223 research outputs found

    Ketidaklaziman Kolokasi Pembelajar Bipa dan Implikasinya terhadap Pembelajaran Bahasa

    Get PDF
    Unacceptable Collocations by Learners of Indonesian as a ForeignLanguage and the Implication in Language Learning. Foreign language learners\u27ability to collocate words that are natural and acceptable in the target language isimportant in foreign language learning; however, it is notoriously difficult forforeign language learners and sometimes makes them frustrated. This studyattempts to describe the negative transfer of English collocations into Indonesiancollocations made by learners of Indonesian as a foreign language in their writingassignments. This study employed a qualitative descriptive method. The data werecollected from 36 writing assignments by 12 learners whose mother tongue isEnglish. They were trainee teachers with experience in teaching Indonesian inAustralia. The finding shows that there are 176 unnatural Indonesian collocations,some of which are negative transfers of learners\u27 mother tongue. This suggests thatdirect teaching of collocations should be given special emphasis in teachingIndonesian as a foreign language

    Genome-Wide Analysis of Gene Expression Provides New Insights into Cold Responses in Thellungiella salsuginea

    Get PDF
    Low temperature is one of the major environmental stresses that affects plant growth and development, and leads to decrease in crop yield and quality. Thellungiella salsuginea (salt cress) exhibits high tolerance to chilling, is an appropriate model to investigate the molecular mechanisms of cold tolerance. Here, we compared transcription changes in the roots and leaves of T. salsuginea under cold stress using RNA-seq. We identified 2,782 and 1,430 differentially expressed genes (DEGs) in leaves and roots upon cold treatment, respectively. The expression levels of some genes were validated by quantitative real-time-PCR (qRT-PCR). Among these DEGs, 159 (11.1%) genes in roots and 232 (8.3%) genes in leaves were annotated as various types of transcription factors. We found that five aquaporin genes (three TIPs, one PIPs, and one NIPs) responded to cold treatment. In addition, the expression of COR47, ICE1, and CBF1 genes of DREB1/CBF-dependent cold signaling pathway genes altered in response to low temperature. KEGG pathway analysis indicated that these cold regulated genes were enriched in metabolism, photosynthesis, circadian rhythm, and transcriptional regulation. Our findings provided a complete picture of the regulatory network of cold stress response in T. salsuginea. These cold-responsive genes could be targeted for detail functional study and utilization in crop cold tolerance improvement

    Cloning and expression analysis of peanut ( Arachis hypogaea L.) CHI gene

    Get PDF
    Chalcone isomerase (CHI) is the key enzyme that catalyzes chalcone into (2S)-flavanol or (2S)-5-desoxidation flavanol. The full length cDNA (1050 bp) of AhCHI ( Arachis hypogaea CHI gene) was cloned by large scale EST sequencing using a peanut immature seed cDNA library. Sequence analysis results indicated that it was a type I CHI gene (with the accession number JN660794). The ORF of AhCHI was 768 bp, encoding a peptide of 255 amino acids with a pI of 5.189. Sequence alignment showed that the coding region of AhCHI gene is highly conserved to compare with CHI genes from other plant species. Peanut cDNA microarray and semi-quantitative RT-PCR analysis indicated that AhCHI was highly expressed in pegs. The expression level in flower and root was higher than the expression level in stem and leaf. AhCHI was expressed in a high level in seeds with a purple seed coat, while its expression was low in seed with white seed coat

    Development and application of KASP marker for high throughput detection of AhFAD2 mutation in peanut

    Get PDF
    Background: Cultivated peanut ( Arachis hypogaea L.) is a major oilseed cropworldwide. Fatty acid composition of peanut oil may affect the flavor and shelf life of the resulting food products. Oleic acid and linoleic acid are the major fatty acids of peanut oil. The conversion from oleic acid to linoleic acid is controlled by the \u39412 fatty acid desaturase (FAD) encoded by AhFAD2A and AhFAD2B, two homoeologous genes from A and B subgenomes, respectively. One nucleotide substitution (G:C \u2192 A:T) of AhFAD2A and an \u201cA\u201d insertion of AhFAD2B resulted in high-oleic acid phenotype. Detection of AhFAD2 mutation had been achieved by cleaved amplified polymorphic sequence (CAPS), real-time polymerase chain reaction (qRT-PCR) and allele-specific PCR (AS-PCR). However, a low cost, high throughput and high specific method is still required to detect AhFAD2 genotype of large number of seeds. Kompetitive allele specific PCR (KASP) can detect both alleles in a single reaction. The aim of this work is to develop KASP for detection AhFAD2 genotype of large number of breeding materials. Results: Here,we developed a KASPmethod to detect the genotypes of progenies between high oleic acid peanut and common peanut. Validationwas carried out by CAPS analysis. The results fromKASP assay and CAPS analysis were consistent. The genotype of 18 out of 179 BC4F2 seeds was aabb. Conclusions: Due to high accuracy, time saving, high throughput feature and low cost, KASP is more suitable for determining AhFAD2 genotype than other methods

    Two decades of association mapping: Insights on disease resistance in major crops

    Get PDF
    Climate change across the globe has an impact on the occurrence, prevalence, and severity of plant diseases. About 30% of yield losses in major crops are due to plant diseases; emerging diseases are likely to worsen the sustainable production in the coming years. Plant diseases have led to increased hunger and mass migration of human populations in the past, thus a serious threat to global food security. Equipping the modern varieties/hybrids with enhanced genetic resistance is the most economic, sustainable and environmentally friendly solution. Plant geneticists have done tremendous work in identifying stable resistance in primary genepools and many times other than primary genepools to breed resistant varieties in different major crops. Over the last two decades, the availability of crop and pathogen genomes due to advances in next generation sequencing technologies improved our understanding of trait genetics using different approaches. Genome-wide association studies have been effectively used to identify candidate genes and map loci associated with different diseases in crop plants. In this review, we highlight successful examples for the discovery of resistance genes to many important diseases. In addition, major developments in association studies, statistical models and bioinformatic tools that improve the power, resolution and the efficiency of identifying marker-trait associations. Overall this review provides comprehensive insights into the two decades of advances in GWAS studies and discusses the challenges and opportunities this research area provides for breeding resistant varieties
    corecore