suitability of sorghum grains for various end uses. Partial least squares regression models on near infrared (NIR) spectra were developed to estimate starch and amylose contents in intact grain sorghum samples. Sorghum starch calibration model with a coefficient of determination (R2) = 0.87, root mean square error of cross validation (RMSECV) = 1.57% and slope = 0.89 predicted the starch content of validation set with R2 = 0.76, root mean square error of prediction (RMSEP) = 2.13%, slope = 0.93 and bias = 0.20%. Amylose calibration model with R2 = 0.84, RMSECV = 2.96% and slope = 0.86 predicted the amylose content in validation samples with R2 = 0.76, RMSEP = 2.60%, slope = 0.98 and bias = −0.44%. Final starch and amylose cross validated calibration models were constructed combining respective calibration and validation sets and used to predict starch and amylose contents in 1337 grain samples from two diverse sorghum populations. Protein and moisture contents of the samples were determined using previously tested NIR spectroscopy models. The distribution of starch and protein contents in the samples of low amylose (<5%) and normal amylose (>15%) and the overall relationship between starch and protein contents of the sorghum populations were investigated. Percent starch and protein were negatively correlated, low amylose lines tended to have lower starch and higher protein contents than lines with high amylose. The results showed that NIR spectroscopy of whole grain can be used as a high throughput pre-screening method to identify sorghum germplasm with specific starch quality traits to develop hybrids for various end uses.

Use of trifluoromethanesulfonamide (TFMSA), a male gametocide, increases the opportunities to identify promising B‐lines because large quantities of F1 seed can be generated prior to the laborious task of B‐line sterilization. Combining TFMSA technology with genomic selection could efficiently evaluate sorghum B‐lines in hybrid combination to maximize the rates of genetic gain of the crop. This study used two recombinant inbred B‐line populations, consisting of 217 lines, which were testcrossed to two R‐lines to produce 434 hybrids. Each population of testcross hybrids were evaluated across five environments. Population‐based genomic prediction models were assessed across environments using three different cross‐validation (CV) schemes, each with 70% training and 30% validation sets. The validation schemes were as follows: CV1—hybrids chosen randomly for validation; CV2—B‐lines were randomly chosen, and each chosen B‐line had one of the two corresponding testcross hybrids randomly chosen for the validation; and CV3—B‐lines were randomly chosen, and each chosen B‐line had both corresponding testcross hybrids chosen for the validation. CV1 and CV2 presented the highest prediction accuracies; nonetheless, the prediction accuracies of the CV schemes were not statistically different in many environments. We determined that combining the B‐line populations could improve prediction accuracies, and the genomic prediction models were able to effectively rank the poorest 70% of hybrids even when genomic prediction accuracies themselves were low. Results indicate that combining genomic prediction models and TFMSA technology can effectively aid breeders in predicting B‐line hybrid performance in early generations prior to the laborious task of generating A/B‐line pairs.

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Six sorghum [Sorghum bicolor (L.) Moench] germplasm lines, Tx3483 through Tx3488 (Reg. no. PL-313 to PL-318, PI 698643 to PI 698648), are proposed for release by Texas A&M Agrilife Research. These lines were developed and tested by the Agrilife Research sorghum breeding and genetics program. Tx3483 through Tx3488 are pollinator parents that combine waxy endosperm with improved agronomic performance and grain functionality. In combination with a waxy endosperm seed parent, these lines produce waxy endosperm hybrids with consistently higher yield than the currently available waxy check hybrid. Additionally, some of these germplasms produce hybrids with improved grain composition and functional properties of the derived flour.

Sorghum [Sorghum bicolor (L.) Moench] germplasm lines Tx3489 (Reg. no. GP-943, PI 698649) and Tx3490 (Reg. no GP-944, PI 698650) with yellow seed, favorable agronomics, and popping attributes in hybrid combinations were developed by the Texas A&M AgriLife Research sorghum breeding and genetics program in 2020. Compared with a grain sorghum hybrid check, these lines produced hybrids with similar agronomic performance and superior popping performance. In hybrid combinations, the two lines produced hybrids comparable to the agronomic productivity of standard grain sorghum hybrids. Additionally, these two lines produced hybrids with 84 and 78% popping efficiency, 9:1 and 7.4:1 expansion ratios and 0.35-and 0.34-cm 3 flake sizes. In contrast, the check hybrid produced grain with 74% popping efficiency, 6.3:1 expansion ratio and a 0.25-cm 3 flake. Ultimately these two lines produce grain sorghum hybrids with comparable agronomic productivity and superior popping performance. While these lines can be used as pollinator parents to produce grain sorghum hybrids for popping, they may also be a parent for the development of new pop sorghum parental lines.