| The growth characteristics, economic traits and genetic diversity of eight wild populations of P. hantanensis which were collected from different coasts of Fujian province were studied. Expect to make clear the genetic background of wild life P. hantanensis germplasm resource, and make the fundaments for select breeding.Among these populations, the blades of WP3 and WP6 is filate-lanceolate-type which have bright coloured shade, fast growing (growing 5-6cm every day) and precominance in growth rate and thickness. But WP2、WP4 and WP5 are worse (growing lower than 3cm every day). The blades of WP1 and WP4 are not easy to maturate, which mature rate are 37% and 35.5% after cultured 15 days in the laboratory respectively. But the mature rate can reach 46.5% in WP2 after 5 day’s cultured.The contents of phycobiliprotein,chlorophyll and crude protein have significant difference among different groups. WP3 has superiority than others in the content of crude protein, super- phycobiliprotein and chlorophyll. WP6 has the highest content of total phycobiliprotein and chlorophyll in spite of the lowest content of crude protein.The content of amino acid has also significant difference. The content of -amino acid is highest in WP2 and WP3 but lowest in WP5. WP2 and WP7 have the maximum variety of free amino acid but WP5 has the minimum. The content of THR, Ser and Ilu are highest in WP1, Glu in WP2, Asp and Leu in WP3, Gly and Ala in WP4, and Ly in WP8. Pro in all groups and Arg in WP3 and WP5 are not found. CYS is only detected in WP7 and Met only in WP5 and WP6.Sequence-related amplified polymorphism (SRAP) markers were used to investigate the genetic variations within and among 8 wild population of P.haitanensis. The thalli samples were collected from 80 individuals. 34 pairs of SRAP combined primers were selected from 50 pairs and gave rise to 1507 discernible DNA bands of which 1480(98.21%) were polymorphic. The sizes of these DNA bands are between 120bp to 1900bp. Genetic similarity of the three regional populations (Dongshan, Pingtan and Nanri) are 0.8872 to 0.8993 and 0.8993 on average. But the genetic similarity of the populations among the regional populations are 0.9489,0.9100 and 0.9293, which higher than the regional populations.Thedifference of effective number of alleles, expected heterozygosity and Shannon’s information index in the three regional populations is not significant (P>0.05). The effective number of alleles is 1.6862 at specific level, 1.7130, 1.7095 and 1.6018 at population level respectively. The expected heterozygosity and shannon’s information index are 0.3876 and 0.5671at species level, but at population level, the expected heterozyogsity are 0.4014,0.3992 and 0.3446, shannon’s information index are 0.5850,0.5815 and 0.5089.This indicated that a considerable genetic diversity in the wild populations of P.haitanensis and obvious difference was not found in the three groups.According to the value of Gst, a large proportion of genetic variance (87.84%) of P. haitanensis was among individuals within population, only 12.16% genetic variance was among populations, the results indicated that the genetic differentiation level among the 3 populations of P. haitanensis was low. And according to the value of Nm, the reason of the low genetic differentiation level among populations of P. haitanensis was the sufficient gene flow. The value of gene flow among populations of P. hantanensis in three areas (Dongshan, Pingtan, Nanri) is 3.6124 and 8.7790, 4.6987 and 6.6694 repectively among populations in these areas. This indicated that gene exchange of P. hantanensis is very frequently among populations in every area, but is less take place among regional populations. Maybe, gene exchanges among populatins of P. hantanensis were related to the geography distance.UPGMA cluster analysis based on Nei’s genetic distance of 8 wild P. hantanensis individuals showed that most individuals clustered according to their geography resource. But when cluster analysis was made on each population among the three areas, the individuals from the same area were cluster randomly, and its randomness increased along with the Nm’s value increasing. |
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