Molecular Identification And Phylogenetic Analysis Of Foilose Lichens And Its Phycobionts On Different Growth Matrixs

The lichen association is a mutualistic interaction between a mycobiont (fungal partner) and a phycobiont (cyanobacteria or green algal); the most successful example of symbiosis is known as the "pioneer organisms". Now there is cyanobacteria in Parmeliaceae which is not reported recently, furthermore, the relationship between algae-fungus symbiosis and growth matrix also has no reports. Ten specimens of lichens that collected from Yunnan province of China were identified by morphological identification, chemical development process and molecular biology method. Meanwhile, we isolated, purified and identified the phycobionts of the ten specimens. Furthermore, we discussed the relationships of phycobionts- mycobionts symbiosis on different growth matrixs.GADPH and ITS sequences were analyzed (The serial numbers of ten lichens specimens are respectively D1, D2, D3, D4, D5, D6, D7, D8, D9, D10 in the laboratory. D1, D4, D5, D6, D9 are corticolous lichens, D2, D10 are tecolous lichens, D3, D7, D8 are saxicolous lichens). The results show that the specimens of lichens are identified as Lecanorales, Parmeliaceae, Parmotrema. Thereinto, D1, D3, D4, D5, D6, D7, D8, D9 are closest affiliation with Parmotrema tinctorum, D3, D4, D6 are belonged to Parmotrema tinctorum, D2, D10 are belonged to Parmotrema perlatum.The phycobionts were isolated and purified (The serial numbers of ten phycobionts are Z1, Z2, Z3, Z4, Z5, Z6, Z7, Z8, Z9, Z10 in the laboratory) from ten specimens of lichens. Morphological identification and ITS, rbcL sequences were analyzed. The results show that five specimens of phycobionts from corticolous lichens, numbered Z1, Z4, Z5, Z6, Z9 respectively, are identified as Nostocales Nostocaceae Nostoc. Two specimens of phycobionts from tecolous lichens, Z2, Z10 are identified as Tetrasporales, Coccomyxaceae coccomyxa. Three specimens of phycobionts from saxicolous lichens, Z3, Z7, Z8 are identified as Chlorococcales Scenedesmaceae desmodesmus. Furthermore, the localities of lichens and phylogenetic analysis reveal that Z1, Z5, Z9 have closest affiliation. Similarly, it is closest affiliation that Z4, Z6 and Z2, Z10 and Z7, Z8. In concluding, mycobionts and phycobionts have rare relationships to the geographical origin, but it has obvious correlation with the growth matrix.Many scholars had tried to realize the artificial resynthesis of lichens. However, few successful experiments were reported besides Stahl and Ahmadjian. Ahmadjian and Heikkila repeated the Stahl's experiment about the artificial resynthesis of Endocarpon pusillum, it further confirmed that no-algae ascospores and sterile phycobionts were able to form the thallus of lichens which had perithecium. Stocker-W(o|¨)rg(o|¨)tter researched that the resynthesis of foliose thalli of the cyanobacterial lichen Peltigera praetextata was achieved on a soil substratum under laboratory conditions. On agar plates mycelia formation by this lichen fungus only occurred when a sufficient number of photobiont cells was present. The artificial resynthesis of lichens is very successful on a soil substratum under laboratory conditions. Our results show that mycobionts and phycobionts have rare relationships to the geographical origin, but it has obvious correlation with the growth matrix. Therefore, the artificial resynthesis of lichens is very difficult. We consider that the artificial resynthesis conditions are different with growth matrix and actual environment.So far, according to reports, the cyanobacterias existed in Peltigerales only, such as Peltigeraceae, Lobarlaceae, Collemataceae, Leptogiummenziesii. There was no cyanobacteria in Parrneliaceae. However, this results show that the phycobiont is Nostoc in Parrneliaceae (corticolous lichens), Which improve the traditional view that all the phycobionts are green algae in Parrneliaceae.