Studies on the character variation and phyletic relationship among Coix lacryma-jobi L. in Taiwan based on RAPD markers

• Main Authors: Tsung-Chen Su, 蘇宗振
• Other Authors: Mau-Shing Yeh
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/54900594641180480999

博士 === 國立中興大學 === 農藝學系 === 91 === Coix lacryma-jobi L. is a popular crop in Taiwan. Owing to its function of curing many diseases, including cancer, allergy and other diseases, this crop is also titled as ‘the king of cereals’. Despite the identification of phenotypic characteristics through different varieties is simple and fast, little is known about the DNA markers level, such as RAPD analysis, in this crop. In this thesis, the main objectives were to study the agronomic characters, various chemical components analysis and relationships of 66 coix varieties (lines) from different countries through RAPD method. To identify fourteen agronomic characters in 66 coix varieties (lines), we found grain yield revealed the significantly positive correlation with spikelet number, total leaf number and fertile seed weight. According to the PCA analysis, it revealed that the diversity of germplasm was caused by he traits of plant height, lowest spikelet, silking period and harvesting time. And there are three clusters had been classified using the cluster analysis. Among these three clusters, the variety of Indonesia sumatra san had the farthest distance with others. The investigation of various chemical components from the dehulled grains of 66 varieties (lines) revealed the percentage of 1.7%, 7.4%, 13.9%, 0.16% and 27.7﹪in ash, crude fat, crude protein, crude fiber and coixenolide respectively. The same investigation from the grains with hull appeared 6.7%, 3.9%, 8.9%, 0.29% in ash, crude fat, crude protein, crude fiber each. We also discovered that the crude protein in dehulled grains showed the significantly positive correlation (r=0.586) with the crude fiber in the grains with hull. The similar result also appeared in the amount of coixenolide and crude protein in the grains with hull. Based on the typical correlation analysis, it showed that 100 grain weight, silking time, harvesting time, and grain width are the main agronomic traits to affect crude fiber in grains with hull and dehulled grains, however the traits mentioned above showed negative correlation with the color of the grains’ hull. In this section, there were 3 groups which were classified through quality analysis and 22 agronomic traits analysis, and the group C was confirmed as the major sub-variety. In the primary RAPD analysis in coix germplasm, we obtained 78 polymorphic bands from 258 bands in total with 41 valid primers (about 30% polymorphism ratio). And about 8-10 valid primers (with highly polymorphic ratio) were chosen from the former 41 ones for the subsequent RAPD analysis. Nevertheless, there are some genetic differences existed in the coix germplasm via the results of genetic distance. By using the mixed DNAs from different plants of same variety as the template, we deduced that above 80% of bands showed the representatives in often-cross-pollinated crops and the ability to distinguish between the sub-varieties of major and mayuen. And the result from the RAPD analysis is as similar as the cluster analysis of agronomic traits. Conclusion to the results showed above, the outcomes from RAPD analysis can close to the results from morphological differences, but not absolutely. The pattern III would be more efficient to identify the sub-variety of major and mayuen.