The bread wheat (Triticum aestivum L.) analysed in this study has been produced by genetically eliminating the starch synthase IIa and shows apparent high amylose (HA) in the flour starch. Some starch properties of the HA wheat were analysed. The HA wheat contained 2.8–3.6% resistant starch (RS), much more than the normal (control) wheat, which contained almost no RS. Autoclaving the HA and normal wheat starches increased RS. The former contained 10.5% RS and the latter 5.9 or 6.8% RS. Swelling of the HA wheat starch and its pasting properties using Rapid ViscoAnalyzer (RVA) were investigated. Swelling power (g/g) of the HA wheat in 0.1% AgNO3 and swelling volume (mL/g) in urea solution were significantly less than those of the normal wheat. The RVA profile of the HA wholemeal and starch also differed from the normal. The peak viscosity, minimum viscosity, and final viscosity of HA were low, and breakdown (peak minus minimum viscosity) was very small. These findings show that amount of resistant starch and pasting properties are unique in the HA wheat starch, probably caused by lack of starch synthase IIa.

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A linkage map for watermelon (Citrullus lanatus) was constructed on the basis of RADP, ribosomal DNA restriction fragment length polymorphism (RFLP), isozyme, and morphological markers using F1 BC 1 . A segregating population of 78 individuals was the result of a backcross of a cultivated inbred line (H-7 ; Citrullus lanatus ; 2n = 22) and a wild form (SA-1 ; C. lanatus ; 2n = 22), in which the latter was the recurrent (male) parent . A total of 69 RAPD, one RFLP, one isozyme, and three morphological markers was found to segregate in the BC 1 population . Linkage analysis revealed that 62 loci could be mapped to 11 linkage groups that extended more than 524 centimorgans (cM), while 12 loci segregated independently of all other markers . The locus for exocarp color was linked to two RAPD markers within a region of 5 cM on linkage group 4 . The locus for flesh color was linked to a RAPD marker within a region of 30 cM on linkage group 6 . The isozyme marker GOT was located on the linkage group 1 . Linkage group 2 contained a locus for ribosomal DNA within 5 cM of a RAPD marker . Half of the RAPD markers on the linkage group 7 displayed severely distorted segregation . The construction of linkage map using molecular markers is necessary for the breeding of watermelon to introduce useful gene of wild watermelon efficiently . However the linkage map that was constructed for the most part on the basis of RAPD markers could not cover significant parts of the genome, the linkage map provides breeders of watermelons the possibility of tagging useful agronomic traits, as well as the gene for exocarp color .Abbreviations : RAPD -random amplified polymorphic DNA ; RFLP -restriction fragment length polymorphism ; GOT -glutamate oxaloacetate transaminase ; MDH -malate dehydrogenase ; ACP -acid phosphatase ; 6PGH -6-phosphogluconate dehydrogenase

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