RESUMEN
The basal stem rot disease incidence ranged from 0 to 5% in Karnataka India during the year 2019-20. Twenty pathogenic isolates of Ganoderma sp varied with cultural characteristics and virulence on coconut seedlings of the variety Tipatur Tall. The identity of each isolate was confirmed through morphological characters and through ITS sequencing. Two isolates viz., G4 and G5 were identified as Ganoderma applanatum and remaining all isolates were identified as G. lucidum. The genetic diversity analysis of Ganoderma isolates was done using ten Random Amplified Polymorphic DNA (RAPD) and fifteen Inter Simple Sequence Repeat (ISSR) primers. Among the ten RAPD primers, only eight primers recorded polymorphism (33.30-66.70%). The primer SBS-Q3 exhibited the highest polymorphism of 66.70%. In case of ISSR primers, all primers recorded polymorphism (33.30-60.00%). The primer UBC866 was the most polymorphic primer with 60.0% polymorphism. RAPD and ISSR markers were compared for their efficacy in assessing the genetic diversity by taking the band frequency, Shannon's index, polymorphic information content, resolving power, and mean resolving power into consideration, and it was concluded that ISSR was marker of choice over RAPD. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-023-03872-w.
RESUMEN
Anton de Bary first coined the genus, Phytophthora, which means "plant destroyer", viewing its devastating nature on potatoes. Globally plants have faced enormous threat from Phytophthora since its occurrence. In fact, a century ago, Phytophthorapalmivora was first reported on Dendrobium maccarthiae in Sri Lanka. Since then, members of beautiful flowering crops of the family Orchidaceae facing the destructive threat of Phytophthora. Several Phytophthora species have been recorded to infect orchids with economic loss worldwide. To date, orchids are attacked by 12 species of Phytophthora. Five Phytophthora species (P. palmivora, P. nicotianae, P. cactorum, P. multivesiculata, P. meadii) are the major pathogenic Oomycetous Chromista" rather than true fungi frequently occurred on Orchidaceae. Phytophthora palmivora (having ~32 orchid host genera in 15 countries), Phytophthora nicotianae (having ~15 orchid host genera in 16 countries), Phytophthora cactorum (having ~43 orchid host genera in 6 countries), Phytophthora multivesiculata (having 2 orchid host genera in 5 countries) and Phytophthora capsici (having 2 orchid host genera in all Vanilla growing countries) are potential destroyers of Orchidaceae. Most of them are water loving Oomycetes cause disease in moist environments (> 80% RH) at 16-28°C. In artificially constructed orchidaria, anthropogenic factors are mostly contributed to the dissemination Phytophthora diseases in addition to many other factors. Water management, clean cultivation, and agro-chemicals are the major options for effective management of orchid Phytophthora, as the eco-friendly management options like development of resistant hybrids/cultivars, biological disease management, transgenic approaches, RNAi technology remained in the infant stage. In this review, we intended to highlight the insight of Phytophthora diseases associated with the orchid disease with reference to the historical aspect of the diseases, symptoms and signs, the pathogens, taxonomy, geographic distribution, host range within the Orchidaceae, pathogen identification, molecular diagnostics, mating types and races, management options and strategies and future perspectives.