Chromosome Doubling in Genetically Diverse Bilberry (Vaccinium myrtillus L.) Accessions and Evaluation of Tetraploids in Terms of Phenotype and Ability to Cross with Highbush Blueberry (V. corymbosum L.)

To expand the gene pool and introduce new traits to the tetraploid cultivars of Vaccinium corymbosum from wild diploid species V. myrtillus, it is necessary to double the chromosome number in diploid species in order to overcome a post zygotic crossing barrier and a strong triploid block, existing within the genus Vaccinium. Five genetically diverse bilberry genotypes were selected from 21 accessions taken from the breeding collection of the National Institute of Horticultural Research (Skierniewice, Poland) for this study. The bilberry genotypes were derived from the Polish locations of Bolimów Landscape Park, Budy Grabskie and forest complex Zwierzyniec (Łódź Province), and habitats in Norway. The selection of genotypes was made based on the analysis of amplified fragment length polymorphism (AFLP-PCR). Analysis of the Jaccard similarity indexes and the UPGMA method revealed that the examined accessions formed two main groups on the dendrogram. The first group consisted of accessions from Norway, while the second group agglomerated Polish accessions. A further two classes were distinguished in the Polish group: the first included accessions from Budy Grabskie and the second from Zwierzyniec, located ca. 9 km from Budy Grabskie. In order to obtain plant material for in vitro polyploidisation, in vitro shoot cultures of the selected accessions were initiated and multiplied. Both antimitotics used, colchicine and APM, induced tetraploids for all of the accessions. The obtained tetraploids were multiplied, rooted ex vitro and grown in a greenhouse and then in a field. The first flowering was observed in 1.5-year-old plants, either diploid or tetraploid. Diploids bloomed slightly earlier and more profusely than tetraploid plants. Compared to diploids, autotetraploids had significantly larger flowers by ca. 64% and larger pollen tetrads by ca. 35%. The germination capacity of pollen tetrads was high in tetraploids (87.8%), although slightly lower than in diploids (94.3%). After pollinating the flowers of three highbush blueberry cultivars with pollen from the bilberry tetraploid accession, J-4-4x, the plants formed fruits, some of which contained properly formed seeds. The effectiveness of interspecific crossing between V. corymbosum and tetraploid V. myrtillus, defined as the percentage of obtained seedlings in relation to the number of pollinated flowers, was highest (53.3%) in the blueberry ‘Liberty’, and lower in ‘Bluecrop’ and ‘Northland’, 14.8% and 10.0%, respectively. Before using the seedlings for further breeding, their hybridity will be confirmed by molecular markers and the phenotype will be evaluated.

Short Communication: Cross-species amplification of microsatellite markers developed for Jatropha curcas within five species of Jatropha

Saptadi D, Heliyanto B, Sudarsono. 2020. Short Communication: Cross-species amplification of microsatellite markers developed for Jatropha curcas within five species of Jatropha. Biodiversitas 21: 5072-5076. The transferability of SSR markers can be used to access the genetic diversity of related species. There are four close relatives of Jatropha curcas L in Indonesia, which can be utilized as a new diversity source through the interspecific crossing. This research was conducted to determine the ability of cross-species amplification of SSR markers developed from J. curcas to other Jatropha species (J. integerrima, J. multifida, J. gossypifolia, J. podagrica). It also investigated the relationship between these species. Out of 28 primers checked,11 primers showed cross-species amplification in all the species tested. Primer pairs EU099519, EU099528, and EU099525 have no transferability to other species. The overall percentage of polymorphism (PP) among all species tested was 95%, with the mean genetic similarity (GS) was 0.34. Least PP (17.35%) and highest GS (0.60) was found between pairs of J. podagrica and J. multifida. The correlation between the PP with GS was relatively high (0.75). The farthest and closest genetic distance was found between J. curcas/J. gossypifolia and J. podagrica/J. multifida, respectively. Further, selected primers from this study can be utilized in species differentiation, molecular identification of interspecific hybrids, and exploiting the genetic resource.

Use of chinese hazel (Corylus chinese French.) in hazelnut breeding (Corylus domestica Kos. st Opal.)

Aim. The need to improve the domestic assortment of hazelnuts and encouraging results obtained due to the involvement of Chinese hazel Corylus chinensis Franch. in hybridization with the best of its cultivars, prompted the research. Methods. The hybridization program included the most adapted to the conditions of Ukraine domestic and foreign cultivars of hazelnuts, as well as pollinators from natural populations of Corylus avellana L. and Corylus chinensis. Isolation of maternal and collection of pollen from paternal components of crossing was made using standard methods. Pollination was made by blowing pollen into bags with a medical insufflator MO-03 with a special needle (without removing the bag) and after 2–3 days, the pollination was repeated. Hybrid nuts were sown in autumn with wrappers without stratification. Other operations for growing seedlings and further maintenance were performed according to the standard methods. Results. Sufficiently high levels of fruit binding in variants with C. avellana pollen confirm the genetic proximity of the studied cultivars to this species, and the indicators from pollination by C. chinensis were 3–5 times lower. They confirm the remoteness of Chinese hazel from the modern cultivar assortment, but they make it possible to use this species in the hazelnut breeding. Thanks to this, a valuable material was created from which a new cultivar Sofiyvsky 15 was selected. It entered fruiting in the third year after crossing and combines high potential productivity with adaptability, a spherical shape of the fruit and a high content of raw protein and oil in them. Conclusions. The ‘Sofiyivsky 15’ has significantly exceeded the ‘Halle’ and the conditional standard due to its adaptability, quickness, processability and quality of nuts. It can be recommended for wide introduction in farms of all agro-climatic zones of Ukraine. Keywords: Corylus chinensis Franch., Corylus spp., cultivar Sofiyivsky 15, hazelnut hybrids, hybrid orchard, interspecific crossing.

PHYLOGENETIC RELATIONSHIPS OF AUSTRALIAN AND INDOCHINESE COTTON SPECIES

The article presents data on phylogenetic relationships of Australian and Indo-Chinese cotton species. A relatively close relationship of the wild species G.nelsonii with the subspecies G.arboreum is established. ssp. nanking when used as a maternal form during hybridization. It is noted that this wild species can be used as a valuable source material for breeding and genetic research in the creation of unique forms of cotton. KEY WORDS: cotton, species, interspecific crossing, comparative morphology, hybridization

Evaluation of the progeny produced by interspecific hybridization between Camelina sativa and C. microcarpa

Background and aims Camelina (Camelina sativa, Brassicaceae) has attracted interest in recent years as a novel oilseed crop, and an increasing number of studies have sought to enhance camelina’s yield potential or to modify the composition of its oil. The ability of camelina to cross-hybridize with its wild relative, C. microcarpa, is of interest as a potential source of genetic variability for the crop. Methods Manual crosses were performed between the crop C. sativa and its wild relative C. microcarpa; F1 and F2 progenies were obtained. Cytology was used to study meiosis in the parents and F1s and to evaluate pollen viability. Flow cytometry was used to estimate nuclear DNA amounts and fatty acid methyl ester analysis was used to evaluate the lipid composition of F3 seeds. Key Results The F1 plants obtained by interspecific crossing presented severe abnormalities at meiosis and low pollen viability, and produced very few F2 seeds. The F2s presented diverse phenotypes and in some cases severe developmental abnormalities. Many F2s were aneuploid. The F2s produced highly variable numbers of F3 seeds, and certain F3 seeds presented atypical lipid profiles. Conclusions Considering the meiotic abnormalities observed and the probability of aneuploidy in the F2 plants, the C. microcarpa accessions used in this study would be difficult to use as sources of genetic variability for the crop.

Cytological Evaluations of Advanced Generations of Interspecific Hybrids Between Allium cepa and Allium fistulosum Showing Resistance to Stemphylium vesicarium

Interspecific crossing is a promising approach for introgression of valuable traits to develop cultivars with improved characteristics. Allium fistulosum L. possesses numerous pest resistances that are lacking in the bulb onion (Allium cepa L.), including resistance to Stemphylium leaf blight (SLB). Advanced generations were produced by selfing and backcrossing to bulb onions of interspecific hybrids between A. cepa and A. fistulosum that showed resistance to SLB. Molecular classification of the cytoplasm established that all generations possessed normal (N) male−fertile cytoplasm of bulb onions. Genomic in situ hybridization (GISH) was used to study the chromosomal composition of the advanced generations and showed that most plants were allotetraploids possessing the complete diploid sets of both parental species. Because artificial doubling of chromosomes of the interspecific hybrids was not used, spontaneous polyploidization likely resulted from restitution gametes or somatic doubling. Recombinant chromosomes between A. cepa and A. fistulosum were identified, revealing that introgression of disease resistances to bulb onion should be possible.

Multivariate techniques in the determination of genetic diversity in pest-resistant mini tomato genotypes

ABSTRACT The objective of this study was to compare methods of multivariate analysis on the evaluation of genetic diversity of mini tomato and to identify promising genotypes with resistance to pests. The experiment was conducted at the Vegetable Experiment Station of the Universidade Federal de Uberlândia, Monte Carmelo campus, from April 2013 to November 2016. The experimental design was a randomized complete block design with 16 treatments and four replications totaling 64 plots, and each plot represented by five plants. Sixteen genotypes were characterized, 12 from the F2RC1 generation, obtained through the interspecific crossing between the wild access LA-716 (Solanum pennellii) and pre-commercial lines of mini tomato (UFU-73 and UFU-2) (Solanum lycopersicum) and the UFU-2 lines. The content of acyl sugar, the amount of glandular trichomes (types I, IV, VI and VII), twospotted spider mite and whitefly resistance were evaluated. We concluded that there exist genetic variability between the genotypes. The number of groups formed by the canonical variated analysis was higher (four groups) than that obtained by the Tocher method (three groups) and UPGMA (three groups), demonstrating a greater discrimination power. The Tocher and UPGMA methods were consistent in the analysis of the genetic divergence in pest resistant germplasm of tomato, with the acyl sugar content being the most important variable. Genotype UFU-73-F2RC1 # 11 is resistant to pest attack, while the other studied lines have intermediate resistance.