Survey, identification and genetic diversity of Phytophthora capsici causing wilt of chilli ( Capsicum annuum L.) in Bhu
- PDF / 1,387,409 Bytes
- 11 Pages / 547.087 x 737.008 pts Page_size
- 46 Downloads / 173 Views
Survey, identification and genetic diversity of Phytophthora capsici causing wilt of chilli (Capsicum annuum L.) in Bhutan Ganja S. Rai & Edward C. Y. Liew & David. I. Guest
Received: 24 June 2020 / Revised: 20 August 2020 / Accepted: 25 August 2020 # Koninklijke Nederlandse Planteziektenkundige Vereniging 2020
Abstract Chilli (Capsicum annuum L.) is one of the most important crops in Bhutan, but currently production is seriously affected by a wilt disease. Although chilli wilt was first reported in Bhutan in 1995, the causal pathogen has never been formally identified. The aim of this study was to identify the causative agent of wilt epidemics on chilli in Bhutan and to investigate the morphological and genetic variations in the pathogen. A survey of the disease was conducted in all three chilli growing regions of Bhutan in 2018 and the pathogen isolated from 54 diseased plants. Morphological and PCR evidence identified the pathogen as Phytophthora capsici in 100% of the diseased plants. All isolates were of the A1 mating type. Four random amplified micro-satellite (RAMS) markers were employed to assess genetic variation among the 54 isolates of P. capsici collected. Genetic analysis showed
Electronic supplementary material The online version of this article (https://doi.org/10.1007/s10658-020-02108-4) contains supplementary material, which is available to authorized users. G. S. Rai : D. I. Guest (*) Sydney Institute of Agriculture, School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW 2006, Australia e-mail: [email protected] G. S. Rai Agriculture Research and Development Centre Bhur, Ministry of Agriculture and Forests, 31101 Gelephu, Bhutan E. C. Y. Liew Australian Institute of Botanical Science, Royal Botanic Gardens and Domain Trust, Mrs Macquaries Road, Sydney, NSW 2000, Australia
26 loci from all four primers and 65.4% of the isolates were polymorphic. Shannon’s index of diversity (I) for the P. capsici isolates collected was 0.42, indicating that the pathogen population is highly clonal. These findings have significant implications for the development of sustainable disease management strategies including resistant genotypes in Bhutan. Keywords Phytophthora blight . Crown and root rot . Disease incidence . Morphological characterisation . Pathogen diversity
Introduction Chilli (Capsicum annuum L.) is an important crop in Bhutan, a small landlocked mountainous country in the eastern Himalayas, providing significant income to growers (Lin et al. 2013). Chilli occupies a very important place in the Bhutanese diet (Ueda and Samdup 2010). Fukuda (1993) concluded that chilli in Bhutan was first introduced from Yunnan in China via Tibet. The crop is cultivated in all districts of the country and in most areas landrace cultivars are grown at different times of the year, depending on the altitudes. In lower elevations, chilli is grown in early spring and again in early autumn. In higher mountains, chilli is grown only once a year in late spring. The yield of landrace varieti
Data Loading...
