Biodiversity of Trichoderma antagonist saprophytic fungi and its use for biocontrol of Fusarium wilt disease on shallots at Lombok Island, West Nusa Tenggara, Indonesia

Abstract

One of the obstacles in the development of shallots in West Nusa Tenggara (NTB) is the presence of Fusarium wilt disease. The use of antagonistic saprophytic fungi Trichoderma spp. is a biological control technique. The aim of this research is to explore the biodiversity of Trichoderma spp. and its use for controlling Fusarium wilt disease. Research using exploratory methods conducted at the shallot planting center on Lombok Island included isolation of antagonistic saprophytic fungi, purification and identification of isolates. Furthermore, research was carried out in the laboratory using experimental methods including in-vitro antagonism tests by direct opposition and culture steam. The research was continued in Greenhouses in planta and in field conditions in the Highlands of Sembalun Village, Medium Plains of Santong Village and Senteluk Village Lowlands. The results concluded that: there were 6 isolates of saprophytic fungi that were antagonistic, namely T. viride, T. longibrachiatum, T. koningii, T. piluliferum, T. harzianum, and T. hamatum. The mechanism of antagonism is physically through space competition, mycoparasites and antibiosis. Three isolates, namely T. virede, T. harzianum and T. hamatum, were effective in suppressing Fusarium wilt disease and even causing immunity.

Negative impact of some fungicide applications on Trichoderma harzianum as biocontrol agent of shallot moler disease

“…Efficacy value for controlling moler diseases with the treatment of T. harzianum at the planting time is 62.50 (Table 1). The effectiveness of T. harzianum as a biological control agent for moler disease has been shown in the previous studies [12][13][14]. T. harzianum has been widely reported as a biological control agent for plant diseases caused by fungi such as F. oxysporum [15][16][17][18].…”

“…T. harzianum controls F. oxysporum by colonizing the rhizosphere and plundering nutrients [23]. T. harzianum does mycoparasitism by producing the enzymes (1,3) glucanase and chitinase that cause exolysis of the host hyphae [14]. Trichoderma enzymes could degrade the cell walls of the pathogenic fungus [24].…”

Fungi of the Trichoderma Genus: Future Perspectives of Benefits in Sustainable Agriculture

“…The results of the analyses indicated that the colony diameter of the pathogen in the control sample was 82.66 mm, while in the bicultures, the diameters of A. solani were 30.6 mm, 27.3 mm, and 23.3 mm for T. atroviride, T. harzianum, and T. longibrachiatum, respectively. Sudantha and Suwardji [110] proved that T. hamatum, T. harzianum, T. koningii, T. longibrachiatum, T. piluliferum, and T. viride reduced the growth of F. oxysporum on a PDA medium by an average of 64.8-77.2%. In turn, Modrzewska et al [111] reported that T. atroviride, T. viride, and T. viridescens inhibited the development of F. cerealis and F. culmorum by 24-66%.…”

Isolation and antagonistic test of fungi associated with pummelo citrus against Botryodiplodia theobromae in vitro

“…Microscopic observation of the contact area of B. theobromae and antagonistic fungi in figure 4 showed that cell lysis occurred in B. theobromae hyphae. The competition mechanism occurs when antagonistic fungal colonies cover pathogenic colonies and the growth of antagonistic fungi is faster to fill the petri dish and in the contact area, pathogenic hyphae underwent lysis [12]. Aspergillus sp.…”

“…The initial growth of the Trichoderma sp. mycelia elongates, then entangles and penetrates the host fungal hyphae untill vacuolization, lysis and finally disintegrates [12]. Furthermore, these antagonists grow and coil in the pathogenic hyphae to inhibit the pathogen's spread [9,21].…”