Patogeni lista trešnje i višnje u Srbiji

In recent years, sweet and sour cherry production in Serbia has increased. Under Serbian agroecological conditions, pathogens causing leaf diseases threaten the success of sweet and sour cherry production. In the period 2012-2019, the health status of cherries was monitored in more than 30 locations. Depending on the production system, the following leaf pathogens were identified: Blumeriella jaapii, Wilsonomyces carpophilus, Mycosphaerella cerasella, Phoma prunicola, Podosphaera clandestina and Pseudomonas syringae pv. syringae and morsprunorum race 1. Leaf pathogens caused premature defoliation, which adversely affected bud formation for the next growing season and increased susceptibility to freezing. Therefore, attention should be focused on correct leaf pathogen identification, and proper selection, application and rotation of fungicides.Poslednjih godina proizvodnja trešnje i višnje u Srbiji je povećana. U našim agroekološkim uslovima, patogeni lista ugrožavaju proizvodnju ovih perspektivnih voćnih vrsta. U periodu 2012-2019. godine praćeno je zdravstveno stanje trešnje i višnje, na više od 30 lokaliteta. avisno od sistema proizvodnje identifikovani su sledeći patogeni lista: Blumeriella jaapii, Wilsonomyces carpophilus, Mycosphaerella cerasella, Phoma prunicola, Podosphaera clandestina, Pseudomonas siringae pv. syringae i morsprunorum rasa 1. Patogeni lista izazivaju prevremenu defolijaciju, što negativno utiče na formiranje pupoljaka za narednu vegetaciju i povećanu osetljivost na izmrzavanje. Stoga pažnju treba usmeriti na ispravnu identifikaciju patogena, pravilan izbor i rotaciju fungicida različitog mehanizma delovanja, kao i optimalno vreme za njihovu primenu

Proučavanje osetljivosti komercijalnih i autohtonih sorti jabuke prema najznačajnijim bolestima u Srbiji u uslovima spontane zaraze

This study presents the results of a multiple-year evaluation (1991-1996; 2005-2007) of susceptibility of more than 100 apple cultivars to Venturia inaequalis, Podosphaera leucotricha and Erwinia amylovora under agroecological conditions existing in Serbia. Some of the most popular cultivars were found highly susceptible to V. inaequalis (Cripps Pink, Mutsu, Gloster 69, Wellspur); while Golden Delicious, Richared, Gala, Čačanska pozna, Čadel and Jonagold were susceptible; Idared, Granny Smith and Jonathan moderately susceptible; Lord Lamburne and London Pepping, as well as several autochthonous cultivars were moderately resistant; and a group of resistant cultivars included Prima, Priscilla, Williams Pride, Dayton, Enterprise, Gold Rush, Golden Orange, many of the Re-cultivars (Germany), as well as Baujade, Selena, Dukát, Produkta, Topaz, some older cvs. (Worcester Pearmain, Merton Worcester, James Grieve, Akane, Astilish, Astrachan Red and Discovery), some Co-op selections (USA) and NS hybrids (Serbia). Regarding powdery mildew, Idared and Jonathan were highly susceptible; Gala, Akane, Jonagold, Priscilla, Mutsu, Čačanska pozna, Golden Delicious, Granny Smith, Čadel and GoldRush were susceptible; Wellspur, Astrachan Red, Richared, Jonadel, Dayton and several autochthonous cultivars were moderately susceptible; Lord Lamburne, Astlisch, Prima, Champagne Reinette, Discovery and many autochthonous cultivars were moderately resistant; while most Re-cvs. (Germany), several cultivars from the Czech Republic, some selections from the USA and UK and most NS hybrids (Serbia) were resistant. Also, some cultivars showed variable susceptibility depending on location (Williams Pride, Gloster 69, Baujade and Produkta). E. amylovora was observed only in 2007 and at relatively low intensity (up to 12% infection). The highest disease severity was observed on cv. Elstar, then Granny Smith, Idared and Jonagored; while the lowest was found on Red Chief and Hapke apple trees.Ovaj rad prikazuje rezultate višegodišnjeg proučavanja (1991-1996; 2005-2007) osetljivosti više od 100 sorti jabuke prema patogenima Venturia inaequalis, Podosphaera leucotricha i Erwinia amylovora u agroekološkim uslovima Srbije. Neke od dobro poznatih sorti su visoko osetljive prema V. inaequalis (Cripps Pink, Mutsu, Gloster 69, Wellspur); osetljive su Golden Delicious, Richared, Gala, Čačanska pozna, Čadel i Jonagold; umereno osetljive su Idared, Granny Smith i Jonathan; umereno otporne su Lord Lamburne i London Pepping, kao i nekoliko autohtonih sorti; grupa otpornih uključuje sorte Prima, Priscilla, Williams Pride, Dayton, Enterprise, Gold Rush, Golden Orange, mnoge Re-sorte (Nemačka), Baujade, Selena, Dukát, Produkta, Topaz, neke starije sorte (Worcester Pearmain, Merton Worcester, James Grieve, Akane, Astilish, Astrachan Red i Discovery), neke Co-op selekcije (USA) i NS hibridi (Srbija). Prema pepelnici vrlo osetljive su bile sorte Idared i Jonathan; osetljive Gala, Akane, Jonagold, Priscilla, Mutsu, Čačanska pozna, Golden Delicious, Granny Smith, Čadel i GoldRush; umereno osetljive Wellspur, Astrachan Red, Richared, Jonadel, Dayton i nekoliko autohtonih sorti; umereno otporne su Lord Lamburne, Astlisch, Prima, Champagne Reinette, Discovery i mnoge autohtone sorte; i otporne su Re-sorte, nekoliko sorti iz Češke Republike, neke selekcije poreklom iz USA i UK i većina NS hibrida. Takođe, neke sorte su i varirale u osetljivosti (Williams Pride, Gloster 69, Baujade i Produkta). E. amylovora je beležena samo 2007. godine sa relativno malim intenzitetom bolesti (infekcija do 12%). Najveći intenzitet bolesti je primećen kod sorte Elstar, zatim slede sorte Granny Smith, Idared, Jonagored; a najmanji intenzitet je bio kod sorti Red Chief i Hapke

Novi izazovi u oplemenjivanju voćaka

The exciting challenge for all breeders is to release cultivars which the market wants and which can produce a profit for the growers. They have done it in the past and they will continue to do it in the future. Today's fruit breeding program are interrelated with other research disciplines. The complex, dynamic and interdisciplinary interactions require innovative approaches, including modern tools and techniques. The most important areas of collaboration are: database management, genetics, phytopathology entomology, ecology, physiology, molecular biology, fruit quality and sensory perception. Breeders also need to be aware of modern fruit marketing and consumer requirements. The complexity of tasks in modern fruit breeding sometimes leads to the specialization of particular breeding program and a dynamic interaction between complementary programs. Responses from fruit breeders about genetic transformation ranged from strongly negative to actively positive. Fruit breeders are constantly challenged to consider new tools and technology to increase the efficiency of their programs.Generalni, najvažniji izazov oplemenjivačkog rada je stvaranje novih sorti koje će prihvatiti tržište i koje donose profit proizvođačima. Selekcioneri su uspešno ispunjavali ove najviše ciljeve do sada i nema sumnje da će nastaviti da to rade i ubuduće. Današnji oplemenjivački programi su interdisciplinarni. Kompleksnost, dinamičan razvoj i interdisciplinarna interakcija zahtevaju nove prilaze, inventivne i dobro obučene kadrove savremene metode i opremljenost laboratorija. Najvažnije oblasti saradnje predstavljaju baze podataka, genetika, fitopatologija, entomologija fiziologija, ekologija, molekularna biologija, mehanizacija proizvodnje kvalitet ploda i senzorsko ocenjivanje. Oplemenjivači moraju biti svesni modernih zahteva tržišta i potrošača. Kompleksnost ciljeva vrlo često vodi ka specijalizaciji pojedinih oplemenjivačkih programa i dinamičkoj interakciji komplementarnih programa. Odnos oplemenjivača prema genetički modifikovanim organizmima ide od negativnog do pozitivnog. Stalan izazov pred naučnim radnicima je spoznaja novih metoda i tehnologija kako bi unapredili efikasnost svojih oplemenjivačkih programa

Epidemiology studies of Pseudomonas syringae pathovars associated with bacterial canker on the sweet cherry in Serbia

This study was conducted to examine the epidemiological characteristics of two Pseudomonas syringae pvs. – syringae (Pss) and morsprunorum race 1 (Psm) on the sweet cherry in both field and laboratory conditions. Cycled inoculations of one-year-old branches indicated that the sweet cherry became sensitive to Psm race 1 earlier in the season (October) compared to Pss (November). The most severe infections occurred in the dormancy period (November), while the necroses formed in January and March were less in their length. Inoculations of the two-/three-year-old branches performed in November resulted in necrosis, with those induced by Pss being more aggressive. The January inoculations, however, resulted in less formed necroses in length. Laboratory tests performed on excised sweet cherry branches confirmed the results yielded by the field experiments, indicating that the dormancy period poses the greatest risk for the P. syringae pvs. infection. The isolation of Pss and Psm bacteria from naturally infected sweet cherry samples (cankers) during the summer indicated that the bacteria that persists in cankers in low numbers became active during autumn. Significant Pss and Psm race 1 epiphytic bacterial populations were noted during the spring, but decreased in the summer and increased again in the autumn, indicating the presence of inoculum reservoirs. The greater understanding of the control strategies aimed at the epidemiological factors should, thus, facilitate better disease outbreak management

Inheritance of warty fruit texture and fruit color in bottle gourd [Lagenaria siceraria (Molina) Standl.]

Bottle gourd [Lagenaria siceraria (Molina) Standl.] is one of the most interesting species in the plant kingdom, due to the diversity of fruit shapes, sizes and ways of use. Warty genotypes are rare compared to non warty genotypes. Considering unusual external appearance of warty fruits, we focused our research on the investigation of its inheritance patterns. By crossing different bottle gourd phenotypes, we studied the mode of inheritance and identified and verified genes responsible for the fruit skin color and warty phenotype segregation. Two parental lines, LAG 70 (with warty fruit of light green color) and LAG 71 (smooth fruit, variegated), F1, F2 and backcrosses populations along with both parents were evaluated. Genetic analysis indicated that warty fruit type is a result of monogenic inheritance, whereby the warty fruit type is dominant (Wt) trait over to the non-warty fruit type (wt). The mode of inheritance of fruit color was controlled by recessive epistasis, with a ratio of 9 variegated (A-, B-), 3 dark green colored (aaB-) and 4 light green colored (aabb) fruits in the F2 generation

Toxin production by pseudomonas syringae pathovars originating from sweet scherry

Pseudomonas syringae pathovars syringae and morsprunorum race 1, causal agents of sweet cherry die back were investigated for their toxin production. Total of 155 strains isolated from diseases sweet cherries from several location in Vojvodina Province, Serbia were used. In previous study the strains were identified as a pv. syringae(79 strains, based on presence/absence of syrB and syrD genes) and as a pv. morsprunorum race 1 (76, presence cflgene)based on molecular identification.In this study, bioassay for syringomycin production showed that 64 strainsamong pv. syringaeproduced toxin, and 15 have not in the presence of syringomycin sensitive organismsG. candidum,S. cerevisiaeand R. pilimanae. However, using bioassay for coronatine production on the potato slices only few strains out of 76 pv. morsprunorum race 1 strains produced coronatine

Changes in superoxide-dismutase (SOD) activity in auxin treated Prunus sp. softwood cuttings under oxidative stress

Oxidative metabolism of normal cells and different stress situations generate highly reactive oxygen species (ROS). The ROS have been implicated in a number of physiological disorders in plants. Such factors as certain mechanical injuries are known to induce ROS formation in most aerobic organisms. Antioxidant defence systems have co-evolved with aerobic metabolism to counteract oxidative damage from ROS. This includes antioxidant enzymes such as superoxide-dismutase (SOD; EC 1.15.1.1). SOD is of the greatest importance since it catalyzes the dismutation of the superoxide radical (O2.-) to O2 and H2O. Thus, the aim of this study was to measure the intensity of SOD in the leaves of six cherry rootstock selections in order to investigate the effect of exogenously applied auxins on the mechanical injury induced oxidative stress during the process of rooting of softwood cuttings. The experiment was carried out in the plastic house under a fogging system with 95-99% average relative humidity. The 15-20 cm long terminal cuttings were treated with the mix of auxins (IBA, 0.5% and α-NAA, 0.8%) powder prior to insertion into the white sphagnum and perlite substrate mixture. Leaves of six promising rootstock selections of Prunus cerasus L., P. mahaleb L. and P. fruticosa Pall., and one standard rootstock PHL-A were sampled on the 1st, 3rd and 7th day after inserting softwood cuttings into the rooting substrate. The SOD activity was measured by monitoring the inhibition of nitroblue-tetrazolium (NBT) reduction at 560 nm. Results showed that generation of ROS occurred in all investigated genotypes, but they greatly differed in susceptibility towards oxidative stress induces by mechanical injury. Application of auxins on standard vegetative rootstock PHL-A, as well as P. mahaleb selection M6 showed positive effect on lowering SOD activity after the 3rd and 7th collecting day compared to control. On the other hand, selections of P. cerasus OV22 and P. fruticosa SV2 expressed high SOD activity during all collecting days which was from 3.6-54.9% higher compared to control. Enhanced SOD activity in leaves of softwood cuttings indicates induction of the enzymatic antioxidant system in both auxin treated and untreated cutting. According to these results SOD activity could be used as one of the biochemical parameters in further rootstock selection for sweet and sour cherries

Smanjenje intenziteta lipidne peroksidacije u listovima selekcija vegetativnih podloga za višnju i trešnju upotrebom egzogeno primenjenih auksina

The effect of exogenously applied auxins on mechanical injury induced oxidative stress was studied in 6 promising rootstock selections of Prunus cerasus L., P. mahaleb L., and P. fruticosa Pall. Investigated selections were included in low vigorous rootstock breeding programme for sweet and sour cherries. The standard rootstock PHL-A was used as a control, due to successful rooting. Leaves of investigated rootstocks were collected on: 0, 1st, 3rd and 7th day of inserting softwood cuttings into the rooting substrate under a fogging system with 95-99% average relative humidity. Exogenously applied auxin mixture consisted of 0.8% α-naphthylacetic acid (NAA) and 0.5% indolebutyric acid (IBA). Mechanical injuries during rooting period represent one of the factors that induce stress in softwood cuttings. Intensity of LP is used as a valuable biomarker of plant response to various abiotic factors. Differences in intensity of LP between auxin-treated and -untreated cuttings were examined. Almost all of investigated selections had lower LP intensity after auxin application (11.4-47.2%) between 1st and 3rd day. However, the most prominent change was in leaves of PHL-A (49.2%). The best LP-lowering effect were recorded in leaves of P. fruticosa, SV4 selection (56.9%) on 7th day and in P. mahaleb, M4 selection, on 1st and 3rd day (5.9, 5.8%), in comparison to untreated softwood cuttings. As for OV21 selection, LP intensity significantly increased in both treated and untreated cuttings on the 1st, 3rd and 7th day, but auxin-treated cuttings showed lower LP values, except on 7th day, reaching 221.3 nmol MDA equivalents g-1 fresh weight. Intensity of LP during vegetative propagation of selected genotypes could be used as one of the biochemical parameters in further rootstock selection for sweet and sour cherries

Total and individual phenolics in wild and cultivated elderberry during development

Compounds which add to bioactivity of elderberry (Sambucus nigra L.) are mostly phenolic compounds. One wild edible and two cultivated genotypes (’Haschberg’ and ’Ljubostinja’ selections) have been chosen. Leaves and fruits were collected in four stages (April-September). Total phenolics (TP) content was determined from MeOH extracts by Folin-Ciocalteau method while determination of individual compounds was performed using HPLC-DAD-ESI-MSn analysis with a DAD at 280, 350 and 530 nm. TP content in leaves varied through developmental stages, being higher in II and III stage. Leaves and fruits (both unripe and ripe) of ’Ljubostinja’ plants had higher content of TP compared to wild ripe fruits (1.5-fold). Leaves had caffeic acid derivatives (0.3-0.7% in wild, 0.2-0.3% in ’Haschberg’ and 0.4-0.6% in ’Ljubostinja’ in dry weigh) and caffeoylquinic acid derivatives, while fruits had more caffeoylquinic acid derivatives, particularly unripe fruits. The major phenolic acid present in leaves, especially during the II stage of development, was chlorogenic acid (approx. 4% dw) and the same was recorded in fruits (0.03% dw in unripe fruits of wild plants). Content of phenolic acids decreased during ripening of elderberry fruits and the similar was detected in the leaves

Sugars and organic acids content in unripe and ripe fruits of Sambucus nigra

Elderberry (Sambucus nigra L.) is a common plant used for its medicinal and nutritional properties, as for the beverages, jams, liqueurs, flavourings etc. Plant material examined were leaves and fruits of wild edible, and cultivated elderberry plants (’Haschberg’ and ’Ljubostinja’ selections). Determination of organic acids and sugars was performed using high-performance liquid chromatography. Organic acids found in the tested fruit samples were citric, tartaric, malic, quinic, shikimic and fumaric acids, out of which quinic acid content was the highest in unripe, while citric acid content was the highest in ripe fruits. Wild plants had higher contents of organic acids in unripe fruits (16.7 g 100 g-1dw) than cultivated (’Haschberg’ 6.6, and ’Ljubostinja’ 6.3 g 100 g-1dw). ’Ljubostinja’ selection had significantly higher organic acids content (10.2 g 100 g-1dw) in ripe fruits compared to wild specimen and ’Haschberg’ plants which had similar organic acids content (7.0 and 7.4 g 100 g-1dw). The major organic acid in ripe elderberry fruits was citric acid. When it comes to sugars content the presence of sucrose, glucose, fructose and sorbitol was established. Wild specimen had significantly higher sugars content (2.2 in unripe, and 8.4 g 100 g-1dw in ripe fruits)