| Chrysopogon aciculatus (Retz.) Trin. is an important warm-season perennial turfgrass which mainly distributed in tropical and subtropical areas in the world. In China, C. aciculatus are mainly distributed in Fujian, Guangdong, Guangxi, Yuannan and Hainan province. Previous studies of C. aciculatus mainly focued on germplasm investigation, morphological characteristic and physiological characteristics, there is no information published using DNA markers till now. In this study, we collected eighty-six C. aciculatus accessions from Fujian, Guangdong, Guangxi, Yuannan and Hainan province to access the genetic diversity among accessions using molecular markers for the first time combined with morphological markers, habitat characteristics and resistance characteristics for providing a more comprehensive theoretical reference, and provide the scientific basis to breed using molecular marker-assisted. The research results as fellows:1. Research about the morphology diversity among C. aciculatus germplasmsAmong all the 24 indicators using to analyze the morphological diversity of 86 C. aciculatus accessions, all of traits had highly significantly difference (P< 0.01) except the internode length which was significantly difference (P< 0.05), all the accessions have rich diversity. The range of variant coefficient was 9.09% to 90.95%. The variant coefficient of the density of inflorescence was the highest (90.95%) while the variant coefficient of internode length was the lowest (9.09%), the average value was 25.13%. Coefficients between morphology characters were either significantly (P<0.05) or highly significantly (P< 0.01) correlated.2. Assess the water-use efficiency (WUE) on C. aciculatusWe studied the varieties of WUEs among 69 C. aciculatus accessions for accessing their ability of drought-resistant. Populations of C. aciculatus showed a large variation in WUE ranged from 0.28% to 0.95% with a 14.68% coefficient of variation. C. aciculatus from Hainan province had better mean value and higher variations of WUE than other provinces. CA26, CA59 and CA66 (Qiongzhong, Hainan) had the higher WUE value. The value of WUEs showed no relationships with latitude or longitude in this study.3. Assessment of shade-endurance on C. aciculatusThis study took chlorophyll content, withering rate, quality evaluation and quality of dry matter as indexes to access the shade-endurance on 83 C. aciculatus accessions. Among all the traits, chlorophyll content and quality evaluation, quality of dry matter and quality evaluation were highly positive significantly correlation, achlorophyll content and withering rate was highly significantly negative correlation. Accessions were clustered into five groups showed strong, relatively strong, ordinary,weak and bad shade-endurance, respectively. The strongest shade-endurance accessions were CA01 (Haikou, Hainan), CA26 (Yingde, Guangdong) and CA50 (Wengyuan, Guangxi). All the indexes used to accesse the shade-endurance showed no relationships with latitude or longitude in this study.4. Genetic diversity analysis of C. aciculatus germplasms based on ISSRTwenty-five ISSR primers were collected from 100 ISSR primers which amplified clearly and consistently. The percentage of polymorphic bands was 266 (94%) while 293 bands had been amplified. Variation range of observed alleles was 5 to 20, with an average of 10.64. Cofficients of genetic similarity ranged from 0.52 to 0.93.5. Accessment about genetic diversity of C. aciculatus germplasms using SRAPCollected 30 clearly and consistently amplified SRAP primer combinations from 400 SRAP primers combinations. The percentage of polymorphic bands was 576 (91.87%) while 627 bands amplified clearly. Observed alleles varied from 12 to 27, with an average of 19.2. Cofficients of genetic similarity ranged from 0.56 to 0.91.6. Development of microsatellite markers in C. aciculatus germplasmsUsed four Roche 454 pyrosequencing to develop microsatellite markers for C. aciculatus, combined with the magnetic bead enrichment method FIASCO to isolate from the C. aciculatus. A total of 66,198 raw sequencing reads were obtained with 4289 sequences (6.48%) were fit for primer pair design. We tested the primer amplification efficiency in 20 accessions, observed alleles ranged from three to six. Nei's genetic diversity values ranged from 0.085 to 0.493. Shannon's Information index values ranged from 0.141 to 0.686.7. Accessment about genetic diversity of C. aciculatus germplasms using SSRTwenty-five primer combinations amplified 90 clearly bands, the amount of polymorphic bands was 83 (92.22%). The number of observed alleles ranged from 2 to 6 and average value was of 3.32. Range of the cofficients of genetic similarity variation was 0.51 to 0.96.8. The comprehensive analysis of the three markers (ISSR+SSR+SRAP)The Mental test analyzed based on the ISSR, SRAP and SSR markers. The ISSR and SRAP integrated date showed a high correlation between the similarity coefficients matrix (Mantel test:r= 0.8023), which meant ISSR and SRAP were high similarity to each other, and the correlation value of the SSR and SRAP, ISSR and SRAP was low (0.7142 and 0.7021). The results revealed by ISSR and SRAP were similar, and ISSR had more polymorphic bands than SRAP. The result revealed by SSR analysis have great differences compared to ISSR and SRAP analysis. |
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