Estimating the genetic relationships of Chinese water chestnut (Eleocharisdulcis (Burm. F.) Hensch) cultivated in Australia, using random amplified polymorphic DNAs (RAPDs)

Chinese water chestnut is a crop new to Australia. To establish a reputable industry, the influence of both genotype and environment on yield and qual ity need to be evaluated. To that end, the genetic relationships of cultiva ted Chinese water chestnut in Australia were investigated using random ampl ified polymorphic DNA (RAPD) analysis. Initial problems with inhibition of RAPD reactions were solved by precipitation of polysaccharides with 1 M NaC l and the subsequent addition of 0.4 mu g mu l(-1) bovine serum albumin (BS A) in RAPD reactions. Nearly all DNA extracts from then onwards were RAPD-a mplifiable. Ninety-six RAPD markers generated by 14 primers separated the s amples from Taiwan (cv. Shu-Lin), Hangzhou of mainland China (cv. Da Hong P ao), New South Wales of Australia (unknown cv.) and the USA (unknown cv.) f rom the remainder of the samples from Australia. These remaining samples we re too closely related to be differentiated. The dissimilarity observed bet ween these remaining samples (0.78-4.4%) may be due more to scoring errors of undetectable bands and sampling error rather than to real genetic variat ion. It is therefore suggested that the observed morphological and physiolo gical variations in Chinese water chestnuts produced in Australia (e.g. cor m sweetness) are phenotypic and reflect the differences of environment and cultivation rather than genetic diversity.