The Research Of Micro-ecological Control On Shoot Blight Of Pinus Sylvestris Var.Mongolica

The micro-ecological control technique, including the tree surface and rhizosphere of Mongol Scotch Pine (Pinus sylvestris var. mongolica), for shoot blight of Pinus sylvestris var. mongolica was systematically studied using the principles and technologies of forest pathology, plant micro-ecology and microbiology.. The community structure, distribution pattern, as well as the biological diversity of tree-inhabiting fungi of Pinus sylvestris var. mongolica were investigated, and the antagonistic fungi that have inhibiting effects to the pathogen of shoot blight were screened.Totally 59 genera (species) of tree-inhabiting fungi were isolated and identified from the over-ground part of on Mongol Scotch Pine., including 15 species of bud-inhabiting fungi, 43 species of foliage-inhabiting fungi, 19 species of branch-inhabiting fungi and 19 species of stem-inhabiting fungi. The pathogen (Sphaeropsis sapinea) of Shoot Blight of Pinus sylvestris var. mongolica was only isolated from pine needles, with a lower isolation rate Among the isolated and identified tree-inhabiting fungi, 2 species belong to Zygomycotina, 3 species belong to Ascomycotina, 11 species belong to Basidiomycotina, and the others belong to Deuteromycotina. Along with the crown layer down, bud-inhabiting fungi decreased in 'species number, and the distribution was uneven. The species of foliage-inhabiting fungi on the 1—2 year-old needles were least in middle crown layer and most in upper crown layer and lower crown layer. Branch-inhabiting fungi had a slight increase in species number with the increasing of branch age, while the species number of stem-inhabiting fungi gradually decreased with the increase of stem height,. Eleven species of ectomycorrhizal fungi were collected from Mongol Scotch Pine forest. Suillus grevillei, Suillus granulatus, Pisolithus tinctorius are the dominated species in artificial young-age forest, and Russula and Gomphidius rutilus dominates in middle-age forest.The distribution pattern and diversity of tree-inhabiting fungi on Mongol Scotch Pine has a stronger regularity. The distribution patterns of five common tree-inhabiting fungi were divided into 2 types. One is aggregated distribution pattern which obeys the negative binomial distribution, and the other is random distribution pattern which obeys the Poisson's distribution. Alternaria sp., Pestalotiopsis sp., Truncatella sp. and Coniothyrium sp. belong to the aggregated distribution pattern, while Phyllosticta sp. is more close to the random distribution pattern. The diversity and uniformity of tree-inhabiting fungi negatively correlated with disease occurrence, the higher the diversity and uniformity of tree-inhabiting fungi, the lower the possibility of disease occurrence. The diversity and uniformity of bud-inhabiting fungi decrease along with the crown layer lowers, but suffer injury degree of tree unceasingly increases. The diversity index of the foliage-inhabiting fungi on 1-2 year-old needles is higher in upper and lower crown layers, but lower in middle crown layer. For the foliage-inhabiting fungi on the more than 3-year-old needles, its diversity is higher in lower crown layer than in upper crown layer, with a decrease in uniformity. The foliage-inhabiting fungi hardly injure in upper crown layer, slightly injure in middle crown layer, and easily injure in lower crown layer. The diversity index of stem-inhabiting fungi shows a negative correlation with stem height, decreasing with the rise of stem height, still the uniformity index is the highest in base of the stem, moderate in the upper part of stem, and lowest in the middle part of stem.Six species of fungi, with broad distribution and high appeared frequency, were selected from isolated tree-inhabiting fungi for dual culture of antagonism against Sphaeropsis sapinea. Antagonistic effect was examinedaccording to the relative inhibiting effect. The results show that the tree-inhabiting fungi screened all have certain inhibiting effects to Sphaeropsis sapinea. Within 72 h, the inhibiting rates of the 6 species of antagonistic fungi, 001, Trichoderma viride 2, Trichoderma viride 1, Trichoderma harzianum, Chaetomium cochliodes, and Lacellinopsis sp is 87.86%, 75.71%, 74.91%, 71.27%, 69.06%, and 61.08%, respectively, and their relative inhibiting effects reaches separately: 36.07, 73.55, 4.81, 2.59, 6.16 and 3.84.Dual culture of 4 strains of toxic mushrooms against Sphaeropsis sapinea was conducted. The result shows that 4 strains of toxic mushrooms all have definite inhibiting effects to Sphaeropsis sapinea. The order of inhibiting rate from high to low is: Clitocybe dealbata >Lepiota cristata >Ramaria ephemeroderma>Lepiota cfypeolaria, and the relative inhibiting effect is: Lepiota clypeolaria > Lepiota cristata > Ramaria ephemeroderma>Clitocybe dealbata. Lepiota clypeolaria exhibits a highly antagonistic action for inhibiting Sphaeropsis sapinea growth.Ten strains of ectomycorrhizal fungi of Mongol Scotch Pine were obtained by collecting in field, isolating and culturing, synthesizing indoor. The inoculation in field shows that the 10 strains of ectomycorrhizal fungi all have certain promoting effect on seedlings growth of Mongol Scotch Pine. The effect of inoculation by the method of soaking root with fugal liquid is better than that by the method of lister inoculating, but it is only suitable for transplant seedling. The inoculation by the highly effective strain mixed with other strain 'is not as good as that by the highly effective strain solely for promoting seedling growth. The height growth of the seedlings inoculated with strains GT005, 035,009, LH004, and GT001, by the method of soaking root, was raised by 54.24%, 41.53%, 36.44%, 35.59% and 35.59% respectively, compared with that of the control in 130 days. Application of Strains 035, LH004,025,010 and GT001 can raise the collar diameter growth of seedlings by more than 20%. In comparison with control, the collar diameter growth of the seedlings inoculated with strains 035, LH004, and 025 was raised by 56.31%, 39.93%, and 29.01%, respectively. Three-year-old seedlings were inoculated with strains Pt and Gt005 using the method of lister. The seedlings increased by 10.76% in height growth for inoculation with Pt and and 9.96% for inoculation with Gt005 within 100 days, and collar diameter growth was raised by 16.43% for Pt inoculation and 15.18% for Gt005 inoculation. The height growth of the seedlings inoculated with combinations 044/GtOOl and GT001/GT005 by the method of lister was only increased by 3.47% and 2.07% in 100 days, whereas the height growth of seedlings inoculated with 044/025 and 044/009 was lower than the control. The collar diameter growth of the seedlings inoculated with mixed strains was 0.16%~7.98% higher than that of the control.Bacterial fertilizer and plant growth regulator have markedly promoting effect on high growth of Mongol Scotch Pine seedlings. The height growth of seedlings was raised by 20% within 130 days after applying fertilizer, compared to control. The white-color micro-fertilizer can obviously raise the collar diameter of the seedlings. It raised the collar diameter of the seedlings by 20.7%. Applying red-color micro-fertilizer and the plant growth regulator enhanced the collar diameter growth of the seedlings by 13.8% and 17.2%, respectively.