University of Hohenheim

About: University of Hohenheim is a education organization based out in Stuttgart, Germany. It is known for research contribution in the topics: Population & Soil water. The organization has 8585 authors who have published 16406 publications receiving 567377 citations.

QTL mapping of stay-green in two sorghum recombinant inbred populations

Abstract: The stay-green trait is a reported component of tolerance to terminal drought stress in sorghum. To map quantitative trait loci (QTLs) for stay-green, two sorghum recombinant inbred populations (RIPs) of 226 F3:5 lines each were developed from crosses (1) IS9830 × E36-1 and (2) N13 × E36-1. The common parental line, E36-1 of Ethiopian origin, was the stay-green trait source. The genetic map of RIP 1 had a total length of 1,291 cM, with 128 markers (AFLPs, RFLPs, SSRs and RAPDs) distributed over ten linkage groups. The map of RIP 2 spanned 1,438 cM and contained 146 markers in 12 linkage groups. The two RIPs were evaluated during post-rainy seasons at Patancheru, India, in 1999/2000 (RIP 2) and 2000/2001 (RIP 1). The measures of stay-green mapped were the green leaf area percentages at 15, 30 and 45 days after flowering (% GL15, % GL30 and % GL45, respectively). Estimated repeatabilities for % GL15, % GL30 and % GL45 amounted to 0.89, 0.81 and 0.78 in RIP 1, and 0.91, 0.88 and 0.85 in RIP 2, respectively. The number of QTLs for the three traits detected by composite interval mapping ranged from 5 to 8, explaining 31% to 42% of the genetic variance. In both RIPs, both parent lines contributed stay-green alleles. Across the three measures of the stay-green trait, three QTLs on linkage groups A, E and G were common to both RIPs, with the stay-green alleles originating from E36-1. These QTLs were therefore consistent across the tested genetic backgrounds and years. After QTL validation across sites and verification of the general benefit of the stay-green trait for grain yield performance and stability in the target areas, the corresponding chromosomal regions could be candidates for marker-assisted transfer of stay-green into elite materials.

Roots of Iron-Efficient Maize also Absorb Phytosiderophore-Chelated Zinc

Abstract: To investigate the recognition of Zn-phytosiderophores by the putative Fe-phytosiderophore transporter in maize (Zea mays L.) roots, short-term uptake of 65Zn-labeled phytosiderophores was compared in the Fe-efficient maize cultivar Alice and the maize mutant ys1 carrying a defect in Fe-phytosiderophore uptake. In ys1, uptake and translocation rates of Zn from Zn-phytosiderophores were one-half of those in Alice, but no genotypical difference was found in Zn uptake and translocation from other Zn-binding forms. In ys1 and in tendency also in Alice, Zn uptake decreased with increasing stability constant of the chelate in the order: ZnSO4 [greater than or equal to] Zn-desferrioxamine > Zn-phytosiderophores > Zn-EDTA. Adding a 500-fold excess of free phytosiderophores over Zn to the uptake solution depressed Zn uptake in ys1 almost completely. In uptake studies with double-labeled 65Zn-14C-phytosiderophores, ys1 absorbed the phytosiderophore at similar rates when supplied as a Zn-chelate or the free ligand. By contrast, in Alice 14C-phytosiderophore uptake from the Zn-chelate was 2.8-fold higher than from the free ligand, suggesting that Alice absorbed the complete Zn-phytosiderophore complex via the putative plasma membrane transporter for Fe-phytosiderophores. We propose two pathways for the uptake of Zn from Zn-phytosiderophores in grasses, one via the transport of the free Zn cation and the other via the uptake of nondissociated Zn-phytosiderophores.

Exome sequencing of geographically diverse barley landraces and wild relatives gives insights into environmental adaptation

Abstract: Robbie Waugh, Nils Stein, Gary Muehlbauer and colleagues report the exome sequencing of 267 landraces and wild accessions of barley from diverse regions to study adaptations to different agricultural environments. They observe correlations of days to heading and height with environment and find that variation in flowering-associated genes has strong geographical structuring. After domestication, during a process of widespread range extension, barley adapted to a broad spectrum of agricultural environments. To explore how the barley genome responded to the environmental challenges it encountered, we sequenced the exomes of a collection of 267 georeferenced landraces and wild accessions. A combination of genome-wide analyses showed that patterns of variation have been strongly shaped by geography and that variant-by-environment associations for individual genes are prominent in our data set. We observed significant correlations of days to heading (flowering) and height with seasonal temperature and dryness variables in common garden experiments, suggesting that these traits were major drivers of environmental adaptation in the sampled germplasm. A detailed analysis of known flowering-associated genes showed that many contain extensive sequence variation and that patterns of single- and multiple-gene haplotypes exhibit strong geographical structuring. This variation appears to have substantially contributed to range-wide ecogeographical adaptation, but many factors key to regional success remain unidentified.

A divergent gene family encoding candidate olfactory receptors of the moth Heliothis virescens.

Abstract: The antennae of moths have been an invaluable model for studying the principles of odour perception. In spite of the enormous progress in understanding olfaction on the molecular level, for the moth one of the key elements in olfactory signalling, the odourant receptors, are still elusive. We have assessed a genome database of a heliothine moth (Heliothis virescens, Noctuidae) and employed exon-specific probes to screen an antennal cDNA library of this species. Analysis of isolated cDNA-clones led to the discovery of a divergent gene family encoding putative seven-transmembrane domain proteins. The notion that they may encode candidate olfactory receptors of the moth, was supported by a tissue-specific expression; several of the subtypes were exclusively expressed in antennae. By means of double-labelling in situ hybridization studies it was demonstrated that the receptors are indeed expressed in antennal sensory neurons; moreover, each receptor subtype appears to be expressed in a distinct population of sensory cells. The results strongly suggest that the newly discovered gene family indeed encodes olfactory receptors of moth.