Krystyna Górecka

The process was examined or the effect of culture conditions on in vitro gynogenesis in red beet was analyzed, conditions were modified or optimized. A significant influence of the genotype on the gynogenesis process was demonstrated. Of the eight genotypes, 58.3% planted ovules regenerated embryo-like structures in breeding line 411, 2.1% in RA-10, RA-11, RA-12 breeding lines and 0.9% embryo-like structures in Opolski. For the gynogenesis induction, B5 medium containing 0.1 mg L–1 2,4-dichlorophenoxyacetic acid was the most effective from all tested media. On this medium, the highest number of gynogenetic embryo-like structures was obtained. Most of the plants were regenerated on MS medium supplemented with 30 g L–1 sucrose, 0.2 mg L–1 6-benzylaminopurine and 1 mg L–1 indole-3-acetic acid. Thirty nine percent of regenerated plants acclimatized. Cytometric evaluation of gynogenetic plants of four tested genotypes revealed that in three genotypes, 100% of tested plants were haploid. Plants showed diploid ploidy level in one genotype. Isoenzymatic analysis of gynogenetic plants demonstrated that 95% and 70% of examined populations were homozygotic for the phosphohexose isomerase isoenzyme and the aspartato aminotransferase isoenzyme, respectively. During the next generation sequencing, 93% of reads were successfully mapped, from which 83% to 85% were mapped in pairs. For 15% of pairs it was clear that obtained sequence was fully homozygous, the rest of the readings were not unambiguous, but similar to the sequence of a homozygous base pair system.

The influence of polyamines (PAs), putrescine (Put) and spermidine (Spd) on the efficiency of gynogenesis in ovule cultures of red beet (syn. beetroot) (Beta vulgaris L. vulgaris) cultivar “Czerwona Kula” and breeding accessions no. 3/2010 and no. 7/2008 was investigated. The effect of Put on the process of plant regeneration from gynogenetic embryos was studied. The response to the applied PAs was strongly dependent on the genotype. In “Czerwona Kula”, an increase in the number of obtained embryos was achieved by using each of the two PAs in the B5 medium. The effect of Spd was stronger. Put added to the regeneration medium at the concentration of 0.5 mg L⁻¹ increased the number of obtained plants. All shoots placed on the rooting medium supplemented with 160 mg L⁻¹ Put formed roots. The distribution of ploidy and homozygosity of gynogenetic plants depended on the genotype. Of the tested genotypes, the highest number of haploid plants, 68%, was obtained in red beet “Czerwona Kula”. The highest percentage of homozygotes, 69% for the glucose phosphate isomerase (GPI, E.C.5.3.1.9) isoenzyme and 100% for the aspartate aminotransferase (AAT, E.C.2.6.1.1) isoenzyme, was obtained in the population of gynogenetic plants of cultivar “Czerwona Kula”.

Yacon becomes an important plant with strong medical and dietary potential. Therefore, studies on the optimization of yacon micropropagation were undertaken. Reproduction of yacon is conducted by traditional methods with green seedlings or long offsets taken from the underground and aboveground rootstock. The influence of different disinfection methods, various initial explants and growth regulators, their concentrations, and combinations on the efficiency of micropropagation have been analyzed. The most effective disinfection was the use of 70% ethanol and 0.5% Tween 20. The optimal initial explants were apical and lateral buds cultured on Murashige and Skoog (MS) medium with 0.2 mg L–1 kinetin and 1 mg L–1 indole-3-acetic acid. The most intensive shoot regeneration occurred on MS medium with 1 mg L–1 thidiazuron and 1-naphthylacetic acid. Histological observations demonstrated the strong effect of growth substances on shoot organogenesis from callus tissue. Shoots obtained from in vitro cultures rooted easily on modified MS media with ½ or ¼ concentration of macroelements, 20 g L–1 sucrose and 3 mg L–1 1-naphthylacetic acid. All plants adapted to ex vitro conditions.