Barley genetic resources: economic characteristics of hybrids collection

Nustatyta 17 miežių hibridų ir jų tėvinių formų produktyvumas, grybinių ligų intensyvumas ir dažnumas. Tirtos grybinės ligos yra tinkliškoji dryžligė (sukėlėjas Drechslera teres (Sacc.) Shoem.) ir miltligė (sukėlėjas Blumeria graminis (DC.) Speer). Grybinės ligos plito, priklausomai nuo meteorologinių sąlygų. 2005 – 2006 m. nebuvo palankūs šioms ligoms plisti. Hibridai buvo atsparesni grybinėms ligoms, derlingesni negu jų tėvinės formos tw, Hiproly ir Hassan nutans.Grain productivity of barley hybrids and their parental forms was studied as well as intensity and frequency of fungal diseases. The fungal diseases studied were net blotch, disease agent Drechslera teres (Sacc.) Shoem. and powdery mildew, disease agent Blumeria graminis (DC.) Speer. The spread of infections depended on meteorological conditions, while the study years 2005-2006 were relatively dry and not favourable for the diseases. It was observed that hybrids were less susceptible to the diseases and more productive then their parental forms tw, Hiproly and Hassan nutans

Application of barley tweaky spike mutants for the study of effects of plant immunity‐related substances

Barley developmental mutants tweaky spike (tw) with disturbed auxin pathways possess a unique feature of an increased level of mouldy germinating grains (MGG), which serves as a convenient model to investigate the effects of plant immunity‐related substances. The effects of the auxin 2,4‐dichlorophenoxyacetic acid (2,4‐D), auxin inhibitors, salicylic acid (SA), and trans‐cinnamic acid (TCA) were studied using the tw‐WT system in surface‐sterilized and unsterilized germinating grains under high rates of natural infection. Significant differences among the allelic tw mutants were revealed at the natural MGG level and in response to 2,4‐D, SA, and TCA. The most effective means against MGG were sterilization and TCA. 2,4‐D inhibited root growth in tw and tw2 mutants, occurring only in unsterilized and not sterilized germinating grains, while the opposite was observed for TCA and SA. The tw mutations influenced variations in the seed‐borne fungal spectra, decreasing the frequency of Bipolaris sorokiniana and increasing Fusarium spp. Hypochlorite‐based surface sterilization methods should be used with caution in studies where the action of exogenous 2,4‐D will be analysed in germinating grains. Auxin pathway disturbances specific for pleiotropic tw mutants are generally restricted to organogenesis but not to germination events

Different Habitats Show Similar Genetic Structure of <i>Bunias orientalis</i> L. (Brassicaceae)in Lithuania

We studied genetic diversity within and among populations of warty cabbage (Bunias orientalis L.), which is an alien species in Lithuania and other Baltic countries. In Lithuania, this weed colonises two main types of habitats: railway/roadsides and meadows on riversides. The aim of this study was to assess the genetic structure of invasive populations of B. orientalis in Lithuania and consider the impact of diverse habitats on the partitioning of genetic diversity using inter-simple sequence repeat (ISSR) markers. An analysis of molecular variance (AMOVA) carried out on the basis of ISSR showed that there is high genetic differentiation (46%) among populations of B. orientalis, which is probably caused by the founder effect and limited gene flow. However, we observed no impact of habitat on the genetic difference among populations. Similar levels of ISSR polymorphic loci were observed in riverside (P = 31.67%) and railway/roadsides (P = 30.51%) populations. UPGMA cluster analysis and principal coordinate analysis (PCoA) also did not show grouping of studied populations according to habitat type. High genetic differentiation among populations, as indicated by ISSR markers, confirm multiple independent introductions of this species in Lithuania