Leaf Anatomy of Apple Trees during Seasonal Periods under Subtropical Conditions

Abstract

<jats:p>Water deficits are considered the primary environmental stress in agriculture, and improving the growth and production of plants under this stress is one of the primary goals of breeding and crop management programs. The apple tree is a plant that is negatively affected by water stress. Plants that develop under a water deficit may develop physiological and anatomical strategies to survive or even produce fruits in these environments. In view of the importance of and lack of studies of the leaf anatomy of apple trees in areas with a water deficit that are intended to support genetic improvement programs for this fruit either to introduce cultivars in regions with water deficits or to select potential progenies for future crosses, the aim of this study was to compare the anatomical characteristics of apple leaves from two distinct environments (water deficit and precipitation) under tropical conditions. Twelve fully expanded leaves were collected from seven apple cultivars (Eva, Rainha, Princesa, Julieta, Imperatriz, Baronesa, and Gala Real), which are planted in the experimental orchard at Universidade Federal de Lavras, during water deficit (September) and precipitation (February) seasons. Sixteen anatomical characteristics were evaluated in addition to the anatomical description of the apple leaves. The experimental design was completely randomized in a 7×2 factorial arrangement. The means were analyzed using the Scott-Knott method for grouping means at the 5% level of error probability. Genetic divergence, cultivar clustering and principal component analyses were also performed based on the anatomical characteristics evaluated during the two seasons. The apple leaves had anatomical characteristics that can favor the production of this fruit tree in areas experiencing water deficits within subtropical regions. According to their anatomical characteristics, there was genetic divergence among the apple cultivars studied here. The cultivars Gala Real, Eva, and Baronesa presented anatomical and morphological characteristics that showed adaptation potential in areas with water deficits.</jats:p>

Alleviating the adverse effects of deficit irrigation in Flame seedless grapevine via Paulsen interstock

“…A thicker palisade tissue may have a role in increasing the number of CO 2 -fixation sites. A thicker spongy paraenchyma could result in easier diffusion of Co 2 to these sites, thus maintaining the photosynthesis rate of leaves under deficit water (ENNAJEH et al, 2010;LOCATELLI et al, 2019). The thickening of the vascular bundles of plant leaves allows for greater flows of water and mineral salts during the water deficit, thus adaptive it to water stress conditions (Queiroz-Voltan et al 2014).…”

“…The thickening of the vascular bundles of plant leaves allows for greater flows of water and mineral salts during the water deficit, thus adaptive it to water stress conditions (Queiroz-Voltan et al 2014). On the other hand, Locatelli et al, (2019) reported that the xylem vessels of leaves were increased in number and were reduced in diameter under deficit water. Thus, it increases resistance to high pressures in the water column.…”

Genetic divergence based on leaf vegetative and anatomical traits of Coffea canephora clones

“…This information has great relevance for the selection of promising materials, as the higher stomatal frequency and density represent an important tolerance response to water deficit (I. Oliveira et al, 2018;Locatelli et al, 2019). It occurs because a higher stomatal density allows the stomatal opening in a period in which it is possible to capture CO 2 and prevents excessive transpiration.…”

“…Leaf anatomy studies associated with vegetative traits provide support for the identification of promising genotypes, considering early selection and the use of selection indices that consider the combination of various characteristics as selection criteria, seeking to identify genotypes that present a set of favorable characteristics (Gama, Sales, Castanheira, Silveira, & Azevedo, 2017;Oliveira, Meyerb, Afonso, & Gonçalves, 2018;Viana et al, 2018a,b;Locatelli et al, 2019).…”

Effects of Metamitron under Different Relative Humidity Conditions on the Fruit Abscission of Malus domestica Borkh. Cultivars

“…There are many factors affecting leaf chemical uptake dynamics, with relative humidity being one of them [17][18][19][20]. High relative humidity conditions can affect the leaf morphological structure, reducing the thickness of the parenchyma and both the adaxial and abaxial epidermis [30,31], leaving a softer and thinner (less waxy and more permeable) cuticle, which is more prone to chemical absorption. Previous observations [20] confirmed these aspects as a 50% increase of urea leaf absorption was observed after a relative humidity increase from 35% to 50%.…”