The random amplified polymorphic DNA (RAPD) technique was used to amplify DNA fragment, aiming at finding markers linked to the sex trait in Cycas tanqingii D. Y. Wang. A total number of 160 random primers were screened in the RAPD-PCR and more than 2500 RAPD fragments were generated from the male or the female plants. One fragment of about 500 bp was amplified steadily and repeatedly by the S0465 (CCCCGGTAAC) primer only from female plants but not male plants. The RAPD marker was then converted into female-linked dominant SCAR (Sequence Characterized Amplified Regions) marker named STQC-S465-483. The development of this sex-linked SCAR marker provides a possibility of identifying the sex of Cycas tanqingii before sexual maturation, which is very important to in situ or ex situ conservation.
Base Sequence ; Cycas ; genetics ; Genes, Plant ; Genetic Markers ; genetics ; Molecular Sequence Data ; Polymerase Chain Reaction ; methods ; Random Amplified Polymorphic DNA Technique ; methods ; Sex Determination Processes

Sago haemolytic disease is a rare but sometimes fatal disease found primarily in the coastal regions of Papua New Guinea and among groups in which sago is a primary source of carbohydrate. It has been known since 1961 and fungi consistently have been suspected of being involved. Investigations carried out on stored sago and samples recovered from poisoning episodes have failed to indicate the consistent presence of mycotoxins. However, fungi (especially Aspergillus, Fusarium, Penicillium, Trichoderma) with strong haemolytic activity have been associated with sago, particularly when stored in open-weave baskets and sago-leaf-wrapped bundles. The haemolytic activity has been attributed to fatty acids (principally oleic, palmitic, linoleic) contained primarily in the fungal hyphae. It is hypothesized that when these acids are released through hyphal breakdown during digestion and are present in individuals with a low serum albumin level, free fatty acid excess occurs resulting in red cell membrane destruction and intravascular haemolysis. In extreme cases, blood transfusion is required. Methods of storage providing high levels of access to oxygen favour the development of fungi: eg, leaf-encased bundles and open-weave storage favour growth over that seen in starch stored under water, such as in earthen vessels. Ensuring storage does not exceed 3-4 weeks, encouraging anaerobic conditions of the starch and maintaining protein nutrition in communities where sago is relied upon should alleviate outbreak episodes.
Anemia, Hemolytic/*epidemiology/*microbiology ; *Cycas ; Dietary Carbohydrates/*poisoning ; Food Handling ; Foodborne Diseases/*epidemiology/*microbiology ; Humans ; Mycotoxicosis/*epidemiology/*microbiology ; Papua New Guinea/epidemiology