Assessment and rationalization of genetic diversity of Papua New Guinea taro (Colocasia esculenta) using SSR DNA fingerprinting

Abstract

Taro (Colocasia esculenta) accessions were collected from 15 provinces of Papua New Guinea (PNG). The collection, totalling 859 accessions was collated for characterization and a core collection of 81 accessions (*10%) was established on the basis of characterization data generated on 30 agro-morphological descriptors, and DNA fingerprinting using seven SSR primers. The selection of accessions was based on cluster analysis of the morphological data enabling initial selection of 20% accessions. The 20% sample was then reduced and rationalized to 10% based on molecular data generated by SSR primers. This represents the first national core collection of any species established in PNG based on molecular markers. The core has been integrated with core from other Pacific Island countries, contributing to a Pacific regional core collection, which is conserved in vitro in the South Pacific Regional Germplasm Centre at Fiji. The core collection is a valuable resource for food security of the South Pacific region and is currently being utilized by the breeding programmes of small Pacific Island countries to broaden the genetic base of the crop.

Diversity of 21 taro (Colocasia esculenta (L.) Schott) accessions of Andaman Islands

“…Prevalence of high genetic diversity as compared to reference three genotypes might be the result of geographical speciation (Cailln et al 2006;Singh et al 2008) and differences in microclimatic factors at islands and mainland India. Considerable functional diversity supported with DNA markers points out certain strategic issues for germplasm explorers.…”

“…The islands have great diversity of plant species including C. esculenta (Abraham et al 2008). The variation for biochemical compounds as well as morpho-physiological traits in C. esculenta germplasm has been created by evolutionary forces (Stebbins 1957) including geographical speciation (Singh et al 2008). Moreover, being near to equator there is abundance of intense sunlight including ultra violet rays which probably influence the evolution through mutations.…”

“…Genetic resources of C. esculenta (L.) Schott have been analysed for diversity and evolutionary pattern (Singh et al 2008;Pillai and Lekha 2008), but none of the studies included the germplasm from Andaman & Nicobar Islands so far. Therefore, the present study was conducted with objective of genetic diversity analysis in 21 accessions of C. esculenta collected from Andaman and Nicobar Islands using both morphological and DNA markers.…”

Taro Leaf Blight—A Threat to Food Security

“…These genotypes also performed well in field trials in Hawaii [77,78] and many other Pacific Island countries. The genetic diversity of available resistance is, however, considered to be limited although germplasm from South-east Asia is considered to be more diverse than that in the Pacific [79][80][81]. The Centre for Pacific Crops and Trees (CePaCT formerly the Regional Germplasm Centre (RGC)) of the Secretariat of Pacific Community (SPC) maintains a collection of taro varieties with varying levels resistance to TLB.…”

Genetic structure and diversity of East African taro [Colocasia esculenta (L.) Schott]

“…Worldwide production is on the increase, with Food and Agriculture Organization (FAO) records indicating that taro production has doubled over the past decade (FAOSTAT, 2000), and it is now the fifth mostconsumed root vegetable worldwide. Cultivated types are mostly diploid (2n = 2x = 28), although some triploids are also found (2n = 3x = 42) (Singh et al, 2007). Taro plays an important role in the livelihood of millions of relatively poor people in less developed countries.…”