Repozytorium

Qualitative characteristics (kernel and volume weights, the contents of protein, lysine and pentosan, extract viscosity and falling number) of inbred lines created in hybrid breeding program of rye was evaluated in two consecutive years, 1998 (no 135) and 1999 (no 78). Two groups of rye inbred lines were selected, which present opposite physicochemical properties and thus fulfilling requirements either for bread making or animal feeding. Some lines might be directly utilised as components of experimental hybrids or as donors of qualitative traits for the development of the second cycle inbred lines.

The F2-type population derived from the cross between DS2 and RXL1O inbred lines was used for interval mapping of five growth related traits i.e. plant height, spike length, thousand grain weight, kernel length and kernel thickness. Scanning of the whole 1,140 cM length of rye genetic map consisting of 286 marker loci revealed the existence of 6 regions containing QTL5 on chromosomes 1R-5R. Plant height was strongly affected by 1-3 linked dwarfing genes from a distal region of the chromosome 5RL and by 1 gene on the chromosome 3RL, tightly linked to a marker loci Xpsr4 75. These same genes regulated also thousand grain weight and kernel length and thickness. Spike length was determined only by the QTL from chromosome 5RL. In addition a single QTL from chromosome 2R affecting thousand grain weight and kernel thickness was identified, near the molecular marker locus Xrsq8OS. 1. Kernel length and kernel thickness were additionally controlled by QTL5 on chromosomes 2R and 1R and 4R, respectively.

Rye ESTs from public sequence databases proved to be a valuable resource to develop micro­satellite markers in rye. One hundred and twenty-one EST-derived Secale cereale microsatellites (SCM) were genetically analyzed in a BC1 population. Fourty-three percent of the studied SCM markers displayed a polymorphism in this mapping population. Linkage analysis in relation to genomic SSR anchor markers as well as AFLP markers allowed to arrange 41 polymorphic EST-derived SCM markers into seven linkage groups which correspond to the seven rye chromosomes. In total, 56 rye SSR markers could be integrated in this second-generation linkage map of rye comprising 685 cM of the rye genome. Distorted segregations with excess of heterozygous progeny were found for most of the markers on chromosome 7R and possible reasons for these are discussed.

In addition the rye variety is included into the Register of Cultivars on condition of satisfactory economic value (value for cultivation and use or VCU). Entry of the variety into the Register of Cultivars is rye variety seed marketing requirement. In Poland the administration of the statutory variety examination (DUS and VCU tests) and the maintenance of the Register of Cultivars and the Register of Plant Breeder’s Rights are provided by the Research Centre for Cultivar Testing (COBORU) located at Slupia Wielka. The organization and procedure of the examination of DUS of rye varieties for Polish requirements are outlined. Every rye variety must pass the examination of Distinctness, Uniformity and Stability (DUS testing) before entry into the Register of Cultivars (National List) and/or granting of Plant Breeder’s Rights (PBR).

Estimation of initial materials and selection of resistant biotypes were carried out in stress conditions of field, greenhouse and laboratory experiments. Classical and biotechnological methods (callus and cell selection) were used in creation of initial materials. Some cultivars had high level of aluminum resistance (RRL 80-100%). Activity of root acid phosphatases indicated high level of resistance of these cultivars. Root oxidizing activity allows distinguish these cultivars between each other, but not correlated with field data on their productivity. Aluminium stress leaded to reduction of number of productive caulis, reduction of autumn tillering, significant decrease of number of caulis in winter-spring period, decrease of regenerative ability after snow mould. Cultivar “Kirovskaja 89” was referred as relative acid- and aluminium resistant. The population “Cyprez” was obtained from cultivar “Kirovskaja 89” by periodical selection and had higher thickness of productive caulis and exceeded initial form by productivity. Cultivars “Falenskaja 4” and “Snezhana” were created by using classical methods of breeding. Short-stem cultivar “Regina” was formed from best regenerant plants, obtained by methods of cell selection. This cultivar exceeded standard “Vjatka 2” under alu­minium field condition on 0.76 t/ha. Investigations confirm the opportunity of creation of winter rye cultivars, which combine acid and aluminium resistance with high stable produc­tivity, high winter hardness and resistance to logging. In Poland the administration of the statutory variety examination (DUS and VCU tests) and the maintenance of the Register of Cultivars and the Register of Plant Breeder’s Rights are provided by the Research Centre for Cultivar Testing (COBORU) located at Slupia Wielka.

An analysis of combining ability of rye, based on F1 generation hybrids, was performed in order to select lines of high effects of general combining ability which are useful for creation of population and synthetic varieties as well as hybrids giving high effects of specific combining ability. The main aim of the present paper was to recognize the actions of genes responsible for quantitative traits and combining ability of rye inbred lines on the basis of F1  and F2  hybrids analysis.The study material included 56 F1 generation hybrids obtained though diallel-cross with 8 parent lines as well as 56 F2  generation hybrids crossed with 8 parent lines.A genetic analysis of generation F2 yields results and GCA estimates which substantially correspond with those obtained for generation F1. The closest results were obtained for plant height, ear length and 1000-grain weight. For cultivation purposes, an analysis of generation F2  will be reliable and the selection based on it successful. Most of the studied lines were found to essentially influence the effects of general combining ability. The most recommendable is the line SMH-49 whose progeny was characterized both by shortened leaves and increased 1000-grain weight and the weight of grains per ear.

Polish F1 rye hybrids were tested in the field trials under Belarussian climatic conditions and compared to local varieties used as standards. Five-year investigations proofed that in spite of harder Belorussian winter conditions in comparison to these ones in Poland, winter-hardiness of hybrids was at the same level as of the population local standards. All hybrids were characterized by higher lodging resistance compared to standards, mainly due to lower plants height. One of the main problems which have to be solved is to find a reliable restorer. Use of population cultivars as pollinators so far was not resulted in a development of high-yielding hybrids. It is known that for P-CMS the genes of fertility restoration are scarce.

Male fertility restoration of F1 crosses between male sterile lines (P lines) and restorers (R) was studied in 2000. Pollen fertility of 50 F1 crosses derived by crossing 10 P lines to 5 restorers was estimated. The degree of male sterility/fertility was assessed by visual anther score of single plants on a 1-9 scale, restorer indices and visual pollen shedding scores of plots on a 1-9 scale. @Abstract = Coefficients of correlation between the above fertility traits were calculated. The analysis of variance showed that the degree of male fertility of F1 crosses strongly depends on a restorer genotype, a P line genotype as well as on the P ´ R interaction. The restorer and P line genotypes were a major source of variation.A considerable range of pollen fertility was evident in the single crosses. The mean restorer index of F1 crosses ranged from 3,4 to 98,7%. The P lines under study were divided into three groups on the basis of mean restorer indices of their crosses with five restorers: easy, medium and difficult to restore. All the restorers tested, provide a sufficient restoration of male fertility of the F1 crosses with majority of the P lines. The new restorer, 330 R appeared to be more effective in restoration of pollen fertility than the other currently used lines

General (GCA) and specific (SCA) combining abilities for four agronomic characters were determined in two experiments. The first included 24 F1 hybrids produced by crossing 6 restorers (R) to four CMS single crosses (CMS-SC). The second experiment included 20 F1 hybrids derived by crossing ten restorers to two CMS single crosses. The following characters were assessed: grain yield, heading date, plant height and lodging. Analysis of the combining ability was carried out according to the factorial mating design (North Carolina II Design) with the WAKOMBK (TP) computer software. General combining ability of both males and females was significant for all the characters in the experiment 1. In the second experiment GCA of females proved to be significant for all the characters, but GCA of males was significant only for plant height. Significant specific combining ability was detected only for the heading date in the first experiment and for all the characters except for plant height in the second one. Additive gene effects seems to be more important than nonadditive gene effects in controlling all the characters under study. The restorers and CMS single crosses with significant and favourable GCA effects were selected for further stages of hybrid breeding programme.

Male-sterile plants of G-type were found in rye cv. Schlagler alt. The major recessive gene controlling this male-sterility is allelic with male-sterility genes of the C- and R-types. The genetic system of the Pampa-type is completely different; it is controlled by dominant gene(s) and mt-DNA showed different restriction fragment patterns. The major gene of G-type msl(Rfgl) is located on chromosome arm 4RL; the sites of the minor genes ms2 and ms3 were found on chromosomes 3R and 6R. Hybrids produced by crossing male­steriles of G-type with inbred lines have normal pollination and, are therefore less sensitive to ergot, like population rye. In 2000 the mslnr-system of G-type rye was registered as "Guelzowerl". Male-sterile plants of "Guelzowerl" were used to produce the rye hybrid cultivar "Novus", which was also registered in 2000. "Novus" is the first rye hybrid cultivar with resistance to powdery mildew.

The aim of the study was to show epistatic effects of genes responsible for inheritance of important morphological traits in winter rye populations. Furthermore, the thesis that the environment plays very important role in epistatic effects in winter rye populations was verified. The study showed very significant epistasis for inheritance of the important yield components in 1985-1999 years. It was confirmed that epistasis increased or reduced values of the traits under study. It was also showed that epistasis depended on investigated varieties and environments (year of the study). The method described by Comstock and Robinson (1952), and Kearsey and Jinks (1968) consisting in crossing of selected populations with three different testers: T1 (SMH-49), T2 (SMH-75) and T3 (hybrid T1 × T2) was used. The obtained F1 hybrids were sown in 3-replications every year (1985-1999). The epistatic effects were estimated according to formula; Ji = L1i + L2i – 2L3i, where Ji is the epistatic effects of i-th variety, L1i, L2i, 2L3i are the mean values of characters for the hybrids obtained from the crossing between i-th variety and tester. The study concerned following traits: plant height, heading date, length of ear and uppermost internode of ear, grain yield per ear, grain number per ear, 1000-grain yield, grain yield per plot, test weight, falling number, protein content, resistance to brown rust and powdery mildew. Relationships between epistatic effects for selected traits and precipitation and temperature coefficient were evaluated according to Spearman coefficient of correlation.

Winter rye in the Central-Chernosem Region of Russia carries out the role of the «insurance culture». To carry out this role, winter rye should have varieties with genetic protection against unfavorable conditions, which might threaten the potential productivity. For that new genetic sources were created. On the basis of the created breeding material new varieties with better (than earlier created) resistance to severe weather conditions, were developed.

Model calculations were conducted to optimize and compare alternative schemes of CMS-line development in hybrid rye breeding on the basis of their expected selection gain per year assuming a fixed annual budget. Selection gains are predicted using current estimates of the relevant quantitative-genetic and economic parameters. Two alternative schemes are dealt with here. The first scheme (STD) represents a standard procedure in present-day second-cycle breeding. The second scheme (POP) is especially suited for population material that has not undergone intense inbreeding and selection yet. We:(i) give the optimum dimensioning of the schemes and their relative efficiency, (ii) study the effect of alterations in the dominance variance, the genotype × environment-interaction variance, and the budget, and (iii) assess how deviations from the optimum dimensioning affect the selection gain.Assuming identical genotypic variances, scheme STD is clearly superior to POP. It should thus always be used for second-cycle material. If, however, the population material used with scheme POP offers larger genotypic variances than the second-cycle material, POP becomes competitive. Changes in genetic and economic parameters affect the dimensioning but not the ranking of the schemes. Deviations from the optimum dimensioning only slightly reduce the selection gain as long as they are not too severe. This is shown for suboptimum numbers of testers and locations. All in all, the results demonstrate the importance of optimizing breeding schemes with respect to genetic, technical, and economic aspects.

Effects and variances of general (GCA) and specific (SCA) combining ability have been estimated from two experiments. For the first experiment (EXP 1) 19 homozygous lines originating from the Petkus pool were crossed with two CMS single cross testers derived from the Petkus pool (intra-pool test crosses) and with two testers from the Carsten-Danko pool (inter-pool test crosses), respectively. In the year 2000 grain yield was measured at 5 locations in Germany. The second experiment (EXP II) comprised a factorial of inter-pool crosses by using 4 homozygous CMS Petkus pool lines as seed parents and 6 Carsten-Danko lines as pol­len parents. The respective 24 inter-pool crosses were evaluated for grain yield on several locations in 1996 and 1998.In EXP I GCA-variance of candidate lines (4.7 —5.9 q/ha2 was estimated to have a similar size as SCA-variance. Possible reasons for an overestimation of SCA-variance are extreme divergence between testers, insufficient removal of inbreeding effects in the intra-pool test crosses and bias due to SCA × year interaction-variance. The use of intra-pool testers should be restricted to breeding material where inbreeding due to consanguinity between testers and can­didate lines is either absent or will evenly affect test cross performance of all candidates.In EXP II GCA-variances for female 9.2 q/ha2 and male 2.4 q/ha2 lines were much higher than SCA-variance. Repeatability for GCA-effects over different environments was medium (r=0.67), whereas for SCA-effects it was low (r=0.13). Selection intensity for yield should there­fore be moderate, if based on a single year of testing only. Selection of parental components for hybrids and prediction of hybrid performance should mainly base on GCA-effects. Alterna­tive to the use of factorial crosses test crosses with testers representing the opposite pool are recommended. Testing for SCA-effects and for SCA x environment interaction- effects can be a valuable diagnostic tool, to become aware of strengths and weaknesses of the elite material used to build new hybrids. SCA-tests should therefore be performed by using highly divergent environments.

The study presents a formula of producing double cross hybrids of rye. The aim of the research was a generation of double and three way cross hybrids by using the same female parents and comparing chosen properties of them. The subject of the research were ten double cross hybrids, ten three way cross hybrids, two male parents and three standard varietes. The field trials were conducted in two places (Smolice, Rogo±ewo). A statistical analysis showed that grain yield of double cross hybrids was significantly higher than grain yield of three way cross hybrids. Both types of the hybrids did not differ in plant height and lodging resistance indeed.

A laboratory test for evaluating the tomato leaf resistance to Phytophthora infestans in the seedling stage has been developed. The test is suitable for evaluation of breeding lines and selection within large populations. The following standard varieties and accessions representing a whole range of variability of known resistance were used: Moneymaker, New Yorker, West Virginia`63, West Virginia 700 and Ottawa 30. Various P. infestans isolates were used in the tests. Tomato seedlings grown in a liquid medium were cultured and tested in a growth chamber. The infection of individual seedlings was evaluated using 9-degree logistic key and data were statistically estimated. The results were reproducible in the same growth   conditions. Ranking of infection degree was as follow: Moneymaker ≥ New Yorker > West Virginia`63 > West Virginia 700 = Ottawa 30 irrespectively of test conditions or the isolates applied. The laboratory ranking was consistent with field observations. The results of tests depended on concentration of liquid medium (lower infection at lower concentration), on the isolate used and its spore concentration. The method proposed meets all requirements necessary for breeding and research as a routine method for evaluation of the tomato leaf resistance to P. infestans.

Interrelationship between physical and chemical properties and milling value of spring and winter triticale grain was examined. Correlation coefficients were calculated on the basis of laboratory tests carried out on qualitatively differentiated material collected in 1995-1998. Physical and chemical properties of spring and winter triticale grain correlated first of all with the yield of middlings, as well as with the reduction and total flour yields in laboratory milling. Triticale grain of high 1000 grain weight, high vitreosity, high HL-weight and of over 2.8 mm thickness was characterized by good milling value. The content of total protein in winter triticale grain was correlated positively with reduction, flour yield but negatively with breaking flour yield. Worse results of milling, expressed by raised ash content of flour and lower milling effectiveness index, were obtained with the grain containing more protein and mineral components.

Methods for detection and identification of seedborne pathogens are discussed. Traditional, immunodiagnostic and nucleic acid-based methods are briefly described including their use for fungi, bacterial and viral pathogens finding and identification in seeds.

Influence of weather conditions on downy mildew and Ascochyta blight development on 12 pea genotypes, cultivated in Central Poland was examined in 1990-2000. Plants were somewhat more infected by Peronospora viciae f.sp. pisi than by Ascochyta complex fungi. Standard cultivars were less infected than breeding lines. Two periods of higher (1990, 1991 and 1995-1997) and two of lower (1992-1994 and 1998-2000) disease intensity were noted during 11 years of testing.

Grains from basal (4th), central (8th) and apical (12th) spikelets of a wheat (Triticum aestivum L.) cultivar Lok-1 were investigated for their fresh weight, dry weight and water content. Each spikelet had 3 grains and so in all 9 grains were analyzed. Grain dry weight data was fitted to polynomial equations and biphasic linear regression analysis. The experiments described here indicated that grains having maximum water content had maximum grain weight and vice versa. Maximum water content and maximum grain weight showed a highly significant linear correlation (P < 0.001). It is suggested that in genetic manipulation in wheat, maximum water content can be a used as a reliable criterion to help in selection for final grain weight.

Effect of sowing time on productivity of sunflower was studied. Sunflower seeds were first sown in August (early) and the second sowing was done in September (late). Growth analysis was done at an interval of 5-6 days from germination to maturation. Growth was measured in terms of dry weight and leaf area. Various growth indices like RGR, RLGR, NAR, LAR, LWR, SLA, etc. were calculated. Cubic polynomial was the best fit for all the growth parameters. The dry matter accumulation, leaf area, leaf dry weight and leaf number were significantly more in late grown crop than early grown one. The rate of total dry weight, leaf area and leaf dry weight were higher in late grown crop as compared to early grown one. RGR, RLGR and NAR were higher in the late grown crop from the beginning, which gradually decreased later on, in both the crops. LAR was distinctly more in late grown crop between d 30-40. Changes in SLA were similar to LAR while LWR was more in the beginning and decreased afterwards. RGR showed more correlation with NAR and very low correlation with LAR in both the crops. Thus it is concluded that the late sown crop had better growth, but still, to obtain maximum productivity in sunflower, improvement in RGR and NAR is required.

Three cotton genotypes (Gossypium hirsutum L. H-4, H-6, G. herbaceum V797) varying in their final seed weight were analyzed for the growth and glycosidases activity. Five glycosidases, viz., a-b-galactosidases, a-b-glucosidases and a-mannosidases were estimated in cytoplasmic and wall-bound fractions. Data on dry weight and water content were fitted to polynomial equations and third degree polynomial equation was best-fit. Rate of dry matter accumulation showed closed relationship with water content in all three genotypes. The values for correlation coefficient {r= 0.956(H-4), r= 0.892(H-6) and r= 0.983 (V797)}, were statistically significant. No correlation between ionically wall-bound glycosidases and sink development was observed. In cytoplasmic fraction, the activities were higher during latter phase of dry matter accumulation. Probable role of these enzymes in mobilization of storage products during seed development is discussed.

Abstract Combining ability of 27 potato parents was evaluated in three factorial cross experiments (North Carolina II design) at Młochów Research Center of Plant Breeding and Acclimatization Institute (IHAR). The pool of tested forms comprised 18 cultivars and 9 parental lines. Depending on the experiment 60 or 90 unselected individuals per each family were evaluated. Completely randomised block design was applied for the purposes of each experiment. Progenies were evaluated for 7 traits. Important from the point of view of processing quality traits: fry colour, percentage of defect-free chips, tuber shape and the incidence of secondary growth seem to be determined by both additive and non-additive action of genes. However, in the case of fry colour the proportion of general combining ability were considerably higher than that for specific combining ability. There were identified five valuable parents for breeding of cultivars suitable for chip processing (Atlantic, Brodick, Panda, Signal, M-62633), and two parents (Agria, Shepody) for breeding of cultivars for French fries processing.

reezing of winter oilseed rape, because of severe winters, in the last few years in Poland, caused increase of interest in spring oilseed rape cultivation. The aim of research was to define the relationship between fertilisation with sulphur and glucosinolate content and pathogenic fungi occurrence on seeds of spring oilseed rape ‘Star’. Sulphur was applied as ionic and elementary in three different doses: 0, 20, 60 kg ××ha-1. The results showed that sulphur fertilisation modified the glucosinolate level. Total alkenyl glucosinolate content depended mainly on the way of sulphur application and its form. The doses of sulphur applied were the main factor influencing on indole glucosinolate content Alternaria brassicae was an only pathogenic fungus frequently occurring on investigated seeds. Sulphur fertilisation resulted partially in decrease of intensity of disease. Negative correlation between indole glucosinalate content in seeds and the occurrence of Alternaria brassicae on them was found.

Physiological seed conditioning is applied to improve and enhance seed performance. The treatment is based on prolonged hydration. It creates suitable conditions to pathogenic seed-borne mycophlora development. One of the conditioning method which employs the matric properties of solid water carrier is matriconditioning. In this procedure seeds are subjected to hydration for several days. The aim of research was to examine mycophlora development during matriconditioning and to find out, if commonly recommended chemical seed treatment is effective in seed protection.Following treatments were used: untreated – control seeds „C”, seeds treated with chemicals (carbendasim, thiram, metalaxyl and carbosulphate) – „C+CH”, seeds matriconditioned with Micro Cel-E – „MC” and seeds treated with above mentioned chemicals and then matriconditioned (MC+CH). Fungi isolation and development were conducted on medium and fungi diagnosis was taken under light microscopy.The results revealed stimulating effect of matriconditioning on pathogenic and saprophytic fungi occurrence on onion seeds. Significant differences between isolated fungi were observed in comparison to control. In population of mycophlora isolated from matriconditioned seeds, high percentage of occasional parasites were observed such as Alternaria porri, Alternaria tenuis as well as fungi of species Botrytis and Penicillium. Matriconditioned seeds were more infected by all above mentioned fungi. In vitro, fungicides showed differentiate effect on pathogenic and saprophytic mycophlora, from almost total control up to a high tolerance. The lowest seed infection presented C+CH treatment- it is chemical control with no matriconditioning. Chemical seed treatment applied before matriconditioning improved seed health status of matriconditioned seeds (MC+CH).

Immunochemical diagnostics of Clavibacter michiganensis subsp. sepedonicus (Spieckerman and Kotthoff) Davis et al., the causal agent of bacterial ring rot of potato, is based on the use of high quality polyclonal and monoclonal antibodies. The specificity and sensitivity of the polyclonal Po-Cs 6 and monoclonal Mn-Cs 1 antibodies for detection and identification of C. m. subsp. sepedonicus in pure culture and extracts of potato tuber samples were compared by double antibody sandwich enzyme-linked immunosorbent assay (DAS ELISA). The polyclonal antibody Po-Cs 6 cross-reacted with strains of several Clavibacter michiganensis subspecies, Pantoea agglomerans, and weakly with Pseudomonas fluorescens and Ralstonia solanacearum (race 3)in all serological tests. After cross-absorption with these bacteria, the threshold level of homologous antigen NCPPB 3467 was 10H7 cfu/ml in DAS ELISA. The monoclonal antibody Mn-Cs 1 did not cross react with other michiganensis subspecies or with other plant pathogenic bacteria tested. The monoclonal antibody Mn-Cs 1 cross-reacted very weakly with the saprophytic bacteria P. agglomerans and P. fluorescens. The threshold level of homologous antigen NCPPB 3467 was 104 cfu/ml in DAS ELISA. The monoclonal antibody Mn-Cs 1 proved to be more sensitive and specific than the polyclonal antibody Po-Cs 6 in all serological tests.

The Gli B1 locus controlling the synthesis of certain fractions of wheat storage proteins belonging to the group of ω-gliadins is tightly linked with the Rg1 gene responsible for red glume colour. The inheritance of selected ω-gliadin subunits and of glume colour was studied in order to identify markers of this trait among protein fractions specific to spelt wheat. Electrophoretic analysis for 217 single plants of the F2 generation in the cross Tr. aestivum (cultivar Elena) × Tr. spelta was done. Four out of five protein subunits specific for spelt wheat (O1, O3, O4 and O5) as well as gliadin block Gli B1-1 of the Elena cultivar were inherited according to Mendelian segregation ratio 1:2:1 assumed for two allelic protein variants of one gene. The above mentioned fractions of spelt wheat formed a block, which has been denoted by the symbol Gli B1-6. The results of segregation analysis regarding glume colour indicate Mendelian, single-gene inheritance of this trait (3:1 ratio of red and white glumes), which differs from the results of other investigations suggesting the existence of two genes controlling the red colour. The genetic distance between loci Gli B1 and Rg1 has been estimated to be 1.9 cM.

The aim of studies was testing for presence of 1BL/1RS translocation in 17 lines derived from wide crosses of Aegilops ventricosa and Aegilops juvenalis with common and durum wheats, along with parental forms. PCR analyses detected translocated chromosome in Lanca and CZR1406 wheats and in 4 hybrid lines (JCPC, JCCP, JCC and JCCC). The lack of 1RS arm in lines (VGL and VGLL) derived from crosses with Lanca suggests that another chromosomal rearrangements occurred. We confirmed the usefulness of applied STS-PCR assays for fast and robust identification of 1BL/1RS translocation in breeding materials.

A total of 187 Triticum durum (Desf.) genotypes were studied. These included 102 mutants, 15 local genotypes, 22 lines from ACSAD and 48 lines from ICARDA. Polyacrylamide gel electrophoresis under acidic conditions of pH 3.1 (A-PAGE) was used to separate gliadins groups of storage proteins for the identification and the classification of the genotypes under study. Results showed that the region of w-gliadins had a wider range for the number of bands than all other regions of gliadins (a-,  b- ,   and  g-gliadins). Cluster analyses using the Unweighted Pair Group Mean Average (UPGMA) method put the genotypes of all groups in trees on the basis of the gliadin bands distribution. Three categories were obtained. 1) Complete correspondence of the pedigrees and the trees, reflecting the importance of the gliadins as a decisive factor for the genotype position in the cluster. 2) The presence of genotypes with similar banding patterns but were unrelated in their pedigrees. And, 3) The genotypes originate from the same cross but are unrelated in the tree. It was concluded that tree clustering based on gliadin electrophoregrams may be used as an additional tool in revealing genetical relations among genotypes. However, one should keep in mind that several factors may influence the resulting tree. These include heterogeneity, incorrect band designation and uncertain or false pedigrees.

During last 22 years in the Potato Genetics and Parental Lines Department at Młochów Research Center more than 210 parental lines resistant to Potato virus M (PVM) have been bred. Genes controlling resistance to PVM originated from two sources Solanum megistacrolobum (the gene Rm) or/and S. gourlayi (the gene Gm) were introduced into tetraploid breeding material. From these resistant lines 59 progenitors were chosen and offered to the potato breeders. The first resistant to PVM cultivar Triada and second one cv. Korona were registered in Poland in 1996 and 2002, respectively. At present 13 advanced breeding clones from different breeding stations derived from progenitors offered to breeders in 1986-1990 are evaluated in Preliminary Trials. One candidate cultivar tested in Registration Trials appeared to be resistant to PVM. Moreover 15 advanced breeding clones derived from progenitors offered during 1991-1995 were tested in Preliminary Trials. The mechanical and graft inoculations were used to identify the type of resistance to PVM in potatoes. The parental lines, which resistance to PVM is controlled by the gene Rm or/and Gm, express field resistance even under the high natural infection pressure. Increasing number of resistant to PVM new potato cultivars is expected.

The response in growth and final weight of grains from basal, middle and apical spikelets to increases in assimilate availability was studied by modifying source-sink relationships during the grain growth period in a wheat cultivar Lok-1. The source-sink relationship was altered in 1500 plants by removing spikelets in various positions i.e. either apical, middle or basal spikelets were pinched off on the day of anthesis. The final grain weight, grain growth rate and grain filling period (duration) was significantly affected by increasing the source capacity per grain by trimming i.e. removing some spikelets. The final grain weight was positively significantly correlated with grain growth rate while it was significantly but inversely correlated with grain filling duration. A clear effect of position of grain in spikelet and its (spikelet) position on the spike could be visualized. The results imply that there is a possibility that the availability of photosynthates is limiting and does not fully satisfy grain growth requirements. It is suggested that in this cultivar during post-anthesis period, grain yield is source limited.

In order to find a rapid, reliable method for estimating leaf area in wheat, field experiments were conducted with three wheat (Triticum aestivum L.) cultivars viz. Sonera, Lok-1 and Raj-1555. On the basis of correlation and regression analyses, the product of length and maximum width (LW) was found to be the best independent variable for determining the leaf area. The Y intercept had little affect on leaf area calculation and hence leaf area in wheat can be calculated by the simple equation Y = 0.75 LW. During the entire growth period leaf area and leaf dry weight was closely correlated but the logarithmic equation fitted better than the linear equation. Leaf area and total plant weight did not show any significant linear correlation.

The studies carried out in 1997-1998 were aimed at evaluating the incidence of Broad bean stain virus (BBSV) in pea seed material, susceptibility of pea cultivars to the virus and transmission of BBSV by seeds of selected pea cultivars. Experiments were performed in field conditions and in a greenhouse. The presence of the virus in pea plants and seeds was determined by isolation onto Chenopodium murale or serologically by ELISA test. In the seed material, the virus was detected only in 0.1% of the seeds. The pea cultivars: Cud Kelvedonu, Delisa II, Hejga, Iłówiecki, Konserwowy IHAR, Maraton, Nefryt, Pegaz, Sześciotygodniowy and Telefon, appeared to be susceptible to the infection by BBSV and percentage of infected plants ranged from 6.6 to 35%. Transmission of the virus by seeds occurred in all cultivars mentioned above except for cv. Maraton and percentage of infected seeds ranged from 2.9 to 50.0, depending on cultivar of pea.

Fourteen hydroxyproline-resistant cell lines were selected by plating 7 days old cell suspensions of Solanum tuberosum L. cvs. Desiree and Maris Piper on a cell plating medium containing 5 or 10 mM hydroxyproline (hyp). Cell suspensions were either plated directly on selective media or after mutagenic treatment with gamma rays at a dose of 20 Gy or after freezing to –6°C. The frequency of resistant colonies varied from 0.15 to 0.35 x 10-6. Almost all the selected lines possessed increased levels of frost tolerance as compared to their non-selected controls except one indicating that hyp resistance and frost tolerance are not necessarily linked.

Twenty-five inbred lines of maize assigned to six heterotic groups and developed in Poland were studied electrophoretically to determine their purity and mutual relationships. The electrophoretic data were analyzed by principal component and cluster analyses. All lines (except five) were monomorphic in each enzyme studied. Electrophoretic affinities of inbred lines were, with some exception, were in accordance with the expectation inferred from their pedigrees. Lines of identical pedigree but with small differences in phenotypic or developmental characteristics had the lowest dissimilarity coefficient values and in cluster and principal component analyses behaved accordingly. They showed however diverse levels of clustering and dissimilarity coefficient values, which most likely reflected their departure from the common parental gene pool, which occurred in the course of breeding manipulations. Lines, which had one parent in common, were less similar to each other than those with identical pedigree. The most distinct electrophretically were lines with complex or dissimilar pedigree formulae as was confirmed by cluster and principal component analyses.

A total of 46 barley cultivars and breeding lines (35 spring and 11 winter) tested in 1998 - 2000 Polish registration trials were tested for powdery mildew resistance with 23 differential isolates of E. graminis f. sp. hordei. The isolates were chosen according to differences in virulence spectra that were observed on 'Pallas' isoline differential set and on 8 additional differential cultivars. The experiment was conducted in the IHAR Radzików greenhouse 1999-2000.From 35 tested spring cultivars and breeding lines 6 (17%) were composed of different lines carrying different genes for resistance. Eight different resistance alleles [Mla1, Mla7, Mla12, Mla6, Mla14, Mlg, Ml (CP) and mlo] were detected alone or in combinations. Among tested cultivars and breeding lines of spring barley, majority (94%) had combination of different genes for resistance. The most common resistance gene was Mla12 and this gene was present in 12 (34%) spring breeding lines. Seven spring cultivars and breeding lines possessed Mlo resistance.Seven different resistance alleles [Mla12, Mla6, Mla14, Mla13, Ml (Ru3), Ml (Bw), Mlra] were detected alone or in combination in tested winter cultivars and breeding lines. From 11 tested cultivars and breeding lines of winter barley 3 were composed of different lines carrying different genes for resistance. Majority (91%) of these cultivars and breeding lines had combination of different genes for resistance. Major strategies for control of powdery mildew using resistance genes are discussed.

The investigations of the effects of incorporation of some recessive genes into cv. Radius of alfalfa on seed productivity were performed in greenhouse and in field experiments. BC2 progenies were produced and compared to the standard cultivar Radius. Introduction of recessive genes lp (long raceme), tf (top flowering) and br (branched raceme) affected type of inflorescence: 1) the lp trait significantly increased floret and pod number per raceme, seed number per raceme and seed weight per sq. m., 2) the tf trait increased significantly number of raceme per stem and seed yield per sq. m., 3) the branched raceme trait governed by a single recessive gene br enhanced 6 – 10 times floret number per raceme.

Poland is an important horseradish grower in Europe, therefore the problems concerning its cultivation and diseases are considered vital. Horseradish diseases can be classified as non-infectious and fungal, bacterial or virus origin. The most important fungal disease is white-rust caused by Albugo candida, which can be responsible for up to 50% loss of yield, in the case of heavy infection. Bacterial diseases are not very important now. Turnip mosaic virus (TuMV), arabis mosaic virus (AMV) and tomato black ring virus (TBRV) were found so far on horseradish in Poland. The most important is TuMV, which was found in almost 100% collected horseradish samples and caused yield loss about 40%. The virus TuMV belongs to the Potyvirus genus (VC57.0.1) from the Potyviridae family (VC57), which is the largest family of plant viruses. It infects many economically important plants. Attempts to eradicate TuMV by means of thermotherapy proved ineffective. At the Research Institute of Vegetable Crops, methods of obtaining TuMV-free horseradish plants (together with methods of its fast multiplication) have been developed in in vitro cultures.

In previous investigations it was observed that the high content of Mg in sugar beet seed pericarp increased the resistance of seedlings to A. cochlioides Drech. The experiments conducted in 1991 - 95 aimed at verification of this fact. Beet seed pricarp was enriched with mineral elements in field conditions using different fertlization of stecklings. In laboratory conditions seeds washed twice in water were soaked in salt solutions (MgSO4, Mg (NO3)2, KCl) or PEG 6000. Washing sugar beet seeds with water without any additional protection favours infection of the emerging seedlings with A. cochlioides. The mean results obtained from field experiments show that the lowest number of dead seedlings and significantly the highest number of survived ones were observed in the seeds washed and soaked in PEG. Similar results were found using KCl. The question still remains whether the protective effect is of a specific or osmotic character. The results confirmed a possibility of seedling protection in the above described way.