Using markers and field evaluation to identify the source of eyespot resistance gene Pch1 in the collection of wheat breeding lines

Pch1 gene translocated from Aegilops ventricosa provides effective resistance to eyespot in wheat. To track the Pch1 gene introgression, we investigated 372 genotypes obtained from various breeding programs using endopeptidase EpD1b marker, sequence-tagged-site (STS) marker XustSSR2001-7DL, and the score of infection index (K-index) evaluated after in vivo inoculation test. These genotypes were divided into three groups with 136, 124 and 112 genotypes for the field test lasting three years. In 2011, the mean K-index was 0.81, while 2012 and 2013 the mean K-indexes were 1.60 and 1.46, respectively. Both marker results indicated that 18 genotypes possessed Pch1 gene. Statistical analysis of the level of K-index showed that these 18 genotypes were resistant to eyespot, which verified the proper assignment of wheat genotypes with Pch1 gene based on the marker data. Thus, the endopeptidase and XustSSR2001-7DL are useful for identifying sources of eyespot resistance gene Pch1 in wheat breeding program

The exchange activities of [Fe] hydrogenase (iron–sulfur-cluster-free hydrogenase) from methanogenic archaea in comparison with the exchange activities of [FeFe] and [NiFe] hydrogenases

[Fe] hydrogenase (iron–sulfur-cluster-free hydrogenase) catalyzes the reversible reduction of methenyltetrahydromethanopterin (methenyl-H4MPT+) with H2 to methylene-H4MPT, a reaction involved in methanogenesis from H2 and CO2 in many methanogenic archaea. The enzyme harbors an iron-containing cofactor, in which a low-spin iron is complexed by a pyridone, two CO and a cysteine sulfur. [Fe] hydrogenase is thus similar to [NiFe] and [FeFe] hydrogenases, in which a low-spin iron carbonyl complex, albeit in a dinuclear metal center, is also involved in H2 activation. Like the [NiFe] and [FeFe] hydrogenases, [Fe] hydrogenase catalyzes an active exchange of H2 with protons of water; however, this activity is dependent on the presence of the hydride-accepting methenyl-H4MPT+. In its absence the exchange activity is only 0.01% of that in its presence. The residual activity has been attributed to the presence of traces of methenyl-H4MPT+ in the enzyme preparations, but it could also reflect a weak binding of H2 to the iron in the absence of methenyl-H4MPT+. To test this we reinvestigated the exchange activity with [Fe] hydrogenase reconstituted from apoprotein heterologously produced in Escherichia coli and highly purified iron-containing cofactor and found that in the absence of added methenyl-H4MPT+ the exchange activity was below the detection limit of the tritium method employed (0.1 nmol min−1 mg−1). The finding reiterates that for H2 activation by [Fe] hydrogenase the presence of the hydride-accepting methenyl-H4MPT+ is essentially required. This differentiates [Fe] hydrogenase from [FeFe] and [NiFe] hydrogenases, which actively catalyze H2/H2O exchange in the absence of exogenous electron acceptors

Diffraction techniques and vibrational spectroscopy opportunities to characterise bones

From a histological point of view, bones that allow body mobility and protection of internal organs consist not only of different organic and inorganic tissues but include vascular and nervous elements as well. Moreover, due to its ability to host different ions and cations, its mineral part represents an important reservoir, playing a key role in the metabolic activity of the organism. From a structural point of view, bones can be considered as a composite material displaying a hierarchical structure at different scales. At the nanometre scale, an organic part, i.e. collagen fibrils and an inorganic part, i.e. calcium phosphate nanocrystals are intimately mixed to assure particular mechanical properties

Infection of triticale varieties with Pseudocercosporella herpotrichoides and Fusarium spp.

The degree of infection witb Pseudocercosporella herpotrichoides (Fron.) Deighton and Fusarium spp. Of 10 triticale varieties was evaluated in vegetation periods 1995-1996 and 2 localities of Poland. In Choryń, varieties Ugo and Lasko were significantly more infected with eyespot pathogen at the stages of shooting (GS 30) and waxy ripe (GS 87), respectively, than other varieties tested. Infection of variety Bogo was significantly lowest at waxy ripe stage, as compared with other varieties. In the case of infection with Fusarium spp. differentation between varieties was insignificant.W doświadczeniu oceniono poziom porażenia przez Pseudocercosporella herpotrichoides i Fusarium spp. na 10 odmianach pszenżyta w sezonach 1995 i 1996 (w 2 lokalizacjach). W Choryni odmiany Ugo i Lasko były najsilniej porażone przez P. herpotrichoides odpowiednio w fazach: w fazie strzelania w źdźbło (GS 30) i w fazie dojrzałości woskowej (GS 71 ). Odmiana Bogo była najsłabiej porażona w fazie woskowej dojrzałości. W przypadku porażenia przez Fusarium spp. nie stwierdzono istotnych różnic między odmianami