Analysis of morphological traits of bird's foot trefoil plants cv. Bokor transformed with Agrobacterium rhizogenes

An efficient method for genetic transformation and shoot regeneration was achieved in bird's foot trefoil cv. Bokor using A. rhizogens. The transformed shoots were regenerated on hairy root segments in high frequency. After rooting and acclimation, transformed To plants were grown in experimental field. Analysis of morphological traits and chemical content in ten unintentionally chosen To bird's foot trefoil plants (genotypes no. 2 and no. 5) was performed. They were compared to those of control non-transformed plants. The traits as a number of stems per plant, length of internodes in longest stem, number of flowers per plant and plan high were very significant differed than the same traits in control plants, while there were no significant differences in the leaf area. No signs of the rol genes genotype and "T" phenotype were present. The transformed plants had significantly higher content of cellulose, while the protein and nitrogen contents of are in the range of control plants

Inheritance of in vitro response in wheat

The inheritance of in vitro culture response was studied by using immature embryos from five wheat cultivars and their reciprocal hybrids. In vitro culture response was evaluated according to callus formation, percentage of regenerative calli and the number of plants per embryo. By crossing the cultivar Vesna (VS) with highest tissue culture response and the two cultivars with lowest response Leda (LD) and Zajecarska 65 (ZA), it was demonstrated that the regeneration potential was heritable. VS as female parent, enhanced regeneration response in hybrids VSxLD and VSxZA, while as a male parent, VS did not affect the regeneration ability of hybrids LD and ZA. However, hybrids having LD and ZA as a male parents exhibited a decreased regeneration potential, as compared to self-pollinated VS. The results suggest the presence of a class of extra-nuclear factors in the VS cultivar. They significantly account for relatively higher regeneration capacity in the hybrids having this cultivar as a female parent than in those where the VS was male parent

Variability of in vitro culture response in wheat genotypes, genotype and environmental effects

The tissue culture response (TCR) of immature embryos, evaluated according to callus formation, percentage of regenerative green-spotted calli and the number of plants per embryo, was investigated in 96 wheat genotypes of worldwide origins. Immature embryos were collected 12-15 DAP from field-grown plants during three successive years 2003, 2004 and 2005. Year 2003 was with high air temperatures and tropical days during a period of vegetation, while the environmental conditions were more favorable for plant growth in the next two years, 2004 and 2005. Embryos were cultured on standard MS medium containing 2 mg l-1 2, 4-D. In all genotypes calli were efficiently induced, ranging from 36.7 to 100% (2003), 68.4 to 100% (2004), and 94.3 to 100% (2005). The calli occasionally formed green spots, but frequencies markedly differed among genotypes that varied from 0 to 72.5% (2003), 0 to 97.9% (2004), and 0 to 94.0% (2005). Coefficient of variation was highest in term of percent of regenerative calli (66.7%) following by a number of plants per embryo (35.6%) and callus formation (5.1%). Components of phenotypic variance showed that factor year (71.4%) had the highest impact on expression of callus formation, genetic factor (47,1%) on percentage of regenerative green-spotted calli and interaction year/genotype (30.3%) on number of plants per embryo. The results indicated factor genotype as the most important for determining regeneration potential in wheat

Fruit characteristics in walnut tree population in relation to growing season onset

The objective of walnut selection is to obtain promising genotypes characterized by later growing season onset, shorter period of vegetation, resistance to diseases, stable fruit productivity and high fruit quality. Aiming at obtaining genotypes with favorable properties, in five localities of Eastern Serbia, where walnut is widely grown, we studied the correlation among growing season onset on the one hand, and major pomological properties and fruit quality on the other. In the studied population, trees with early growing season onset and fruit mass up to 8.0 g (30.1%) were predominant, whereas those with late growing season onset were in minority, fruit mass ranging from 10.1 to 12 g (0.07%). Kernel ratio was highest in the former (20.69%), and the lowest in the latter (0.07%). Similar was observed in oil and raw proteins content in kernel which was highest in fruits of early trees (33.62%, 47,55%), while it was remarkably lower in late ones (0.72%, 0.49%). The obtained results suggest that the studied population was dominated by early trees and unfavorable or less favorable fruit properties. In spite of that, we evidenced some trees with favorable properties which can be used in breeding as donors of useful genes.Selekcija oraha u cilju izdvajanja perspektivnih genotipova sa kvalitetnim osobinama je još uvek aktuelna u svetu. Iz ovih razloga sprovedena su istraživanja na području istočne Srbije u pet lokaliteta, gde je orah masovno zastupljen. U svakom lokalitetu metodom slučajnog uzorka odabrano je od 280 do 330 stabala oraha generativnog porekla (ukupno 1464) koja su bila predmet izučavanja u trogodišnjem periodu. Ispitivana je zakonomernost, odnosno uticaj vremena početka vegetacije na važnije pomološke osobine plodova (masa plodova, sadržaj jezgre, kao i sadržaj ulja i sadržaj sirovih proteina u jezgri oraha). U ispitivanoj populaciji dominiraju stabla sa plodovima rane vegetacije sa masom do 8,0 g (30,1%), a najmanje je poznih stabala (0,07%) sa masom od 10,1 do 12,0 g. Sadržaj jezgre je takođe najveći u plodovima stabala rane vegetacije (20,69%), a najmanji kod poznih (0,07%). Sadržaj ulja je bio najveći u plodovima sakupljenih sa stabala rane vegetacije (33,62%), a najmanji kod poznih (0,72%), kao i sadržaj sirovih proteina 47,55%, odnosno 0,49%. Na osnovu dobijenih rezultata zaključeno je da su u ispitivanoj populaciji oraha dominirala stabla sa ranijim početkom vegetacije i sa nepovoljnim i manje povoljnim osobinama plodova. Uprkos tome registrovana su pojedinačna stabla sa povoljnim osobinama, koja mogu da se koriste u procesu oplemenjivanja kao donori korisnih gena u cilju stvaranja sorti oraha sa boljom kombinacijom poželjnih svojstava.Projekat ministarstva br. TR-20013

Efficient genetic transformation of Lotus corniculatus L. using a direct shoot regeneration protocol, stepwise hygromycin B selection, and a super-binary Agrobacterium tumefaciens vector

Cotyledons from 6-day-old Lotus corniculatus cv. Bokor seedlings, transversally cut into two halves, were capa­ble of regenerating buds without intervening callus formation. The explants were co-cultivated with the Agrobacterium tumefaciens LBA4404/pTOK233 superbinary vector carrying the uidA-intron gene and the genes hpt and nptII. They were cultured for 14 days on a regeneration medium, then subjected to a stepwise hygromycin B selection procedure consisting of gradually increasing antibiotic concentrations (5-15 mg L-1) over 21 weeks. Transformed shoots were obtained within 5 months after co-cultivation. Out of 124 initially co-cultivated explants, 52 (42%) plants survived hygromycin B selection. The presence of transgenes in regenerated plants was verified by β-glucuronidase histochemical assays and PCR analysis for the presence of uidA gene sequences. Hygromycin B-resistant and PCR-positive T0 plants were cultured in the greenhouse to produce flowers and seeds. The obtained data demonstrate that the reported transformation protocol could be useful for introducing agriculturally important genes into the new L. corniculatus cultivar Bokor

Pomological and technological characteristics of collected selections of cherry plum Prunus cerasifera Erhr.

A plantation collection containing 32 genotypes selected from spontaneous populations of cherry plum Prunus cerasifera Erhr. was set up in the region of the Eastern Serbian town of Svrljig. The fruit trees budded from Prunus cerasifera seedlings and were planted at 5x4 m spacing on a mild slope of south-western aspect. This study shows the most important characteristics of the 19 selections in the collection, and the average results recorded in the 2000-2003 period. The most significant characteristics of the trees, their productivity, and fruit and stone characteristics are presented. The average coarseness of fruits, i.e. their length, width and thickness, measured 25.0x 24.4x25.0 mm, while stone coarseness was 14.4x10.3x3.6 mm. The average fruit weight was 12.1 g (24.3-4.8 g), and stone weight 0.85 g (2.2-0.3 g). Depending on fruit and stone weight, the mesocarp content was 93% (96.3-90.3%). Taking into consideration the possibility of fruit exploitation for the production of biologically high-quality food, the mesocarp chemical composition was thoroughly examined. The fruits were found to have increased contents of total acids, achieving an average of 3.09% (3.44-2.60%), which was the initial objective of this selection. Total solids content was 13.5% (16.2-10.3%), total soluble solids 12.5% (14.5-9.5%) and total sugars 6.00% (11.45-3.14%). Considering these characteristics, the selections that were singled out deserve more attention in terms of preserving their biodiversity, forming a gene bank and commercial cultivation

Cytokinins and urea derivatives stimulate seed germination in Lotus corniculatus L.

We studied the effects of various cytokinins and urea derivatives on germination of aged seeds of in Lotus corniculatus L. The following substances were applied: N6-isoprenoid cytokinins (isopentenyl adenine and zeatin), adenine sulfate, N6-aromatic cytokinins (kinetin, benzyladenine) and their N9-ribosides, N-benzyl-9-(2- tetrahydropyranyl)adenine, and urea derivatives (diphenylurea, thidiazuron, and chloro-pyridyl phenylurea). With the exception of adenine sulfate, all cytokinins increased the percentage of seed germination up to twofold, depending on their kind and concentration. It is concluded that cytokinins may be among the missing factors in aged seeds of L. corniculatus contributing to the implementation of their full germination potential. They could be used to improve germination of both freshly harvested and aged seed samples, if necessary.

Variability of pomological characteristics of the Šumatovka apple

Variability refers to a process by which differences occur among individuals of the same plant species. However, some characteristics change very little while others, especially quantative ones, change rather quickly and readily even when environmental conditions change slightly. This fact has prompted an investigation aimed to establish the variability of pomological characteristics of the Šumatovka cv. apple tree, a rather old and autochthonous cultivar grown widely throughout Eastern Serbia. Its special characteristic is an ability to grow and bear fruit without any particular care and cultivation, and in conditions of especially severe water deficiency and drought. Šumatovka cv. fruits are small- or medium-sized on the average, the length Measuring 51.3 ± 6.62 mm (CV 12.9%), width 55.5 ± 6.35 mm (CV 11.4%), pedicel lenght 19.5 ± 3.2 mm (CV 16.4%) and fruit mass 66.0 ±20.6 g (CV 31.3%). Total soluble dry matter content of the mesocarp varies between 15.6 and 1.92% (CV 12.31%), total sugars 14.3 ± 4.7% (CV 32.8%) and total sour substances 0.95 ± 0.11% (CV 18.6%). Especially examined were the large-sized Šumatovka fruits measuring 72.0 mm in lenght and width, and 169.4 g in mass

Fruit characteristics in walnut tree population in relation to growing season onset

The objective of walnut selection is to obtain promising genotypes characterized by later growing season onset, shorter period of vegetation, resistance to diseases, stable fruit productivity and high fruit quality. Aiming at obtaining genotypes with favorable properties, in five localities of Eastern Serbia, where walnut is widely grown, we studied the correlation among growing season onset on the one hand, and major pomological properties and fruit quality on the other. In the studied population, trees with early growing season onset and fruit mass up to 8.0 g (30.1%) were predominant, whereas those with late growing season onset were in minority, fruit mass ranging from 10.1 to 12 g (0.07%). Kernel ratio was highest in the former (20.69%), and the lowest in the latter (0.07%). Similar was observed in oil and raw proteins content in kernel which was highest in fruits of early trees (33.62%, 47,55%), while it was remarkably lower in late ones (0.72%, 0.49%). The obtained results suggest that the studied population was dominated by early trees and unfavorable or less favorable fruit properties. In spite of that, we evidenced some trees with favorable properties which can be used in breeding as donors of useful genes.Selekcija oraha u cilju izdvajanja perspektivnih genotipova sa kvalitetnim osobinama je još uvek aktuelna u svetu. Iz ovih razloga sprovedena su istraživanja na području istočne Srbije u pet lokaliteta, gde je orah masovno zastupljen. U svakom lokalitetu metodom slučajnog uzorka odabrano je od 280 do 330 stabala oraha generativnog porekla (ukupno 1464) koja su bila predmet izučavanja u trogodišnjem periodu. Ispitivana je zakonomernost, odnosno uticaj vremena početka vegetacije na važnije pomološke osobine plodova (masa plodova, sadržaj jezgre, kao i sadržaj ulja i sadržaj sirovih proteina u jezgri oraha). U ispitivanoj populaciji dominiraju stabla sa plodovima rane vegetacije sa masom do 8,0 g (30,1%), a najmanje je poznih stabala (0,07%) sa masom od 10,1 do 12,0 g. Sadržaj jezgre je takođe najveći u plodovima stabala rane vegetacije (20,69%), a najmanji kod poznih (0,07%). Sadržaj ulja je bio najveći u plodovima sakupljenih sa stabala rane vegetacije (33,62%), a najmanji kod poznih (0,72%), kao i sadržaj sirovih proteina 47,55%, odnosno 0,49%. Na osnovu dobijenih rezultata zaključeno je da su u ispitivanoj populaciji oraha dominirala stabla sa ranijim početkom vegetacije i sa nepovoljnim i manje povoljnim osobinama plodova. Uprkos tome registrovana su pojedinačna stabla sa povoljnim osobinama, koja mogu da se koriste u procesu oplemenjivanja kao donori korisnih gena u cilju stvaranja sorti oraha sa boljom kombinacijom poželjnih svojstava.Projekat ministarstva br. TR-20013

The influence of meteorological factors on major fruit properties of hazelnut cultivars

Variability of pomological and technical properties of fruits of hazelnut cultivars and their dependence on precipitation and air temperature over different phases of vegetation were studied. Average results of 19 hazelnut cultivars over 1997-2006 were analyzed. Obtained results infer that it was precipitation that had a direct impact on fruit properties (fruit dimensions, fruit weight, kernel content) of the studied hazelnut cultivars. On the other hand, air temperature had no direct influence on the stated fruit properties, which is in accordance with water and air temperature requirements of hazelnut. .Izučavana je varijabilnost pomološko-tehnoloških osobina plodova sorti leske u zavisnosti od raspoloživih padavina i temperatura vazduha u različitim fazama tokom vegetacije. Analizirani su prosečni rezultati za 19 sorte u periodu od 1997 do 2006. godine. Dobijeni rezultati ukazuju da su padavine direktno uticale na osobine plodova (krupnoća, masa, sadržaj jezgre) ispitivanih sorti leske. Nasuprot tome, temperature vazduha nisu direktno uticale na navedene osobine plodova. To je u skladu i sa potrebama leske za vodom odnosno temperaturama vazduha. .nul