Global patterns of cereal diseases and the impacts of breeding for host plant resistance

Plant breeding for host plant resistance to pathogens brings together different disciplinary domains, especially genetics and plant pathology. The strategies underpinning plant breeding have therefore, logically, been influenced by a number of paradigms that have dominated the field of disease management. This chapter provides a brief overview of these paradigms, where the authors link the implications for plant breeding. In doing so, the authors try to follow an approximate (1) linear and (2) chronological order. Yet the authors are aware that, depending on the considered crop and region, (1) there might have been occasional jumps and step-backs leading to non-linear paths, and (2) the chronology of events may have much varied.

Bipolaris omanensis, a novel saprobic species of Bipolaris from Oman based on morphology and sequence data

Bipolaris species are responsible for important cereal diseases, worldwide and are often isolated as endophytes as well as saprobes. We are investigating the fungi in Oman. In this paper, we report a novel taxon of Bipolaris, collected from the leaves of Hibiscus rosa-sinensis, during the survey. The taxon is shown to be novel based on morphological and sequence data and introduced here as Bipolaris omanensis sp. nov. Bipolaris omanensis forms a sister clade to B. cookei based on the combined sequence analysis of internal transcribed spacers (ITS) and partial glyceraldehyde-3-phosphate dehydrogenase (GAPD) region, being distinct from the latter species in having shorter conidiophores, narrower conidia and having a higher number of septa.

Impact of cereal diseases on the qualitative traits of spring barley breeding lines

Summary The differences between individual breeding lines of spring barley and a control variety were tested in terms of several measured (continuous) and qualitative traits. The impact of the qualitative traits (diseases) on the quantitative traits, especially yield, was assessed on the basis of the significance of differences for both qualitative traits and yield. Depending on the type of trait, either a logistic model or analysis of variance was used as a statistical tool. The statistically significant differences between some breeding lines and the control variety were shown. It was observed that in fodder barley both infection by mildew and lodging influenced yield. The results of analyses obtained in the so-called pre-preliminary trials and preliminary trials were different. This fact confirmed the necessity of repeating trials over several years.