Genotype-dependent responses of apples to drought stress were evaluated between commercial and traditional apple cultivars. The results indicate different mechanisms of tolerance to investigated ...drought stress conditions. Chlorophyll fluorescence induction (OJIP) parameters, chlorophyll and carotenoid content, malondialdehyde (MDA), hydrogen peroxide (H
O
), proline, phenols and leaf water content (WC) were measured. The traditional cultivar "Crvenka" confirmed the best tolerance to a drought stress condition, presenting higher photosynthetic efficiency, higher leaf water content, higher levels of chlorophyll content and lower lipid peroxidation with greater membrane stability. The commercial cultivar "Golden Delicious Reinders" showed decreased water content in leaves, increased lipid peroxidation levels and photoinhibition. Considering all results, the commercial cultivar "Golden Delicious Reinders" was adversely affected by drought, while traditional cultivars exhibited better tolerance to drought stress.
The aim of this study was to evaluate physiological responses to short-term heat stress in the leaves of traditional (Bistrica) and modern (Toptaste) plum cultivars. In this study, detached plum ...leaves were incubated at 25 °C (control) and 40 °C (stress). After 1 h of exposure to heat (40 °C), chlorophyll a fluorescence transients were measured, and several biochemical parameters were analyzed. Elevated temperature caused heat stress in both plum cultivars, seen as a decrease in water content (WT), but in the leaves of the cultivar Bistrica, an accumulation of proline and phenols, as well as an accumulation of photosynthetic pigments, suggest the activation of a significant response to unfavorable conditions. Conversely, in the leaves of Toptaste, a significant accumulation of malondialdehyde (MDA) and an activation of guaiacol peroxidase (GPOD), all together with a decreased soluble proteins content, indicate an inadequate response to maintaining homeostasis in the leaf metabolism. The impact of an elevated temperature on photosynthesis was significant in both plum cultivars as reflected in the decrease in performance indexes (PIABS and PItotal) and the maximum quantum yield of PSII (Fv/Fm), with significantly pronounced changes found in Toptaste. Unlike the traditional plum cultivar, Bistrica, in the modern cultivar, Toptaste, short-term heat stress increased the minimal fluorescence (F0) and absorption (ABS/RC), as well as Chl b in total chlorophylls. Additionally, the inactivation of RCs (RC/ABS) suggests that excitation energy was not trapped efficiently in the electron chain transport, which resulted in stronger dissipation (DI0/RC) and the formation of ROSs. Considering all presented results, it can be presumed that the traditional cultivar Bistrica has better tolerance to heat stress than the modern cultivar Toptaste. The cultivar, Bistrica, can be used as a basis in further plum breeding programs, as a source of tolerance for high temperature stress.
Cacopsylla pyri L. (Hemiptera: Psyllidae) je jedan od najvažnijih gospodarskih štetnika kruške. S obzirom na nove smjernice o održivoj uporabi pesticida i smanjenja rizika od negativnih učinaka ...pesticida stalno se iznalaze nova, ekološki prihvatljiva rješenja u zaštiti bilja. Cilj ovog istraživanja je bio utvrditi utjecaj biostimulatora na povećanje otpornosti kruške na intenzitet napada kruškine buhe. Istraživanje je obavljeno 2021. godine u pokusnom nasadu kruške, sorte Williams/BA 29, Poljoprivrednog instituta Osijek. U svrhu istraživanja obavljena su dva tretmana (T1 - Katon XT + Bombardier, T2 - kontrolni tretman - voda). Redovito praćenje brojnosti svih razvojnih stadija kruškine buhe provedeno je na prethodno obilježenim jednogodišnjim izbojcima pokusnog stabla u tri ponavljanja. Potvrđen je očekivani rezultat jednogodišnjeg istraživanja da je uporaba kombinacije biostimulatora dala statistički značajnu manju brojnost svih razvojnih stadija u odnosu na kontrolni tretman.
Cacopsylla pyri L. (Hemiptera: Psyllidae) is one of the most important economic pests of pear. With regard to new guidelines on the sustainable use of pesticides and reducing the risk of negative effects of pesticides, new, environmentally friendly solutions are constantly being found in plant protection. The aim of this research was to determine the impact of biostimulators in pear production on increasing resistance to the harmful pear psylla population. The research was set up in 2021 in an experimental pear plantation of the Williams/ BA 29 variety of the Agricultural Institute Osijek in two treatments (T1- Katon XT + Bombardier, T2- control treatment - water). Regular monitoring of the abundance of all developmental stages of the pear psylla was done on marked one-year-old shoots of the experimental tree in three repetitions. The expected result of the one-year study was confirmed, that the use of a combination of biostimulators gave a statistically significant lower number of all developmental stages compared to the control treatment.
The aim of this study was to determine how different locations, years and cultivars influenced polyphenol and anthocyanin content in fruits of different sour cherry cultivars (Prunus cerasus L.). ...Fruits of five sour cherry cultivars were harvested in two locations (Osijek and Zadar) over three consecutive years (2010, 2011 and 2012). Factorial ANOVA showed that year and location significantly influenced the accumulation of polyphenols and anthocyanins in sour cherry fruits. 2010 was the best year with 9.89 mg/g of polyphenols and 5.08 mg/g of anthocyanins on average. Although year and location revealed a strong influence, cultivar is the principal source of variation, as it is proved by the polyphenol content in the range from 5.89 to 10.78 mg/g and the anthocyanin content in the range from 3.15 to 4.76 mg/g. Cv. Maraska appears to be the most significant source of bioactive compounds, while cvs. Heimanns Konservenweichel and Rexelle gave very similar but significantly lower contents of polyphenols and anthocyanins than cv. Maraska. Cv. Oblačinska had significantly the lowest contents of investigated bioactive compounds.
•Effects of elevated temperature and light were examined on apple cultivars.•The apples presented different responses under the experimental conditions.•Gala Galaxy had lower photosynthetic ...efficiency of performance index (PIABS).•Gold Rush had less damage to OEC activity and better stability of the PS II system.
In orchards, high temperature and high light stress are the most common abiotic stresses, which negatively affect fruit yield and quality. In this study, the physiological response of apple (Malus × domestica Borkh) cultivars to combination of increased temperature and excess light, which causes disorder of photosynthesis, was investigated. The PSII functionality and regulatory mechanisms in leaves of two apple cultivars in the field, under elevated temperature and excess light at midday, were evaluated. Chlorophyll a (Chl a) fluorescence transient was recorded using Plant efficiency analyzer (PEA), analyzed according to JIP test (analysis of O-J-I-P fluorescence transient) and several parameters were derived to explain the PSII behavior and photosynthetic efficiency. Tested cultivars showed different responses to investigated conditions and PCA analysis identified the cultivar Gold Rush as more tolerant with better thermostability of PSII. The lower efficiency of PSII antenna complexes in the Gala Galaxy cultivar caused higher increase in the heat dissipation value of excess absorbed light per active reaction center (DI0/RC) and a decrease in the captured photon flow rate and energy dissipation (TR0/DI0), which significantly contributes to its lower photosynthetic efficiency of performance index (PIABS) and total photosynthetic performance (PItotal). Cultivar Gold Rush had higher connectivity of light harvesting complexes to its reaction centers, less damage to OEC activity and better stability of the PS II system. The results obtained in this study may be useful in apple breeding programs, particularly for the selection of apple cultivars more tolerant and adjustable to higher temperature and irradiation.
BACKGROUND: Salt stress has recently emerged as one of the most significant abiotic stresses with negative impact on crop production. Photosynthesis is a vital biochemical process in plants, very ...sensitive to environmental constraints, including salt stress. OBJECTIVE: The aim of this study was to evaluate the impact of salt stress on photosystem II in the leaves of blackberry cultivars (Rubus fructicosus L.). METHODS: Two blackberry cultivars (Thornfree and Boysen) were exposed to salt stress (20, 40, and 60 mM NaCl) for 28 days in in vitro culture. The photosynthetic activity was evaluated by probing chlorophyll a fluorescence (JIP test) and photosynthetic pigments. RESULTS: The maximum quantum yield of PSII (Fv/Fm), performance indexes (PIABS and PItotal), and photosynthetic driving force (DFABS) were greatly affected by salt stress in the leaves of Boysen cultivar. Lower photosynthetic efficiency was confirmed by the increased values of absorption flux per RC (ABS/RC), trapping flux per PSII RC (TR0/RC), dissipation flux per RC (DI0/RC), decreased values of chlorophyll and carotenoid contents, disruption in the interaction between the light-harvesting complex and the core proteins of PSII, as well as disruption of the oxygen-evolving complex. CONCLUSIONS: The provided informations suggest that the photosynthetic apparatus of Thornfree cultivar was found to be more tolerant to salt stress compared to Boysen.
Alfalfa and red clover are the most widespread and most important perennial legumes, primarily used as a high-quality feed for livestock. Both alfalfa and red clover, as well as some other plant ...species from Fabaceae family, are a rich natural source of phytoestrogens, nonsteroidal compounds with an estrogenic activity whose beneficial effects in the prevention and treatment of many diseases are demonstrated in numerous scientific studies.
Nowadays, various herbal preparations are present on the world market and their use is constantly increasing, as well as the growing demands of consumers for environmentally sound and health-safe production of plant species used as sources of active substances. Because of their widespread distribution, the possibility of organic breeding, and also significant increases in surface area under genetically modified crops in most EU countries, alfalfa and red clover have become more interesting alternative sources of phytoestrogens. The most common phytoestrogens in these forage legumes are genistein, daidzein, glycitein, formononetin, biochanin, coumestrol, kaempferol and apigenin. The content of these substances is significantly influenced by a number of factors including genotype, environment, production technology, plant maturity stage, and individual plant parts.
Available evidence suggests that forage legumes represent high promising sources of health-promoting phytoestrogens. Due to numerous favorable features, they can find commercial application in different industries such as pharmaceutical, nutraceutical, cosmetic, and agriculture.
Apple is the most represented fruit species in Croatia. Codling moth, Cydia pomonella L, is one of the most important apple pests whose population is growing from year to year. The aim of this study ...was to determine the economic effectiveness of four treatments against codling moth (1 - based on baculovirus; 2 - based on the group of synthetic pyrethroid; 3 - based on kaolin, 4 - control treatment), on the three apple varieties. The experiment was performed at the Agricultural Institute Osijek, Croatia, during three years (2012-2014). In order to analyze the results of apple production it was necessary to calculate production efficiency, labor productivity, and profitability of production. The results of the research of economic efficiency according to market prices treatment 1 and treatment 2 had economic coefficient above 1 with tendency of significant growth, while treatment 3 and 4 were uneconomical. The treatment 1showed advantage over the treatment 2 because of its positive effects on human health and biodiversity, as well as satisfactory economic efficiency.
Number of lateral branches and overall development of seedlings is a crucial parameter for achieving the required quality standards dedicated to modern intensive production systems. Branched ...seedlings have formed the structure of the canopy, which is defined and cultivation model for future plantations. In addition to the uniformity of the plantation better and earlier productivity is achieved. The research, in order to standardize the techniques for induction of lateral branching, was conducted in 2013 in the nursery (Koprivna, Eastern Croatia) on 3 cherry cultivars grafted on Gisela 6 rootstock. The treatments included the application of different combinations of Bioregulators 6-Benzyladenine and gibberellic acid 4 and 7 (BA+GA4+7) as well as cyclanilide on cultivars ´Carmen´, ´Grace Star´ and ´Black Star´. All applied treatments resulted in a significant increase in the number of new branches compared to the control. Cultivar Black Star induced the development of the highest number of branches. Treatment BA + GA4 + 7 increased the number of lateral shoots compared to the control in all the investigated cultivars. The most significant induction in the number of branches has been achieved with Cyclanilide treatment which improved more correct distribution and resulted in a more uniform length of induced shoots. Combination of the treatment cyclanilide and BA + GA4 + 7 has not resulted in synergistic increase in the number of branches in response to treatment with cyclanilide. The applied treatments also significantly influenced the length of the branches and the branching angle. Results of this study indicate the need for further testing of cyclanilide as a potential regulator of growth in nursery production.
Cacopsylla pyri L. (Hemiptera: Psyllidae) is one of the most important economic pests of pear. With regard to new guidelines on the sustainable use of pesticides and reducing the risk of negative ...effects of pesticides, new, environmentally friendly solutions are constantly being found in plant protection. The aim of this research was to determine the impact of biostimulators in pear production on increasing resistance to the harmful pear psylla population. The research was set up in 2021 in an experimental pear plantation of the Williams/ BA 29 variety of the Agricultural Institute Osijek in two treatments (T1- Katon XT + Bombardier, T2- control treatment - water). Regular monitoring of the abundance of all developmental stages of the pear psylla was done on marked one-year-old shoots of the experimental tree in three repetitions. The expected result of the one-year study was confirmed, that the use of a combination of biostimulators gave a statistically significant lower number of all developmental stages compared to the control treatment.
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