Buckwheat : a multi-purpose, short-season alternative (1994)

Most Americans know of buckwheat only from its use in buckwheat pancakes. Those more familiar with the crop know it to be a versatile, easy-to-grow, short-season grain crop adapted to many regions. It tolerates poor soils and is often used as a soil-improving crop, a role it served for such notables as Thomas Jefferson and George Washington on their Virginia farms

Molecular phylogeny of Diabrotica beetles (Coleoptera: Chrysomelidae) inferred from analysis of combined mitochondrial and nuclear DNA sequences

The phylogenetic relationships of thirteen Diabrotica (representing virgifera and fucata species groups) and two outgroup Acalymma beetle species (Coleoptera: Chrysomelidae) were inferred from the phylogenetic analysis of a combined data set of 1323 bp of mitochondrial DNA (mtDNA) cytochrome oxidase subunit 1 (COI) and the entire second internal transcribed spacer region (ITS-2) of nuclear ribosomal DNA of 362 characters. Species investigated were D. adelpha, D. balteata, D. barberi, D. cristata, D. lemniscata, D. longicornis, D. porracea, D. speciosa, D. undecimpunctata howardi, D. u. undecimpunctata, D. virgifera virgifera, D. v. zeae, D. viridula, and outgroup A. blandulum and A. vittatum. Maximum parsimony (MP), minimum evolution (ME), and maximum likelihood (ML) analyses of combined COI and ITS-2 sequences clearly place species into their traditional morphological species groups with MP and ME analyses resulting in identical topologies. Results generally confer with a prior work based on allozyme data, but within the virgifera species group, D. barberi and D. longicornis strongly resolve as sister taxa as well as monophyletic with the neotropical species, D. viridula, D. cristata and D. lemniscata also resolve as sister taxa. Both relationships are not in congruence with the prior allozyme-based hypothesis. Within the fucata species group, D. speciosa and D. balteata resolve as sister taxa. Results also strongly supported the D. virgifera and D. undecimpunctata subspecies complexes. Our proposed phylogeny provides some insight into current hypotheses regarding distribution status and evolution of various life history traits for Diabrotica

Extended Recurrence Plot Analysis and its Application to ERP Data

We present new measures of complexity and their application to event related potential data. The new measures base on structures of recurrence plots and makes the identification of chaos-chaos transitions possible. The application of these measures to data from single-trials of the Oddball experiment can identify laminar states therein. This offers a new way of analyzing event-related activity on a single-trial basis.Comment: 21 pages, 8 figures; article for the workshop ''Analyzing and Modelling Event-Related Brain Potentials: Cognitive and Neural Approaches`` at November 29 - December 01, 2001 in Potsdam, German

Tissue-specific regulation of Na+ and K+ transporters explains genotypic differences in salinity stress tolerance in rice

Rice (Oryza sativa) is a staple food that feeds more than half the world population. As rice is highly sensitive to soil salinity, current trends in soil salinization threaten global food security. To better understand the mechanistic basis of salinity tolerance in rice, three contrasting rice cultivars - Reiziq (tolerant), Doongara (moderately tolerant), and Koshihikari (sensitive) - were examined and the differences in operation of key ion transporters mediating ionic homeostasis in these genotypes were evaluated. Tolerant varieties had reduced Na+ translocation from roots to shoots. Electrophysiological and quantitative reverse transcription PCR experiments showed that tolerant genotypes possessed 2-fold higher net Na+ efflux capacity in the root elongation zone. Interestingly, this efflux was only partially mediated by the plasma membrane Na+/H+ antiporter (OsSOS1), suggesting involvement of some other exclusion mechanisms. No significant difference in Na+ exclusion from the mature root zones was found between cultivars, and the transcriptional changes in the salt overly sensitive signaling pathway genes in the elongation zone were not correlated with the genetic variability in salinity tolerance amongst genotypes. The most important hallmark of differential salinity tolerance was in the ability of the plant to retain K+ in both root zones. This trait was conferred by at least three complementary mechanisms: (1) its superior ability to activate H+-ATPase pump operation, both at transcriptional and functional levels; (2) reduced sensitivity of K+ efflux channels to reactive oxygen species; and (3) smaller upregulation in OsGORK and higher upregulation of OsAKT1 in tolerant cultivars in response to salt stress. These traits should be targeted in breeding programs aimed to improve salinity tolerance in commercial rice cultivars

Integrating the Genetic and Physical Maps of Arabidopsis thaliana: Identification of Mapped Alleles of Cloned Essential (EMB) Genes

The classical genetic map of Arabidopsis includes more than 130 genes with an embryo-defective (emb) mutant phenotype. Many of these essential genes remain to be cloned. Hundreds of additional EMB genes have been cloned and catalogued (www.seedgenes.org) but not mapped. To facilitate EMB gene identification and assess the current level of saturation, we updated the classical map, compared the physical and genetic locations of mapped loci, and performed allelism tests between mapped (but not cloned) and cloned (but not mapped) emb mutants with similar chromosome locations. Two hundred pairwise combinations of genes located on chromosomes 1 and 5 were tested and more than 1100 total crosses were screened. Sixteen of 51 mapped emb mutants examined were found to be disrupted in a known EMB gene. Alleles of a wide range of published EMB genes (YDA, GLA1, TIL1, AtASP38, AtDEK1, EMB506, DG1, OEP80) were discovered. Two EMS mutants isolated 30 years ago, T-DNA mutants with complex insertion sites, and a mutant with an atypical, embryo-specific phenotype were resolved. The frequency of allelism encountered was consistent with past estimates of 500 to 1000 EMB loci. New EMB genes identified among mapped T-DNA insertion mutants included CHC1, which is required for chromatin remodeling, and SHS1/AtBT1, which encodes a plastidial nucleotide transporter similar to the maize Brittle1 protein required for normal endosperm development. Two classical genetic markers (PY, ALB1) were identified based on similar map locations of known genes required for thiamine (THIC) and chlorophyll (PDE166) biosynthesis. The alignment of genetic and physical maps presented here should facilitate the continued analysis of essential genes in Arabidopsis and further characterization of a broad spectrum of mutant phenotypes in a model plant

Intra-seasonal climate prediction: linking weather and climate forecasts.

The Madden-Julian Oscillation (MJO) is a tropical atmospheric phenomenon, associated with periods of active convection in the eastern hemisphere tropics. The MJO?s temporal scale (22-90 days) coincides with a gap between weather (synoptic forecasts out to 10 days) and climate (seasonal and longer forecasts).Analysis of 35 years of daily rainfall data shows significant modulation of tropical and extra-tropical rainfall by the equatorial passage of the MJO that begins to address the weather-climate forecasting gap. The BMRC?s Real-time multivariate Madden-Julian (RMM) Index( (Wheeler and Hendon, 2004) is a good proxy for the amplitude (strength) and location (Phases 1-8) of the MJO in the eastern hemisphere. As the centre of active convection that distinguishes the MJO travels east along the equator, corresponding rainfall patterns can be identified throughout the tropics and also at higher latitudes. We also observed weather states in standardised MSLP anomaly maps that explain these rainfall patterns. These weather states provide a mechanistic basis for an MJO-based forecasting capacity that bridges the weather-climate divide. Knowledge of these tropical and extra-tropical MJO-associated weather states can significantly improve the tactical management of climatesensitive systems such as agriculture