Fruit growing
and viticulture of South Russia

Annotation

Improving the fruit aroma is one of the promising directions of modern strawberry breeding. The strawberry fruit aroma is a complex trait, formed by a combination of a large number of volatile compounds. The present study shows the results of assessing the allelic state of the FaOMT gene, determining biosynthesis of mesifurane (volatile compound) in strawberry selected forms created in the �I.V. Michurin FSC�. The biological objects of the study were 22 strawberry selected intervarietal forms from 12 crossing combinations. The allelic state of the FaOMT gene was identified using codominant SCAR marker FaOMT-SI/NO. As a result of the studies, the marker fragment of the functional allele FaOMT+ was identified in 86.4 % of forms. A heterozygous combination of alleles of the FaOMT gene (average level of mesifurane accumulation in fruits) was detected in 9.1 % forms. The homozygous state of the functional allele was detected in 77.3% forms. The homozygous state of the non-functional allele FaOMT- (mesifurane is not produced) is characterized by three genotypes (13.6 %). The greatest value for strawberry breeding use are forms with the homozygous state of the FaOMT+ allele: 1/6-41 (Vima Zanta × Polka), 2/2-32, 2/2-41 (Faith × Tea), 3/2-62 (Vima Zanta × Privlekatelnaya), 3/4-6, 3/4-7 (Malwina × Tea), 3/9-5, 3/9-12 (Florence × Faith), 5/1-105 (Polka × Vima Zanta), 5/2-23, 5/2-26, 5/2-32 (San Andreas × Monterey), 6/3-5, 6/3-21 (Kimberly × 9/2-2), 7/2-78 (Asia × Maya), 9/2-2, 9/2-7 (Kimberly × Honeoye). These forms are characterized by the maximum level of mesifurane biosynthesis in fruits and their involvement of which in hybridization allows the transmission of the target allele to 100 % of the hybrid seedlings.

Annotation

To date, about 50 S-alleles have been identified in the apple tree, but in most study, the foreign varieties are analyzed, whereas for many wild apple species and domestic varieties, information on the allelic state of the S gene is insufficient. The present study presents the results of PCR analysis of wild-type forms of the genus Malus Mill., as well as a number of apple cultivars homologous for individual alleles of the S-locus. Wild species and varieties of the genus Ma-lus Mill., and cultivated apple cultivars of domestic origin (Malus domestica Borkh.) were used as biological objects of the study. The extraction of genomic DNA was carried out according to the minutes of the company Diversity Arrays Technology P/L with modifications. Relative frequencies of occurrence of S-alleles in the studied collection are determined. The allelic status of the S-locus is established for the species forms M. cerasifera 29494 (S3S10), M. purpureav. pendula 2396 (S2S3S10), M. prunifoliav. ringo (S7S9), M. spectabilisv. Rubraplena (S3S10); and for the varieties of Currency (S5S9), Cascade (S3S10), Krasula (S7S9), Uspenskoe (S2S3), Frigate (S3S10), Sorceress (S9S10). There was no clear correlation between the allele state of the S-locus and the taxonomic identity of the genotype. For the Malus series are identified S2, S3, S5, S7, S9, S10 alleles; the Baccatae and Kirghisores series have S2, S3, S5, S9, S10 alleles (the S7 allele is absent). Analysis of the allelic state of the S-locus can be used as an indirect marker of the level of ploidy. Since the presence of two S-alleles is characteristics for organisms with a diploid set of chromosomes, the presence of three alleles in the species M. Purpurea v. pendula 2396 (S2, S3 and S10) indirectly indicates a triploid genome.

Annotation

The creation of new apple varieties is a long and laborious process involving several successive stages: the breeding work, the primary study, and State variety tasting. The appearance of new methods in biology, and in particular in molecular biology, requires a rethinking of the approach to the canonical principles of breeding. One of the perspective directions of increase in efficiency of the breeding process on culture of apple-tree is the use of modern methods of the genome molecular genetic analysis based on DNA markers. A combination of classical breeding techniques with DNA analysis of the original forms and hybrid populations is a promising direction of research related to the intensification of the process of genotypes creation with the specific parameters of valuable selective important features Biological objects of our research were the seedlings of apple hybrid fund of academician's of the Russian Academy of Sciences N.I. Saveliev. This article shows the results of the DNA analysis of hybrid seedlings of apple trees on the loci of monogenic resistance to scab (Rvi6 gene) and of columnar growth habit (Co gene) to identify the genotypes with a complex of valuable signs. In the studied combinations of crosses the number of apple seedlings, combining the immunity to scab with the columnar habit of the tree's crown (genotype Rvi6 + Co), was 33.3-40.9 per cent. In the process of our studying it is identified the promising for breeding apple seedlings with genotype of Rvi6Rvi6 + Coco, the involvement of which In the hybridization as the native forms will significantly intensify the breeding process, ensuring the receipt of up to 100 % of seedlings with monogenic resistance to scab and up to 50% of seedlings with columnar growth habit.

Annotation

In the apple breeding the one of the priority tasks is the creation of varieties with monogenic determining immunity to scab. The purpose of this study was the molecular-genetic testing of the original forms and hybrid seedlings of the apple-tree to identify the carriers of the target alleles of the monogenic resistance genes to scab � Rvi6, Rvi4, Rvi2, Rvi8, and also to clarify the nature of their inheritance in the hybrid progeny. Biological objects of the study were the apple varieties of different ecological and geographical origin, as well as seedlings of the hybrid fund of the academician of the Russian Academy of Sciences, doctor of agricultural sciences N.I. Saveliev. The materials of this article show the results of DNA analysis of apple varieties and hybrid seedlings at loci of monogenic resistance to scab (gene Rvi6, Rvi4, Rvi2, Rvi8). Based on the molecular-genetic analysis performed, the genotypic structure of the initial forms was refined. Molecular genetic analysis of the initial apple forms using the VfC and AL07-SCAR markers showed the presence of the Rvi6 gene in the geterozis state (Rvi6rvi6) in the genomes of the Bylina, Kandil Orlovski, Akademik Kazakov, Imant, Valuta, Belarusskoe Sladkoe, Uspenskoe, Prima. The Golden Delicious variety and the NR12740-7A form have a recessive homozygous genotype. As a result of research carried out and on the molecular genetic analysis, the genotypic structure of the initial forms was refined and joint inheritance in the hybrid progeny of the apple-tree of loci of monogenic resistance to scab was analyzed. The sources of the genes Rvi6, Rvi4, Rvi2, Rvi8, which are promising for apple-tree breeding, have been identified.

Annotation

Powdery mildew, white and brown spots, as well as recent anthracnose black rot, late blight and verticellosis wilt are the most important diseases that cause the significant damage to the strawberry plantations. The losses of a strawberry commodity crop from anthracnose damage can reach 80 %. The most strawberry varieties are susceptible to anthracnose black rot in various degree. The resistance of garden strawberry to anthracnose is controlled polygenically and monogenously. The causative agent of late blight root rot (late blight wilting) is Phytophthora fragariae var. fragariae Hickman. The causative agent of late blight affects the root system, causing the inhibition of growth, withering and subsequent death of plants. One of the promising methods for identifying wild strawberry forms resistant to late blight and anthracnose is analysis using diagnostic DNA markers linked to the target alleles of resistance genes. DNA markers are successfully used both at the stage of selection of initial sources for hybridization and in the subsequent analysis of hybrid material. The results of DNA analysis of varieties and selected seedlings of strawberry on the genes of resistance to late blight wilt Rpf1 and anthracnose Rca2 are shown. The SCAR-R1A marker linked to the Rpf1 gene was not detected in the studied strawberry varieties and forms, that presumably indicates their recessive homozygous genotype for the Rpf1 gene (rpf1rpf1). The STS-Rca2_240 marker linked to the Rca2 gene was detected in Borovitskaya and Aprica varieties and in the selected form of 933-4 (F. virginiana Duch. Ssp. Platypetala × Rubinovy Kulon), which allow us to recommend them for breeding as a promising source of anthracnose resistance.