Molecular characterization of cDNA encoding resistance gene-like sequences in Buchloe dactyloides

Current knowledge of resistance (R) genes and their use for genetic improvement in buffalograss (Buchloe dactyloides [Nutt.] Engelm.) lag behind most crop plants. This study was conducted to clone and characterize cDNA encoding R gene-like (RGL) sequences in buffalograss. This report is the first to clone and-characterize of buffalograss RGLs. Degenerate primers designed from the conserved motifs of known R genes were used to amplify RGLs and fragments of expected size were isolated and cloned. Sequence analysis of cDNA clones and analysis of putative translation products revealed that most encoded amino acid sequences shared the similar conserved motifs found in the cloned plant disease resistance genes RPS2, MLA6, L6, RPM1, and Xa1. These results indicated diversity of the R gene candidate sequences in buffalograss. Analysis of 5' rapid amplification of cDNA ends (RACE), applied to investigate upstream of RGLs, indicated that regulatory sequences such as TATA box were conserved among the RGLs identified. The cloned RGL in this study will further enhance our knowledge on organization, function, and evolution of R gene family in buffalograss. With the sequences of the primers and sizes of the markers provided, these RGL markers are readily available for use in a genomics-assisted selection in buffalograss

Registration of NPM-4, a Dwarf White Grain Pearl Millet Germplasm

Dwarf grain pearl millet [Pennisetum glucum (L.) R. Br.] germplasm NPM-4 (Reg. no. GP-37, PI 634545) was released in September 2003 by the Institute of Agriculture and Natural Resources, University of Nebraska, Lincoln, NE. NPM-4 was derived from open-pollinated outcrosses of white grain inbred line 57028R1w grown in a 1998 Puerto Vallarta winter nursery. The source of the outcross pollen was from primarily genetically diverse, dwarf, early maturing, gray seeded lines being developed as parents for grain yield. Line 57028R1w was derived from 89C57028R1/3*90PV0121. Line 89C57028R1 is gray-seeded, and line 90PV0121 has white seed. Line 90PV0121, an F5 was derived from the cross 85C53005/ZW10. Line 89C57028R1was an A1 (Burton, 1958) cytoplasmic nuclear male-sterility (cms) restorer S5 selection out of row 84M:17101-1 of segregating germplasm obtained in the late 1970s from Dr. A.J. Casady, Kansas State University, that had undergone random mating and selection for at least 3 cycles before 1984. Line 85C53005 was an A1 maintainer S2 selection (84H:14014) also from the segregating Casady germplasm. The line ZW10 was a white seeded introduction from Zambia obtained in 1988. The 1998 winter nursery outcrosses of 57028R1w were grown in isolation at the Department of Agronomy Farm at the University of Nebraska’s Agricultural Research and Development Center (ARDC), Mead, NE, in 1998 and productive dwarf white seeded plants were selected for harvest and bulked together. The harvested bulk was grown in 1999 at Mead and plants were selfed and selected for all white seed on panicles. The white seeded selfs were grown in isolation in 2000. Nineteen open-pollinated white grain selections were made and random mated in isolation in 2001. Open pollinated seed of the best six white grain families was combined to form the bulk for seed release. Final selection was for panicle size, kernel size, and lodging resistance. Top-crosses of NPM-4 with cms lines NE68A1, NE59043A1, and KS1163A1 (a CMS A1–line from W.D. Stegmeier, Kansas State University-Hays) in 2002 indicated that NPM-4 was a good restorer of A1 cms with good combining ability for grain yield

Sweet Sorghum as an Ethanol Feedstock in Western Nebraska – Could It Happen?

It has been proposed that non-irrigated sweet sorghum might be grown in western Nebraska as a seasonal substitute for corn grain in corn ethanol plants. In the research summarized here, we examine the economic feasibility of this possibility, based on the technical data that are currently available about sweet sorghum production

Sweet Sorghum as Feedstock in Great Plains Corn Ethanol Plants: The Role of Biofuel Policy

This research examines whether sweet sorghum, a crop considered more drought-tolerant and suitable for semi-arid areas than corn, could result in an economically viable sweet sorghum ethanol pathway in the Great Plains. We find that that if the D5–D6 RIN price spread exceeds the $0.35/gal recently experienced, the benefits of the pathway would be equivalent to about$90/acre of sweet sorghum, or $0.38/gal of ethanol. Because of sparse cultivation potential, only four the six existing plants in the Nebraska–Colorado High Plains area might expect transportation costs to be low enough for economic feasibility

Tonoplast Sugar Transporters (SbTSTs) Putatively Control Sucrose Accumulation in Sweet Sorghum Stems

Carbohydrates are differentially partitioned in sweet versus grain sorghums. While the latter preferentially accumulate starch in the grain, the former primarily store large amounts of sucrose in the stem. Previous work determined that neither sucrose metabolizing enzymes nor changes in Sucrose transporter (SUT) gene expression accounted for the carbohydrate partitioning differences. Recently, 2 additional classes of sucrose transport proteins, Tonoplast Sugar Transporters (TSTs) and SWEETs, were identified; thus, we examined whether their expression tracked sucrose accumulation in sweet sorghum stems. We determined 2 TSTs were differentially expressed in sweet vs. grain sorghum stems, likely underlying the massive difference in sucrose accumulation. A model illustrating potential roles for different classes of sugar transport proteins in sorghum sugar partitioning is discussed

Tonoplast Sugar Transporters (SbTSTs) Putatively Control Sucrose Accumulation in Sweet Sorghum Stems

Carbohydrates are differentially partitioned in sweet versus grain sorghums. While the latter preferentially accumulate starch in the grain, the former primarily store large amounts of sucrose in the stem. Previous work determined that neither sucrose metabolizing enzymes nor changes in Sucrose transporter (SUT) gene expression accounted for the carbohydrate partitioning differences. Recently, 2 additional classes of sucrose transport proteins, Tonoplast Sugar Transporters (TSTs) and SWEETs, were identified; thus, we examined whether their expression tracked sucrose accumulation in sweet sorghum stems. We determined 2 TSTs were differentially expressed in sweet vs. grain sorghum stems, likely underlying the massive difference in sucrose accumulation. A model illustrating potential roles for different classes of sugar transport proteins in sorghum sugar partitioning is discussed

An efficient and improved method for virus-induced gene silencing in sorghum

Background: Although the draft genome of sorghum is available, the understanding of gene function is limited due to the lack of extensive mutant resources. Virus-induced gene silencing (VIGS) is an alternative to mutant resources to study gene function. This study reports an improved and efficient method for Brome mosaic virus (BMV)-based VIGS in sorghum. Methods: Sorghum plants were rub-inoculated with sap prepared by grinding 2 g of infected Nicotiana benthamiana leaf in 1 ml 10 mM potassium phosphate buffer (pH 6.8) and 100 mg of carborundum abrasive. The sap was rubbed on two to three top leaves of sorghum. Inoculated plants were covered with a dome to maintain high humidity and kept in the dark for two days at 18 °C. Inoculated plants were then transferred to 18 °C growth chamber with 12 h/12 h light/dark cycle. Results: This study shows that BMV infection rate can be significantly increased in sorghum by incubating plants at 18 °C. A substantial variation in BMV infection rate in sorghum genotypes/varieties was observed and BTx623 was the most susceptible. Ubiquitin (Ubiq) silencing is a better visual marker for VIGS in sorghum compared to other markers such as Magnesium Chelatase subunit H (ChlH) and Phytoene desaturase (PDS). The use of antisense strand of a gene in BMV was found to significantly increase the efficiency and extent of VIGS in sorghum. In situ hybridization experiments showed that the non-uniform silencing in sorghum is due to the uneven spread of the virus. This study further demonstrates that genes could also be silenced in the inflorescence of sorghum. Conclusion: In general, sorghum plants are difficult to infect with BMV and therefore recalcitrant to VIGS studies. However, by using BMV as a vector, a BMV susceptible sorghum variety, 18 °C for incubating plants, and antisense strand of the target gene fragment, efficient VIGS can still be achieved in sorghum

Genetic Variability, Heritability, and Genetic Advance for Ethanol Yield and Yield Components in Sweet Sorghum (Sorghum Bicolor Var. Saccharatum (L.)

Sweet sorghumis a strong candidate for a cheap and renewable source of energy and play a vital role for the uplift of socio-economic status of the farmers of Turkey through the development of high yielding varieties along with a reasonable amount of fodder and biofuel production. The objective of this research was to evaluate the potential of sweet sorghum as a source for fodder and biofuel production, also the magnitude of genetic variability, heritability and genetic advance for yield and contributing characters of forty-nine sweet sorghum genotypes. The experiment was carried out in a randomized complete block design with four replications in Turkey. Analysis of variance revealed that there are highly significant differences among the genotypes in all investigated traits indicating the presence of variability. The genotypes Smith and Batem-3 with high juice, sugar and ethanol yield can be used for breeding of biofuel production in the Mediterranean region of Turkey. High heritability accompanied with high genetic advance was observed fortheflowering day, fresh biomass weight, stem fresh weight, juice volume, estimated sugar yield, and estimated ethanol yield. Therefore, these characters could be used for the development of high yielding sorghum varieties through selection in a breeding program

Estimation of the Degree of Diversity for Some Iraqi Wheat Varieties through ISSR, SRAP and RAPD Markers

DNA-based molecular markers such as Inter Simple Sequence Repeat (ISSR), Sequence-Related Amplified polymorphism (SRAP) and Random Amplified Polymorphic DNA (RAPD) were used in this study to examine the genetic differences among sixteen Iraqi wheat varieties. Seventy three primers out of 177 were reproducible and showed clear amplified bands. The degree of genetic diversity, Polymorphism information content (PIC) and resolving power (RP) were estimated. All the studied molecular markers were informative and showed good ability to classify and distinguish 16 wheat varieties. Total number of polymorphic bands is 134, 221 and 55 for ISSR, SRAP and RAPD respectively. PIC and RP values were 0.259, 0.264 and 0.262 and 9.06, 7.87 and 2.7

Grain sorghum whole kernel oil lowers plasma and liver cholesterol in male hamsters with minimal wax involvement

The lipid fraction of the grain sorghum whole kernel (GS-WK) (i.e., phytosterol rich oil or policosanol rich wax) responsible for lowering cholesterol in hamsters fed the crude lipid (wax + oil) was determined. As expected, hamsters fed an atherogenic diet for a four week period presented with higher plasma non-HDL plasma and liver esterified cholesterol than those on the low fat diet. However, the atherogenic diet containing 5% (w/w) oil significantly lowered non-HDL plasma and liver cholesterol. Although the 5% wax supplement did not affect either plasma or liver cholesterol, excreted neutral sterol and bile acid were slightly higher than produced by the atherogenic diet. Still, cholesterol excretion negatively correlated with liver cholesterol concentration (r = –0.681, p \u3c 0.001) across diets with the oil fraction producing the greatest impact. These combined results indicate that oil plays the most significant role in modulating cholesterol, most likely by inhibiting absorption, but subtle interactions by the wax may be involved. However, the sorghum oil would be the most potent component to serve as a possible heart health ingredient in functional foods