RESUMEN
The diversity of Ganoderma remains largely unexplored, with little information available due to fungiphobia and the morphological plasticity of the genus. To address this gap, an ongoing study aims to collect and identify species with this genus using nuclear ribosomal DNA regions called the "Internal Transcribed Spacer" (ITS1-5.8S-ITS2 = ITS). In this study, a new species, Ganoderma segmentatum sp. nov., was discovered on the dead tree trunk of the medicinal plant, Vachellia nilotica. The species was identified through a combination of morpho-anatomical characteristics and phylogenetic analyses. This new species was closely related to Ganoderma multipileum, G. mizoramense, and G. steyaertanum, with a 99% bootstrap value, forming a distinct branch in the phylogenetic tree. Morphologically, G. segmentatum can be distinguished by its frill-like appearance on the margin of basidiome. Wilt or basal stem rot, a serious disease of trees caused by Ganoderma species and V. nilotica, is brutally affected by this disease, resulting in substantial losses in health and productivity. This Ganoderma species severely damages V. nilotica through deep mycelial penetration in the upper and basal stems of the host species. Pathogenic observational descriptions of G. segmentatum on dead tree trunks showed the exudation of viscous reddish-brown fluid from the basal stem portion, which gradually extended upward. Symptoms of this disease include decay, stem discoloration, leaf drooping, and eventual death, which severely damaged the medicinal tree of V. nilotica.
RESUMEN
Sclerotinia sclerotiorum is a typical necrotrophic plant pathogenic fungus, which has a wide host range and can cause a variety of diseases, leading to serious loss of agricultural production around the world. It is difficult to control and completely eliminate the characteristics, chemical control methods is not ideal. Therefore, it is very important to know the pathogenic mechanism of S. sclerotiorum for improving host living environment, relieving agricultural pressure and promoting economic development. In this paper, the life cycle of S. sclerotiorum is introduced to understand the whole process of S. sclerotiorum infection. Through the analysis of the pathogenic mechanism, this paper summarized the reported content, mainly focused on the oxalic acid, cell wall degrading enzyme and effector protein in the process of infection and its mechanism. Besides, recent studies reported virulence-related genes in S. sclerotiorum have been summarized in the paper. According to analysis, those genes were related to the growth and development of the hypha and appressorium, the signaling and regulatory factors of S. sclerotiorum and so on, to further influence the ability to infect the host critically. The application of host-induced gene silencing (HIGS)is considered as a potential effective tool to control various fungi in crops, which provides an important reference for the study of pathogenesis and green control of S. sclerotiorum.