Mitogenomic Research of Silverleaf Sunflower (<i>Helianthus argophyllus</i>) and Its Interspecific Hybrids

Interspecific hybridization is widespread for sunflowers, both in wild populations and commercial breeding. One of the most common species that can efficiently cross with Helianthus annuus is the Silverleaf sunflower—Helianthus argophyllus. The current study carried out structural and functional organization analyses of mitochondrial DNA in H. argophyllus and the interspecific hybrid, H. annuus (VIR114A line) × H. argophyllus. The complete mitogenome of H. argophyllus counts 300,843 bp, has a similar organization to the mitogenome of cultivated sunflower, and holds SNPs typical for wild sunflowers. RNA editing analysis predicted 484 sites in H. argophyllus mitochondrial CDS. The mitochondrial genome of the H. annuus × H. argophyllus hybrid is identical to the maternal line (VIR114A). We expected that significant rearrangements in the mitochondrial DNA of the hybrid would occur, due to the frequent recombination. However, the hybrid mitogenome lacks rearrangements, presumably due to the preservation of nuclear–cytoplasmic interaction paths

SSR-MARKERS OF RICE RESISTANCE TO THE TOTAL FLOODING

The present work deals with the study of the SSR-markers informativeness, associated with the locus of resistance to flooding Sub1A, to introduce this locus into the genotypes of highly productive varieties of domestic breeding. The SSR-analysis of the rice samples according to 7 micro satellite markers (RM 219, RM 316, RM 444, RM 464, RM 7481, RM 8303, RM 23877) showed that the marker RM 7481 gave the special and well-produced ranges, and was informative for the identification of the locus Sub1A. The hybridization among the donors of the locus of resistance to flooding BR-11, Inbara-3, CR-1009, TDK-1 and the early maturing Russian variety ‘Novator’ has been carried out to estimate the relationship of the inheritance of RM 7481 marker and the trait of resistance to flooding. The DNA-analysis of the hybrid F2 revealed the samples with the different allele variants of the locus Sub1A, the part of them has been found homozygous. The assessment of the resistance to water stress of rice hybrids and their parental forms in 21-day germination and the data of the molecule-genetic analysis showed that the increased water level significantly reduced this index of the variety ‘Navator’ and of the hybrids which did not inherit the locus of resistance. The lines-donors of the resistance and hybrid plants, which possess the locus Sub1A in homozygous and heterozygous states turned to be the most resistant forms according to the survival index. Thus, the study of SSR-markers connected with the locus of resistance Sub1A showed the high informativeness of co-dominant marker RM 7481 for the marker-associated breeding of the rice forms resistant to total flooding

The marker-assisted breeding of salinity tolerant forms of rice

The work deals with the study of DNA-markers for obtaining salinity tolerant rice on the basis of varieties of Russian breeding. In order to validate the informational value of the developed marker system and to obtain new salinity tolerant forms there has been carried out a hybridization of salt sensitive domestic variety ‘Novator’ with the lines ‘IR 52713-2B-8-2B-1-2’, ‘IR 74099-3R-3-3’, ‘IR 61920-3B-22-2-1 (NSIC Rc 106)’ as the donors of the locus of salinity tolerance SalTol QTL. The samples salinity response was assessed with 1.0% of NaCl concentrate. The plants were grown in the climatic chamber with the temperature of 26ºС, 70% of humidity and light cycle of 14/10 hours. In 14 days the length of the roots and sprouts and the per cent of seed germination were calculated. The markers ‘RM 140’, ‘RM 237’, ‘RM 8094’, ‘RM 8095’, ‘RM 3412’, ‘RM 7075’, ‘RM 8046’, ‘AUT 10777’, ‘RM 3412 b’, ‘RM 10746’, ‘RM 10782’, ‘RM 493’, ‘RM 10776’, ‘RM 10793’ with the locus of salinity tolerance SalTol were used in the SSR-analysis. It has been shown that the co-dominant markers ‘RM 493’ and ‘RM 7075’ possess high efficiency during the introduction of the locus SalTol QTL into the domestic varieties of rice. 90 samples have been selected from the plants of the second generation, which were analyzed on the presence of the introduced alleles SalTol with the PCR-method. The DNA-analysis of the hybrids F2, obtained from the hybridization of the highly productive early-maturing variety ‘Novator’ and the lines-donors of SalTol ‘IR 52713-2B-8-2B-1-2’, ‘IR 74099-3R-3-3’, ‘IR 61920-3B-22-2-1 (NSIC Rc 106)’ determined that 17 samples were salinity tolerant in homozygous state, 29 samples had the allele SalTol in heterozygous state and the rest of the studied plants had only the alleles inherited from the variety ‘Novator’