Analysis on Genetic Similarity of Japonica Rice Variety from Different Origins of Geography in the World

The genetic similarity and genetic difference among improved japonica rice varieties from different countries （or regions and organizations） were detected. The aim is to provide genetic basis to the breeding of japonica rice varieties. The genetic similarity and cluster of 313 improved japonica varieties from 20 countries （or regions and organizations） were analyzed using the SSR marker. With 34 SSR primers which were polymorphic and uniformly distributed in rice genome, totally 198 alleles were detected among these improved varieties with the average number of alleles per pair of primers of 5.8235. RM320, RM531, RM1, RM21, and RM336 located more alleles, which were 16, 13, 12, 10, and 10 respectively. RM320, RM336, RM286, RM531, and RM21 showed higher genetic diversity indexes, which were 2.3668, 2.0041, 1.9684, 1.9508, and 1.7203, respectively. The genetic similarity for improved japonica varieties among different countries （or regions and organizations） were ranged from 0.279 to 0.918, and the mean value was 0.653. The rice varieties from countries whose latitude and geography position were all nearer were clustered together with higher genetic similarity indexes. The rice varieties from countries who had more different latitude and far geography position were clustered separately with lower genetic similarity indexes. The results indicated the genetic similarity indexes among improved japonica varieties had a close relationship with the geographical position, especially with the latitude.

Analysis of Genetic Similarity for Improved Japonica Rice Varieties from Different Provinces and Cities in China

To provide a genetic basis for japonica rice breeding, the genetic similarity and cluster of 139 accessions of improved japonica rice varieties from 12 provinces and cities of China were analyzed using 34 SSR markers. Totally 198 alleles were detected among these improved japonica rice varieties with the average number of alleles per pair of primers was 5.3235. RM320, RM531, RM1, RM286, and RM336 showed more alleles, which were 15, 12, 11, 9, and 9, respectively. RM320, RM336, RM286 and RM531 showed higher genetic diversity indexes; which were 2.3324, 2.0292, 1.8996, and 1.7820, respectively. The range of genetic similar index among improved japonica rice varieties from different provinces was from 0.321 to 0.914, with the average of 0.686. There was a high genetic similarity among improved japonica rice varieties from Heilongjiang, Jilin, Liaoning, Ningxia, and Yunnan, which were located in similar latitude or similar ecological environment, while there was a low genetic similarity between improved japonica rice varieties from Guizhou and Jiangsu, and other provinces which were located in more different latitudes and ecological environments. The markers of RM320, RM531, RM1, RM286, and RM336 fit to be used in analysis of genetic diversity for improved japonica rice variety. The genetic similarity among improved japonica rice varieties from different provinces was closely associated with genetic basis of parents, and was also correlated with latitude and ecological environment where the varieties were bred.

Genetic Diversity of Chinese Temperate and Exotic Tropical, Subtropical Quality Protein Maize Inbreds by SSR Markers

Information on genetic relationship is of great value to maize (Zea mays L.) breeding. Theobjectives of this study were: 1) to classify 22 quality protein maize (QPM) inbreds intodifferent groups by using simple sequence repeats (SSR) markers, which included exotictropical, subtropical and domestic temperate QPM and normal maize inbreds; 2) to examine theconsistency of grouping results obtained from SSR, specific combining ability (SCA) analysis,and genetic backgrounds of these inbreds. A set of 39 polymorphic SSR primers was selected from70 primer pairs, which detected 136 alleles among the 22 lines. The mean polymorphisminformation content was 0.55. Based on analysis of genetic similarities, five groups wereidentified including Luda Red Cob, Sipingtou, Reid, Lancaster and a miscellaneous group withseveral tropical inbreds which could not be classified into the above four groups. The resultsgenerally agreed with previous results based on analysis of yield combining ability andpedigree data.

Genome-wide assessment of genetic diversity and fiber quality traits characterization in Gossypium hirsutum races

Gossypium hirsutum races are believed to be potential reservoirs of desirable traits, which can play crucial roles to overcome the existing narrow genetic base of modern Upland cotton cultivars. However, prior to utilizing the races in cotton improve- ment programs, understanding their genetic constitutions is needed. Thus, this study used molecular and morphological techniques to characterize 110 G. hirsutum germplasm including 109 semi-wild accessions and one Upland cotton cultivar, CRI12. In the study, 104 SSR markers detected 795 alleles, with an average of 7.64 alleles per marker, ranging from 3 to 14, and average polymorphism information content （PIC） value of 0.71. And 96 of the markers were found to be highly informative, with PIC value〉0.50. Pairwise genetic similarity coefficient across the accessions ranged from 0.19 to 1.00, with an average value of 0.46. Morphological characterization was done using fiber length, fiber strength, micronaire, fiber uniformity index, and fiber elongation. Pairwise taxonomic distance within the accessions ranged from 0.17 to 3.41, with a mean of 1.33. The SSR and fiber quality traits data set based unweighted pair group method of arithmetic mean （UPGMA） analysis grouped the accessions into 7 and 12 distinct clusters, respectively, that corresponds well with the results of prin- cipal component analysis （PCA）. Our study revealed the existence of vast molecular and morphological diversities within the accessions and provided valuable information on each semi-wild accession for quick and better informed germplasm utilization in cotton breeding programs.

Genetic Diversity and Relationships among Diploid and Tetraploid Cotton Using RAPD Markers

Gossypium species(+49) represent a vast resource of genetic diversity for improvement of cultivated cotton.To determine intra-and inter-specific genetic diversity and relationships,we

Comparisons of Several Similarity Coefficients for Cluster Analysis of Hot Pepper Germplasm Resources

An appropriate genetic similarity coefficient is particularly important for accurately estimating the genetic similarity and phylogenetic relationship between individuals and evaluating the genetic diversity of populations. In this study, five genetic similarity coefficients were compared for analysis of phylogenetic relationship among 31 hot pepper inbred lines based on SRAP. The applicability of different genetic similarity coefficient was investigated by means of SRAP data of hot pepper inbred lines. According to the experimental results, the variation ranges of Nei ＆ Li, Jaceard, Sorensen, Simple matching and Yule coefficients were 0. 598 - 0. 973, 0. 427 - 0. 947, 0. 598 - 0. 973, 0.427 - 0. 947 and 0. 133 - 0. 997, respectively. Results of cluster analysis based on different similarity coefficients varied greatly. To be specific, clustering results based on Nei ＆ Li, Jaccard and Sorensen coefficients were consistent; clustering with Simple matching and Yule coef ficients led to consistent classification of category in different order and slightly different classification of subcategory. Comprehensively comparing the results of cluster analysis and the dendrograms of hot pepper inbred lines, Yule coefficient is suitable for SRAP analysis of hot pepper.

Morphological Difference and DNA Diversity Between Flower-colour Sport and Original Cultivar of Chrysanthemum with Small Flowers

A total of 58 morphological characteristics were measured on flower-colour sport and original cultivar according to Disticness, Uniformity, Stability＇ （DUS） Test for New Plant Cultivar of Chrysanthemum published by Ministry of Agriculture of China The results showed that five characteristics such as the surface colour, the back color of ray floret among them were siginificantly different, their MS （mo by AFLP showed that rphological s GS （genetic imilarity） was 91.4%, and MD （morphological difference） was 8.62%. DNA polymorphic analysis similarity） was 98.6%, and GD （genetic polymorphic diversity） was 2.81%. Five distinct bands which may include the flower-colour sport genes or be the molecular marker linkaged flower-color characteristics were amplified.