Linked morphological and molecular markers associated with common root rot reaction in barley

Abstract

Selection of common root rot [Cochliobolus sativus (Ito & Kurib.) Drechsl. ex Dastur] resistant barley germplasm is difficult due to the influence of environment on disease expression and the quantitative nature of resistance. Morphological and molecular markers associated with common root rot resistance could be used to increase the efficiency of selection of resistant germplasm and facilitate transfer to desirable barley genotypes Forty-five morphological marker sets consisting of four to six backcross-derived lines for each marker in a common background (cultivar Bowman) were planted in disease nurseries at two locations in each of 3 yr. Disease reactions of the back-cross-derived lines were tested for a difference from the disease reaction of Bowman, which indicated a putative association between the marker and common root rot reaction. An association was obtained between common root rot reaction and one set of backcross-derived lines that contained two linked markers: glossy-sheath (gs4) and orange lemma (o). A RAPD marker closely linked to gs4 and o was also associated with common root rot reaction. The RAPD marker was associated with the allele for resistance, while gs4 and o were associated with the allele for susceptibility. The RAPD marker would be most useful in the selection of common root rot resistant germplasm and the transfer of this resistance to other genotypes. Key words: Common root rot, Cochliobolus sativus, barley, morphological markers, molecular markers

Low Lignin Mutants and Reduction of Lignin Content in Grasses for Increased Utilisation of Lignocellulose

“…Rob1 was initially used in inheritance studies and considered to be monofactorial recessive following Mendel with a 3:1 ratio [79,120]. The mutation is located on chromosome 6 near the male-sterile 36 locus and the uniculm 2 locus [121] and used as a morphological markers [122][123][124]. With regards to chemical analysis, one published poster presents the results of rob1 forage quality, however no differences have been identified between the mutant and the elite cultivars [117], despite measurement of lignin content being 10-15% lower in rob1 mutants of different backgrounds, as well as altered lignin composition with decreased S:G ratio and increased saccharification efficiency compared to wild type [116,118].…”

Changes in soluble carbohydrate level in Hordeum vulgare (L.) and Festuca pratensis (Huds.) calli treated with metabolites of Bipolaris sorokiniana (Sacc.) Shoem

“…It has been a subject of numerous studies for several years (Chawla and Wenzel 1987, Kutcher et al 1996, Conner et al 1996, Ptazek and Filek 1998. under influence of Bipolaris sorokiniana metabolites were estimated.…”

Molecular Genetics, Genomics and Biotechnology of Crop Plants Breeding

“…Previous studies have described the significance of plant hormones in metabolic and signaling aspects and their probable role in the maintenance and release of dormancy in seeds of cereal crops [43,119,120]. Among plant growth hormones, abscisic acid (ABA) and gibberellin (GA) play important roles in regulation of dormancy and germination, ABA induces dormancy and GA stimulates seed germination [121,122]. A change in balance between ABA and GA levels in seed constitutes a regulatory mechanism that results in maintenance or release of seed dormancy [120,123].…”

“…Transgene-free methods rely on the possibility to transiently express SDNs in plant cells (e.g., protoplasts), and this can be achieved either by the transfer of a DNA-based expression cassette that does not undergo stable integration in the genome [122][123][124], or alternatively by the transfer of ribonucleoproteins (RNPs) [125,126]. The use of transgene-free methods can lead to genome-edited plants (SDN1 and SDN2 on case-by-case), which are indistinguishable by spontaneously mutated crops or mutants obtained by classical mutagenesis approaches (i.e., ethyl methanesulfonate, ionizing radiation) [115].…”