Kecskebúza (Aegilops) fajok stressztűrő képességének vizsgálata a termesztett búza génforrásainak bővítése céljával. = Analysis of the stress tolerance in Aegilops species to expand the gene-pool of bread wheat

A pályázat keretében kitűzött céloknak megfelelően a mediterrán és nyugat-ázsiai elterjedésű, különböző mértékben száraz termőhelyekről származó Aegilpops fajok vonalait első lépésben a vízhiány, a magas hőmérséklettel, ill. fényintenzitással szembeni ellenálló képesség alapján szelektáltuk. Ehhez olyan több paraméter alapján minősítő szelekciós rendszert alkalmaztunk, amely költség hatékony és jól reprezentálja a növény stressztoleranciáját. A módszer alkalmazásával kiválasztott vonalak szárazságtűrését vízkultúrában és talajkísérletekben jellemeztük és több fiziológiai paraméter alapján 3 olyan "stratégiá"-t állapítottunk meg, amely szerepet játszik a száraz periódus átvészelésében: abszolút szárazságtűrők, vízmegtartók, vízvesztők. Emellett sikerült közös vonásokat felfedni a három környezeti tényező kivédésére irányuló mechanizmusokban, valamint rávilágítottunk nettó fotoszintézis sztóma és mezofillum gátlásának eltérő arányaira az egyes stratégiák esetében. A kr1 gént tartalmazó Mv9kr1 genotípusú őszi, valamint a ph1b mutációt hordozó Chinese Spring tavaszi búzát a legperspektivikusabbnak bizonyult Aegiliops vonalakkal keresztezve F1 hibrideket állítottunk elő. Mindez a későbbiekben alapját képezheti olyan addíciós vonalak előállításának, amely a búza kromoszómákon kívül már csak egy idegen kromoszómát tartalmaz. | According to the aims of this grant, Aegilops species originating from Mediterranean and Asiatic arid or semi-arid regions were examined and selected with respect to major abiotic stress factors. A relatively fast and economical selection system using several parameters was employed for the estimation of stress tolerance in these plants and for the selection of tolerant genotypes. Additionally, on the basis of several physiological parameters, some strategies can be assumed to have a bearing on the plants' survival of the dry period: drought-tolerant genotypes, water-preserving genotypes and water-losing genotypes. On the other hand, it seems likely that the protection against excess light, high temperature, and water deficit reveals common characteristics, and the extent of stomatal and mesophyll limitation of net photosynthesis is different in the given strategy types during drought. F1 hybrids were developed by intergeneric crossing of the Aegilops accessions having the best stress tolerance traits with the winter wheat genotype Mv9kr1 and ph1b mutant Chinese Spring. These F1 hybrids are the first stage in developing various wheat/Aegilops translocations having valuable traits for wheat improvement

The effect of the excess Titanium content on the microstructure of Al – Si foundry alloys

Grain refining is an important technological step for the nucleus growth of the melt, in order to increase the number of nuclei, to improve mechanical properties (tensile strength, yield strength, hardness, elongation), feeding conditions and to decrease the tendency of hot tearing and the degree of sintering. [1][2] The aim of the experiments was the determination of the grain refining effects of titanium (Ti) addition in the form of AlTi5B1 master alloy to the examined alloys (AlSi7MgCu0.5 – AC 42 000, AlSi9Cu3Fe0.5 – 46 500; AlSi9Cu1 – AC 46 400). The results prove that the addition of small amount of master alloy has a favourable effect on the foundry practice

Foraging decisions with conservation consequences: Interaction between beavers and invasive tree species

1. Herbivore species can either hinder or accelerate the invasion of woody species through selective utilization. Therefore, an exploration of foraging decisions can contribute to the understanding and forecasting of woody plant invasions. Despite the large distribution range and rapidly growing abundance of beaver species across the Northern Hemisphere, only a few studies focus on the interaction between beavers and invasive woody plants. 2. We collected data on the woody plant supply and utilization at 20 study sites in Hungary, at two fixed distances from the water. The following parameters were registered: taxon, trunk diameter, type of utilization, and carving depth. Altogether 5401 units (trunks and thick branches) were identified individually. We developed a statistical protocol that uses a dual approach, combining whole‐database and transect‐level analyses to examine foraging strategy. 3. Taxon, diameter, and distance from water all had a significant effect on foraging decisions. The order of preference for the four most abundant taxa was Populus spp. (softwood), Salix spp. (softwood), Fraxinus pennsylvanica (invasive hardwood), and Acer negundo (invasive hardwood). The diameter influenced the type of utilization, as units with greater diameter were rather carved or debarked than felled. According to the central‐place foraging strategy, the intensity of the foraging decreased with the distance from the water, while both the taxon and diameter selectivity increased. This suggests stronger modification of the woody vegetation directly along the waterbank, together with a weaker impact further from the water. 4. In contrast to invasive trees, for which utilization occurred almost exclusively in the smallest diameter class, even the largest softwood trees were utilized by means of carving and debarking. This may lead to the gradual loss of softwoods or the transformation of them into shrubby forms. After the return of the beaver, mature stages of softwood stands and thus the structural heterogeneity of floodplain woody vegetation could be supported by the maintenance of sufficiently large active floodplains. 5. The beaver accelerates the shift of the canopy layer's species composition toward invasive hardwood species, supporting the enemy release hypothesis. However, the long‐term impact will also depend on how plants respond to different types of utilization and on their ability to regenerate, which are still unexplored issues in this environment. Our results should be integrated with knowledge about factors influencing the competitiveness of the studied native and invasive woody species to support floodplain conservation and reconstruction