The objective of this study was to estimate gene effects and genetic variability for some quantitative traits of two winter wheat crosses (Soissons/Zitarka and Soissons/Sana) by generation mean analysis. In most cases a digenic epistatic model was sufficient to explain variation in generation means. The additive-dominance model was adequate for plant height and grain weight per spike of the longest culm. In two cases (grain yield per plant and single grain weight) these models failed to explain variation in generation means, implying the presence of higher order interactions or interactions between linked loci. Dominance effects and additive x additive epistasis were more important than additive effects and other epistatic components. Only complementary type epistasis was observed.The estimated values of narrow-sense heritability (h 2 n ) varied for plant height (54-81%), number of heads per plant (9-76%), number of grains per spike (11-99.8%), grain weight per spike (23-73%), grain yield per plant (21-78%) and single grain weight (49.7-72%). The adequacy of certain modes of inheritance as well as the importance and significance of gene effects and genetic components of variance for analyzed traits were dependent upon the particular crossing combination and experimental site.

'Topaz' is a modern Czech apple cultivar well accepted by consumers and scab-resistant, providing reasons for the significant spreadof cv. 'Topaz' in European orchards, especially in the organic fruit production industry. Growing the apple trees on their own rootsprovides some advantages in comparison with grafted trees. Micropropagation is the method of choice for plantlet production for thispurpose as well as for the establishment of healthy mother stock trees as a source of scions. The efficiency of axillary shoot proliferationwas examined on four media differing in plant growth regulators and their concentrations, and from three explant types: intact ordecapitated and defoliated microshoots placed vertically and one-nodal segments placed horizontally. All media consisted of Quoirin and Lepoivre (QL) macroelements and Murashige and Skoog (MS) microelements. Furthermore, rooting efficiency on six different media/treatments was analyzed. Media with 1 mg/L 6-benzylaminopurine (BA) or BA (0.5 mg/L) + 1.5 mg/L kinetin (Kin) produced similarnumber of microshoots per inoculated one (2.5 and 2.4, respectively). Medium with 1 mg/L thidiazuron (TDZ) produced significantlyhigher number of shoots (3.6) but they were fasciated. Three different explant types also produced similar numbers of microshoots.High rooting efficiency (68.7%), a high number of roots per shoot (6.6) and the best quality of shoots were obtained in rooting mediumcontaining 2 mg/L of indole-3-butyric acid (IBA). An efficient method of shoot proliferation was established, and, since rooting was themost critical step, an efficient procedure for rooting apple cv. 'Topaz' was established.

Caper (Capparis orientalis Veill.) is a species rich in bioactive compounds, with positive effects on human health. It has a great adaptability to harsh environments and an exceptional ability to extract water from dry soils. In Croatia, the caper grows as a wild plant, and its cultivation is insignificant, which is probably due to propagation difficulties. Micropropagation could be a solution for this. The aim of this study was to investigate the success of the micropropagation, in vitro rooting, and acclimatization of Capparis orientalis Veill. Shoot proliferation was tested in a Murashige and Skoog (MS) medium, with sucrose or glucose, and in 13 treatments, presenting the combined effect of different cytokinins and their concentrations. The success of rooting was examined in relation to the impact of various auxins, durations of rooting, and carry-over effects. A better proliferation was achieved when sucrose was used. The highest number (18) of shoots/explants was obtained in the medium supplemented with 0.6 mg·L−1 meta-topolin, while the rooting was equally efficient in the media supplemented with 2 mg·L−1 of indole-3-acetic acid or indole-3-butyric acid, or in hormone-free rooting medium. A prolonged time in the media increased the rooting efficiency, while the carry-over effect had no influence. The acclimatization rate reached 66%. Additional efforts should be made to find out how to speed upthe rooting and enhance the acclimatization rate of caper grown in Croatia.

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Stability of breadmaking quality of four Croatian bread winter wheat cultivars was investigated using rheological traits from the farinogram (dough development time, stability, degree of so�ening, water absorption, Hankoczy quality number) and the extensogram (extensibility, maximum resistance, ratio of resistance to extensibility, energy) and the indirect traits (protein content, wet gluten content, Zeleny sedimentation volume, Hagberg falling number). Stability was evaluated for four cultivars grown in 12 environments in different parts of Croatia. Four stability parameters, covering a wide range of statistical approaches, were used to estimate cultivar stability. Variability for the stability of quality among cultivars was established. The cultivars Kuna and Banica showed high performance for most quality traits and were also identified as stable for the majority of them. The cultivar Žitarka was stable for four farinogram traits showing high level of performance only for dough development time, while Marija showed stability for only three traits but with unfavourable mean values for all of them. The largest contribution of genotype by environment effects in the total sum of variance components was found for the farinogram traits stability and dough development time, while the lowest, but similar to each other for protein content and wet gluten content.

Maksimir 3 Synthetic (M3S) maize population was developed at the Faculty of Agriculture University of Zagreb by intercrossing inbred lines, whose origins trace back to several open-pollinated varieties and local populations from different regions of the former Yugoslavia. The population was subjected to two cycles of selfed progeny recurrent selection for grain yield. The objectives of this study were: (i) to determine genetic distances among the parental inbred lines of the M3S population (M3S progenitors), the M3S population before and after two cycles of recurrent selection, and elite inbred lines representing the BSSS and Lancaster heterotic group; and (ii) to examine the effect of two cycles of recurrent selection on allele frequency changes in the population. Nine M3S progenitors, three BSSS lines, and three Lancaster lines were genotyped at 24 SSR loci, out of which nine randomly chosen loci were used for genotyping 96 individuals from both C0 (the M3S population before selection) and from C2 (M3S population after two cycles of selection). A total of 101 alleles were detected across 24 loci in the 15 lines, whereas 83 alleles were found in the nine M3S progenitors. Among the latter 83 alleles 31 were unique, i.e. found only in one of the progenitors. Mean genetic distance among nine M3S progenitors was 0.61 indicating a broad genetic base of the M3S population. High mean genetic distance was found between M3S progenitors and BSSS lines (0.69) and M3S progenitors and Lancaster lines (0.71). This indicates that the M3S population represents a germplasm source unrelated to both the BSSS and Lancaster germplasm. Mean genetic distance between the M3S population and BSSS as well as Lancaster lines decreased slightly after two cycles of recurrent selection suggesting the need to introduce testers from both groups in future selection in the M3S population in order to maintain heterotic complementarity of the M3S population to these groups. A test of selective neutrality identified several non-neutral loci in the population whose allele frequency changes from the C0 to the C2 cannot be explained by genetic drift. The majority of nonneutral alleles, whose frequency increased after two cycles of selection, were present in at least one line from the BSSS or Lancaster heterotic group.

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Terminal drought i.e. drought during grain-filling phase is the most devastating environmental stress to wheat production. In present study the effect of terminal drought on physiological traits and its influence on yield and yield components in two winter wheat varieties (Kuna and Karla) were investigated. Terminal drought stress was applied from the beginning of anthesis by installing mobile plastic roof above the crops. Leaf gas exchange parameters, chlorophyll content index (CCI), relative water content (RWC), and nitrogen (N) content were measured three times during grain-filling phase, at early milk maturity (EMM), late milk maturity (LMM), and at early wax maturity (EWM). Grain yield and 1000 grain weight were measured by harvesting of each plot at crop maturity. Terminal drought enhanced leaf senescence and caused reduction of RWC, CCI, net photosynthetic rate (A), stomatal conductance (gs), and transpiration rate (E) as well as, grain yield and all measured yield components. However, grain yield and grain weight per ear were less affected in Karla indicating enhanced tolerance to terminal drought compared to Kuna variety. Higher tolerance to terminal drought in Karla is based on staygreen strategy. Stay-green strategy in Karla was characterized by retention of CCI at early wax maturity, which contributed to higher E and lower intercellular CO2 concentration compared to Kuna under terminal drought. Stay-green strategy as trait that enhanced terminal drought tolerance in Karla should be used in breeding programs and utilized to ensure maximum economic yields under terminal drought conditions.