Rearrangement of leaf traits with changing source-sink relationship in blueberry (Vaccinium corymbosum L.) leaves

Abstract

The source-sink relationship is one of major determinants of plant performance. The influence of reproductive sink demand on light-saturated photosynthesis (P (max)), dark respiration (R (D)), stomatal conductance (g (s)), intrinsic water-use efficiency (WUEi), contents of soluble sugar (SSC), nitrogen, carbon, and photosynthetic pigments was examined in blueberry (Vaccinium corymbosum L. cv. 'Brigitta') during the final stage of rapid fruit growth. Measurements were performed three times per day on developed, sun-exposed leaves of girdled shoots with 0.1, 1, and 10 fruit per leaf (0.1F:L, 1F:L, and 10F:L, respectively) and nongirdled shoots bearing one fruit per leaf (NG). Girdling and lower fruit amount induced lower P (max), g (s), N, and total chlorophyll (Chl) and higher WUEi, SSC, R (D), Chl a/b ratio and carotenoids-to-chlorophylls ratio (Car/Chl) for the 1F:L and 0.1F:L treatments. The impact of girdling was counterbalanced by 10F:L, with NG and 10F:L having similar values. Variables other than P (max), R (D), g (s), WUEi, and SSC were unaffected throughout the course of the day. P (max) and g (s) decreased during the course of the day, but g (s) decreased more than P (max) in the afternoon, while WUEi was increasing in almost all treatments. SSC increased from the morning until afternoon, whereas R (D) peaked at noon regardless of the treatment. Generally, P (max) was closely and negatively correlated to SSC, indicating that sugar-sensing mechanisms played an important role in regulation of blueberry leaf photosynthesis. With respect to treatments, P (max) and N content were positively related, while R (D) was not associated to substrate availability. The enhanced Car/Chl ratio showed a higher photoprotection under the lower sink demand. Changes in the source-sink relationship in 'Brigitta' blueberry led to a rearrangement of physiological and structural leaf traits which allowed adjusting the daily balance between carbon assimilation and absorbed light energy.CONICYT (Chile) FONDEF D06I1100 Universidad de La Frontera (Temuco, Chile) FRO0601 FONDECYT 113050

Vegetative and Physiological Responses of “Emerald” Blueberry to Ammoniacal Sources with a Nitrification Inhibitor

“…3). In this sense, as evidenced by Jorquera-Fontena et al (2016) in Brigitta blueberries, it is possible that the elimination of strong sink organs such as flowers and/or berries in our experiment induced a limitation in the maximum expression of photosynthesis. However, studies conducted by Fan et al (2010) and Nebauer et al (2011) on apple and citrus, respectively, reported that the roots of young plants can exert a demand for sugars similar to fruits.…”

Nitrogen form and root division modifies the nutrimental and biomolecules concentration in blueberry (Vaccinium corymbosum L.)

“…According to Latsague et al (2014), the photosynthetic capacity of leaves is related to the N content, because an adequate supplement of N is essential in the establishment of maximum demand capacity and photosynthetic capacity; but excessive use of N causes excessive expansion of the foliar area. Jorquera-Fontena et al (2016) observed that the accumulation of photosynthetic pigments in blueberry plants is an indicator of biomass production and the nutritional status of N. According to most of the research done, the ratio of chlorophyll a and b is 3:1, which varies depending on plant growth and development, cultivar, and environmental factors (Bojovic and Stojanovic, 2005). Sánchez et al (2018) obtained a positive and significant correlation of the concentration of chlorophyll a, chlorophyll b and carotenoids with the nutritional state of N, in bean (Phaseolus vulgaris L.).…”

Editorial: Interdisciplinary Approaches to Improve Quality of Soft Fruit Berries

“…Pereira et al found that trunk girdling applied at veraison, in "Cabernet Sauvignon" wine grapes (Vitis vinifera L.) increased anthocyanin and flavonol concentrations in skin/pulp tissues of grape berries without affecting primary metabolites. Trunk girdling trials might be applied to change the source-sink relationship on blueberry as already reported by Jorquera-Fontena et al (2016). Zuñiga et al demonstrated that increasing the number of methyl jasmonate preharvest applications (maximum three treatments) on strawberry (Fragaria ananassa "Camarosa") improved the anthocyanin, proanthocyanidin, and ascorbic acid content of the fruit, as well as the antioxidant-related enzymatic activity during postharvest storage.…”

“…found that trunk girdling applied at veraison, in “Cabernet Sauvignon” wine grapes ( Vitis vinifera L.) increased anthocyanin and flavonol concentrations in skin/pulp tissues of grape berries without affecting primary metabolites. Trunk girdling trials might be applied to change the source-sink relationship on blueberry as already reported by Jorquera-Fontena et al. (2016) .…”