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The present work compiles the results of three-year expeditions organized between 2011 and 2013 aimed at plant crop collection in the area of Lithuania, an Eastern European country. Accessions of fruit trees, vegetables, cereals, forage, industrial, fibrous, medical, and spice crops as well as accompanying segetal plants were collected in 5 ethnographic regions of Lithuania. In total, 1010 samples of seeds, bulbs, and plant grafts were obtained. The majority of the collected samples belonged to the Cucurbitaceae, Fabaceae, Solanaceae, Alliaceae, and Rosaceae families. The accessions were described and deposited in the long-term storage in Lithuanian and Polish Gene Banks. Almost all collected cucumbers, pumpkins, squashes, and oat plants were morphologically characterized in field experiments. Cucurbita pepo accessions showed high morphological diversity, while limited diversity of cucumber accessions was observed. Oat plants were characterized by high morphological diversity and resistance to diseases present in some of the investigated accessions. Further characterization of collected apple trees and other accessions is underway. Obtaining germplasm in the area of Lithuania fulfills a gap in current plant crop collections. Collected material could be valuable for pre-breeding evaluation and further breeding programs as well as the study of genetic diversity.

Cucurbita maxima Duchesne squash and pumpkins are cultivated world-wide. Cucurbita maxima fruits are produced for fresh market and are valuable for food processing. Therefore, fruit characteristics and yield are the traits of high economic importance for breeders. To date, the genetic basis of fruit-associated traits in C. maxima have been poorly understood. In the present study, we evaluated fruit-associated traits and conducted quantitative trait locus (QTL) analysis using recombinant inbred lines (RILs) derived from a cross of two inbred lines with different fruit morphotypes. Phenotypic data for nine fruit traits (earliness, weight, number per plant, yield per plant, length and diameter, shape index, flesh thickness, sucrose content and dry matter content) were collected for RILs in two open-field experiments. Pairwise analysis of the phenotypic data revealed correlations among the fruit and yield-associated traits. Using a previously developed genetic map, we identified 26 QTLs for eight traits. The QTLs were found in 10 locations on eight chromosomes of C. maxima. The QTLs were detected across experiments and explained up to 41.4% of the observed phenotypic variations. Major-effect QTLs for multiple fruit-associated traits were clustered on chromosome 4, suggesting that this genomic region has been under selection during diversification and/or domestication of C. maxima.

Although many Pseudomonas syringae strains have already been determined, only a few genomes of strains belonging to pathovar lachrymans have been sequenced so far. In this study we report the genome sequence of P. syringae pv. lachrymans strain 814/98, which is highly virulent to cucumber. The genome size was estimated to be 6.58 Mb, with 57.97% GC content. In total, 6024 genes encoding proteins and 92 genes encoding RNAs were identified in this genome. Comparisons with the available sequenced genomes of pathovar lachrymans as well as with other P. syringae pathovars were conducted, revealing the presence of three unique plasmids and 24 type III effector proteins (TTEs) in strain 814/98. The phylogenetic analyses of MLST loci and TTEs clearly showed the existence of two distinct clusters of strains within pathovar lachrymans, which were grouped into either phylogroup 1 or 3, supporting non-monophyly within this pathovar.

Molecular marker examinations of genetic diversity are valuable for assessment of within-species diversity and relationships, genotype identification, to assist selection for crop improvement programs, and to handle coherently germplasm collections. Cucurbita maxima is a highly diverse cucurbit crop, but its genetic diversity at the molecular level is inadequately characterized. Presently, genomic simple sequence repeat (SSR) markers that were described and employed for Cucurbita moschata and Cucurbita pepo were screened on C. maxima. A set of 23 highly informative SSRs was selected to evaluate genetic diversity within a collection of 85 C. maxima accessions. This collection contained cultivars and breeding lines from Europe, North America, Asia, Australia, and New Zealand, of six horticultural groups. Based on the genotyping results and statistical analyses, a fundamental division was observed in C. maxima above the level of horticultural groups. One major cluster was comprised between accessions from the Banana, Buttercup, and Hubbard horticultural groups. The other major cluster was divided in two sub-clusters, the larger of which included all accessions of the Mammoth (Show) Pumpkin horticultural group and the smaller, more outlying cluster was comprised of accessions of the Australian Blue horticultural group, with the one representative of the Turban group most outlying. Generally, the horticultural groups formed sub-sub-clusters, as most accessions within these respective groups showed close affinity. The selected set of 23 Cucurbita-conserved SSR markers is expected to be of great value for further germplasm characterization in this species and for taxonomical identifications within the genus Cucurbita.

Styrian hull-less pumpkins are valued for their use in health-promoting foods such as oils and snacks. Although deriving from Styria, they are now cultivated globally. Seeds of Styrian oil pumpkins are rich in lipids and represent a high-value product. Thus, seed yield and quality are traits of economic importance. These seed characteristics depend mostly on the cultivated variety and plant growing conditions. This study aimed to assess the variation in hull-less seed lipids of new hybrids of Styrian oil pumpkin developed recently for cultivation in moderate/colder climate zones of the north-eastern part of Poland. The study showed that the newly-developed hybrids have a relatively high content of total lipids in seeds, with a substantially higher share of linoleic acid (up to 63%). However, sterols, tocopherols, and squalene content and composition were similar to pumpkin seed oils produced from plants cultivated in other, warmer regions. This study provides insights into the chemical composition of Styrian pumpkin oil produced from hybrids grown under the relatively severe climatic conditions of north-eastern Poland.

The high content of carotenoids, sugars, dry matter, vitamins and minerals makes the fruit of winter squash (Cucurbita maxima Duchesne) a valuable fresh-market vegetable and an interesting material for the food industry. Due to their nutritional value, long shelf-life and health protective properties, winter squash fruits have gained increased interest from researchers in recent years. Despite these advantages, the genetic and genomic resources available for C. maxima are still limited. The aim of this study was to use the genetic mapping approach to map the ovary colour locus and to identify the quantitative trait loci (QTLs) for high carotenoid content and flesh colour. An F6 recombinant inbred line (RIL) mapping population was developed and used for evaluations of ovary colour, carotenoid content and fruit flesh colour. SSR markers and DArTseq genotyping-by-sequencing were used to construct an advanced genetic map that consisted of 1824 molecular markers distributed across linkage groups corresponding to 20 chromosomes of C. maxima. Total map length was 2208 cM and the average distance between markers was 1.21 cM. The locus affecting ovary colour was mapped at the end of chromosome 14. The identified QTLs for carotenoid content in the fruit and fruit flesh colour shared locations on chromosomes 2, 4 and 14. QTLs on chromosomes 2 and 4 were the most meaningful. A correlation was clearly confirmed between fruit flesh colour as described by the chroma value and carotenoid content in the fruit. A high-density genetic map of C. maxima with mapped loci for important fruit quality traits is a valuable resource for winter squash improvement programmes.

Trichoderma strains that are beneficial to both the growth and health of plants can be used as plant growth-promoting fungi (PGPF) or biological control agents (BCA) in agricultural and horticultural practices. In order to select PGPF or BCA strains, their biological properties and taxonomy must be carefully studied. In this study, 104 strains of Trichoderma collected at geographically different locations in Poland for selection as PGPF or BCA were identified by DNA barcoding, based on the sequences of internal transcribed spacers 1 and 2 (ITS1 and 2) of the ribosomal RNA gene cluster and on the sequences of translation elongation factor 1 alpha (tef1), chitinase 18-5 (chi18-5), and RNA polymerase II subunit (rpb2) gene fragments. Most of the strains were classified as: T. atroviride (38%), T. harzianum (21%), T. lentiforme (9%), T. virens (9%), and T. simmonsii (6%). Single strains belonging to T. atrobrunneum, T. citrinoviride, T. crassum, T. gamsii, T. hamatum, T. spirale, T. tomentosum, and T. viridescens were identified. Three strains that are potentially pathogenic to cultivated mushrooms belonging to T. pleuroticola and T. aggressivum f. europaeum were also identified. Four strains: TRS4, TRS29, TRS33, and TRS73 were classified to Trichoderma spp. and molecular identification was inconclusive at the species level. Phylogeny analysis showed that three of these strains TRS4, TRS29, and TRS33 belong to Trichoderma species that is not yet taxonomically established and strain TRS73 belongs to the T. harzianum complex, however, the species could not be identified with certainty.

The nuclear male sterility gene ms8 is expected to facilitate the production of sweet pepper (Capsicum annuum L.) hybrids as it provides means for hybridization without the labor-intensive hand emasculation of female inbred lines. The development of molecular markers linked to ms8 locus will help the breeding practice for the selection of hybrid parental lines. In this study, F2 population resulting from a cross between the sweet pepper male sterile line 320 and the male fertile variety Elf was used to identify DNA markers linked to the ms8 locus. With the use of RAPD–BSA technique, seven markers linked to the ms8 locus were found. Four of them were converted into SCAR markers. In addition, two COSII/CAPS markers linked to the ms8 locus were identified. Comparative mapping with reference pepper maps indicated that the ms8 locus is located on the lower arm of the pepper chromosome P4. Identified markers are useful for molecular breeding, however, at present markers tightly linked to ms8 locus are still lacking. Identification of molecular markers linked to the ms8 locus and determination of its chromosomal localization are useful for fine mapping and also provide the perspective for ms8 gene cloning.

Angular leaf spot is a common disease of cucumber (Cucumis sativus) caused by Pseudomonas syringae pv. lachrymans. Genetics of resistance to this disease was investigated using two sets of parameters: (i) disease severity, i.e. the number and size of necrotic and chlorotic lesions on the infected leaves, and (ii) presence or absence of a chlorotic halo around the necrotic spots on the infected leaves. Disease severity appears to be controlled by multiple genes and the heritability of the resistance was estimated to be 53%. The presence or absence of the chlorotic halo was determined to be governed by a single gene, with the presence of the halo (the susceptible phenotype) being a dominant character. A RAPD marker linked to the gene conferring the chlorotic halo was identified. Genetic distance between this marker, OP-AO07, a polymorphic 420 bp amplicon in the DNA of the susceptible plants, and the locus encoding the chlorotic halo was estimated to be 13 cM.

Several strains of Pseudomonas syringae pathovar (pv.) lachrymans and related bacterial pathogens were isolated from cucumber (Cucumis sativus) leaves collected in central and southern Poland in 2001 and 2002. Twenty five original strains, together with five reference strains of P. syringae pv. lachrymans, pv. syringae and pv. tomato, were genetically characterized by PCR-RFLP (polymerase chain reaction − restriction fragment length polymorphism), ADSRRS (amplification of DNA fragments surrounding rare restriction sites), and PCR-MP (PCR − melting profiles) fingerprinting techniques. Genetic similarity analyses of the PCR-RFLP and ADSRRS fingerprints showed that strains of P. syringae pv. lachrymans form distinct clusters. The results also indicated that the ADSRRS and the PCR-MP fingerprinting techniques may serve as more efficient tools for evaluating genetic similarity among pathovars and strains of P. syringae than PCR-RFLP. The 25 strains showed diverse pathogenicity to cucumber seedlings and biochemical tests were varied. The syrB gene was identified in four cucumber strains, characterized as P. syringae pv. syringae.

The cucumber MSC16 mutant was obtained by regeneration from cell cultures of the inbred line B and it is associated with complex mitochondrial genome rearrangements causing DNA deletions and duplications. We compared cell suspensions of cucumber MSC16 and the control wild type line B. MSC16 growth intensity in cell cultures was the same as a control line B. There were differences, however, in ability to undergo somatic embryogenesis. In auxin-dependent cell suspension (ADS) the MSC16 formed abnormal embryos not able to convert into the plantlets, however, 14% of MSC16 somatic embryos were normal after application of the cytokinin-dependent cell suspension (CDS) procedure. There were no differences between MSC16 and wild type line B observed in liquid culture of meristematic clumps (LMC). An electron microscopy revealed long fasciated mitochondria present in MSC16 ADS culture and mitochondria organized in clumps present in MSC16 CDS culture, with a control showing typical mitochondria appearance. An accumulation of large starch grains in chloroplasts appeared in cell cultures of the MSC16. These differences are discussed in the context of MSC16 mutant formation and its unique features.

A Lycopersicon esculentum Mill. (tomato) cDNA clone with high similarity to a Nicotiana plumbaginifolia Viv. (tobacco) cytochrome P450 gene was isolated using 5' and 3' rapid amplification of cDNA ends (RACE). The isolated cDNA (GenBank Accession No. AF249329) has an open reading frame of 1494 base pairs (bp) and encodes a protein of 498 amino acids with 75% identity to the N. plumbaginifolia cytochrome P450 (CYP72A2) and 45% to a Catharanthus roseus G. Don (Madagaskar periwinkle) CYP72A1 protein sequence. By Southern-blot analysis, one or two highly homologous genes were detected in the L. esculentum genome. Expression of the cloned P450 gene was regulated by circadian rhythm and enhanced by wounding. Leaf transcripts were detected in the light but not dark. Highest transcript levels were observed 3 hours after mechanical wounding. No increase in expression was seen in response to applications of zeatin as with the N. plumbaginifolia gene. Of the tissues analyzed, shoot tips and young leaves and fruit had the highest detectable transcript levels. Attempts to transform more than 1400 cotyledon explants of L. esculentum with sense or antisense CYP72A2 gene constructs produced no transgenic plants.

The parameters of chlorophyll a fluorescence induction were measured: Fv/Fm, Sc/Fm, Rfd and coefficient of Ld delayed luminescence decay kinetics, related with a course of primary photosynthesis reactions on leaves of strawberry plants, cultured in vitro by means of the micropropagation methods. Strawberry plants cv. Ananasowa from in vitro cultures in optimal condition show significantly higher values of luminescence parameters indicating better condition of plants of this variety in comparison with the variety Senga Sengana. After temperature lowering, however, these values were more reduced than for plants of Senga Sengana, which can be interpreted as higher susceptibility of this variety to chill. Addition of BAP caused disturbance of primary photosynthesis reactions rate, particularly in lower temperature. Auxin 2,4-D had no effect on the luminescence parameters in comparison with control cultures. Dehydration stress strongly diminished the values of measured parameters for Ananasowa variety what indicates the inhibition of primary photosynthesis reaction in leaves. The old culture of Senga Sengana variety showed higher tolerance on linuron in comparison with the new one.

This work was done to determine the diversity of pathogenic Pseudomonas syringae pv. lachrymans and pv. syringae strains, isolated from cucurbit plants. Pathogenicity tests performed in this work on cucumber indicated that the 22 tested strains differed dramatically in virulence level. Genetic characterization using MLST loci, as well as ITS1, ERIC and REP fingerprinting, allowed the grouping of strains into four phylogenetic groups. After amplicon sequencing and BLAST alignment the collected strains comply with P. syringae pathovars: lachrymans and syringae and with saprophytic P. fluorescens. The strains of Pseudomonas syringae pv. lachrymans may be categorized into at least two types differing in both disease symptoms and molecular characteristics. We confirmed that MLST-loci-based grouping of strains corresponds well to grouping based on pathogenicity tests.

This study was undertaken to remedy significant yield losses in commercial tomato (Lycopersicon esculentum Mill.) and tobacco (Nicotiana tabacum L.) production caused by tomato spotted wilt virus (TSWV). One of the possible sources of resistance can be incorporation into the host plant of a viral nucleoprotein (N) gene by Agrobacterium-mediated transformation. Twelve primary transformants of tomato and 141 of tobacco were analyzed for the expression of the N gene and for resistance to the TSWV infection. The tests have demonstrated that transgenic plants were protected against virus infection irrespective of whether or not they contained detectable levels of the translational product.