Repozytorium

IHAR – PIB collection of potato viral pathogens has been maintained since 1970s. Currently there are 258 isolates in the collection representing 12 potato viruses, named PVY, PVM, PVS, PLRV, PVA, PVX, PAMV, BMYV, TBRV, AMV, CMV and TRV. The viruses are maintained in potato plants in vivo in the greenhouse (246 isolates), in potato plantlets cultured in vitro (12 isolates), in frozen leaves (two copies each of the 246 isolates) and in freeze-dried tissue (234 isolates).

The paper describes testing potato cultivars for resistance to potato viruses in field and greenhouse condi-tions according to the scheme of the statutory trials. Seed tubers of tested cultivar are planted in the field in two replications with 30 tubers each. On both sides of each cultivar, 15 PVY-infected tubers, i.e. the source for PVY inoculation, are planted. The evaluation includes standard cultivars of known resistance levels to PVY. The progeny tubers are collected in autumn and growing-on testing is carried out in greenhouse condi-tions to estimate the number of plants infected with PVY. The other method is to evaluate the resistance of potato cultivars in greenhouse conditions. At present, the resistance of cultivars is evaluated only with respect to PVY, the most important potato virus. Two strains are used in the evaluation, i.e. PVYN-Wi and PVYNTN. For each testing cultivar, 10 plants are mechanically inoculated with each PVY strain. The analysis of the results makes it possible to classify the cultivars into four resistance groups on a 1-9 scale: highly resistant (with the resistance score of 8), resistant (with a value of 7), mid-resistant (with a value 5-6), and susceptible (with a value of 3-4). The ”9” rating is specified after the registration of the cultivars based on molecular tests, that validate the presence of a marker linked to extreme resistance (ER) gene Rysto.

The PVY population in the potato has been studied continuously using tobacco bait plants in potato fields at Młochów since 1980 at two-year intervals and in potato tuber samples collected from different regions of Poland since 2001 yearly. The paper presents the combined biological, serological and molecular assays for PVY identification and strain classification. Biologically, PVY strains are defined with respect to their ability to elicit hypersensitive resistance (HR) mediated by N genes in differential potato cultivars (King Edward, Desiree and Pentland Ivory) and to symptoms in the tobacco (cultivar Samsun). Serologically, an ELISA assay based on polyclonal or monoclonal cocktail antibodies recognizes all PVY strain types, while the specif-ic monoclonal antibodies help to recognize PVYN or PVYO/PVYC strains. Multiplex RT-PCR, Real-time RT-qPCR and sequencing-based assays are used to define the PVY genome structure. In the Polish population of PVY, the strains PVYO, PVYNTN, PVYN-Wi, PVYZ-NTN and PVYE were identified, while the PVYC strain was not detected.

Potato virus Y (PVY), a type member of the genus Potyvirus (family Potyviridae), is currently the most important virus infecting the potato crop. PVY is also a dangerous pathogen of the tomato, pepper, and tobac-co. The reverse transcription loop-mediated amplification (RT-LAMP) is gaining recognition as a good alter-native to RT-PCR in diagnosing plant viruses. Here, we provide a detailed description of a simple protocol for fast and sensitive detection of PVY by the RT-LAMP assay, which can be easily adapted to detect other plant pathogens, harboring both RNA and DNA genomes.

Blackleg of potato plants and soft rot of tubers are caused by several species of pectinolytic bacte-ria from genera Pectobacterium and Dickeya. The text describes simple methods of isolating bacteria from symptomatic and symptomless organs of potato plants, their identification using Polymerase Chain Reaction (PCR) and preservation.

Two diseases of the potato, blackleg of potato plants and soft rot of tubers, are caused by several species of pectinolytic bacteria which belong to two genera: Pectobacterium and Dickeya. Resistance to these bacteria is polygenic and the expression of resistance in tubers and plants is only partially related, as well as strongly dependent on the aggressiveness of the bacteria and on environmental factors. Two methods of assessing tuber and stem tissue resistance of potato cultivars and breeding lines are described.

Nematodes are among the most important agents affecting potato crops. Heavy infestations by Globodera rosto-chiensis and G. pallida can cause significant yield losses and limit the choice of potato cultivars that can be grown effectively (Oerke, 2006). Breeding of new potato cultivar resistant to G. rostochiensis and G. pallida is a long-term process. It is preceded by screening of potato breeding lines for resistance in repeated biotests, which seems to be the most effective and safest method of protection. Evaluation of nematode resistance is an important element of charac-terization of breeding lines and new cultivars. Resistance to Globodera spp. is evaluated in biological tests. The use of DNA markers for detecting nematode resistance genes may be an alternative approach to phenotypic evaluation of resistance degree of potato plants (Jena and Mackill, 2008). The goal of this report is focused on a description of resistance assessment procedure of breeding lines and varieties of potato to PCN and on comparison of biological and molecular methods of resistance evaluation. Presented information is addressed to both breeders and Polish inspec-tion services.

Phytophthora infestans causes potato and tomato late blight, economically the most important disease of these plant species. The Oomycete pathogen is frequently sampled, isolated to pure cultures, stored, and char-acterized. The knowledge of its diversity, migrations and evolution is essential for breeding resistant plants and for designing appropriate control strategies. The article presents methods for collection, storage and prep-aration of P. infestans isolates for inoculation of plant tissues, based on the publication by Zarzycka (2001), later updated and modified.

Resistance breeding is a very important alternative to chemical control of late blight. Many resistance (R) genes from the wild Solanum species have been discovered and introduced into the cultivated potato. The laboratory methods to assess the resistance to late blight such as tests on detached leaflets, leaves, tuber slices, or whole tubers, are easy, cheap, fast and provide a good estimation of resistance that can be further con-firmed in field trials for the selected material. Laboratory assessment is particularly useful for materials, in which major resistance genes segregate and the resistance is qualitative rather than quantitative.

Although development of potato cultivars resistant to late blight has long been one of the primary goals of potato breeding programs, several different methods of field resistance evaluation have been used by potato breeders. Recently, within the EucaBlight network (www.euroblight.net), common methods of late blight evaluation have been agreed on, and these methods are currently highly recommended for use by all those interested in evaluating the resistance of the potato to late blight. Here, we describe a method of evaluating potato resistance in field conditions routinely used at Młochów Research Center, which is compliant with recommendations of the EucaBlight protocol.

Plant Breeding and Acclimatization Institute – National Research Institute (IHAR-PIB) is responsible for pathotype identification of Synchytrium endobioticum isolates collecting from Poland. Pathogenicity tests are carried out using the Glynne-Lemmerzahl method, according to EPPO Standard PM 7/28. Pathotypes are defined based on their reaction to a range of well-characterized differential cultivars of potato. Assessment of one isolate of the fungus requires more than 20 differential cultivars. All pathotypes of S. endobioticum from Polish reference collection are multiplied and maintained (fresh warts) on tubers of extremely susceptible cultivars continuously. For all references pathotypes and isolates of S. endobioticum, the compost with winter sporangia are prepared for long-term of maintenance.

In Poland the Plant Breeding and Acclimatization Institute - National Research Institute (IHAR-PIB) is responsible for officially assessing the resistance of potato breeding lines and cultivars to Synchytrium endobi-oticum. In the official assessment of wart resistance the modified Glynne-Lemmerzahl method is used. A full cycle of assessment of the wart disease resistance requires 42 - 45 tubers per cultivar/breeding line. Forty two tubers are used in laboratory tests. To complete the laboratory tests, another 10 tubers are inoculated with winter sporangia of the fungus, using ring test. The final results are available after 3 years of investigation. If necessary, the full cycle of resistance tests to S. endobioticum can be performed during one year on 15 tubers in each of the 3 replications (45 tubers in total). Molecular verification of potato genotypes resistance to pathotype 1(D1) is possible with the use of SCAR marker Nl25-1400. Nevertheless, an official phenotypical assessment of advanced breeding lines, as the final verification of their resistance, is required.

Fungi of the genus Fusarium cause dry rot, a potato disease which develops during long-term storage of tubers. The disease-inducing capabilities differ among Fusarium spp., but may also vary within species uni-versally considered main dry rot agents. Identification of Fusarium spp. present on diseased tubers in a surveyed area can help minimize crop losses and mycotoxin contamination by, for example, applying proper fungicides or planning crop rotation. Here, we present a procedure of obtaining single spore colonies of Fusarium spp. from potato tubers infected by dry rot, their identification using molecular methods and ways of preservation.

Fungi of the genus Fusarium display inter- and intraspecific variation in their pathogenic capabilities. Although no resistance genes against dry rot have been identified, some indications of the possible defense responses are noticeable, since a single isolate might cause lesions of various sizes when infecting tubers of different potato cultivars. Pathogenicity tests are routinely used to assess potato tubers resistance against dry rot; a setup of pathogenicity test performed at Młochów Research Center is described in this work.

The efficiency of breeding new potato cultivars may be increased by pre-breeding that is by developing parental lines, which have new traits, not present in the genetic pool available for breeders or have new combinations of genes, or have improved level of economically important traits. The use of parental lines in commercial breeding programs is expected to ensure the biological progress in the newly created cultivars of potato. At the beginning, the development of parental lines in Młochów Research Center of Plant Breeding and Acclimatization Institute – Nation-al Research Institute (IHAR-PIB) was focused on resistance to viruses and later on resistance to late blight and other pathogens. The procedures of selecting resistant parental lines are described. These procedures were initially based on purely phenotypic tests for resistance, which lately were supplemented with marker assisted selection (MAS) apply-ing molecular markers linked with some resistance genes.

Potato cultivars are classified into maturity groups according to the length of the vegetation period re-quired to produce a harvestable product. Although accurate classification of potato cultivars to a specific maturity group is of great practical importance, there is no standard method to characterize the maturity type of potato cultivars. In this work, the method of evaluation of vegetation period routinely used at IHAR-PIB, Młochów Research Center is described.

Potato plants free of viruses, bacteria and viroid could be maintained in vitro for a long time. Proper prepa-ration of potato plants for in vitro culture provide its long-term storage in good condition. First step is to es-tablish in vitro culture from young greenhouse grown plants in early developmental stage. Explants are main-tained and propagated by nodal subculture on hormone-free Murashige and Skoog (MS) medium at tempera-ture 20-22°C. After rooting, for longer preservation plants are maintained at temperature 8-10°C.

Cryopreservation is a frequently used method of long-term storage of potato meristems and pollen in liq-uid nitrogen (LN) in temperature of -196°C. This technique allows for theoretically unlimited storage of pota-to material. The most popular method of potato shoot tips preservation is cryopreservation by the solidifica-tion of liquids without crystallization (vitrification).The best method of pollen conservation is its direct im-mersion in LN. The successful regeneration after vitrification is genotype-dependent, which require optimiza-tion of protocol.

The routine and the most effective method of viruses elimination from potato plants is in vitro culture of apical shoots combined with thermo- and/or chemotherapy. At times electrotherapy or cryotherapy is also applied. Elimination of potato viruses by thermotherapy required treatment of infected plants with high tem-perature (35°C - 45°C) for about two weeks. Thermotherapy is useful for elimination of PLRV and PVY from potato plants. In chemotherapy antimetabolite, like ribavirin is used. Chemotherapy is dedicated for elimina-tion of PVM, PVS and PVX. Very often the successful virus elimination require a few cycles of thermo- and/or chemotherapy.

Relationship between genotypes represented by two fibrous hemp varieties and some agrotechnical factors was investigated in the study. The aim of it was finding how selected factors (three sowing dates, two sowing densities and five harvest dates) influence on total fiber content using osmotic degumming of fibrous plants method for fiber content determination. Results showed 34% higher fiber content for Beniko in comparison to Tygra. It was also shown that fiber content in plants was stronger correlated with harvest date than date of sowing and its density.

The principle of the market competitiveness of breeding companies implicates a fast production of new varieties. One way to achieve this goal brings single seed descent (SSD) methodology, which requires kernels collection (18-23 days after pollination) , fast drying amd germination. Seed drying conditions influence the germination. In present work the influence of lightings: Sanyo LED and incandescent lamp vs. dark control during drying were studied. Kernels were harvested 18 and 23 days after pollination of wheat, triticale and barley cultivars grown in the same field experiment in 2015. It was found that: • the germination ability of non-mature kernels depends on all studied factors: lighting during drying, terms of harvesting and the interaction light * term; • non mature kernelsare more sensitive to drying conditions; • lighting during seeds drying can have a positive effect on ability to germination; • for breeding practice it would be better to harvest kernels at 23 DAF and dry them at room conditions under incandescent lamp.

Biological insecticides are an effective method used in plant protection. One of the most widely used active substances in biological insecticides is Cry1Ab protein, which is toxic for lepidopteran insects. This protein is produced during bacterial sporulation by Bacillus thuringiensis. Other sources of Cry1Ab protein are genetically modified plants (GM) with expression of cry1Ab gene. Cry1Ab protein in both bioinsecticides and GM plants is present in the form of protoxin, which requires activation by enzymatic treatment in the gut of susceptible insects. So far, Cry1Ab mode of action is not fully understood, but there are 3 main concepts describing it. Two of them assume that a toxic protein after binding to receptors in the insect gut penetrates into the cells, causing pore formation in the gut, which leads to the death of the sensitive insect. In the third model Cry1Ab toxic action is a result of toxin-induced chemical processes initiating a cell death pathway. This work describes the structure and mode of action of Cry1Ab protein, present in biological insecticides and genetically modified plants.

In order to study effects of saline water on seed germination of various soybean cultivars, an experiment was conducted using completely randomized design with factorial method and three replications in 2012. The factors were salinity stress levels (A) (0, 30, 60 and 90) mM NaCl, soybean cultivars (B) (Including 12 seed cultivars of II and III maturity groups). Five traits including seed germination, seed vigor, dry weight of radical and, plumule and biologic yield were studied. The results of analysis of variance showed significant differences between cultivars on studied traits at 1 % level of significance. The highest biologic yield belonged to Hy-1 and Steel under 90 mM. It was belong to M9, Clark and Union under 60 mM and belonged to Hy-1, Halcor and Union under 30 mM. The results of comparison means using Duncan’s method showed L17 and Steel not only had the high seed germination and vigor but also they had dry weight of radicles and biologic yield than others. It was identified although Union, Elgine and Williams were in second grade on seed germination and vigor but they had considerable growth and dry weight. Based on display scatter plot with two STI and GMP indices, L17 and Elgine were placed in A region of plot under 30 mM NaCl, while they were in B region under 60 and 90 mM salinity stress. The cultivars such as Union and Hy-1 were in C region of mentioned scatter plot.

The aim of the study was to determine the effect of mechanical harvest on the seed quality of yellow lupin. Two effects were studied: the cultivar of yellow lupin (the indeterminate cultivar - Mister and the determinate cultivar - Perkoz) and harvest methods: hand-picked plants with manual shelling of seeds as a control and mechanical shelling with a plot harvester. In comparison with manual shelling of seeds, the mechanical harvest reduced the seed germination and increased the number of abnormal seeds both cultivars. Determinate cultivar was more sensitive, because the loss of its quality was higher (germination of 10%) than indeterminate cultivar (6%). Perkoz had also higher electrical conductivity, with the mean value of 34.3 μS × cm-1 × g-1. Manual shelled seeds were characterized by a significantly lower leakage of exudates (24.9 μS × cm-1 × g-1), and hence, it exhibited greater vigour than mechanical harvested seeds. Most relations of Pearson correlation coefficient between vigour tests and germination were strong or practically functional.

The aim of this study was to describe and characterize the relationships between yielding factors and grain yield per doubled haploid (DH) plant of spring barley as well as relation between yield components and duration of each stage of plant development. To describe these relations structure equation modeling was used. The study included plants of doubled haploid spring barley lines (Hordeum vulgare L.) derived from tworowed form of Scarlett cultivar. The SAS® system was used to analyze the model of relationships between grain yield per plant and yield components. Our results indicate that the number of spikes per plant and grain yield per spike had a direct and decisive influence on the grain yield of the investigated DH plants of spring barley. Based on the path model analysis it was found that the most important factor determining grain yield per DH plants of spring barley was the number of spikes per plant and the duration of tillering and shooting stages.

In this study, the effect of different alkaline concentrations (0, 10, 20, 30, 40, 50, 60 mM) on germination and biochemical characteristics of the two sesame (Sesamum indicum L.) cultivares (Dashtestan and GL-13) which are registered cultivars of Iran were investigated. The experiment was carried out in a completely randomized design with three replications. Results showed that , germination percentage, germination rate, shoot length and dry weight, root length and dry weight and K+ content decreased, whereas, malondialdehyde (MDA), proline, total soluble sugars and Na+ contents increased with increasing alkalinity stress. GL-13 cultivar had the least root and shoot length, proline and K+ content than Dashtestan.

Research into nanotechnology has advanced in almost all fields of technology and the aim of this study was to evaluate the role of nano-silicon dioxide (nano-SiO2) in germination performance sunflower. Germination and seedling growth are the most important stage of plant development and are critical factors to crop production and are essential to achieve optimum performance. The effects of pre-germination hydration in solutions of nano-SiO2 (0, 0.2, 0.4, 0.6, 0.8, 1 and 1.2 mM for 8 h) on germination characteristics of sunflower were investigated. The trait by treatment (TT) biplot explained 93% of the total variation of the standardized data (77% and 16% for the first and second principal components, respectively). According to polygon- view of TT biplot, T2 (0.2 mM) had the highest values for all of the measured traits except mean germination time and the time to 50% germination. The germination percentage was determined as the best trait and showed the high association with promptness index, energy of germination and germination rate traits. The results of the present study indicated that pre-sowing seed treatments with low concentration of nano-SiO2 had favorable effect sunflower seed germination and seedling early growth. Such a similar outcome could be applied in the future to outline other crops in response to nano-particles as well as to help define tolerance tools for recommendations in stressful conditions in the world.

The objective of this study was to study the seed quality aspects of wheat (Triticum aestivum L.) and the extent of weed seed contamination present in wheat seeds produced in different regions of Iran. Four districts (cities), each including 12 fields (six certified seed fields and six farm-saved seed fields), were selected in each regions (provinces). One kilogram of the wheat seed sample was collected from each field for analysis in the laboratory. Wheat seeding was commonly done by farm-saved seed sourced from within the farm due to the high costs of certified seeds purchased from outside sources, followed by the low seed quality. The use of a farm-saved seed resulted in a higher germination rate and a lower mean time to germination compared with another system. The more positive temperatures experienced by mother plants could decrease the number of normal seedling and seedling length vigor index. Generally there was virtually no difference about physiological quality between certified seed and farm- saved seed sector that is related to lower quality of certified seed. The certified produced seeds had the lower number of weed seed, species and genus before and after cleaning. The highest seed purity and 1000 seed weight was obtained from the certified seed production system. The need for cleaning the farm-saved seed samples before sowing is one of the important findings of this survey.

Barley (Hordeum vulgare L.) is an important cereal crop for its high demand for grain feed and forage/grazing for the animals as well as for human food in the WANA region under the low rainfall situations and thus creating an urgent need for developing high yielding barley genotypes. A total of 542 hulled and hulless genotypes with seven checks were evaluated at three locations with diverse agro-ecological conditions, Terbol in Lebanon and Marchouch and Allal Tazi in Moracco. The aim of this study was to understand the nature of genotype x environment interaction (GEI), quantify the genotypic variability and identify high yielding genotypes. The mixed models were fitted to evaluate heritability and predicted means to identify gentypes with specific adaptation to the locations using GGE-biplot. GEI across locations was significant for days to heading, days to maturity, plant height, spike lenght and grain yield. On a trial-wise analysis, days to maturity was most heritable (49 - 50% broad sense heritability on mean basis) while the grsain yield was the least (5 - 13 %). The genotype G427 (4812 kg/ha) at Marchouch, the check VMorales (4889 kg/ha) at Allal Tazi and G528 (6995 kg/ha) at Trebol were the highest yielding genotypes. Several hulled and hulless genotypes with higher grain yield and early flowering time in the three environments were idntifield for utilization by the national programs globally. The test locations, Marchouch and Allal Razi, were found comprising one mega environment while Terbol showed maximum discrimination of genotypes for grain yield.

Phenotypic correlation coefficients and heritability of the characters determining seed yield of panicle inflorescence forms of alfalfa was examined. Seed yield per plant, which was positively correlated with 10 generative and morphological traits, depended upon the number of pods per panicle and the number of seeds per pod. Variability of these characters determined about 60% of the variability of seed yield. Multiple linear regression and phenotypic correlations show that simultaneous selection for increased pod number per panicle and increased seed number per pod and number of branches per panicle resulted in enhanced seed yield potential. The share of the additive genetic effects in the phenotypic variance for number of pods per panicle was low and about 23%, while for number of seeds per pod and seeds per panicle amounted to about 75-77% and 56-57% respectively.

Ionizing radiation has extensive applications in agriculture for inducing mutagenic changes in major field crops, potential breeding purposes, varietal development and crop improvement. This study was conducted to test the efficacy of 0.8, 1.6, 2.4 and 3.6 kGy gamma irradiation doses (Cobalt-60) upon growth and yield performance of edible pea (Pisum sativum L.) in pot culture experiment during 2009. Results demonstrated that higher radiation doses (1.6 and 3.2 kGy) significantly influenced the studied attributes of P. sativum. It was observed that 3.2 kGy had detrimental effects on shoot and pod lengths of pea which were reduced by 14.60 and 17.71 % respectively when compared to control. Differential response of the number of seeds pod-1, 1000 grain weight and dry biomass of pea were recorded at the applied doses. Significant reduction in number of seeds (-14.21 %) but increase in 1000 grain weight (+13.93 %) and dry biomass (+11.32 %) of pea were recorded at 1.6 kGy which revealed stimulatory effects on grain weight and dry biomass. Conversely, radiation dose 3.2 kGy was found detrimental to all the studied parameters except number of pods plant-1 and number of seeds pod-1 which were not affected.

The seeds of 3 populations from >Satureja bachtiarica were collected from three native vegetation areas (Simirom2, Sharkord and Yazd). The different treatments including: cold stratification, gibberlic acid (50 and 100 ppm) Potassium nitrate (0.2 and 0.4 percent). Physical scarification (sand paper), chemical scarification (Ethylic alcohol %70) and distilled water (control) were used for breaking dormancy of the seed samples. For greenhouse experiment, the seed samples were treated with treatments and then were sown in pots using randomize design with three replications. Emergence percentage, emergence speed, length of root and shoot, seedling length, root/shoot length ratio, vigor index, seedling fresh and dry weight, dry/fresh weight ratio were evaluated during 45 days of experiment. Comparing of population Semirom2 form savory of Bachtiary was higher than other population. It was concluded that effect of gibberlic acid and potassium nitrate was higher than physical scarification and chemical scarification comparing with control.

The rapidly increasing multifarious use of metallic nanoparticles in technology has necessitated evaluation of their impact on environmental, biotic and human health. The present study investigated the effects of different concentrations of bulk and nanosized CuO on seed germination and seedling growth of Ricinus communis in a randomized completely design with four replications. The experimental treatments included four concentrations of bulk CuO (10, 50, 100 and 500 ppm), four concentrations of nanosized CuO (10, 50, 100 and 500 ppm), and the control without CuO. The results indicate that only the weighted germination index and seedling dry biomass of Ricinus communis were significantly affected by the treatments. Other germination characteristics, plumule and radicle length, and seedling fresh weight were not significantly affected by bulk and nanosized CuO concentrations. It can be concluded that bulk and nanosized CuO in this cocentrations not toxic for germination and growth of Ricinus communis.

Salt stress is a major abiotic stress that limits agricultural productivity in many regions of the world. To understand the molecular basis of the salt stress response, two wheat (Triticum durum Desf.) cultivars, Karim and Azizi, which are of agronomic significance in Tunisia, were grown under non-saline and saline conditions (100 mM). Leaves and roots of control and salt-stressed plants were harvested after 11 days of salt treatment. Karim cultivar may behave as a typical Na+ include, which compartmentalizes Na+ within the leaf cell vacuoles where it could be used as an osmoticum to lower the osmotic potential necessary for the maintenance of the plant hydric status. While, accumulation of K+ was greater in Karim cultivar compared to Azizi, in both organs, presenting an important manifestation of salinity tolerance. Significant changes in metabolism of antioxidative system were observed, with an increase in protein tyrosine nitration, which indicates that salinity stress induces a nitro-oxidative stress.

Criteria used for evaluating drought tolerance of wheat cultivars demanding more time and efforts are usually not efficient and conclusive. Present study was conducted to evaluate ABA sensitivity as a criterion for evaluating drought tolerance of wheat cultivars at an early stage. Ten cultivars of wheat were subjected to drought at 3-leaf stage to select the most sensitive and two tolerant cultivars using mortality rate. Tatara was found the most susceptible whereas GA-2002 and Chakwal-50 were the cultivars with maximum drought tolerance. These cultivars were used to study sensitivity to applied absicic acid (based on germination index and relative growth inhibition rate) and physiological responses (leaf water content, chlorophyll stability index, coefficient of relative inhibition and proline accumulation) under drought stress. Highest ABAsensitivity was recorded in GA-2002 and Chakwal-50 whereas Tatara manifested minimum sensitivity. ABAsensitivity corresponded to physiological indices of drought tolerance. Results show that ABA-sensitivity is an efficient criterion that can be used to evaluate drought tolerance of wheat cultivars at early stage.

To study the effect of sonication on the seed germination percentage and rate as well as the cell area of barley (Hordeum vulgare L.) a laboratorial experiment was performed as Completely Randomized Design (CRD) with 3 replications. The results indicated that the ultrasonic waves affect the seed germination, germination rate and cell area significantly (at 0.05). The results of the mean comparison tests (LSD, 0.05) showed that the highest germination percentage (100 %), germination rate and cell area (1370.71 µ2) is achieved through 15 minutes exposure to ultrasonic waves. It is concluded that weakening the seed’s cell wall rigidity by sonication results in more and faster water imbibition by the cells and improved germination.

Large number of parental plants are required during hybridization in order to generate enough progeny needed for evaluation. Cowpea is propagated through seeds, this increases the waiting period as the plant has to complete its juvenile phase before flowering. Asexual propagation approach was employed on cowpea using the vine cuttings of flowering plants. The vine cuttings were planted in sterilized top soil and they began flowering 14 days after cutting without adding fertilizer. Success was obtained using this method which increases the rate at which the hybrids needed for multi-location trial were obtained.

Nanotechnology is an emerging field of science widely exploited in agriculture in recent years. In this investigation, application of nanotechnology in agriculture via application of some nano-particles (nano-iron and nano-silicon) have been investigated in seed priming of dragonhead. Seeds were subjected to prehydration treatments by factor nano-silicon dioxide as; (S1) 0 mM or distilled water, (S2) 1 mM concentration and (S3) 2 mM concentration and and factor nano-iron oxide as; (F1) 0 Mm or distilled water, (F2) 1 mM concentration and (F3) 2 mM concentration. Germination percent, root fresh weight, shoot fresh weight, root length, shoot length, dry weight of the seed residue, root dry weight and shoot dry weight were measured. Analysis of variance showed significant variation for the main effect of nano-silicon dioxide as well as nanoiron dioxide in root length and dry weight of the seed residue. The interaction effect of nano-silicon × nanoiron priming treatments were significant in all of the measured traits except germination percentage and root fresh weight. The highest germination percentage was recorded in S2-F3, S3-F1 and S3-F3 while the root fresh weight was high in S2-F3 and treatments S1-F1 following to S2-F3 and S3-F2 produced the highest shoot fresh weight. Also, S2-F3 has the highest root length (16.1 cm) and the highest shoot length (18.4 cm). The best treatment combination suitable for obtaining of high values of germination characteristics of dragonhead was identified as S2-F3 (1 mM nano-silicon dioxide plus 2 mM nano-iron dioxide).

Fatty acid levels and gene expression profiles for selected genes associated with the synthesis of fatty acids (FA), triacylglycerol, and oil body proteins were examined in three oilseed rape (Brassica napus) cultivars that have utility for cultivar development in our spring canola breeding program. The seed oil content of Bronowski, Q2, and Westar was 39.0, 40.1, and 40.6%, respectively at 40 days after flowering (DAF). During the 20 to 40 day period of seed development, cultivars had varying levels of palmitic, stearic, oleic, linoleic,
-linolenic, eicosenoic, and erucic acid. In general, the percentage of each FA was similar among the cultivars during seed development. However, the level of oleic acid was lower and the levels of eicosenoic acid and erucic acid were higher in Bronowski than in Q2 and Westar seeds; linoleic acid also tended to be lower in Bronowski. Gene expression among the cultivars was similar from 10 to 40 DAF. The few exceptions were that expression of KAS1 and SAD were higher in Westar and Q2 than in Bronowski at 25 DAF, SAD was highest in Q2, intermediate in Westar, and lowest in Bronowski at 35 DAF, FAD2 was higher in Q2 than in Bronowski at 35 DAF, FAD3 was higher in Q2 than in Bronowski at 15 DAF and Q2 and Westar at 25 and 30 DAF, and FAE1 was higher in Westar and Q2 than in Bronowski at 30 DAF. Correlation analysis for gene expression against DAF for each genotype supported a common trend in gene expression among the three cultivars with gene expression tending to decrease over time; except for LPAAT, which tended to increase. The correlation between the level of FAs and expression of genes by genotype indicated no general trend; rather correlations seem to depend on the genotype.

The yield-forming potential of winter wheat is determined by several factors, namely total number of shoots per plant and total number of spikelets per spike. The field experiments were conducted during three vegetation seasons at the Plant Breeding and Acclimatization Institute – National Research Institute (PBAI– NRI), located in Radzików, Poland. The objective of this study was a comparative analysis of the structural yield-forming factor levels, which determine grain yield per spike and per plant of the DH lines and standard Izolda cultivar. Results indicate that several DH lines showed some differences in tested morphological structures of plant, yield factor levels and in grain yield per spike and per plant in comparison to standard Izolda, regardless of the year. Mean grain yield per plant of DH lines was 26.5% lower in comparison to standard Izolda only in the second year of study. It was caused by a reduction of productive tillers number. Structural yield-forming potential of DH lines was used in 38% and 59% and in case of Izolda in 47% and 61% (the second and the third year of experiment, respectively). The mean grain yield per spike of DH lines was 14.8% lower than Izolda cultivar only in third year of experiment and it was caused by about 12% lower number of grains per spike. Structural yield-forming potential of DH spikes was used in 82.4%, 85.4% and 84.9% and in case of Izolda in 83.8%, 87% and 89.5% (the first, the second and the third year of experiment, respectively). The grain yield per winter wheat plant (both DH lines and standard Izolda) was significantly correlated with the number of productive tillers per plant (r = 0.80). The grain yield per winter wheat spike (both DH lines and Izolda cultivar) was significantly and highly correlated with the number of grains per spike (r = 0.96), number of fertile spikelets per spike (r = 0.87) and the spike length (r = 0.80). Variation of spike and plant structural yield-forming factors determining grain yield levels were also analyzed. Calculated total variation coefficients values of each analyzed trait during three-year long studies were different depending on plant material – DH lines or standard Izolda. Low variation coefficients values characterized following traits (traits ranked by increasing values for DH lines and standard Izolda, respectively): total spikelets number per spike (6.6 and 6.3%), spike length (11.1 and 12.6%), fertile spikelets number per spike (13.7 and 11.7%), single grain weight (15.0 and 12.2%), shoot length (16.2 and 13.3%), grains number per spikelet (26.4 and 23.3%), total shoots number per plant (23.4 and 29.6%), grains number per spike (30.1 and 28.2%). Higher variation coefficients values were obtained for the following traits: grain yield per spike (40.0 and 35.7%), plant immature tillers number (35.8 and 42.6%), plant productive tillers number (42.2 and 43.2%), spike sterile spikelets number (46.6 and 44.7%) and number of grains per plant (58.3 and 60.5%). The highest values characterized grain yield per plant (66.9 and 60.8%).