ABSTRACT
Food engineering, food chemistry, and consumer segmentation were used to evaluate ready-to-eat rice. The aromatic Louisiana Clearfield Jazzman (CJ) and Thai Jasmine (TJ), and a non-aromatic parboiled (PB) rice were hydrated during the first 10 min of processing with reciprocal agitation followed by static retort processing. The aroma compound, 2-Acetyl-1-pyrroline (2-AP) was more heat-stable in CJ than TJ rice but decreased 15-fold compared to the rice cooker method. Pareto analysis indicated that rice type and agitation had the main effect on amylose and total starch and chroma and hue. Color differences of rice agitated during hydration and between rice cooker or static retort processed rice, indicated only slight differences for each rice variety. Hydration of dry rice during retort cooking and similar starch, color, and aroma quality were achieved with reciprocal compared to static or rice cooker methods. Survey responses categorized consumers into three, mindsets driven by rice consumption, convenience, or packaging.
ABSTRACT
BACKGROUND: Aroma is an important grain quality trait in rice, controlled by mutations within the BADH2 gene. The trait is simply inherited, and its importance in variety development makes it a practical target for marker-assisted selection in applied breeding programs. The predominant functional mutation within BADH2, an 8-bp indel, can be reliably detected using a PCR-based assay, but the available assays and associated genotyping platforms are insufficient for large-scale applied molecular breeding applications and are not compatible with outsourcing genotyping services. RESULTS: We first characterized SNP diversity across the BADH2 gene in a collection of 2932 rice varieties to determine the number of gene haplotypes in O. sativa. Using 297 gene-based SNPs, 11 haplotype groups were detected, and subsequently identified a minimal set of nine informative SNPs that uniquely identified the BADH2 haplotypes. These nine SNPs were developed into KASP assays and used to examine a panel of 369 U.S. rice accessions. The panel represented modern breeding germplasm and included all known aroma pedigree sources in U.S. rice. Six haplotypes were detected within the U.S. panel, of which two were found in majority (85%) of varieties. A representative set of 39 varieties from all haplotype groups was evaluated phenotypically to distinguish aromatic from non-aromatic lines. CONCLUSION: One haplotype (Hap 6) was found to be perfectly associated with the aromatic phenotype. A single KASP SNP unique to Hap 6 was demonstrated to reliably differentiate aromatic from non-aromatic rice varieties across U.S. germplasm.
ABSTRACT
Potassium (K) has an important impact on physiological and biochemical processes in plants. Soybean, Glycine max (L.) Merrill, requires high K availability for optimal yield. However, changes in nutrient availability in plants may also affect herbivore population size and/or development. Soybean looper, Chrysodeixis includens (Walker) (Lepidoptera: Noctuidae), is one of the most destructive pests of soybean in the southern United States. In this study, we evaluated the effects of different K fertilization rates on soybean looper development, soybean seed weight, and soybean seed nutritional quality. Soybean plants were supplied with six different rates of K fertilizer (0, 33.6, 67.3, 100.9, 134.5, and 168.1 kg/ha as K2O). Soybean leaves were sampled at R1, R3, R5, and R6 stages and fed to soybean looper in laboratory bioassays. Soybean looper mortality, fecundity, and fertility were not significantly affected by feeding on leaf tissues of soybean treated with different potassium fertilizer rates. However, soybean looper consumed more leaf tissue and spent less time completing larval development when fed on foliage from treatments of 134.5 and 168.1 kg/ha. Pupal weight significantly increased at 134.5 and 168.1 kg/ha. There was no significant difference in percentage of protein, oil, and fiber in soybean seeds among six K fertilizer rates. Percentage of K in soybean seeds and 100 seed weight were significantly enhanced at 168.1 kg/ha. Nitrogen (N) content of foliage was not affected by applying K fertilizer at different rates. Our results indicate that higher K fertilizer rates can enhance soybean seed weight but also facilitate soybean looper development.
Subject(s)
Fabaceae , Moths , Animals , Fertilizers , Potassium , Glycine maxABSTRACT
Previous reviews have quantified factors affecting greenhouse gas (GHG) emissions from Asian rice ( L.) systems, but not from rice systems typical for the United States, which often vary considerably particularly in practices (i.e., water and carbon management) that affect emissions. Using meta-analytic and regression approaches, existing data from the United States were examined to quantify GHG emissions and major practices affecting emissions. Due to different production practices, major rice production regions were defined as the mid-South (Arkansas, Texas, Louisiana, Mississippi, and Missouri) and California, with emissions being evaluated separately. Average growing season CH emissions for the mid-South and California were 194 (95% confidence interval [CI] = 129-260) and 218 kg CH ha season (95% CI = 153-284), respectively. Growing season NO emissions were similar between regions (0.14 kg NO ha season). Ratoon cropping (allowing an additional harvestable crop to grow from stubble after the initial harvest), common along the Gulf Coast of the mid-South, had average CH emissions of 540 kg CH ha season (95% CI = 465-614). Water and residue management practices such as alternate wetting and drying, and stand establishment method (water vs. dry seeding), and the amount of residue from the previous crop had the largest effect on growing season CH emissions. However, soil texture, sulfate additions, and cultivar selection also affected growing season CH emissions. This analysis can be used for the development of tools to estimate and mitigate GHG emissions from US rice systems and other similarly mechanized systems in temperate regions.
