Efficient In Vitro Screening for Higher Soil pH Adaptability of Intersectional Hybrids in Blueberry

Abstract

<jats:p>We tested efficient in vitro methods for screening the genotypes with higher pH tolerance using multiple shoots of intersectional hybrids between <jats:italic>Vaccinium corymbosum</jats:italic> ‘Spartan’ and <jats:italic>V. bracteatum</jats:italic>. The response of the four hybrid clones tested to different pH levels was clone-dependent in vitro. An apparent difference was found in the rooting rate among the hybrid clones even at higher pH levels; the rooting rates of JM4 (91%) at pH 8.0 indicated a significantly high value compared with other clones (JM1: 24%, JM2: 9%, JM3: 8%, ‘Spartan’: 0%). Furthermore, JM4 showed constantly high rooting rates (91% to 100%) at all pH levels with no significant differences. Similar differences in the root characters of the hybrids were also confirmed by checking the viability of roots using fluorescein diacetate (FDA)/propidium iodide (PI) staining after dipping the roots of in vitro-produced shoots in liquid medium at different pH levels for 6 hours. These results suggest that an in vitro screening method using the rooting rate of multiple shoots and the viability test of roots by FDA/PI staining as a marker could become a very useful tool for the selection of germplasm with tolerance to higher pH within a short time using small planting spaces. In addition, JM4, which showed a high rooting rate at pH 8.0, could be useful in breeding new cultivars with higher pH tolerance.</jats:p>

Ammonium Uptake Is the Main Driver of Rhizosphere pH in Southern Highbush Blueberry

“…Our results suggest that using NO 3 for blueberry fertilization might lead to rhizosphere alkalization. In blueberry, high rhizosphere pH can lead to nutrient deficiencies, stunted growth, and low survival (Finn et al, 1993;Tsuda et al, 2014). Thus, NO 3 use would exacerbate the need for soil amendments and soilless substrates for blueberry cultivation.…”

“…Plants in family Ericaceae (i.e., acid-loving plants) thrive in acidic soils (pH 4.2-5.5) where NH 4 + is the most abundant form of N (Marrs and Bannister, 1978). When acid-loving plants are grown in neutral or high-pH soils, they exhibit stress, nutritional deficiencies, stunted growth, and low survival (Finn et al, 1993;Marrs and Bannister, 1978;Paya-Milans et al, 2017;Tsuda et al, 2014). Acidic soils are rare in agricultural and landscape settings.…”

Growth, Fruit Yield, Photosynthetic Characteristics, and Leaf Microelement Concentration of Two Blueberry Cultivars under Different Long-Term Soil pH Treatments

“…Different blueberry species and cultivars usually have different resistances to high pH levels. Tsuda et al [10] found that the interspecific hybrids of highbush blueberry 'Spartan' and V. bracteatum had higher survival and rooting rates than their parents, of the 'Spartan' variety, did, at a pH level of 8.0; moreover, there were significant differences among the different hybrids. Finn et al [4,9] found that the survival or germination rates and biomasses of different highbush blueberries, lowbush blueberries, and their hybrid offspring were different under high pH conditions, and the resistance of some lowbush blueberry offspring could be improved through a hybrid method.…”

“…Breeding blueberry cultivars with a high pH tolerance is one of the appropriate ways to solve this problem. Different species and cultivars of Vaccinium have different abilities to tolerate high pH values [4,9,10], so new cultivars of blueberry with more tolerance to high-pH soil can be bred through a breeding program. However, new blueberry germplasms created by crossing or other breeding methods usually take several years to bloom and bear fruit.…”

There and back again; historical perspective and future directions for Vaccinium breeding and research studies

“…It also possesses tolerance to higher pH soils. Tsuda et al (2013) using a colchicine-doubled species selection [ 30 ], produced 66 4 x hybrids and some hybrids were shown to have pigmented flesh a subsequent manuscript Tsuda et al (2014) documented the superior rooting of several hybrids at higher pH levels [ 31 ]. Vaccinium meridionale Swartz is a tetraploid native to Jamaica and Colombia.…”