RAPD analysis of genetic diversity of nine strains of Auricularia auricular cultivated in Heilongjiang Province

Polymorphism of nine strains （CF05, CF09, 29, 916, AU9, Chang10, Chang7, 8808 and AU. Japanese） of A. auricular cultivated in Heilongjiang Province were analyzed by RAPD （Random Amplication polymorphic DNA）. Thirteen primers were selected from forty PCR primers with 10bp long random primer. The results showed that nine strains of A. auricular have a high level of genetic diversity and the percentage of DNA polymorphic was 96.05. The genotypes of 9 strains of Auricularia auricular were identified by the fingerprints from primer 27 and primer 46 by RAPD analysis. The results are helpful for quickly identifying strains of A. auricular in its early breeding time, and also provides a powerful theoretic basis to differentiate strains （Auricularia auricular） whose morphology is very similar in breeding programs of edible fungus.

GENETIC DIVERSITY OF FIVE FRESHWATER MUSSELS IN GENUS ANODONTA (MOLLUSCA: BIVALVIA) REVEALED BY RAPD ANALYSIS

Unionidae are an important group of benthic freshwater species. Due to the convergence phenomenon within freshwater mussels, there is still much controversy in the classification of Chinese Unionidae. In China, most studies on freshwater mussels emphasized resource investigation, biology and morphology, while little has been done in genetics, and particularly not in population genetic structure as well as genetic diversity. In order to further understand the status of genetic diversity of different species, random amplified polymorphic DNA (RAPD) markers were used to detect genetic diversity of populations in five species of the genus Anodonta: Anodonta arcaeformis, A. arcaeformis flavotincta, A. fluminea, A. woodiana woodiana and A. w.pacifica. DNA extraction method was based on phenol-chloroform and extracted genomic DNA from the adductor muscle and mantle tissues. Sixteen random primers were used for RAPD amplification and the polymorphism of amplified loci were analyzed. The results demonstrated that the percentage of amplified polymorphic loci for various populations ranged from 34.5% to 62.8%, the mean Shannon’s genetic diversity indices ranged from 0.2021 to 0.3552, and the mean intra-population Nei’s genetic distance ranged from 0.1386 to 0.1713. In all populations of the five species, the genetic diversity for A. arcaeformis was the largest, and that of A. fluminea was the lowest. The inter-population genetic distance between A. w. woodiana and A. w. pacifica was 0.3186, so they can be considered as two sister species at the genetic angle.

RAPD analysis on the four kinds of color-flowered Salvia splendens Ker-Gawl

In this study, we used RAPD to analyze four kinds of color-flowered Salvia splendens Ker-Gawl, and the optimal RAPD reaction conditions were the optimal reaction mixture （25 μL total volume） that contained 2.0 μL 10×buffer, 0.45 mmol·L^-1 dNTPs, 2.0 mmol· L^-1 Mg^2＋, 2 U Taq DNA polymerase, 0.30 umol·L^-2 primer and 40 ng genomic DNA. Total 84 bands were amplified from 12 primers used, and the differential bands had 28 bands, which was 33% of total bands. In cluster group analysis, the four kinds of color-flowered were divided into two styles. One style is that the red color and red-white color were grouped together, then they grouped with purple color into one cluster, and the white color was another style.

RAPD analysis of natural populations of Acanthopanax brachypus

Random Amplified Polymorphic DNA (RAPD) analysis is a new technology of molecular marking which has proved very powerful in detecting genetic diversity at the level of population. The genomic DNAs used in our experiment were extracted from fresh leaves taken from 59 individuals sampled from three natural populations in Yan An, Shanxi Province. Through more than 2,000 PCRs, deep-going RAPD analysis was carried out on DNA samples from 49 inviduals. The percentage of polymorphic RAPD loci found in these three populations were respectively 27.2 %, 18.6 % and 5.4 %; the average genetic distances within population, 0.055, 0.036 and 0.008; the average genetic distances between populations (Ⅰ-Ⅱ), (Ⅰ-Ⅲ) and (Ⅱ-Ⅲ), 0.105, 0.096 and 0.060. The genetic diversity of A. brachypus within and between populations was found, for the first time, to be rather poor,thus revealing innate factors as the cause contributing to its endangered status. In addition, our work also provides basic materials for elucidating the underlying cause of its endangerment and for its protection biology.

RAPD-PCR Analysis on Genetic Relationships Between Cultivars of Tree Peony

Random amplified polymorphic DNA (RAPD) was used to analyze genetic polymophism of 35 Tree Peony cultivars with 7 different color groups. Thirty four primers amplified 418 DNA fragments and 337 polymorphic bands (80.6%), including specific DNA markers for 18 cultivars that could be used to differentiate cultivars. The UPCMA method was used to analyze the genetic relationship among cultivars. The results showed that 35 Peony cultivars could be divided into 2 cluster groups when using similarity criteria of 1.5, and into 4 cluster groups when using similarity criteria of 1.0. The result confirmed that the flower color has no relation to the genetic clusters and the Tree Peony cultivars originated from the same area has close genetic relationship. Therefore, genetic background has no large effect on the genetic relationship. The sequence based on polymorphic rate from high to low was Blue groups > Yellow groups > Bark red groups > Blake groups > White groups>Green groups>Red groups.

Graft-induced Inheritable Variation in Mungbean and Its Application in Mungbean Breeding

Graft can induce inheritable variations in the progenies of the scion plants. Seedling of mungbean ( Vigna radiata (L.) Wilczek) was grafted onto the stem of sweet potato ( Ipomoea batatas (L.) Lam.). The growth of the scion was maintained until the scion produced selfed seeds. We sowed the seeds for several generations under normal conditions. Distinct genetic variations appeared in the progenies. Similar variations did not appear in the generations of the scion sowed normally without graft. The variations seemed to be induced by the graft and they inherited steadily. For understanding the possible mechanism of the phenomenon (graft_induced inheritable variation), we analyzed the cytoplasmic and genomic DNA of the variations. The results showed that there was no restriction fragment length polymorphism (RFLP) in the cytoplasmic DNA between the original scion and the variation. However, significant difference between the scion and variation was recognized by random amplified polymorphic DNA (RAPD) analysis. In addition, there was no evidence that indicated the gene transformation from stock to scion. Our results suggest that the non_specific grafting has a pragmatic potential for plant breeding and crop improvement and, the genetic variation seems not to be caused simply by DNA transformation but most likely the stress induced mutation.

Study on Several Characteristics of Agaricus blazei MurrilStrain J_3 Irradiated by ^(60)Co

A new mutant strain J3 from Agaricus blazei Murril was obtained by 60Co irradiation. The yields of successive generations were increased more than 70% to compare with their original strain. The component analysis on amino acids and fatty acid illuminated that the nutrient value of strain J3 fruiting body was better than the original strain. The apparent nodule structure was found in the hyphea of J3 strain through the observation by scanning electron microscope. RAPD analysis showed the great difference of PCR fingerprints between J3 and its original strain. It is a promising mutant strain for further commercial development in the future.

Genetic Dissimilarity of Clonal Populations of Leymus chinensis (Trin.) Tzvel in Heterogeneous and Homogeneous Habitats in Southwestern Heilongjiang Province of China

Leymus chinensis （Trin.） Tzvel is the characteristic of the Eastern Asia, and is a perennial herbaceous rhizome species on L. chinensis steppe of the Northern China, the Eastern Mongolia, and area of Outer-Baikal of Russia. It has both vegetative and sexual reproductions, and results in complexity of the population structure. Thus, it is difficult to identify distinct clones. Author used the randomly amplified polymorphic DNA （RAPD） technique to identify the clonal structure of heterogeneous and homogeneous habitats in two populations ofLeymus chinensis, analyzed 260 ramets samples using 12 primers and 60 polymorphie markers （reproducible RAPD bands）. The results proved elonal diversity described using PD, D, and E was higher in the HCS habitat than that in the HPS habitat. The PD, D, and E in the HCS of Songzhan population were 0.21, 0.90, and 0.91, respectively, whereas the PD, D, and E in the HPS of Songzhan population were only 0.09, 0.68, and 0.77, respectively; the PD, D, and E in the HCS of Yongle population were 0.19, 0.92 mad 0.90, respectively, correspondingly, these measures in the HPS of Yongle population were only 0.09, 0.63, and 0.79, respectively. The results also indicated that clonal population ofL. chinensis in HPS habitat had lower genetic dissimilarity index than that in the HCS habitat.

Analysis of the Genetic Structure of Sclerotinia sclerotiorum （Lib.） de Bary Populations from Different Regions and Host Plants by Random Amplified Polymorphic DNA Markers

: The genetic diversity and genetic structure of a population of isolates of Sclerotinia sclerotiorum (Lib.) de Bary from different regions and host plants were investigated using the random amplified polymorphic DNA (RAPD) method with 20 random decamer primer pairs in order to provide some information on the phylogenetic taxa and breeding for resistance to sclerotinia stem rot. A minimum of three and a maximum of 15 unambiguously amplified bands were generated, furnishing a total of 170 bands ranging in size from 100 to 3 200 bp, corresponding to an average of 8.5 bands per primer pair. One hundred and four of these 170 bands (61.2%) were polymorphic, the percentage of polymorphic bands for each primer pair ranging from 0.0% to 86.7%. The genetic relationships among the isolates, based on the results of RAPD analysis, were examined. The genetic similarity of all selected isolates was quite high. At the species level, the genetic diversity estimated by Nei's gene diversity (h) was 0.197 and Shannon's index of diversity (I) was 0.300. The unweighted pair-group mean analysis (UPGMA) cluster analysis showed that most isolates from the same regions were grouped in the same cluster or a close cluster. The population of isolates from Hefei (Anhui Province, China) was more uniform and relatively distant to other populations. The Canadian population collected from carrot (Daucus carota var. sativa DC.) was relatively close to the Polish population collected from oilseed rape (Brassica napus L.) plants. There was no relationship between isolates from the same host plants. An analysis of molecular variance (AMOVA) revealed that the percentage of variance attributable to variation among and within populations was 50.62% and 49.38%, respectively. When accessions from China, Europe, and Canada were treated as three separate groups, the variance components among groups, among populations within groups, and within populations were ?0.96%, 51.48%, and 49.47%, respectively. The genetic differentiations among and within populations were highly significant (P < 0.001). Similarly, the coefficient of gene differentiation (Gst) in total populations calculated by population genetic analysis was 0.229 4, which indicated that the genetic variation among populations was 22.94%. The gene flow (Nm) was 1.68, which indicated that the gene permutation and interaction among populations was relatively high.