Response of the Five Highbush Blueberry Cultivars to In Vitro Induced Drought Stress by Polyethylene Glycol

Abstract

Stress caused by drought is an important factor that affects the growth and development of highbush blueberry plants. In vitro screening for drought stress tolerance is of major importance in identifying cultivars that have optimal stress tolerance and productivity. The aim of this study was to evaluate the responses of five in vitro-grown highbush blueberry cultivars (Bluecrop, Brigitta Blue, Duke, Goldtraube and Hortblue Petite) under drought stress. Five concentrations of polyethylene glycol (PEG 6000), 0 g/L, 10 g/L, 20 g/L, 30 g/L, 40 g/L, 50 g/L, were applied to induce drought stress in the culture media. Significant differences were found in shoot length and number, proliferation rate, fresh weight, dry weight, water content, chlorophyll, and carotenoid content. Drought stress had a negative impact on shoots length, chlorophyll, and carotenoid content for all highbush blueberry varieties. The conclusion of the study highlights that Goldtraube had the highest drought tolerance efficiency, followed by Bluecrop, Hortblue Petite, Duke, and Brigitta Blue.

Micropropagation of Vaccinium corymbosum L.: An Alternative Procedure for the Production of Secondary Metabolites

“…Regarding shoot lengths (Figure 2b), they recorded maximum values at Hortblue Petite on solid culture medium supplemented with 0.5 mg/L Z (3.40 ± 0.20 cm), while Duke had the longest shoots in the TIS in the culture medium supplemented with 5 mg/L 2iP (3.07 ± 0.28 cm), in agreement with our previously reported results [34,46,51].…”

“…In solid media, Hortblue Petite had again the highest PR (7.94 ± 0.25) in the medium supplemented with 1 mg/L Z while Duke presented a PR of just 2.98 ± 0.25 (Figure 2a). Similar results were obtained in our previous studies where the Duke variety had the lowest proliferation rate (2.11 ± 0.15) compared to Hortblue Petite (8.50 ± 0.51) on agar gelled with WPM culture medium and supplemented with 1 mg/L Z [51]. Another study showed [44] that Duke cultivar cultured on Anderson (1980) culture medium supplemented with 0.5 mg/L Z or 2iP generated a similar number of shoots/explant, their numbers ranging from 2 to 4.…”

Review on blueberry drought tolerance from the perspective of cultivar improvement

“…Blueberry is especially prone to adverse effects from drought events ( Erb, 1993 ; Améglio et al., 2000 ; Molnar et al., 2022 ) ( Figure 1 ). Limited drought tolerance of blueberries is a byproduct of their superficial root system, with most blueberries growing roots less than 40 cm deep ( Molnar et al., 2022 ) ( Figure 1 ).…”

“…Blueberry is especially prone to adverse effects from drought events ( Erb, 1993 ; Améglio et al., 2000 ; Molnar et al., 2022 ) ( Figure 1 ). Limited drought tolerance of blueberries is a byproduct of their superficial root system, with most blueberries growing roots less than 40 cm deep ( Molnar et al., 2022 ) ( Figure 1 ). Additionally, blueberries lack root hairs, which reduces their absorptive root surface by 90% compared to root systems with root hairs ( Eck, 1966 ; McElrone et al., 2013 ).…”

“…In many cases the decrease in fluoresce parameters ( Estrada et al., 2015 ; Balboa et al., 2020 ) is also related to the decrease in chlorophyll and carotenoid content during drought ( Chen et al., 2017 ; Mazurek et al., 2021 ; Molnar et al., 2022 ). Additionally, membrane damage as result of ROS accumulation can also be monitored through malondialdehyde (MDA) content, which is a product of membrane lipid peroxidation because of membrane damage ( Ma et al., 2015 ).…”