| Konjac, a perennial herb, belongs to the genus Araceae. The genus Amorphophallus includes163species and reproduce both sexually vegetatively There are26species in China,21species of them are specific species. It is the one of the most important tuber corps in the world. It contains many of useful components, such as starch and KGM, etc.With the development and utilization of the Amorphophallus, more and more problems have been discovered, such as cultivation technique, plant diseases and insect pests. And most fundamental problem is that there are no superior varieties, especially the cultivars with disease resistances so far. There are a lot of Amorphophallus resources in our country, using molecular marker assisted selection to improve them must be the best way to solve the problems. The principal goals of this study are as follows:(1) Isolation and characterization of microsatellite loci for Amorphophallus konjac by the method of small fragments DNA cloning.(2)The genetic diversity analyses of the samples including10population of Amorphophallus konjac,18species of Amorphophallus and some cultivars by AFLP,(3) The genetic relationship analyses of18species of Amorphophallus by FLORICAULA/LEAFY of second intron sequences. The main results are presented1. SSR(Simple sequences of polymorphism) molecular markers based on PCR technology, as the second generation of molecular markers, is a useful tool to construct high-density molecular map and analyze genetic diversity. In this study, the FIASCO method was applied to construct SSR enriched library of A. konjac, and13pairs of specific primers were developed, in order to lay the foundation for the development of strategies for germplasm resources protection, cultivar identification and genetic analysis of A. konjac in the future.2. In this Study, the AFLP molecular markers were used to analyze the Amorphophallus, which include10populations of A. konjac and some cultivated plants. The genetic diversity was high.(Shannon’s information index,I=0.3381) AMOVA (Analysis of molecular variance) indicated that30%of the genetic diversityamong the tested populations and70%of the genetic diversity within each tested population. The analysis of IBD (Isolation by distance) showed that the population traits of A. konjac were effected by IBD. Through the analysis we knew that all of the cultivated konjac plants were mainly originated from native wild types. For example, cultivars in Enshi Dstrict were from this dstrict instead of other one. In addition, clustering analysis for some varieties of Amorphophallus konjac showed that the currently existing Amorphophallus konjac cultivars were those obtained by cross breeding with the parents from similar area. Moreover, breeding work was rough and blind. For example, some cutivars, such as Chongqing konjac No.1and the like, were still unstable genetically and showed obvious genetic differentiation within a cultivar. It demonstrate that the konjac breeding work is seriously lagging behind production requirements. However, the native varieties have retained a higher genetic richness, so they provide a broad platform for future researchers.3. The tested25Amorphophallus samples were analyzed by sequencing of FLORICAULA/LEAFY second intron, The result showed all of25Amorphophallus samples could be divided into three types. The first type included A.konjac、A.sutepensis、A.yunnanensis and A. tokinensis and the second type included A.dubius and A.bulbifer as well as the third type included A.yuloensis A.pingbianensis、A.mairei、A.dunnii、A.guripingensis and A.kachinensis. Bootstrap validation of the method showed a more detailed classification of the low statistical credibility, suggesting that the Amorphophallus genus taxonomy tool needs to be further excavated.This study provides useful information in the further genetic and breeding as well as diversity protection research. The basic research about Amorphophallus breeding remains to be completed. |
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