The Study On Cytological Germplasm Resources And Main Physiological Indexes Of Wild Portulaca Oleracea L.

Purslane (Portulaca oleracea L.) is an annual herb, belonging to Portulacaceae and Purslane, it has a long history in our country as a kind of medicinal and edible plants. It has been observed as a nutrient-rich vegetables in folk; The Compendium of Materia Medica and other ancient medical books records that,the purslane had efficiency of dissipating blood and detumescence, benifit intestinal and supermoto, detoxification tonglin, treating governance postpartum and so on, so it’s known as "natural antibiotics". Polysaccharide and flavonoids as Portulaca extracts have good antivirus, antitumor, antioxidation and prevent senility activity. Purslane widely distributed in China, it growed in fields, roadsides, and irrigation ditches, and there had rich germplasm resources. The current study were mainly focused on purslane medicinal ingredients, medicinal physiology, medical functions, clinical application and cultivation technique, and it’s few reports the study of Portulaca oleracea germplasm, it has inconclusive on chromosome number and ploidy yet; We often use wild resources on production, lack of high quality varieties of purslane.In this study, we used 20 different wild purslane from different regions of China as materials, study different populations of wild purslane chromosome number, karyotype and positioning of rDNA in chromosome use conventional cytology methods and FISH technique in order to provide cytogenetic evidence for the classification of germplasm resources and evaluation; Provide the theoretical basis and foundation for development and utilization of wild resources purslane and breeding materials combined with the determination of physiological analysis. The main results were as follows:1. Cytological studiesWe researched 20 different populations of wild portulaca and its related species flowering purslane (P. grandiflora L.) on cytological. The results showed that: chromosome behaved normal on the process of meiosis for Portulaca pollen mother cells meiosis purslane meiotic, it become 26 bivalents in diakinesis, provide evidence for the chromosome number of Portulaca oleracea was 2n=52, and the meiosis was simultaneous; All the tested materials had the same number of chromosomes, they were both 2n= 4x= 52, x= 13. B chromosomes was found in somatic cell of 11 social Purslane, and it had significiant difference in different populations and different individuals; nuclear-type analysis for four populations shows that, karyotype of M7, M13, M15 was 1B, and that of M20 was 2B; different populations of purslane had differences in karyotype formula, karyotype type and number of aspects. It showed that different populations of purslane exists genetic diversity in the level of chromosome. The chromosome number of Large flower Portulaca oleracea was 2n=2x=18, karyotype was "1A" type. Compared with purslane, it’s in the original position in evolution.2. FISH analysis based on rDNAWe used Two-color fluorescence in situ hybridization technology with 45S and 5S rDNA as a probe, made positioning analysis for 2 populations (M20 and M18) of purslane and M21 (large flower Portulaca oleracea) in the Orientation. The results show that, M20 populations have four pairs of 45S rDNA sites and four pairs of 5S rDNA signal sites; M18 populations have five pairs of 45S rDNA sites and two pairs of 5S rDNA signal sites.45S rDNA and 5S rDNA had differences on the upper points in chromosomes, it’s indicated that there was a big divide in the level of chromosome structure, different populations of wild purslane existed genetic diversity on genome evolution. And the relatives of large flower purslane purslane (M21) had one pair of 45S rDNA sites and one pair of 5S rDNA signal sites, indicated purslane had higher level than large flowers purslane in evolution.3. Measurement of physiological indexes on different populations of Purslane20 populations of soluble protein content, polysaccharide content and flavonoid content were determined, the results showed that, it had significantly difference in soluble protein content of different populations of purslane, and it had different best harvest time as deep processing; Polysaccharide content were significantly different in screened different populations, it showed dynamic change, the content increased with the different growing seasons, which was higher in august and september, suited to harvest as a medicinal; Flavonoid content had different in sceened different populations, which was higher in july and august, it can as best harvest time for the production of dehydrated vegetables and oral best harvest respectively; Maybe it’s prcessed long-term evolutionary for adapting the local environment, so resulted in the difference of physiological indexes on the different population, and related to its genetic mechanism. Meanwhile, determined the population of biological yield, combined with the above these three physiological indicators, initially selected four basic materials for breeding.