in vitro response of Colletotrichum to chitosan. Effect on incidence and quality on tropical fruit. Enzymatic expression in mango

Colletotrichum is considered one of the fungal genera with the greatest diversity of species of phytopathogenic fungi and with a wide range of hosts including tropical fruits. In this study, the concentration of chitosan applied was a key factor in the in vitro inhibition of the three Colletotrichum isolates with the most sensitive being the one from banana. Germination was the development stage most affected by the application of this polymer. At the end of 10 days of storage, control of anthracnose in soursop, mango and banana fruit was considerable with the application of 1 % chitosan, with 80 to 100 % inhibition. Likewise, the ripening process of fruit with and without chitosan was generally similar. Activity of the peroxidase (POD) and polyphenol oxidase (PPO) enzymes was observed only in fruit of mango cv. 'Tommy Atkins,' inoculated and non-inoculated with C. gloeosporioides, the activity of both enzymes was higher in the chitosan treatments and the 1.0 % concentration was able to induce gene expression of POD and PPO, occurring until 24 h

EVALUACIÓN in vitro DE PRODUCTOS QUÍMICOS NO CONVENCIONALES PARA EL CONTROL DE Penicillium citrinum.

El ajo (Allium sativumL.), es un cultivo que esta expuesto al ataque de patógenos importantes del género Penicillium provocando pérdidas económicas importantes. De manera tradicional, la alternativa para controlar fitopatógenos es mediante la aplicación de fungicidas sintéticos. Sin embargo, debido a la aparición de cepas resistentes y problemas ambientales, es necesario la búsqueda de tratamientos alternativos que sean efectivos  y amigables con el medio ambiente. En este sentido, el uso de quitosano, peróxido de hidrógeno (H2O2), sorbato de potasio (SP) y bicarbonato de sodio (BS) representa una alternativa amigable con el medio ambiente con propiedades antimicrobianas. En este estudio, P. citrinum fue aislado e identificado mediante herramientas moleculares. En el ensayo in vitro, el H2O2al 0.5%, el BS al 3% y el quitosano al 1% resultaron efectivos en la inhibición del desarrollo del patógeno (crecimiento micelial, esporulación y germinación). Se observó un efecto sinérgico de los tratamientos evaluados en combinación a bajas concentraciones. Por lo tanto, los tratamientos evaluados pueden ser una alternativa viable y amigable con el medio ambiente el control de P. citrinumen ajo

Antifungal Activity of Chitosan against Postharvest Fungi of Tropical and Subtropical Fruits

In the present chapter, results about the efficacy of chitosan (Chi) on sporulation, mycelial growth, germination, as well as quality parameters on fruits are shown. The results demonstrate that chitosan can control various phytopathogen isolates from diverse fruits. The pathogens in the genera Colletotrichum, Fusarium, and Rhizopus are involved in important postharvest disease losses throughout the world. In Nayarit, producers had reported high postharvest losses not only at field but also during the commercial chain with their products, besides the resistance of several pathogens to fungicides, which traditionally are applied for controlling diseases. In this sense, the aim of this research group is focused on the research of alternative and effective methods for controlling postharvest diseases. In vivo results are promising due to a good control in important tropical fruits like banana, avocado, mango, and jackfruit. An enhancement in the chitosan antimicrobial activity is reported with the combination with GRAS substances, as well as the use of nanotechnology. Chitosan can be an environment-friendly alternative to the use of chemical fungicides for controlling postharvest diseases in fruits

A Review Study on the Postharvest Decay Control of Fruit by <em>Trichoderma</em>

This chapter consists of an overview with the most relevant results about the efficacy of Trichoderma on postharvest disease control. The results of investigations demonstrate that this fungus can control several phytopathogens in different fruits. Postharvest losses represent a major problem in several countries. The constant application of fungicides not only at field but also at postharvest stage has led to microbial resistance cases, which make the control of these pathogens difficult. Biological control is a promising alternative to chemical fungicide applications. In this sense, an eco-friendly alternative and effective approach for controlling diseases is the use of microbial antagonists like Trichoderma, which have several mechanisms of action to stop disease development. A crucial treat in biological control is related to the maintenance of microbial viability and efficacy, that is why other technologies like their incorporation into edible films and coatings, nanotechnology, microbial mixtures, among others have been applied in combination with Trichoderma successfully. An enhancement in biocontrol activity is achieved when alternative systems are combined like GRAS substances, biopolymers, and other antagonists. Thus, Trichoderma is an eco-friendly alternative to threat postharvest diseases as an alternative to chemical treatments

Alternative Eco-Friendly Methods in the Control of Post-Harvest Decay of Tropical and Subtropical Fruits

The effectiveness on several fruits by the application of alternative methods against fungi is summarized in the present chapter. Several investigations have reported the efficacy of these technologies for controlling fungal infections. Currently, high post-harvest loses have been reported due to several factors such as inefficient management, lack of training for farmers, and problems with appropriate conditions for storage of fruits and vegetables. Even now, in many countries, post-harvest disease control is led by the application of chemical fungicides. However, in this time, awareness about fungi resistance, environmental, and health issues has led to the research of eco-friendly and effective alternatives for disease management. The pathogen establishment on fruits can be affected by the application of GRAS compounds like chitosan, essential oils, salts, among others; besides, their efficacy can be enhanced by their combination with other technologies like ultrasound. Thus, the applications of these alternatives are suitable approaches for post-harvest management of fruits

in vitro response of Colletotrichum to chitosan. Effect on incidence and quality on tropical fruit. Enzymatic expression in mango

Colletotrichum is considered one of the fungal genera with the greatest diversity of species of phytopathogenic fungi and with a wide range of hosts including tropical fruits. In this study, the concentration of chitosan applied was a key factor in the in vitro inhibition of the three Colletotrichum isolates with the most sensitive being the one from banana. Germination was the development stage most affected by the application of this polymer. At the end of 10 days of storage, control of anthracnose in soursop, mango and banana fruit was considerable with the application of 1 % chitosan, with 80 to 100 % inhibition. Likewise, the ripening process of fruit with and without chitosan was generally similar. Activity of the peroxidase (POD) and polyphenol oxidase (PPO) enzymes was observed only in fruit of mango cv. 'Tommy Atkins,' inoculated and non-inoculated with C. gloeosporioides, the activity of both enzymes was higher in the chitosan treatments and the 1.0 % concentration was able to induce gene expression of POD and PPO, occurring until 24 h