Cape gooseberry has coped with abiotic and biotic stresses such as prolonged waterlogging periods and vascular wilt in recent years. The aim of this study was to evaluate the influence of four waterlogging periods on stomatal conductance (g_s), leaf water potential (Ψ_wf), plant growth, leaf photosynthetic pigments, malondialdehyde (MDA) production, proline content and chlorophyll fluorescence parameters in cape gooseberry plants infected with Fusarium oxysporum f. sp. physali (Foph). Two-month-old ecotype “Colombia” plants were arranged in a completely randomized factorial design in eight treatments: plants without waterlogging (control), plants with waterlogging for 4, 6 and 8 d with and without Foph, respectively. The area under the disease progress curve was higher in inoculated plants subjected to 6 and 8 d of waterlogging (55.25 and 64.25) compared to inoculated plants but without waterlogging (45.25). The results also showed a lower plant growth, g_s, Ψ_wf, leaf photosynthetic pigments and chlorophyll fluorescence parameters (F_v/F_m, electron transport rate (ETR), Y (II) and qP) as waterlogging periods in plants with Foph increased. However, this group of plants showed a greater proline and malondialdehyde (MDA) accumulation and a higher NPQ. In conclusion, cape gooseberry shows a low acclimation to waterlogging conditions of more than 6 d in soils with Foph.

Cape gooseberry production has been limited by vascular wilt caused by Fusarium oxysporum f. sp. physali (Foph). Fusaric acid (FA) is a mycotoxin produced by many Fusarium species such as F. oxysporum formae speciales. The effects of the interaction between this mycotoxin and plants (such as cape gooseberry) under biotic stress (water deficit, WD) have been little explored. Three experiments were carried out. The objectives of this study were to evaluate (i) different Foph inoculum densities (1 × 10⁴ and 1 × 10⁶ conidia ml⁻¹; experiment (1); (ii) the effect of times of exposure (0, 6, 9, and 12 h) and FA concentrations (0, 12.5, 25, 50, and 100 mg L⁻¹; experiment (2), and (iii) the interaction between Foph (1 × 10⁴ conidia mL⁻¹) or FA (25 mg L⁻¹ × 9 h), and WD conditions (experiment 3) on the physiological (plant growth, leaf stomatal conductance (g_s), and photochemical efficiency of PSII (F_v/F_m ratio) and biochemical [malondialdehyde (MDA) and proline] responses of cape gooseberry seedling ecotype Colombia. The first experiment showed that Foph inoculum density of 1 × 10⁶ conidia ml⁻¹ caused the highest incidence of the disease (100%). In the second experiment, g_s (~40.6 mmol m⁻² s⁻¹) and F_v/F_m ratio (~0.59) decreased, whereas MDA (~9.8 μmol g⁻¹ FW) increased in plants with exposure times of 9 and 12 h and an FA concentration of 100 mg L⁻¹ compared with plants without FA exposure or concentrations (169.8 mmol m⁻² s⁻¹, 0.8, and 7.2 μmol g⁻¹ FW for g_s, F_v/F_m ratio and MDA, respectively). In the last experiment, the interaction between Foph or FA and WD promoted a higher area under the disease progress curve (AUDPC) (Foph × WD = 44.5 and FA × WD = 37) and lower g_s (Foph × WD = 6.2 mmol m⁻² s⁻¹ and FA × WD = 9.5 mmol m⁻² s⁻¹) compared with plants without any interaction. This research could be considered as a new approach for the rapid scanning of responses to the effects of FA, Foph, and WD stress not only on cape gooseberry plants but also on other species from the Solanaceae family.

This study aimed to assess the soil application of mixtures of biological control agents (BCAs) (Trichoderma virens and Bacillus velezensis) and organic additives (chitosan and burnt rice husk) on the physiological and biochemical behavior of cape gooseberry plants exposed to Fusarium oxysporum f. sp. physali (Foph) inoculum. The treatments with inoculated and non-inoculated plants were: (i) T. virens + B. velezensis (Mix), (ii) T. virens + B. velezensis + burnt rice husk (MixRh), (iii) T. virens + B. velezensis + chitosan (MixChi), and (iv) controls (plants without any mixtures). Plants inoculated and treated with Mix or MixChi reduced the area under the disease progress curve (AUDPC) (57.1) and disease severity index (DSI) (2.97) compared to inoculated plants without any treatment (69.3 for AUDPC and 3.2 for DSI). Additionally, these groups of plants (Mix or MixChi) obtained greater leaf water potential (~−0.5 Mpa) and a lower MDA production (~12.5 µmol g⁻² FW) than plants with Foph and without mixtures (−0.61 Mpa and 18.2 µmol g⁻² FW, respectively). The results suggest that MixChi treatments may be a promising alternative for vascular wilt management in cape gooseberry crops affected by this disease.

Vascular wilt caused by Fusarium oxysporum is the most limiting disease that affects cape gooseberry (Physalis peruviana L.) crops in Colombia. The use of synthetic elicitors for vascular wilt management is still scarce in Andean fruit species. The objective of the present study was to evaluate the effect and number of foliar applications of synthetic elicitors such as jasmonic acid (JA), salicylic acid (SA), brassinosteroids (BR), or a commercial resistance elicitor based on botanical extracts (BE) on disease progress and their effect on the physiology of cape gooseberry plants inoculated with F. oxysporum f. sp. physali. Groups of ten plants were separately sprayed once, twice, or three times with a foliar synthetic elicitor, respectively. Elicitor applications were performed at the following concentrations: JA (10 mL L⁻¹), SA (100 mg L⁻¹), BR (1 mL L⁻¹) and BE (2.5 mL of commercial product (Loker^®) L⁻¹). The results showed that three foliar BR, SA, or BE applications reduced the area under the disease progress, severity index, and vascular browning in comparison to inoculated plants without any elicitor spray. Three BR, SA, or BE sprays also favored stomatal conductance, water potential, growth (total dry weight and leaf area) and fluorescence parameters of chlorophyll compared with inoculated and untreated plants with no elicitor sprays. Three foliar sprays of SA, BR, or BE enhanced photosynthetic pigments (leaf total chlorophyll and carotenoid content) and proline synthesis and decreased oxidative stress in Foph-inoculated plants. In addition, the effectiveness of three foliar BR, SA, or BE sprays was corroborated by three-dimensional plot and biplot analysis, in which it can evidence that stomatal conductance, proline synthesis, and efficacy percentage were accurate parameters to predict Foph management. On the hand, JA showed the lowest level of amelioration of the negative effects of Foph inoculation. In conclusion, the use of the synthetic elicitors BR, SA, or BE can be considered as a tool complementary for the commercial management of vascular wilt in areas where this disease is a limiting factor.

Cape gooseberry (Physalis peruviana) fruit has gained recognition owing to its nutritional value and versatility to be consumed processed or as a fresh product. These characteristics have made it an important product in both national and international markets. One of the main limitations for this crop is Fusarium wilt caused by the fungus Fusarium oxysporum f. sp. physalis, for which biological control is emerging as an alternative to conventional management with chemical synthesis products. However, information on the effect that biological control agents have on the growth and development of plants is scarce. In this research, the physiological response of cape gooseberry plants (stomatal conductance, leaf water potential, growth parameters, total chlorophyll, carotenoid, and proline and malondialdehyde contents) to the treatment with three potential biocontrol agents (BCAs) Trichoderma koningiopsis, Trichoderma virens, and Bacillus velezensis was determined. The study was conducted under greenhouse conditions; F. oxysporum was inoculated in the soil, and BCAs were soil drenched in the germination and transplanting stages. Plants inoculated with the pathogen and plants without inoculation were used as controls. It was found that the plants inoculated and treated with T. virens showed the lowest disease levels (area under the disease progress curve of 48.5 and disease severity index of 2.1). Additionally, they showed a lower water potential (−0.317 Mpa), a greater leaf area (694.7 cm²), and a higher stomatal conductance (110.3 mmol m⁻² s⁻¹) compared with the control. Consequently, it can be concluded that T. virens can be a good candidate for the management of Fusarium wilt in the cape gooseberry crop.

Cape gooseberry (Physalis peruviana L.) is one of the most exported Andean fruits in Colombia. Vascular wilt caused by Fusarium oxysporum f. sp. physali (FOph) has led to a reduction in crop areas in recent years. Therefore, the aim of this study was to select genotypes with resistance to vascular wilt that can be useful as rootstocks from a group of six Physalis genotypes (Physalis ixocarpa, Physalis floridana, and Physalis peruviana genotypes Colombia, Sudafrica, Peru, and Accession 62) using physiological variables such as maximum quantum efficiency of Photosystem II (Fv/Fm), leaf gas exchange properties [net photosynthesis rate (Pn) and stomatal conductance (g_s)], and leaf water potential. An experiment was carried out under greenhouse conditions in which plants of the different Physalis materials were inoculated with the F. oxysporum f. sp. physali strain Map5 at a concentration of 1 × 10⁶ conidia mL^–1. Physiological and disease development variables were measured at 15, 23, and 31 days after inoculation (DAI). The results obtained showed that P. peruviana genotypes Colombia and Sudafrica showed greater susceptibility to the disease (disease severity index 3.8 and 3.6, respectively). Net photosynthesis rate (Pn), stomatal conductance (g_s), water potential (Ψ_fw), and Fv/Fm ratio were lower compared to non-inoculated plants. P. floridana and P. ixocarpa plants inoculated with F. oxysporum showed similar behavior to non-inoculated plants for the evaluated variables. In conclusion, the results obtained suggest that these two genotypes can be considered in breeding programs or as rootstock for the establishment of cape gooseberry crops in soils with the presence of the pathogen.