No abstract

Nitrogen nutrition is one of the major factors limiting the growth and production of crop plants. Limited information on proteome changes occurring in response to nitrogen amount have been available up to now. We used 2-DE to investigate proteome differences between two triticale varieties and the changes caused by nitrogen nutrition deficit in the flag leaf tissue. Some physiological features, such as the number of tillers per plant, SPAD index, dry weight, and protein content were measured previous to the proteomic analysis. Statistical analysis identified 29 differential protein spots in the selected pairwise comparisons of experimental conditions and correlated with the expression cluster revealed by the principal component analysis. The 29 protein spots were subjected to matrix-assisted laser desorption ionization time of flight (MALDI-TOF) to deduce their possible functions. Many of these changes referred to enzymes involved in photosynthesis, metabolic pathways implicated in the balance of the energy, and redox status of the cell. This work provides a first characterization of the proteome changes that occur in response to nitrogen deficit in flag leaves of triticale plants.

A field experiment has been conducted in the region of Dobrudja with the aim to investigate the essential oil yield and its chemical composition by four lavender varieties: Hemus, Sevtopolis, Yubileyna and Druzhba. The experiment has been arranged according to the Randomized Complete- Block Design in four replications and a plot size of 10 m2. The essential oil yields varied from 90 l ha-1 by the variety Hemus to 131 l ha-1 by the variety Sevtopolis. The major constituents of the essential oil were linalyl acetate (25.5-39.7%) and linalool (27.6- 38.9%). The content of linalyl acetate was the highest by the variety Hemus, as only by this variety the ratio between linalyl acetate and linalool is 1:0.7, which defined the essential oil as high qualitative.

The aim of this study is to be investigated “Yield - irrigation depth” relationship for white breading rose in the conditions of Kazanlak’s Valley (south part of Bulgaria). The field experiment was carried out during 2009 - 2011 period with following variants: 1) without irrigation; 2) irrigation with 50% of the irrigation depth; 3) irrigation with 75% of the irrigation depth; 4) full irrigation (100% of calculated irrigation depth). This relationship is established in two directions - for blossom and for oil, using the degree equation: Yi=1-(1-Yd)x(1-xi)n, (where Yi is the yield by irrigation depth xi, Yd - yield without irrigation, xi - relative irrigation depth and n - exponent). The results show that used equation presents very accurately the change of the yield depending on level of the irrigation depth. The value of “n” is from 1.0 to 1.2 and R>0.94. There is linear relationship (by R2>0.8), which allows predicting the yield of oil by data for yield of blossom.

During the period from 2014 to 2017 year in the region of Dobrich, Bulgaria, a field experiment has been conducted with the aim to determine some agricultural characteristics of lavender varieties. The following characters have been investigated: number of flowers/plant, length of the flowering stem, number of flower clusters/plant, weight of flowers/plant (g), yield of flowers (kg ha -1 ), essential oil content %, extraction essential oil yield (kg). The experiment has been carried out according the randomized block design in four replications and plot size of 10 m 2 . Four lavender varieties have been used-Hemus, Yubileyna, Druzhba and Sevtopolis. From the performed analyzes, it was established, that the variety Druzhba distinguished from the other varieties in term of yield of fresh flowers, not only by years, but also on average for the study period, as the higher productivity of this variety is due to the higher values of the structural elements of the yield. The highest percentage of essential oil content for the three-year period with 2.1% was realized from the variety Sevtopolis, and the lowest with 1.6% from the variety Hemus.