25 research outputs found
Insights into the evolution of the New World diploid cottons (Gossypium, subgenus Houzingenia) based on genome sequencing
We employed phylogenomic methods to study molecular evolutionary processes and phylogeny in the geographically widely dispersed New World diploid cottons (Gossypium, subg. Houzingenia). Whole genome resequencing data (average of 33X genomic coverage) were generated to reassess the phylogenetic history of the subgenus and provide a temporal framework for its diversification. Phylogenetic analyses indicate that the subgenus likely originated following trans-oceanic dispersal from Africa about 6.6 mya, but that nearly all of the biodiversity evolved following rapid diversification in the mid-Pleistocene (0.5-2.0 mya), with multiple long-distance dispersals required to account for range expansion to Arizona, the Galapagos Islands, and Peru. Comparative analyses of cpDNA vs. nuclear data indicate that this history was accompanied by several clear cases of interspecific introgression. Repetitive DNAs contribute roughly half of the total 880 Mb genome, but most transposable element families are relatively old and stable among species. In the genic fraction, pairwise synonymous mutation rates average 1% per my, with non-synonymous changes being about seven times less frequent. Over 1.1 million indels were detected and phylogenetically polarized, revealing a two-fold bias toward deletions over small insertions. We suggest that this genome down-sizing bias counteracts genome size growth by TE amplification and insertions, and helps explain the relatively small genomes that are restricted to this subgenus. Compared to the rate of nucleotide substitution, the rate of indel occurrence is much lower averaging about 17 nucleotide substitutions per indel event
The U.S. National Cotton Germplasm Collection – Its Contents, Preservation, Characterization, and Evaluation
Perancangan Peraga LED Terprogram Berbasis Mikrokontroler AT89C52
Dengan tersedianya mikrokontroler yang memiliki berbagai fasilitas serta murahnya
harga PC yang ditawarkan, maka peluang untuk merancang peralatan pengendalian LED untuk
berbagai keperluan menjadi sangat terbuka. Tujuan dari penelitian ini adalah merancang dan
menguji peraga LED terprogram berbasis mikrokontroler AT89C52. Alat penampil LED matrik
dirancang data-nya bisa dimasukan secara otomatis, sehingga LED dapat menampilkan data
dengan segera. Perancangan sistem penampil LED matrik yang dibuat meliputi dua bagian
utama yaitu bagian perangkat keras dan bagian perangkat lunak. Perangkat keras meliputi
mikrokontroler AT89C52 sebagai pusat pengontrol, penggerak kolom dan penggerak baris serta
LED matrik untuk menampilkan data. Perangkat lunak meliputi bahasa mesin mikrokontroler
dan untuk berhubungan dengan PC menggunakan Borland Delphi. Pengujian dilakukan dengan
membandingkan tampilan LED matrik dengan data masukan dari PC. Alat ini dapat
mengendalikan dan menampilkan LED sesuai data yang diberikan. LED matrik dapat
menampilkan empat baris teks yang masing-masing baris maksimal enam karakter, gambar
serta animasi running text (teks berjalan)
Diversity analysis of cotton (Gossypium hirsutum L.) germplasm using the CottonSNP63K Array
Cotton germplasm resources contain beneficial alleles that can be exploited to develop germplasm adapted to emerging environmental and climate conditions. Accessions and lines have traditionally been characterized based on phenotypes, but phenotypic profiles are limited by the cost, time, and space required to make visual observations and measurements. With advances in molecular genetic methods, genotypic profiles are increasingly able to identify differences among accessions due to the larger number of genetic markers that can be measured. A combination of both methods would greatly enhance our ability to characterize germplasm resources. Recent efforts have culminated in the identification of sufficient SNP markers to establish high-throughput genotyping systems, such as the CottonSNP63K array, which enables a researcher to efficiently analyze large numbers of SNP markers and obtain highly repeatable results. In the current investigation, we have utilized the SNP array for analyzing genetic diversity primarily among cotton cultivars, making comparisons to SSR-based phylogenetic analyses, and identifying loci associated with seed nutritional traits. (Résumé d'auteur
Introgression of the Genes for Sesquiterpene Carboxylic Acid Synthesis From a Wild Tomato, Lycopersicon Hirsutum, Into the Cultivated Tomato for Increased Host -Plant Resistance to Insect Pests
156 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2002.F2 and backcross progeny were assayed for the presence of polymorphic molecular markers using the Amplified Fragment Length Polymorphism (AFLP) protocol. Progeny of each generation were separated into high and low classes for SCA levels and the DNA combined of individual plants within the phenotypic classes. Bulk segregant analysis was used to identify polymorphic AFLP markers present in LA 1777 and absent in 'Chico III' and LA 1033. Comparisons of these polymorphic AFLP markers between high-SCA bulks and the zero-SCA plants ('Chico III' and LA 1033) revealed 10 AFLP markers associated with presence of SCA. Comparisons of the high-SCA bulks with a set of low-SCA bulks revealed one marker associated with high levels of SCA synthesis. Comparisons of the markers with a TA517 line that produces sesquiterpene precursors to SCA revealed three markers putatively associated with synthesis of the olefin to SCA and six putatively associated with modifications to SCA.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD