Effect of different combinations of antibiotics on fruit quality and antioxidant defense system in Huanglongbing infected Kinnow orchards

Abstract

Huanglongbing (HLB), also known as citrus greening disease, is the most devastating disease of citrus across the world, caused by the phloem limited fastidious bacterium ‘Candidatus Liberibacter spp.’. This research was conducted on HLB infected 10-year-old Kinnow orchard located at Multan, Pakistan. Different classes of antibiotics in various combinations were applied on HLB-infected trees. The antibiotic treatments were applied before flowering in February, during fruit setting in April and at fruit growth stage in June. The different antibiotics combinations used were Ampicillin sodium + Rifampicin, Cefalexin + Rifampicin, Ampicillin sodium + Cefalexin, Ampicillin sodium + Cefalexin + Rifampicin and Control (distilled water). Different fruit qualitative and quantitative attributes were examined. The application of antibiotics significantly decreased 2–11% in flower, June and pre-harvest drops as compared to control. Further, antibiotics increased fruit weight and yield by five times while the juice content, total soluble solids, ripening index, total sugars, phenolic and vitamin C content were also increased in fruits. In addition, total soluble proteins, peroxidase and catalase activities were increased in fruits harvested from antibiotic treated plants compared to control, however the superoxidase dismutase activity was decreased in fruits of antibiotic treated plants. Finally, it is concluded that application of different antibiotics combinations helps in improving the fruit yield and different quality attributes of HLB infected Kinnow trees.

Phytogenic Selenium Nanoparticles Elicited the Physiological, Biochemical, and Antioxidant Defense System Amelioration of Huanglongbing-Infected ‘Kinnow’ Mandarin Plants

“…HLB is a bacterial disease that is drastically decreasing citrus production worldwide. HLB is caused by the un-culturable phloem limited fastidious α-proteobacterium Candidatus Liberibacter spp.—having three casual organisms, though the Candidatus Liberibacter asiaticus is the most common in America and Asia—which limits the uptake and movements of essential nutrients in the phloem, ultimately affecting the citrus tree health and fruit quality [ 9 , 10 ]. The bacterium first moves from infected sites toward the roots and multiplies, ultimately damaging the roots first and then the leaves.…”

Evaluation of the control effect of SAR inducers against citrus Huanglongbing applied by foliar spray, soil drench or trunk injection

“…In addition, in HLB-endemic regions, such as Florida, the HLB management focus has shifted to how to improve and sustain the productivity at the presence of HLB. Therefore, multiple approaches were tested to mitigate HLB damage and losses caused by HLB, including maintaining optimal tree growth conditions (Gottwald et al 2012;Stansly et al 2014), targeting Las (Akula et al 2011;Hu and Wang 2016;Barnett et al 2019;Hussain et al 2019;Li et al 2019b), eliciting plant defenses (Zhang et al 2014;Canales et al 2016;Li et al 2016;Li et al 2017;Hu et al 2018;Li et al 2019a), thermotherapy (Thapa et al 2020a;Thapa et al 2020b), and biological control (Riera et al 2017;Wang et al 2017b;Blaustein et al 2018).…”

Antioxidant Metabolites in Primitive, Wild, and Cultivated Citrus and Their Role in Stress Tolerance

“…Prompt endogenous biosynthesis of phenolic compounds in the least time after pathogen invasion is supposed to be more important than their endogenous concentrations in plants [ 16 ]. The plant species that possess a high level of antioxidant phenolic compounds are least attractive to pathogens [ 75 , 76 ]. To conclude, the primitive and wild citrus species have a high concentration of total amino acids, and they biosynthesize antioxidant phenolic compounds (such as flavonoids) more rapidly than cultivated Citrus species.…”