Study On Evaluation Of Wild Germplasm Resources And Their Genetic Relationship With Cultivars Of Rosa Rugosa

The status quo, biologic characteristic and variation of Chinese wild rose (Rosa rugosa) wereinvestigated and studied at the level of morphology, physiology, phytochemistry, Palynology and molecularbiology. The genetic diversities and relationships among wild germplasms and cultivars of Rosa rugosawere analyzed using AFLP. The main results are as following:1. The wild populations of Rosa rugosa distributed over east seacoast of Shandong province, southseacoast of Liaoning province and Hunchun region of jilin province were investigated. The remaineddistribution areas, status quo, Morphological characteristic and variation of wild roses were made clearprimarily, the commensal plant species and the endangerment reasons were investigated and analyzed at thesame time.2. Photosynthetic characteristics of two wild roses (Rosa rugosa, from Hunchun, Jilin province andMouping, Shandong province) and two rose cultivars (R. rugosa 'Purple Branch' from Pingyin, Shandongprovince and R. sertata×R. rugosa from Kushui, Gansu province) were studied comparatively withCIRAS-2 portable photosynthetic instrument and FMS-2 fluorometer. The results showed that the curve ofthe diurnal change in the net photosynthetic rate (P_n) of 'Hunchun' wild rose showed only one peak, butthat of 'Muping' wild rose and R. rugosa 'Purple Branch' were all inapparent bimodal curves, and for R.sertata×R. rugosa, it was a typical bimodal curve. The maximal P_n values of the wild roses weresignificantly higher than those of the two cultivars, especially between 6: 30-14: 30, and the wild rosesshowed the characteristic of high photosynthetic efficiency. 'Midday depression' phenomenon ofphotosynthesis occurred in 'Hunchun' wild rose, R. rugosa 'Purple Branch' and R. sertata×R. rugosa, nor'Muping' wild rose. The depression of P_n in R. rugosa 'Purple Branch' was mainly induced by nonstomatal factors, but for 'Hunchun' wild rose, 'Muping' wild rose and R. sertata×R. rugosa, it was jointlyaffected by stomatal factors and non-stomatal factors. The diurnal changes of the chlorophyll fluorescentparameters showed that photoinhibition occurred in all roses, but the wild roses were more sensible tostrong light and showed a more serious photoinhibition than the rose cultivars at noon, they could use the light to carrying out photosynthesis more efficiently than the rose cultivars in the morning, but the rosecultivars could use the light more efficiently than the wild roses in the afternoon. The reversible inactivationsof PSâ…¡reaction centers and the course of dissipating excess energy efficiently through Non-photochemicalquenching (NPQ) were the main mechanism of protecting PSâ…¡reaction centers of rose leaves fromdamaging by strong light.3. The chemical constitutents of fragrance released from fresh flowers of 4 wild roses (MP, RCH, HCH, ZHH) were analyzed by means of solid phase microextraction (SPME) with gas chromatography-mass spectrometry (GC-MS). The results showed that the aromatic components and contents of 4 wildroses were distinctly different. 64 compounds were identified in MP, including Phenethyl alcohol,β-Citronellol, Nerol, Geraniol, Benzyl alcohol, 3-hexen-1-ol and n-Hexanol, alcohols were the majorconstituents; 48 compounds were identified in RCH, including Phenethyl alcohol,β-Citronellol, Geranioland Nerol, alcohols were the major constituents; 56 compounds were identified in HCH, includingPhenethyl alcohol, Phenethyl acetate,β-Citronellol, n-Hexyl acetate, cis-3-hexenyl acetate, Nerol,α-Myrcene, Geraniol and D-Limonene, alcohols and esters were the major constituents; 56 compounds wereidentified in ZHH, including Phenethyl alcohol, Diethyl phthalate,β-Citronellol, 2-Heptanone and Benzylalcohol, alcohols were the major constituents. Because of different aromatic components and contents, theodour of fresh flower in different wild roses are delicately different.4. The pollen grains of 6 wild roses from Shandong (MP, RCH), Liaoning (ZZH) and Jilin province(HCW, HCN, HCP) were examined under Scanning Electron Microscope (SEM), the clustering analysisaccording to the pollen characteristics was carried out finally. The results showed that the pollen grains of 6wild roses were prelate or perprolate, they were long ellipse, long ellipse leaning toward rectangle or ellipseleaning toward spindle in equatorial view and 3-labed-rounded in polar view, and the two poles were plane orembowed. They all had 3 colposates which annularly distributed in equal space, and the type of pollensbelonged to N₃P₄C₅ model. The sculptural type of the wild roses were all striate-foveolate, there were manystripes and tectum punctures in the exine sculptures, but the morphology and distribution of the stripes andpunctures were markedly different among 6 wild roses, and the exine sculpture could be the importantevidence for classification and identification of wild roses. The result with clustering analysis suggested thatthe relationship between HCW and HCN was close, as well as MP, RCH and ZHH, but the relationship between HCP and the other 5 wild roses was very distant. Finally, the origin and evolution of wild rose inchina were discussed considering the clustering result and the evolutiVe roles of botanic pollen.5. The aroma constituents and contents present in Rosa rugosa during different flower developmentalstages were analyzed by means of solid phase microextraction (SPME) with gas chromatography-massspectrometry (GC-MS). The results showed that aroma constituents and contents were distinctly different indifferent developmental stage of rose flower. 53 compounds were identified in flower bud, includingγ-Muurolene,α-Himachalene,α-Pinene, trans-α-bergamotene, cis-3-hexenyl acetate and Longiverbenone, terpenes were the major constituents; 65 compounds were identified in flower at the early opening stage, includingβ-Citronellol, Citronellol acetate, Phenethyl alcohol, Geraniol, n-Hexyl acetate, Nerol, Phenethylacetate and cis-3-hexenyl acetate, alcohols, esters and terpenes were the major constituents; 62 compoundswere identified in flower at the half opening stage, includingβ-Citronellol, Geraniol, Phenethyl alcohol, Citronellol acetate, Nerol, n-Hexyl acetate, Phenethyl acetate andα-Myrcene, alcohols, esters and terpeneswere the major constituents; 65 compounds were identified in flower at the full opening stage, includingβ-Citronellol, Citronellol acetate, Phenethyl alcohol, Geranyl acetate, Geraniol, Phenethyl acetate, Nerol, n-Hexyl acetate andα-Myrcene, alcohols, esters and terpenes were the major constituents; 58 compoundswere identified in flower at the end of full opening stage, includingβ-Citronellol, Phenethyl alcohol, Phenethyl acetate, Citronellol acetate,α-Myrcene,α-Pinene, Limonene and Geranyl acetate, alcohols, estersand terpenes were the major constituents. With the development of rose flower, the content of alcoholsincreased rapidly, and their maximum concentrations were found at the half opening stage; Esters increasedfirstly and decreased in succession, their maximum concentrations were found at the full opening stage; Themaximum concentrations of terpenes were found in flower bud, and decreased rapidly at the early openingstage, but they increased again at the end of full opening stage; Aldehydes increased firstly and decreased insuccession, their maximum concentrations were found at the full opening stage.β-Citronellol, Citronellolacetate, Phenethyl alcohol, Geranyl acetate, Nerol, Phenethyl acetate, n-Hexyl acetate andα-Myrcene weremain aroma compounds of Rosa rugosa.6. The genetic diversities and relationships among 5 wild germplasms and 25 cultivars of Rosa rugosawere analyzed using 10 AFLP primer combinations. Among the 1771 bands detected, 1704 bands werepolymorphic. The high ratio of polymorphic bands (96.2%) observed in this study indicated abundant genetic diversity among Rosa rugosa germplasm resources. 10 AFLP primer combinations could be used toidentify 24 germplasms being tested depending on specific bands. Genetic similarity coefficient (SC) amongall germplasm resources varied from 0.4977 to 0.8410, and the average SC was 0.6249. The result ofclustering analysis showed that the relationship among wild roses was distant and the genetic diversity wasabundant. The relationship between wild germplasms and cultivars was also distant, but among the main rosecultivars in china, it was close and the genetic diversity was deficient.7. Finally, combined with the results of palynology and AFLP analysis, we thinked that the chinesewild rose probably origined from east seacoast of Shandong province, afterward, it evolved to southseacoast of Liaoning province, and then evolved to Hunchun region of Jilin province from Liaoningprovince.