Vererbung des β-Glucangehaltes der Haferkaryopse

Inheritance process for β-glucan content in oat caryopsis
Due to the fact that there are only few studies concerning β-glucans in oat caryopsis with regard to plant-breeding aspects, three oat crosses were performed (cross 19 = low × high, cross 86 = low × low, cross 98 = high × high). In all of the three oat crosses, lower β-glucan content (% DM) was recorded in F, than in F, indicating that the β-glucan content (% DM) at a higher heterozygoty grade is lower than at a reduced heterozygoty grade. This points to a dominant inheritance of lower β-glucan content (% DM). A tendency towards the female β-glucan content (% DM) could not be proven. Thus, it can be started from a nuclear genetic inheritance of the β-glucan content (% DM). In most cases, the experiments showed a normal distribution of β-glucan content (% DM), indicating for several genes a quantitative inheritance of β-glucan content (% DM). By means of the regression of the F₃-lines to the F₂-plants, the narrow-sense heritability could be calculated for the cross 86 (h²= 0.51***) and the cross 98 (h²= 0.48***). The heritability for the cross 19 was not significant.     

Salinity Tolerance of Rice (Oryza sativa L.) with Reference to Endogenous and Exogenous Abscisic Acid

Experiments conducted m a phytotron on three rice varieties of different salinity tolerance revealed an increase in the content of endogenous abscisic acid (ABA) with increasing NaCl salinity in IR20 (semi salt-tolerant), but in Pokkali (salt-tolerant) and IR28 (salt-sensitive) the increase in ABA content was marginal. Under sahnity stress, in general, 5 weekly sprayings of ABA (10^-4 mol L^-1) decreased Na and K concentrations in the shoot to the extent of 29.5 % and 3.3 %, respectively. However, ABA application significantly improved the K/Na ratio as well as the chlorophyll fluorescence decrease ratio (Rfd, indicator for potential photosynthetic activity), the number of green leaves per plant and the shoot dry weight. The response of IR20 and IR28 to ABA application was significantly better than that of Pokkali. Increasing salinity caused marked nutrient imbalances, decreased Rfd values and shoot dry weight. The results are discussed in relation to possible mechanism of salinity tolerance.     

TRANSLOCATION OF AMINOTRIAZOLE AND DALAPON IN AG ROPY RON REPENS (L.) BEAUV.

Summary. Tracer studies using single drops of solutions containing 3–amino-1,2,4–triazole-5–¹⁴C (aminotriazole-¹⁴C) or 2,2–dichloropropionic acid-2–¹⁴C (datapon-¹⁴C) revealed that in couch plants (Agropyron repens (L.) Beauv.) growing under field conditions in the autumn and at the stage where the aerial shoots were 40–50 cm long, both compounds moved in both symplast and apoplast. Dalapon was less mobile in the symplast than aminotriazole and only negligible amounts of dalapon were translocated to the rhizomes. The nodes of the treated shoots appeared to act as barriers to translocation, a phenomenon more pronounced for dalapon than for aminotriazole.
Application to a basal green leaf led to a more uniform distribution of the compounds within plants and rhizomes than when the application was made to the youngest fully-expanded leaf.
In couch plants with aerial shoots 10–15 cm long treated in the stubble, the distribution of both aminotriazole and dalapon was mainly restricted to the treated shoots. Even 15 days after application only trace amounts of radioactivity could be found in the rhizomes and untreated shoots.