Genetic diversity of Phytophthora colocasiae isolates in India based on AFLP analysis.

Vishnu Sukumari Nath,Syamala Swayamvaran Veena,Muthulekshmi Lajapathy Jeeva,Raj Shekhar Misra,Vinayaka Mahabaleswar Hegde,Mithun Raj,Muthukrishnan Senthil

doi:10.1007/s13205-012-0101-5

Vishnu Sukumari Nath, Syamala Swayamvaran Veena + Show 5 more

Open Access

https://doi.org/10.1007/s13205-012-0101-5

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Journal: 3 Biotech	Publication Date: Dec 4, 2012
Citations: 40	License type: cc-by

Affiliation: Central Tuber Crops Research Institute

Abstract

Phytophthora colocasiae that causes taro leaf blight is one of the most devastating diseases of taro which is widely distributed in India. Inter and intra-specific genetic diversity among P. colocasiae isolates collected from same field was assessed using amplified fragment length polymorphism (AFLP) marker. Seven primer pairs produced 431 markers, of which 428 (99.2 %) were polymorphic. Considerable genetic variability was displayed by the isolates. The average value of the number of observed alleles, the number of effective alleles, mean Nei’s genetic diversity, and Shannon’s information index were 1.993, 1.385, 0.261, and 0.420, respectively. Analysis of molecular variance (AMOVA) showed that the majority (85 %) of the diversity were present within populations of P. colocasiae. Dendrogram based on AFLP molecular data using the unweighted pair group method with arithmetic mean (UPGMA) classified the P. colocasiae isolates into two major clusters irrespective of their geographical origin. Clustering was further supported by principle coordinate analysis. Cophenetic correlation coefficient between dendrogram and original similarity matrix was significant (r = 0.816). The results of this study displayed a high level of genetic variation among the isolates irrespective of the geographical origin. The possible mechanisms and implications of this genetic variation are discussed.

Highlights

Taro ((Colocasia esculenta (L.) Schott) is a major root crop of the family Araceae with wide distribution in tropics
Dendrogram based on amplified fragment length polymorphism (AFLP) molecular data using the unweighted pair group method with arithmetic mean (UPGMA) classified the P. colocasiae isolates into two major clusters irrespective of their geographical origin
All isolates were positively identified as P. colocasiae by comparing their cultural characteristics like colony morphology and sporangial shape with authentic cultures maintained by Central Tuber Crops Research Institute, CTCRI, Thiruvananthapuram

Summary

Introduction

Taro ((Colocasia esculenta (L.) Schott) is a major root crop of the family Araceae with wide distribution in tropics. It is the fourteenth most consumed vegetable in the world (Lebot and Aradhya 1991). Taro is the fifth most harvested root crops in the world with production estimated at 11.8 million t (Food and Agriculture Organization of the United Nations, 2009). Taro corms are utilized in various industries for the preparation of high fructose syrup and alcohols (Misra et al 2008). These prospects make taro as one of the most important tuber crop

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