Incompatible pollen tubes in the plum style and their impact on fertilization success

The pistils of plum (Prunus domestica L.) cv. 'Cacanska Lepotica' were self- and cross-pollinated in order to investigate occurrence of incompatible pollen tubes in the style, and their impact on fertilization success. The investigation also included open pollination variant. The highest percentage of these stopped the growth in the upper third of the style. Under cross-pollination variant, 15.4% and 12.1% of pollen tubes observed in the upper part of the style in the first and the second years of study, respectively, were found incompatible. In view of the above parameters, in the self-pollination variant, 15.0% and 17.0% of pollen tubes were found incompatible by years. As for the open pollination, percentages of incompatible pollen tubes in the upper part of the style by years were 14.0% and 14.4%, respectively. The occurrence of incompatible pollen tubes did not influence the fertilization success in these pollination variants

Application of molecular markers in apple breeding

Apple is economically the most important species of genus Malus Miller. In respect of production, trade and consumption, it ranks first among deciduous fruit and third on a global scale among all fruit species. Apple breeding is carried out on a large scale in several scientific institutes throughout the world. Due to this activity, apple is a fruit species with the highest number of described monogenic traits; 76 genes, encoding morphological traits, pest and disease resistance, as well as 69 genes encoding enzymes. The development of molecular markers (RFLPs, AFLPs, SCARs and SSRs) has allowed the mapping of the apple genome and the development of several saturated genetic maps, to which genes controlling important traits are assigned. Markers flanking these genes not only play an important role in selecting parental combinations and seedlings with positive traits, but they are also particularly important in detecting recessive traits, such as seedless fruit. In addition they enable pre-selection for polygenic quantitative traits. In recent years, particular attention has been paid to biochemical and physiological processes involved in the pathway of important traits e.g., ripening and the storage capability of apple fruit

Viability of Embryo Sacs and Fruit Set in Different Plum (Prunus domestica L.) Cultivars Grown under Norwegian Climatic Conditions

Compatibility and synchrony between specialized tissues of the pistil, female gametophytes and male gametophytes, are necessary for successful pollination, fertilization, and fruit set in angiosperms. The aim of the present work was to study the development and viability of embryo sacs, as well as fertilization success, in relation to the fruit set of the cultivars ‘Mallard’, ‘Edda’, ‘Jubileum’, and ‘Reeves’, under specific Norwegian climatic conditions. Emasculated, unpollinated, and open-pollinated flowers were collected at the beginning of flowering, and on the 3rd, 6th, 9th, and 12th days after flowering, from all four plum cultivars over two years (2018/2019). Ovaries were dehydrated, embedded in paraffin wax, sectioned, stained, and observed under a light microscope. Results showed the existence of synchronization between successive phases in the development of the embryo sac and individual phases of flowering. All plum cultivars had higher percentages of viable embryo sacs, fertilized embryo sacs, and fruit set in 2018 than in 2019. These differences may be related to the very low temperatures during the post-full-flowering period in 2019, and to the low adaptation of some studied cultivars to unfavorable conditions. In our study, the cultivar ‘Jubileum’ showed the highest percentage of viable embryo sacs, fertilized embryo sacs, and fruit set compared to other cultivars, i.e., the best low-temperature adaptation

Pollen germination and pollen tube growth in zp maize lines

The study was conducted on the in vitro pollen germination at 26 degrees, 28 degrees, 32 degrees and 35 degrees C for 24h of male parental lines, pollen tube growth in vivo in cross pollination of female and male parental lines that make couples in four hybrids: ZP 504 su (female ZPPL 51 x male ZPPL 67); ZP 677 (female ZPPL 17 x male ZPPL 201); ZP 704 (female ZPPL 109 x male ZPPL 79), ZP 611 k (female ZPPL 126 x male ZPPL 105), and the open pollination of female parental lines of the above mentioned hybrids. Pollen germination in vitro and pollen tube growth dynamics in vivo showed different genotypic specificities with the tests applied. The obtained results were discussed in the context of reproductive biology of ZP maize lines and aimed to create the preconditions for successful management and direction of the process in practice -seed production in certain environmental conditions

Using scanning electron microscopy to characterise plum (Prunus domestica L.) genotypes

Pollen grain micromorphological characterisation of four plum (Prunus domestica L.) genotypes from two different breeding programmes (Fruit Research Institute, Serbia, and Hohenheim, Germany) was performed using scanning electron microscopy (SEM). The studied characteristics were pollen size and shape, colpus length, mesocolpium width as well as exine characteristics. All genotypes had tricolpate pollen grains and striate exine ornamentation, with more parallel longitudinal ridges. The most significant differences among the analysed genotypes concerned the length of the pollen grain and exine sculpturing. The genotypes 'Pozna Plava', 'Presenta' and 'Čačanska najbolja' had the largest pollen grains (> 57 µm), whereas 'Hanita' showed a smaller pollen size, below 54 µm. 'Pozna Plava' had perprolate pollen in the equatorial view (L/W ratio 2.06), while the other three genotypes had prolate shaped pollen. By analysing the pollen morphological characteristics of the plum varieties in this paper, primarily the shape, size, length of colpi and, most importantly, the sculpture of the exine, each variety showed a specificity which can be used together with other morphological characteristics for description and characterisation

Novi pravci istraživanja u fiziologiji i ekologiji voćaka

New discoveries in all fields of physiology and ecology of fruits reveal high complexity but also inevitable interrelation with other scientific branches and, particularly current, new biotechnologies. Acquisition of new knowledge within the comprehensive and very complex field of fruit physiology shall be presented through the following chapters: new biotechnologies in fruit growing; mineral fertilization - with emphasis on the foliar fertilization; stress physiology; new aspects of fruit pollination and fertilization; heat regime as a factor of phenological dynamics, cropping and fruit zoning.Nova otkrića u svim oblastima fiziologije i ekologije voćaka pokazuju svu kompleksnost, ali i nezaobilaznu interakciju sa dragim naučnim granama i posebno aktuelnim, novim bio-tehnologijama. Ta nova saznanja u obimnoj i veoma složenoj oblasti kakva je fiziologija voćaka biće prezentovana kroz sledeća poglavlja: nove bio-tehnologije u voćarstvu; mineralna ishrana - sa osvrtom na folijama ishranu; fiziologija stresa; novi aspekti oplođenja voćaka i; toplotni režim kao činilac fenološke dinamike, rodnosti i prostornog zoniranja voćaka

In Vitro and In Vivo Performance of Plum (Prunus domestica L.) Pollen from the Anthers Stored at Distinct Temperatures for Different Periods

A study was conducted to investigate the effect of different storage periods and temperatures on pollen viability in vitro and in vivo in plum genotypes ‘Valerija’, ‘Čačanska Lepotica’ and ‘Valjevka’. In vitro pollen viability was tested at day 0 (fresh dry pollen) and after 3, 6, 9 and 12 months of storage at four different temperatures (4, −20, −80 and −196 °C), and in vivo after 12 months of storage at distinct temperatures. In vitro germination and fluorescein diacetate (FDA) staining methods were used to test pollen viability, while aniline blue staining was used for observing in vivo pollen tube growth. Fresh pollen germination and viability ranged from 42.35 to 63.79% (‘Valjevka’ and ‘Čačanska Lepotica’, respectively) and 54.58 to 62.15%, (‘Valjevka’ and ‘Valerija’, respectively). With storage at 4 °C, pollen viability and germination decreased over the period, with the lowest value after 12 months of storage. Pollen germination and viability for the other storage temperatures (−20, −80 and −196 °C) were higher than 30% by the end of the 12 months. Pollination using pollen stored at 4 °C showed that pollen tube growth mostly ended in the lower part of the style. With the other storage temperatures, pollen tube growth was similar, ranging between 50 and 100% of the pistils with pollen tubes penetrated into the nucellus of the ovule in the genotype ‘Čačanska Lepotica’. The results of these findings will have implications for plum pollen breeding and conservation.publishedVersio

Phenolic Compounds and Antioxidant Properties of Field-Grown and In Vitro Leaves, and Calluses in Blackberry and Blueberry

The aim of this study was to evaluate the content and profile of the phenolic compounds (PCs) and antioxidant properties of field-grown leaves, in vitro leaves and in vitro callus cultures of the blackberry ‘Čačanska Bestrna’ and blueberry ‘Toro’. In vitro shoots of the selected genotypes were grown either on original Murashige and Skoog (MS) medium containing 1 mg/L BA, 0.1 mg/L IBA and 0.1 mg/L GA3 (‘Čačanska Bestrna’) or on MS medium with macroelements reduced to 1/2, 2 mg/L zeatin and 0.2 mg/L IAA (‘Toro’). Callus cultures were induced from in vitro leaves and established on MS medium with 2 mg/L BA and 2 mg/L 2,4-D (‘Čačanska Bestrna’) or MS medium with half strength macroelements, 2 mg/L BA, 2 mg/L 2,4-D and 1 mg/L NAA (‘Toro’). Total phenolic (TPC) and flavonoid content (TFC) were the highest in blueberry leaves, whereas low TPC and TFC values were obtained in callus cultures of both cultivars. A higher content of PCs in blueberry leaves compared to blackberry leaves was determined by the UHPLC-DAD MS/MS technique. Quercetin derivatives and phenolic acids were the dominant PCs in the leaves of both berries, whereas gallocatechin was present in a significant amount in blueberry leaves. Callus cultures of both berries had a specific PC profile, with none detected in the leaves except quercetin-3O-glucoside and quercetin-3-O-rutinoside. Blackberry leaves showed the best antioxidant properties as estimated by ferric reducing power (FRP), ABTS•+ and DPPH• scavenging activity assays. Callus cultures of both berries exhibited three to five times lower ABTS•+ and ten to seventeen times lower DPPH• scavenging activity compared to corresponding leaves. The analyzed leaves and callus cultures can be a good source of PCs with good antioxidant properties and specific phenolics, respectively, for applications in the food and pharmaceutical industries

Nove sorte višnje (Prunus cerasus L.) stvorene u Institutu za voćarstvo u Čačku

The paper presents results of the two-year (2014-2015) study of flowering and ripening time, morphometric properties and biochemical composition of fruits, and field resistance to economically important diseases and pests of newly-recognized sour cherry cultivars ‘Iskra’ (Köröser Weichsel × Heimanns Rubin), ‘Nevena’ (Köröser Weichsel × Heimanns Konserven Weichsel) and ‘Sofija’ (Čačanski Rubin × Heimanns Konserven Weichsel). The new cultivars have large and high quality fruits, with light red (‘Iskra’), dark red (‘Nevena’) and red (‘Sofija’) skin colour. The ripening time was in the second decade (‘Sofija’), i.e. in the third decade of June (‘Nevena’ and ‘Iskra’). The cultivars exhibited a high level of field resistance to Blumeriella jaapii (Rehm.) v. Arx. and Monilinia laxa /Ader et Ruhl./ Honey ex Whetz. Due to the numerous positive bio-economic characteristics, the newly recognized sour cherry cultivars developed at the Fruit Research Institute, Čačak, deserve to be given a place in commercial orchards, as well as in parental combinations of sour cherry breeding programmes.U radu su predstavljeni dvogodišnji rezultati (2014-2015. godina) ispitivanja fenofaza cvetanja i sazrevanja, morfometrijskih osobina i biohemijskog sastava ploda, kao i poljske otpornosti na ekonomski najznačajnije bolesti i štetočine, novopriznatih sorti višnje Iskra (Köröser Weichsel × Heimanns Rubin), Nevena (Köröser Weichsel × Heimanns Konserven Weichsel) i Sofija (Čačanski Rubin × Heimanns Konserven Weichsel). Nove sorte se odlikuju krupnim i kvalitetnim plodovima, svetlocrvene (Iskra), tamnocrvene (Nevena) i crvene boje pokožice (Sofija), koji sazrevaju u drugoj (Sofija), odnosno trećoj dekadi juna (Nevena i Iskra). Ispoljavaju značajan stepen poljske otpornosti na Blumeriella jaapii (Rehm.) v. Arx. i Monilinia laxa /Ader et Ruhl./ Honey ex Whetz. Zbog brojnih pozitivnih biološko-privrednih osobina, novopriznate sorte višnje stvorene u Institutu za voćarstvo u Čačku zaslužuju da se nađu u komercijalnim zasadima, kao i u roditeljskim kombinacijama programa oplemenjivanja višnje

Adventitious organogenesis via intermediate callus formation in representatives of Prunus, Pyrus and Rubus genera

The paper presents evaluation of the influence of 30 combinations of plant growth regulators (PGRs) on induction of adventitious organogenesis from leaves of in vitro propagated shoots in 5 genotypes: sour cherry 'Cacanski Rubin', cherry rootstock Gisela 5, pear rootstock Pyrodwarf, blackberry 'Cacanska Bestrna' and raspberry 'Meeker'. Blackberry 'Cacanska Bestrna' showed the highest regeneration capacity (regeneration was induced with 12 PGR combinations, the highest regeneration frequency 41.7%), followed by sour cherry 'Cacanski Rubin' (9 PGR combinations, max. regeneration frequency 20.8%) and rootstocks Pyrodwarf (6 PGR combinations, max. regeneration frequency 12.5%) and Gisela 5 (3 PGR combinations, max. regeneration frequency 8.3%). Raspberry 'Meeker' displayed the lowest regeneration ability (1 PGR combination, 8.3%). Regeneration was mostly indirect via intermediate callus formation. Consistency and quantity of the formed callus were primarily determined by type and concentration of applied auxins. Two main types of callus were observed: hard, compact calli with nodular structures on the surface and soft, friable ones. In most of the genotypes evaluated, friable calli were rarely formed, with the exception of regeneration media containing 2,4-D where the formation of large amount of soft, watery and white or yellowish callus was noticed. Indirect regeneration occurred through hard, compact callus at cross-sectional area of leaf blade, mid vein and petiole, while it was never observed on intact parts of leaves including leaf edges