Validation of Diaporthe toxica resistance markers in European Lupinus angustifolius germplasm and identification of novel resistance donors for marker-assisted selection.

The fungus, Diaporthe toxica, anamorph Phomopsis sp., previously classified as P. leptostromiformis, is a plant endophyte and occasional pathogen, causing Phomopsis stem blight. This disease is damaging not only to lupins but also to the animals grazing on infected plants, due to the toxic secondary metabolites called phomopsins. The aim of this work was to validate markers for resistance to Phomopsis stem blight in narrow-leafed lupins and identify novel germplasm with increased levels of resistance to the disease. Plant inoculations were performed using ten isolates of D. toxica, originating from Australia and Poland. The European core collection of L. angustifolius was evaluated both in a controlled environment and with field experiments to classify the accessions based on their resistance to the disease. Simultaneously, the accessions were assayed with disease resistance markers to identify donors of hypothetical resistance alleles. We have found that the European lupin germplasm collection preserves wild and domesticated donors of at least two resistance genes to Phomopsis stem blight, including Phr1 and PhtjR. Molecular markers PhtjM7, InDel2, and InDel10, tagging PhtjR gene, were applicable for marker-assisted selection targeting the European gene pool with an expected accuracy of 95%. None of diagnostic markers for the Phr1 locus was found useful for European breeding programs; two existing markers Ph258M1 and Ph258M2 were unreliable, due to a high percentage of false-positive results (up to 58%) and a high recombination rate between markers (~ 30%).

Ultrastructure of the transporting epithelium of tubus ventralis in Tetrodontophora bielanensis Waga (Collembola).

The cells of the transporting epithelium of the tubus ventralis in Tetrodontophora bielanensis Waga (Collembola) are polarized, i.e. the major axis of the cell is determined by apical microvilli on one side and basal cell membrane infoldings on the other side. The involvement of this epithelium in fluid transport is indicated by the presence of PMC complexes, a large number of microtubules and glycogen in the middle and basal zones of the cells, and the arrangement of the endoplasmic reticulum, as well as by the presence of septate junctions and intercellular spaces. Typical features of this epithelium also include hemidesmosomes, and a well developed basement membrane to which they are attached. The cuticle covering the transporting epithelium is porous. It has a smooth surface, devoid of the wrinkles typical of other regions of the cuticle, which absorbs moisture and contributes to fluid transport.

Ultrastructure of the trophic chamber and nutritive cord of Aspidiotus hederae (Homoptera, Coccoidea).

Each ovariole of the coccidian Aspidiotus hederae contains a single oocyte connected by means of a nutritive cord to the trophic chamber. The trophic chamber consists of three nurse cells characterized by an enlarged, ramified nucleus with a prominent nucleolus. The perinuclear cytoplasm contains nuage material, large amounts of free ribosomes, and scattered mitochondria. Occasional cisternae of the rough endoplasmic reticulum and bacteroids are found in trophocyte cytoplasm. The nutritive cord contains many microtubules in parallel array interspersed with numerous free ribosomes and a few mitochondria. The nutritive cord is strengthened by trophocyte projections which surround it. Microtubules in the projections are oriented perpendicular to the long axis of the cord.