Inheritance of resistance to Fusarium head blight in the wheat lines 'CJ 9306' and 'CJ 9403'

Fusarium head blight (FHB or scab) caused by Fusarium graminearum is a worldwide serious disease in wheat. Exploitation and genetic studies of elite resistance sources can speed up the development of resistant cultivars. To characterize the inheritance of host plant resistance in two new lines, ‘CJ 9306’ and ‘CJ 9403’, developed from a recurrent selection programme in China, six generations P₁, P₂, F₁, F₂, B₁ and B₂ of four crosses and 137 F_{6 : 7} recombinant inbred lines (RILs) from one cross were evaluated in the greenhouse for scab resistance using single‐floret inoculation. The data of area under disease progress curve (AUDPC) in F₂, backcross (BC) and RIL populations exhibited mono‐modal distributions without clear‐cut demarcations and skewing towards resistance. An additive–dominance model was well‐fitted, additive effects played a predominating role, and dominance effects were also significant. Continuous distributions with two major peaks and one minor peak for the number or percentage of scabby spikelets (NSS or PSS) in segregating populations implied the existence of major genes or quantitative trait loci (QTL) for resistance. The estimates of broad‐sense and narrow‐sense heritabilities based on the six‐generation experiment were 56–76% and 26–67% respectively. The estimates of broad‐sense heritabilities based on anova with RILs were 89–90%. These two improved lines with excellent scab resistance and good agronomic traits are of interest for wheat breeding and production.     

Rewetting of milled peat: laboratory investigation of water movement and storage

Abstract. Air- dried milled peat (0.45 g g^-1 wet weight basis) is used as an electricity generating fuel in Ireland. It is stored on peat bogs in triangular section stockpiles. These stockpiles comprise of milled peat of varying types, classified by poured density, and are subject to rewetting during storage which incurs an economic penalty. A water applicator was constructed to study the nature of rewetting mechanisms in laboratory-scale milled peat stockpiles, and to assess some potential protection strategies. Results indicated that there were few consistent short-term mechanisms linked to milled peat type. Over a longer period, low density milled peat stored most water, high density milled peat generated most runoff from the stockpile surface, and under certain conditions, throughflow was very important in all milled peat types. The industrial implications of the findings conclude that protection strategies should focus on lower density stockpiles.