Pasture Screening Research On Spartin Patens Strains Mutated By Low Energy Heavy Ion

Through two years of planting in greenhouse, over 20 mutated strains of Spartina patens (Ait) Muhl, which were grown from callus radiated by low energy heavy ion, were found having evident differences in phenotype from the wild control. In order to screen out fine pastures adapting to seashores in the east of China, 10 strains of them were grown outdoors simulating the seashore, and phenotype, above-ground biomass, photosynthetic ability, nutrition content and drought-resisting ability of these strains were compared in this paper.Results showed that the size of mutated strains were bigger than that of the control, but due to different strain densities, only biomasses of N1, N3 and N5 strains (esp. N5 strain) were higher than that of control, the lowest of them were N8 and N10 strains; On photosynthetic activity, of the 10 mutated strains, none of them are all the highest in all the photosynthetic indexes assayed, but strains of N1, N2, N3, N5 and N9 had a higher photosynthetic rates in most synthetic indexes than the control had, and the majority photosynthetic indexes of N6, N7 and N8 strains were relatively low; Both inorganic and organic nutrition in N5 and N3 strains were the most comprehensive and the most abundant; N1 and N6 strains have a relatively high level of inorganic nutrition content, but they had not the advantage in organic nutrition content; N7 and N8 strains had relatively low inorganic and organic nutrition contents, and their anti-nutrition content were relatively high. N7, N8 and N10 strains had relative high drought-resisting abilities, while N3, N4 and N5 strains had relative low drought-resisting abilities.Colligating above results, it could be found that radiated by low energy heavy ion differences in biomass, photosynthetic ability, nutrition content and drought-resisting ability were produced among 10 mutated strains used in this study. If fine strains were screened according to the standard of high biomass, high photosynthetic ability, high nutrition content and high drought-resisting ability, N5 strain was the most suitable strain grown as pastures in seashores in the east of China, and N3 and N1 strains came the next; If want to screen out strains only with the characters of high biomass and high inorganic nutrition content, N2 strain would be the best; If want to screen out the strains only with the characters of high biomass and high inorganic nutrition content, N2 strain would be the best; And if want to screen out strains with high stress-resisting ability and want to use it as a zoological restoration tool in high Pb-polluted area, N8 strain would be the best.In order to make sure whether the differences among these 10 strains come from the change of genetic materials or not, some attempts were made to check it. Results showed that ITS sequences from these 10 mutated strains and wild strain were all the same, and they were different at 1～2 sites with strains from states of Texas and Louisiana of USA. These demonstrated that low energy heavy ion radiation had not caused variation in ITS section among these 10 mutated strains. While elementary results from RAPD showed that DNA had changed firmly among these strains, and this result revealed that the differences on phenotype, above-ground biomass, photosynthetic ability, nutrition content and drought-resisting ability etc. probably came from the differences of genetic materials.