Root Development of Bell Pepper (Capsicum annuum L.) as Affected by Water Salinity and Sink Strength

Abstract

Fruits are the dominant sinks for assimilates. At optimal conditions, assimilates supply can meet the demand of fruits and those of the vegetative organs; however, extreme circumstances such as strong sink strength or an environmental stress may disturb this fine balance. While most studies focus on aboveground parameters, information regarding root growth dynamics under variable sink strength are scarce. The objective of this study was to evaluate the effect of sink strength (represented by fruit load) and salinity on bell-pepper root development. Three levels of fruit load were combined with two salinity levels in plants grown in an aeroponic system. Root growth was determined both by root capacitance and destructive measurements. Salinity and sink strength significantly affected root, shoot and fruit growth dynamics. Root growth was less affected by fruit load. Salinity stress was negatively associated with shoot growth, but after an acclimation period, salinity enhanced root development. Additionally, this study shows for the first time that root capacitance is a valid approach for non-destructive measurement of root development in aeroponic systems. The good correlation measured by us (r2 0.86) opens new opportunities for continuous root growth monitoring in aeroponic systems in the future.

Effects of droplet size and spray interval on root-to-shoot ratio, photosynthesis efficiency, and nutritional quality of aeroponically grown butterhead lettuce

“…The pH and EC of the nutrient solution were measured every day from each treatment. A fresh nutrient solution with maintained pH (5.8-6.0) and EC (1.6-2.2 dS/m) value was replaced with recycled one on the fifth day during the entire experiment of 40 d after transplant (DAT) [39,40] . The equipment for measurement of pH and EC were used as reported by our research team Lakhiar et al [8] .…”

“…The fresh weight of roots (RFW), and shoots (SFW) was measured on a scale accurate to 0.0001 g. Furthermore, the root and shoot samples were put into the envelopes and oven-dried at 85°C for 72 h, and the same procedure was applied to measure the dry weight of shoots (SDW), and roots (RDW). The root-to-shoot ratio was calculated as the root weight/shoot weight (fresh and dried) [2,[40][41][42] . Figure 3 shows the shoot and root growth of aeroponically grown lettuce during the experiment.…”

Dry mass input into fruits can be predicted by fine root morphology of pepper cultivars exposed to varied lighting spectra

“…Studies on horticultural plants demonstrate a trend that fine roots compete with fruits for dry mass allocation (Erel et al, 2020). For example, peach tree root growth stagnated at stages of fruiting and regrowth when fruits were being harvested (Villena et al, 2017).…”

The preventive impact of vermicompost on bell pepper (Capsicum annuum L.) salinity resistance: An evaluation

“…Majority of the cultivated plants consist of glycophyte species, which are comparatively sensitive to this particular parameter (Wang et al, 2019). Furthermore, such property is highly accurate for bell peppers or Capsicum annuum L., which is otherwise one of the primarily ingested fruits globally (Erel et al, 2020). In fact, salt stress may potentially pose a highly detrimental influence on the bell pepper production.…”

“…Moreover, the halophytic plant species are made up of several closelyrelated plant species for the Capsicum genus, thereby rendering interspecific crosses a potential alternative for salt-stress-resistant hybrids (Parađiković et al, 2019). Unfortunately, such goal is highly costly, time-consuming, and requires concerted efforts in order to choose the best material equipped with the required agrarian attributes (Erel et al, 2020). Besides, one may further opt for genetic engineering to carry out specific gene transfer; however, it comes with varying population-based issues and is less pragmatic as a solution.…”