Use of Biotechnological Methods to Support the Production of New Peach Hybrids

Abstract

Peach [Prunus persica (L.) Batsch] is among the most demanded fruit crops in the world. Biotechnological methods help to originate new hybrid forms in order to increase the cultivar diversity and create new valuable genotypes. Cross combinations between the cultivars Clyde Wilson, Jerseyglo, Loadel, Summerglo and the promising cultivar ‘Nikitskiy Podarok’ have been done. The embryos of these hybrids germinated and formed plantlets after stratification at 4 °C for 45–60 days. The best regeneration rates in the hybrids ‘Loadel’ × ‘Nikitskiy Podarok’ and ‘Summerglo’ × ‘Nikitskiy Podarok’ (96.30% and 92.59%, respectively) were noted on hormone-free Monnier culture medium supplemented with 400.0 mg L−1 casein hydrolyzate. When the newly formed plantlets had necrosis of the shoot apex or immature roots, nodal shoot segments were used. At the same time, a high regeneration capacity was noted in the hybrids ‘Summerglo’ × ‘Nikitskiy Podarok’ and ‘Loadel’ × ‘Nikitskiy Podarok’ on B5 culture medium with 0.75 mg L−1 6–benzyl–aminopurine (BAP) + 0.1 mg L−1 indole–3–butyric acid (IBA). After the second subculture, the number of new adventitious shoots was 5.18 ± 0.18 and 4.95 ± 0.18 shoots per explant, respectively. The plants obtained from the hybrid embryos in a soil mixture soil: peat: sand (3:1:1) were adapted. The main morphological and anatomical features of the leaf blades in newly originated peach hybrids have been studied: the thickness of their tissues and the distribution of stomatal apparatus, as well as the physiological parameters of the photosystem II activity in regenerants cultured in vitro and during their in vivo acclimatization. The high capacity to post aseptic adaptation in the obtained hybrids has been shown.

Assessment of the Drought-Tolerance Criteria for Screening Peach Cultivars

“…Leaf mass per area, specific leaf area and leaf density had no significant effect on water loss in the studied peach genotypes. Drought tolerance significantly depends on structural features of the leaf lamina [27,63,[70][71][72][73][74].…”