Snježana Bolarić

Morphological, genetic and phytochemical variation of the endemic Teucrium arduini L. (Lamiaceae)

Analysis of the morphological traits of leaves, genetic variability (analyzed by AFLP) and chemical composition of essential oils (analyzed by GC-MS) was conducted on eleven populations of the endemic Illyric-Balcanic species Teucrium arduini L. in Croatia, Bosnia and Herzegovina, and Montenegro. Average blade length and width ranged from 20.00 to 31.47mm and from 11.58 to 15.66mm, respectively. Multivariate analysis (PCA, UPGMA) of morphological traits distinguished two continental Bosnian populations from the remaining populations. AFLP analysis separated the investigated populations into two groups based primarily on geographical distance. Essential oil analysis showed a total of 52 compounds, with two chemotypes distinguished based on the essential oil profile. The first was a sesquiterpene chemotype, with β-caryophyllene, germacrene D or caryophyllene oxide as the major compounds, while the second was an oxygenated monoterpene chemotype, with pulegone and piperitone oxide as the main components. The Mantel test showed a stronger correlation between the morphological traits and AFLP than between the essential oil profile and AFLP. The test also showed a stronger association between the essential oil profile and geographical position than between the morphological traits and geographical position.

Soil assessment based on botanical composition on habitats of autochthonous populations of red clover (Trifolium pratense L.)

One of the biggest challenges for the safe maize production is the yield stability in a wide range of environments with different soil fertility, weather conditions, prevailing pests and diseases as well as cultural practices. In order to achieve it, new hybrids with higher tolerance to biotic and abiotic stress are continuously being created. In order to compare performance of maize hybrids in environments with different levels and types of stress, and relate it to the stalk lodging incidence, we compared performance of 64 maize hybrids obtained by crossing 16 inbred lines with four inbred testers in three different environments. Two environments at same location (Rugvica) differed in crop rotation, and the third environment at location Botinec was considered as dry because of low water capacity of the soil. Mixed models that included all design elements and genetic background of hybrids were used to analyze the effect of lodging on yield in different environments. The results show that stalk lodging had a significant effect on yield, but significant lodging x environment interaction indicates that this effect was rather environment specific.Sweet pepper Istra F1 hybrid was grown in a greenhouse on K rich soil. For evaluation of K antagonism, two K rates (55 and 85 kg ha-1) were applied in a randomized complete block design with four replications. Total number of fruits, total number of BER affected fruits as well as average fruit mass were recorded for each harvest. Fruit and leaf K and Ca content were determined at three plant growth stages (at the stage of the first, third and fifth fruit cluster). Higher K rate gave higher : average fruit mass (169.45 g), total number of fruits per plant (7.95), number of BER affected fruits per plant (3.82), K in leaves (5.44% DM), K in fruits (6.35% DM), but negatively correlated with Ca concentration in fruits (0.57% DM) and leaves (3.24% DM). This resulted in decreased marketable yield of sweet pepper fruits.

Morphological and agronomic characteristics of Croatian red clover ( Trifolium pratense L.) breeding populations tolerant to abiotic stress

Red clover (Trifolium pretense L.) is a temperate species originated from Southeast Europe and Asia Minor near the Mediterranean Sea (Taylor and Quesenberry, 1996). It is a short-lived perennial diploid species with seven pairs of chromosomes (Taylor and Quesenberry, 1996), insect pollinated and self incompatible. Red clover can be grown across a wide range of soil types, pH levels, and environmental conditions, and gives good yields in areas not suitable for growing alfalfa (Smith et al., 1985). Knowledge of the amount and distribution of genetic variability within species is crucial for breeders when selecting breeding germplasm (Muntean and Savatti, 2003). Genetic variation is frequently estimated using morphophysiological characters, which often show multigenic inheritance with strong environmental modification (Kolliker et al., 2001). Tolerance of field crop to abiotic stress, such as drought and cold tolerance (Peter et al., 2006 ; Pepo et al., 2006 ; Czi vek et al., 2006) is of primary importance for sustainable crop production in stress environment. Tolerance to abiotic stresses in red clover was analysed in few studies (Nowak et al., 1992 ; Nelke et al., 1999). Red clover is the most important fodder crop in north-western region of Croatia where climate is humid, soils shallow and wet, and vegetation period short (Gagro, 1998). Due to small producing input and multiplied gain, red clover gets more on its importance in sustainable agricultural production where the complete producing cycle tends to be included within the land and facilities of one farm. Main objective of this research was to estimate variations in morphological and agronomic characteristics among red clover breeding populations tolerant to abiotic stress developed at the Faculty of Agriculture in Zagreb during the last ten years.