Marija Kraljevic-Balalic

The parameters of grain filling and yield components in common wheat (Triticum aestivum L.) and durum wheat (Triticum turgidum L. var. durum)

Final grain dry weight, a component of yield in wheat, is dependent on the duration and the rate of grain filling. The purpose of the study was to compare the grain filling patterns between common wheat, (Triticum aestivum L.), and durum wheat, (Triticum turgidum L. var. durum), and investigate relationships among grain filling parameters, yield components and the yield itself. The most important variables in differentiating among grain filling curves were final grain dry weight (W) for common wheat genotypes and grain filling rate (R) for durum wheat genotypes; however, in all cases the sets of variables important in differentiating among grain filling curves were extended to either two or all three parameters. Furthermore, in one out of three environmental conditions and for both groups of genotypes, the most important parameter in the set was grain filling duration (T). It indicates significant impact of environmental conditions on dry matter accumulation and the mutual effect of grain filling duration and its rate on the final grain dry weight. The medium early anthesis date could be associated with further grain weight and yield improvements in wheat. Grain filling of earlier genotypes occurs in more temperate environments, which provides enough time for gradual grain fill and avoids the extremes of temperature and the stress of dry conditions.

BORON CONCENTRATION VS. CONTENT AS CRITERION FOR ESTIMATING BORON TOLERANCE IN WHEAT

The objective of this study was to investigate the relationships among boron (B) concentration, boron content, and tolerance to excess boron in 40 wheat (Triticum aestivum L.) genotypes. Boron tolerance was estimated at seedling stage by filter paper technique, imposing three boron treatments (50, 100 and 150 mg L−1 boric acid, H3BO3) and comparing the response of root length and dry weight to the control (0.93 mg L−1 H3BO3). Although substantial variation in boron tolerance, concentration, and content has been found among the studied wheat genotypes, regression analysis showed no relationship between neither root length reduction and boron concentration, nor dry weight reduction and boron concentration. On the other hand, a positive linear relationship was found between boron content and both root length and dry weight response to high external boron; tolerant wheat genotypes were characterized by higher boron content than the sensitive ones. The results may be explained by significant decline of root length and dry weight in sensitive genotypes, which caused reduced uptake of all nutrients, including boron. Vice versa, root length and dry weight of tolerant genotypes were affected by boron treatments to the smaller extent, allowing the uptake of higher amounts of boron and resulting in comparatively high boron content.

AMMI analysis of nitrogen harvest index in bread wheat

Nitrogen harvest index - NHI is a measure of efficiency of nitrogen translocation from vegetative organs to grain. The goal of this paper is to investigate variability and stability of nitrogen harvest index of twelve bread wheat genotypes, on three nitrogen levels. ANOVA showed that nitrogen harvest index was mostly under influence of the year x genotype interaction, year of investigation and genotype, and in the smallest amount of the nitrogen rate. Increasing doses of nitrogen did not lead to increased nitrogen harvest index. AMMI analysis showed that most genotypes differed in both the main effect and in GxE interaction. The highest stability i.e. the smallest interaction effect, was found in varieties Axis, Ilona, Sonata and Renan on N0 rate, and in varieties Malyska, Petrana, Axis and Evropa 90 on N100 rate. Cultivar Pobeda with the high average values for nitrogen harvest index, also had small interaction effect, i.e. it proved to be a stable variety.