Seedless Varieties Research Articles

Importance of breeding mulberry trees under vegetative (in vitro) methods in high-quality silk production in Uzbekistan

In the first direction of this article, the new Marhamat, Mustaqillik-18 and Jararik-12 varieties of mulberry have economic value characteristics, such as leaf stem size, leaf length, leaf width, leaf stem length, leaf weight, leaf stem weight, leaf stem weight, and net leaf weight. In addition, the systems of mulberry silkworms Liniya-101 and Liniya-205 were cultivated with Marhamat, Jararik-12 and Mustaqillik-18 and Tajik seedless varieties of mulberry. The second direction of the study was the experiments on in vitro propagation of new varieties of tobacco, and the cost-effectiveness of testing in the conditions of production of positive data obtained on the basis of the results of 2017-2020. At the same time, it can be seen that the economic efficiency of mulberry varieties grown and introduced in vitro is 4,695,300 UZS, net profit is 1,577,500 UZS, and the size of profitability is 39.6% contrast to the comparator.

СТВОРЕННЯ, ПІДТРИМКА ТА ВПОРЯДКУВАННЯ ОЗНАКОВИХ КОЛЕКЦІЙ ВИНОГРАДУ (VITIS VINIFERA L.)

Based on the grapevine genotypes of NSC “Tairov Research Institute of Viticulture and Wine-Making” analysis, traits collections have been created and registered, representing genotypes for breeding programs to obtain new varieties resistant to abiotic and biotic environmental factors (frost and phytopathogens) under conditions implementation of climate change scenarios, varieties with improved quality traits and seedless varieties. Genetic ordering of traits collections has begun on the basis of varieties molecular identification using microsatellite DNA markers (from 5 to 9 MC loci) and identification using DNA markers of genes of interest or gene complexes (primarily a trait of seedlessness). Microsatellite analysis made it possible to identify a total of about 80 genotypes, mainly the varieties breeded at the NSC “Tairov Research Institute of Viticulture and Wine-Making”, belonging to the traits collections of resistance and quality. Visual sanitary control of three traits collections showed a practical absence of virus diseases and grapevine crown gall disease symptoms. Sometimes symptoms similar to the phytoplasma infection manifestation were found. The data of virus diseases agents identification by ELISA showed the absence the most harmful viruses — grapevine fanleaf virus (GFLV) and grapevine leafroll virus 1 (GLRaV I) on 19 samples tested. From samples of resistance traits collection one sample was positive on grapevine leafroll virus 3 and two were positive on grapevine fleck virus (GfkV). These samples should be eliminated from further propagation and genetic material moving between germplasm repositories. The causative agent of grapevine crown gall disease (Agrobacterium vitis) was not detected on 14 samples of 3 traits collections tested by PCR. It has been determined that the sanitary status of grapevine traits collections practically corresponds to the European minimum sanitary requirements, genetic ordering of characteristic collections will be continued.

Comparison of Microwave Short Time and Oven Heating Pretreatment on Crystallization of Raisins.

Crystalline material can develop on the surface of raisins during storage and transport, affecting the final acceptability of the product. In this work, a mild thermal pretreatment was applied to raisins to melt the pre-existing crystals and the effect of such thermal treatments on the development of crystals over a storage period was investigated. The raisins selected for this study were of the Thompson seedless variety from one Chilean company. The thermal pretreatment of raisins at 50 °C and 70 °C for 20 min in an oven and microwave (800 W) irradiation for 15 s resulted in a reduction in the percentage of crystallized raisins (w/w) from more than 50% in the control samples to less than 10% after 35 days of storage at 15 and 25 °C in a 57% relative humidity environment. The results showed that some textural parameters, such as cohesiveness and chewiness, were not affected by thermal treatment and were independent of storage temperature.

Studies on mutation breeding in citrus: Improving seedless types of ‘Kozan’ common orange by gamma irradiation

This study reports an induced physical mutation by gamma irradiation on a local sweet orange variety in order to develop new seedless varieties. Mature autumn shoots of seedy ‘Kozan’ common orange (Citrus sinensis (L.) Osb.) trees were irradiated with gamma rays from 60Co. The survival rate was 65 % for the dose of 60 Gy irradiation treatment of ‘Kozan’ common orange. In order to stabilize the mutation, mV3 plants were developed by re-budding and plants at mV3 generation were transplanted in the orchard in 2016. Observations in the present study were recorded for three consecutive years and trees which produced a sufficient number of fruits were evaluated for 19 fruit quality characters such as seed number, fruit diameter and maturity index. The seed number varied from 0 to 11, 0–10.82, and 0–10 per fruit in 2018, 2019 and 2020, respectively. Besides, high variations were observed in the mV3 population in terms of fruit weight and rind thickness. Through investigation of three years, two clones were completely seedless and selected as promising types. Vitamin C, total phenolic content and antioxidant activity in the fruit juice of the selected types were similar control. Furthermore, ploidy levels of the selections were investigated in order to explain the cause of seedlessness. Selected types were determined as diploid with the aid of flow cytometry. The selected lines were propagated in the field to confirm their stability and new commercial field trials have been conducted to evaluate the performances of the selections on different rootstocks.

Investigating sensory properties of seven watermelon varieties and factors impacting refreshing perception using quantitative descriptive analysis

Watermelon (Citrullus lanatus) is known for its refreshing quality, though its sensory attributes have never been related to its perceived refreshment. Modified quantitative descriptive analysis by a trained panel was used to examine the sensory profile of seven watermelon varieties. Eleven attributes including perceived refreshing intensity were measured on a 0–10 line scale using chemical references. Watermelon samples were evaluated with and without nose clips to control orthonasal and retronasal aroma and temperature was included as a variable to observe their effects on perceived refreshment. The dominant watermelon attributes were wateriness, refreshing, crispness, sweet, mealiness, fresh, ripe, and melon. The varieties were best differentiated by refreshing (p < 0.001), crispness (p = 0.002), sweet (p < 0.001), mealiness (p = 0.016), green (p = 0.007), and sour perception (p < 0.001). Captivation and Excursion were the most refreshing varieties. Captivation, Excursion, and Seedless varieties were less refreshing when flavor perception was inhibited; ratings ranged from 6.8 to 7.2 without nose clips and 5.9–6.0 with nose clips (p = 0.002). Refreshing was most positively driven by wateriness, followed by crispness, fresh, melon, and sweet, and negatively driven by mealiness, as indicated by partial least square regression. Samples served cold were more refreshing (ratings of 7.1 without and 6.0 with nose clips) than those served at room temperature (ratings of 4.9 without and 3.5 with nose clips), p < 0.001. This study defined the sensory profile of seven watermelon varieties and showed that flavor, texture, and temperature were responsible for the refreshing perception of watermelon for the first time.

Molecular Assisted Selection for Pollination-Constant and Non-Astringent Type without Male Flowers in Spanish Germplasm for Persimmon Breeding

Persimmon (Diospyros kaki Thunb) species is a hexaploid genotype that has a morphologically polygamous gyonodioecious sexual system. D. kaki bears unisexual flowers. The presence of male flowers resulted in the presence of seeds in the varieties. The fruits of persimmon are classified according to their astringency and the pollination events that produced seeds and modify the levels of astringency in the fruit. The presence of seeds in astringent varieties as pollination variant astringent (PVA), pollination variant non-astringent (PVNA) and pollination constant astringent (PCA) resulted in fruits not marketable. Molecular markers that allow selection of the varieties according to the type of flowers at the plantlet stage would allow selection of seedless varieties. In this study, a marker developed in D. lotus by bulk segregant analysis (BSA) and amplified fragment length polymorphism (AFLP) markers, named DlSx-AF4, has been validated in a germplasm collection of persimmon, results obtained agree with the phenotype data. A second important trait in persimmon is the presence of astringency in ripened fruits. Fruits non-astringent at the ripen stage named pollination constant non-astringent (PCNA) are the objective of many breeding programs as they do not need removal of the astringency by a postharvest treatment. Astringency in the hexaploid persimmon is a dominant trait. The presence of at least one astringent allele confers astringency to the fruit. In this paper we checked the marker developed linked to the AST gene. Our goal has been to validate both markers in germplasm from different origins and to test the usefulness in a breeding program.

Quality of Grapes Grown Inside Paper Bags in Mediterranean Area

The aim of this study was to evaluate the influence of paper bagging of grape bunches on the morphological, mechanical, and chemical characteristics of berries of three table grapes varieties as an environmentally-friendly technique for protecting clusters from biotic and abiotic agents. Clusters of Italia, Autumn Royal, and Regal Seedless grape cultivars were bagged and compared to a not-bagged control. Air temperature inside and outside the bags was monitored. Bunch weight and length, number of berries per bunch, berry longitudinal and transversal diameter, berry mass, number of seeds per berry (normal in size and aborted), soluble solid content, titratable acidity, and skin color by CIEL*a*b* parameters were determined on four points of each berry. Berries were evaluated using texture analysis, and the main texture profile analysis parameters were compared. The air temperatures around not-bagged clusters were slightly higher than inside the bags. In all the cultivars under evaluation, bagged bunches were heavier compared with not-bagged ones. In Autumn Royal and Regal Seedless, these differences were mainly owing to the higher number of berries and higher berry weight of the bagged bunches. Regarding mechanical properties, in seedless varieties, the bagging treatment increased berry hardness (related to the berry firmness) and decreased berry cohesiveness and resilience, whereas an opposite behavior was found in cv. Italia. Berry skin break force was lower in the bagging treatment in all the analyzed varieties, indicating a softer and easier-to-chew berry skin. The findings demonstrate that the bagging technique affected the three variety parameters to different extents. The main differences were found in the seedless varieties in terms of berry size and bunch characteristics. For all varieties, bagged bunches achieved the quality level required by the market, confirming the suitability of this technique. However, the bag industry is proposing many different bag types (differing in material, shape, color, and closing system); therefore, further studies are needed to obtain more complete and exhaustive technical information.

DNA marker identification of Rpv3 downy mildew resistance gene in seedless grape varieties

Table grapes are a valuable dietary product. Seedless grapes are in high demand among consumers. For this reason, the breeding of seedless varieties is one of the popular trends in modern viticulture, along with the production of environmentally friendly products. Downy mildew (Plasmopara viticola(Berk. &amp; M.A. Curtis) Berl. &amp; De Toni) is one of the most common fungal diseases of the grapevine. Most downy mildew resistant grape accessions belong to North American species likeVitis aestivalisMichx.,V. berlandieriPlanch.,V. cinerea(Engelm. ex A. Gray) Engelm. ex Millard,V. ripariaMichx.,V. rupestris Scheele, etc. The search for donors of resistance genes is an urgent task.Rpv3is one of the most significant resistance genes from a number of North American grape varieties. The aim of this work is to identify the downy mildew resistance geneRpv3in seedless grape varieties by means of DNA-marker analysis. The grape varieties with rudimentary development of seed in berries and with North American species in the pedigree were chosen as the object of the study. The varieties “Dunavski lazur” and “Seyve Villard 12-375” with reference alleles were used as the positive control, whileV. viniferaL. was used as the negative control. UDV305 and UDV737 DNA-markers were used in this study to identify the allelic type of theRpv3gene. The work was performed using the polymerase chain reaction. The reaction products were separated by capillary electrophoresis using the ABI Prism 3130 automatic genetic analyzer. Evaluation of the results was done using the GeneMapper and PeakScanner software. Functional alleles of the downy mildew resistance geneRpv3were revealed in grape varieties “Kishmish zaporozhskiy”, “Lady Patricia”, “Remaily seedless”, “Pamyati Smirnova” and “Shayan”.Rpv3299-279, one of the seven known haplotypes, was identified in all the varieties. The pedigree analysis of the studied varieties indicated that the parental forms – “Seyve Villard” and “Seibel” hybrids – are presumably the donors of the gene. Grape accessions with the identifiedRpv3gene can be used in seedless varieties breeding as donors of resistance to downy mildew.

Transcriptomic study of pedicels from GA3-treated table grape genotypes with different susceptibility to berry drop reveals responses elicited in cell wall yield, primary growth and phenylpropanoids synthesis

BackgroundGibberellins (GA3) are the most sprayed growth regulator for table grape production worldwide, increasing berry size of seedless varieties through pericarp cell expansion. However, these treatments also exacerbate berry drop, which has a detrimental effect on the postharvest quality of commercialized clusters. Several studies have suggested that pedicel stiffening caused by GA3 would have a role in this disorder. Nevertheless, transcriptional and phenotypic information regarding pedicel responses to GA3 is minimal.ResultsCharacterization of responses to GA3 treatments using the lines L23 and Thompson Seedless showed that the former was up to six times more susceptible to berry drop than the latter. GA3 also increased the diameter and dry matter percentage of the pedicel on both genotypes. Induction of lignin biosynthesis-related genes by GA3 has been reported, so the quantity of this polymer was measured. The acetyl bromide method detected a decreased concentration of lignin 7 days after GA3 treatment, due to a higher cell wall yield of the isolated fractions of GA3-treated pedicel samples which caused a dilution effect. Thus, an initial enrichment of primary cell wall components in response to GA3 was suggested, particularly in the L23 background. A transcriptomic profiling was performed to identify which genes were associated with these phenotypic changes. This analysis identified 1281 and 1787 genes differentially upregulated by GA3 in L23 and cv. Thompson Seedless, respectively. Concomitantly, 1202 and 1317 downregulated genes were detected in L23 and cv. Thompson Seedless (FDR < 0.05). Gene ontology analysis of upregulated genes showed enrichment in pathways including phenylpropanoids, cell wall metabolism, xylem development, photosynthesis and the cell cycle at 7 days post GA3 application. Twelve genes were characterized by qPCR and striking differences were observed between genotypes, mainly in genes related to cell wall synthesis.ConclusionsHigh levels of berry drop are related to an early strong response of primary cell wall synthesis in the pedicel promoted by GA3 treatment. Genetic backgrounds can produce similar phenotypic responses to GA3, although there is considerable variation in the regulation of genes in terms of which are expressed, and the extent of transcript levels achieved within the same time frame.

THE BREEDING PROGRAM OF SEEDLESS GRAPES, THE EXISTING PROBLEMS IN REPUBLIC AND A PROSPECTS OF INTRODUCING THE GEN TECHNOLOGIES

This article discusses problems in the breeding programs of the seedless grapes, the way of introducing of the biotechnology and gene technology skills to resolve its issues, and the advantages of molecular markers to select seedlessness among the hybrid progeny of grapes. Uzbekistan is famous for its seedless grapes, but on the other hand, the grape breeding is oriented on the conventional breeding method. In other words, seedless grapes have a recessive character, a male form is using only as a pollinator, and all these factors limit to create new seedless varieties and forms. Nowadays the word grape breeders, especially seedless grape breeders use advantages of the biotechnology and gene technology skills to resolve above listed issues. As a result, except for obtaining hybrid progeny by crossing between ♂seedless × seeded ♀ that was an unchangeable algorithm of the cross combination in the traditional grape breeding. But today, researchers argued that crossing between ♂seedless × seedless ♀ is also possible to obtain a hybrid progeny through “embryo rescue technique”. Thus introducing this novel breeding program directly to grape breeding of Uzbekistan leads to an increase the diversity of the new seedless grape varieties and also for increasing the export potential of the grape industry. KEYWORDS: Seedless grape varieties, variety, cross combination, embryo culture, molecular markers, DNA.

СОРТ ВИНОГРАДА REGAL SEEDLESS В УСЛОВИЯХ НИЖНЕГО ПРИДОНЬЯ

Nowadays, table grape consumers prefer seedless grape varieties, so the market promotion of seedless varieties continues at a rapid pace. Responding to consumer preferences, the breeders have developed numerous various-flavour seedless varieties with large berries and bunches. The study purpose is to assess the prospects of cultivation and use in breeding of a new seedless Regal Seedless grape variety bred in South Africa. By origin, this is an intraspecific hybrid of the species V. vinifera L., with an early middle ripening period. The author carried out the variety study to assess agrobiological, economically valuable traits and properties and compiled a short ampelographic description. The study was carried out in 2017–2019 at the experimental vineyard of Ya.I. Potapenko All-Russian Research Institute for Viticulture and Winemaking – Branch of Federal Rostov Agricultural Research Center. The study focuses on non-irrigated covered and grafted vineyards, the Kober 5BB rootstock, the planting pattern of 3 × 1.5 m, and a fan-shaping thankless bush. As to a set of positive parameters (yield, high vendebility, natural seedlessness without the use of gibberellin, large size characteristics, and good taste), the Regal Seedless variety is of certain interest for industrial viticulture, and this variety can also be recommended for use in further breeding as a source of seedless and large berries. According to preliminary studies, the ripened berries of this variety should not be kept long on the bush to prevent peel browning and deterioration in vendebility. The variety is recommended as a highly commercial table grape without the PPP use, but it is not suitable for the production of raisins due to insufficient sugar accumulation. It is recommended that the variety should be grown in areas of sufficient moisture or as an irrigated crop.

DNA-marker identification of Rpv3 and Rpv12 resistance loci in genotypes of table and seedless grape varieties

DNA markers are widely used in grapevine breeding to create forms with combined resistance genes. Downy mildew is one of the most common fungal diseases of the vine in the world. Growing grapevines with increased resistance allows to reduce the number of chemical treatments. The decrease in the use of pesticides is especially significant for viticulture of table varieties, since berries are directly consumed by humans for food. Currently, more than 20 resistance genes have been identified by molecular methods, and DNA markers for many genes have been developed. The genes Rpv3 (inherited from North American grape species) and Rpv12 (derived from V. amurensis) are among the most effective and have an additive effect. The study of 14 table grape varieties for the presence of the Rpv3 gene and 8 varieties for the presence of the Rpv12 gene was performed by using DNA-marker analysis. The analysis included varieties that could inherit these genes from the parent forms, according to their ancestry. The study was conducted using an automatic genetic analyzer ABI Prism 3130 and special software GeneMapper and PeakScanner, DNA-markers were taken from literature sources. According to the results of DNA-marker analysis, 9 varieties were identified, including 2 seedless varieties, with the Rpv3299-279 allele in the genotypes, which determines resistance to downy mildew, and 3 table varieties with the Rpv12 gene in the genotypes. One table grape genotype was identified with Rpv3 and Rpv12.

Relative susceptibility of commercial watermelon varieties to powdery mildew

Powdery mildew (PM) of watermelon caused by Podosphaera xanthii has been occurring more frequently in recent years than in the past and now growers routinely apply fungicides to manage PM. Powdery mildew is known to be able to cause a significant yield reduction in watermelon. The current study was conducted in 2014, 2015 and 2016 to determine the relative susceptibility of twenty six watermelon varieties (seeded and seedless) and three pollenizers to P. xanthii populations prevailing in Charleston, South Carolina. USVL677-PMS, which is highly susceptible to PM and USVL531-MDR, which is resistant to PM were included as controls. A randomized complete block design with three replications was used each year and plants were rated on a 0–10 scale of increasing disease severity. During all three years, USVL677-PMS was the most susceptible line with the highest values for area under disease progress curve (AUDPC). Disease severity at the last ratings for USVL677-PMS ranged from 61 to 82%. In comparison USVL531-MDR was very resistant to PM based on disease severity (1–3%) and AUDPC. The commercial pollenizers, SP5, SP6 and Lion were all resistant to PM (1–5% disease severity) and had significantly lower AUDPC compared to USVL677-PMS and most other varieties evaluated. Among the red fleshed varieties, Suprema (seedless variety), was relatively resistant compared to other seeded and seedless varieties. Most of the seeded varieties evaluated (e.g. Malali, Black Mama, Mickey Lee) were highly susceptible to PM, however, some were relatively less susceptible (e.g. Declaration) under field conditions. Currently very few to no varieties with high levels of resistance to PM are available and there is a need to develop newer resistant varieties as PM is occurring more frequently during the growing season.

Satsuma mandarins grafted onto Swingle citrumelo for early season harvest in subtropical conditions in Brazil

ABSTRACT Although Brazil is the sixth producer of mandarins in the world, fresh fruit exports are neglectable, and few cultivars are available for the domestic market. Main harvest season comprises May to November, with Ponkan mandarin and Murcott tangor representing more than 70% of the production. Therefore, there is a need for alternative early season, seedless varieties that should also be preferably resistant to Alternaria brown spot. We investigated the horticultural performance of ten selections of Satsuma mandarin in subtropical conditions in Bebedouro, northern state of Sao Paulo, Brazil. Clausellina, Okitsu, Unshu SRA-529, Saigon SRA-227, Panache SRA-579, Salzara SRA-341, Miyagawa SRA-444, Kowano SRA-167, FCAV-59 and A2 60.0 selections were grafted on Swingle citrumelo and evaluated up to 7 years old. Unshu, Miyagawa and A2 60.0 presented the highest tree size. These three selections, in addition to Okitsu and Kowano mandarins, resulted in higher fruit yield for the five first harvests (mean of 31.3 kg∙tree–1∙year–1). Panache had the smallest yield efficiency. Miyagawa and A2 60.0 selections presented lower alternate fruit bearing in the evaluated period due to their early bearing habit. These same selections had the largest fruits with the earliest maturation; similar to the Okitsu mandarin, but with lower soluble solids and higher juice content. The overall performance of the Satsuma mandarin selections grafted on Swingle citrumelo and drip irrigated was promising under subtropical climate. The Okitsu, Miyagawa and A2 60.0 mandarins were selected because of their highest productive potential and their valuable quality traits for the Brazilian domestic market.

Influence of the genetic background on the performance of molecular markers linked to seedlessness in table grapes

One of the leading goals in novel breeding programs on table grapevine is the set-up of novel seedless varieties. Seedlessness has a strong impact on consumers’ choices representing an important added economic value compared to traditional cultivars. Breeding in tree crops greatly benefits from the use of molecular markers associated to a trait of interest. Nevertheless, one of the main limitations hampering marker assisted breeding is the lack of marker validation on multiple genetic backgrounds. To this extent, we evaluated the efficiency of four markers linked to seedlessness on 97 F1 genotypes derived from 16 cross combinations obtained through in vitro embryo rescue. Our results confirmed that the four markers were associated to seedlessness even though all, to a different extent, showed marker-trait inconsistencies. Marker efficiency was then tested on the different genetic backgrounds composing the entire germplasm providing a more acurate overview of the marker performances when the genetic background changes. Overall, the most efficient markers were VMC7f2 and p3_VvAGL11 even though their effectiveness changed remarkably from one genetic background to another. This work reports a marker validation assay on a germplasm created to encompass the actual allelic variability employed by breeders. The results could represent a valuable tool to guide the choice of the best markers to assist selection, a choice that should be based, more than on the absolute efficiency of the marker, on a careful evaluation of its performance on the genetic backgrounds in analysis.

Recent Developments in Seedless Grapevine Breeding

Grapes are one of the most commonly produced fruit crops in the world and are consumed as table grapes, wine grapes and dried grapes. In line with consumer demands, seedlessness continues to be an important feature that increases the chances of marketing grapes. Nearly all of the dried grapes that are offered to the world markets are seedless grapes. In addition, the demand for seedless varieties has increased steadily in the table grape trade over the years. Therefore, the production of new seedless grape varieties with large berries that are suitable for table consumption is one of the important goals of breeding studies in viticulture. In this study, recently bred and released new seedless grape varieties are briefly introduced, seedless grape breeding methods are summarised, and the latest developments in breeding methods are explained.

Extremely diverse structural organization in the complete mitochondrial genome of seedless Phoenix dactylifera L

Mitochondrial genome of seedless (mutant) variety of Phoenix dactylifera is analyzed to understand the probable reason for seedless condition. The size of the genome is 585,493 bp long which is 129,508 bp shorter compared to the normal genome and demonstrate significantly higher rate of nucleotide loss. The loss is evident in coding and non-coding regions. Missing of all rRNA genes and other three genes, i.e., rps14, rps13, rps19 is observed. Total 2726 SNPs are recorded, showed 80.9% identity with the normal genome. The ratio of nonsynonymous (dN) synonymous (dS) substitution (dN/dS) is more than one for nad7, nad1, ccMb, ccmC, cob, matR, matB suggest adaptive selection while less than one for cox2 suggest strong selective pressure on this gene and reduction in size may be start of its transfer to nucleus. Such variations may play an important role in seedless condition is discussed.

Pathological Mitosis and Mixoploidy in the Meristematic Tissues of Grape Plant

The emergence of cells with pathological mitosis and the deviation from diploidity in the meristematic tissue of experimental plants of the genus Vitis (Tournef.) Linn. obtained from stenospermocarpic seeds was evaluated. The grape plants obtained from crossing seedless varieties with seedless and seed pollinators were the material for cytogenetic research. A total of 11 crosses were made. The cytogenetic analysis was carried out according to the recommended methods for fruit crops and grape. A total of 11 039 cells were examined. The pathology of mitosis in the cells of grape plants in vitro was observed, in particular, a hollow metaphase, a three-group metaphase and a metaphase with polar chromosomes as well as haploid, triploid, and tetraploid cells. The total frequency of abnormal cells was 0.15. The pathology of mitosis is observed in meristematic tissue of grape varieties as well. The evaluation of emergence of mitotic anomalies in the meristematic tissue of plants was carried out. The correspondence between the actual distribution of the anomalies in experimental populations and the theoretical distribution, as well as the degree of their relative habit to populations, the indices of absolute, relative, and intrapopulation diversity, was determined. As a result of the study of the polyembrionic hybrid offspring of grapes, differentiation in the equitability of distribution and habit of five mitotic anomalies to 11 populations was revealed, and differences between experimental populations by diversity were detected. The maximum degree of relative diversity of populations reached a value of 0.503. In general, the low relative diversity indicates a lack of complete equalization of anomalies by the presence in the populations.

The results of grapevine breeding in the Republic of Moldova – in context of climatic and socio-economic challenges

The results achieved in Republic of Moldova in using the potential of grapevine Gene pool over the past 40 years are significant: new varieties for diverse utilisation, designed for complex biological resistance to stress factors, for reduced pressing on the environment and for excellent capabilities for ecological agriculture. Breeding programs resulted in modernization of assortment – were created more than 80 new varieties for table and wine grapes, most of them with advanced biological resistance, and 32 varieties were included in actual assortment and other are in the process of testing. An important feature of this assortment is presence of seedless varieties, well adapted to our geographical area. According to their characteristics (resistance, quality, productivity), created seedless varieties are not only a pioneering for the assortment of the Republic of Moldova, but for the entire Euro-Asian region. New seedless varieties and perspective elites manifest an increased percentage of buds started in vegetation after the wintering. High fertility, medium to large and very large grapes, accumulation of sugars and total acidity in must favourably for consumption of fresh grapes or for technological processing, suitability for long-term storage and transportability for some of them, denote their high productive and qualitative potential.

Phenotypic evaluation of segregant population derived by crossing table grape varieties

In the CREA-Viticoltura ed Enologia, Lab of Turi, during the last ten years, we started a breeding program for table grapes to obtain new seedless varieties, by using conventional breeding by crossings, and embryo rescue techniques. Other than seedlessness, additional targets for this breeding program are: the possibility of extending the harvesting period, the attitude to cold storage, transport and shelf-life, resistance to diseases both on the plant and in post-harvest conditions, the good productivity, the quality of the grapes, the easy cultivation management of the vineyard (reduced water, nutritional requirements, etc ...). More than 10.000 new genotypes have been obtained through the use of over 20 table grape varieties and more than 18 different crossing combinations. The following characteristics have been observed on these individuals for more than three years: berry color, length and weight cluster, average berry weight, sugars, pH, acidity, class of seedlessness, floral morphology, resistance to diseases. The results of these activities revealed that some combinations have better performance among all. In the near future, this activity will allow to focus on parental genotypes able to provide individuals with the best desired traits.