Interactions of Gremmeniella abietina and Endophytic Fungi in Shoots of Scots Pine Trees Treated with Simulated Acid Rain

1995 ◽  
Vol 32 (1) ◽  
pp. 67 ◽  
Author(s):  
H. Ranta ◽  
S. Neuvonen ◽  
A. Ylimartimo

1994 ◽  
Vol 72 (8) ◽  
pp. 1108-1113 ◽  
Author(s):  
M. L. Helander ◽  
T. N. Sieber ◽  
O. Petrini ◽  
S. Neuvonen

Within- and among-tree variation in assemblages of endophytic fungi in Scots pine (Pinus sylvestris) needles were studied in a subarctic area where background pollution values are low; the effects of tree density and prolonged simulated acid rain on the occurrence of endophytic fungi were investigated. The needle endophyte most frequently isolated was Cenangium ferruginosum, accounting for 64% of all fungal individuals, followed by Cyclaneusma minus (12% of all individuals). Old needles were colonized more frequently by endophytes than young ones. In young needles the colonization by endophytes increased during the summer, whereas in old ones no seasonal variation was detected. Endophyte colonization was positively correlated with stand density and was reduced on pines treated with spring water acidified with either sulphuric acid alone or in combination with nitric acid. In contrast, nitric acid alone did not affect endophyte colonization. Key words: endophytes, needles, pine, Pinus, simulated acid rain, stand density.



1989 ◽  
Vol 19 (11) ◽  
pp. 1402-1411 ◽  
Author(s):  
Toini Holopainen ◽  
Pekka Nygren

The effects of potassium deficiency and artificial acid precipitation, alone and in combination, on Scots pine (Pinussilvestris L.) needles were studied using transmission electron microscopy. The seedling material was grown in quartz sand culture and watered with nutrient solution containing 45, 20, 10, or 5 mg of potassium/L; the concentration of other nutrients was constant and equally available for all seedlings. A portion of the seedlings from each group received consecutive acidified water spraying of pH 4.5, 4.0, 3.5, and 3.0, each for 4 days with a 3-day resting period between applications. The potassium deficiency caused an increase in the proportional vacuolar space and severe vesiculation of the tonoplast. Irregularly shaped lipid structures increased in number in the cytoplasm, and lipid bodies also appeared in the vacuoles and occasionally in the chloroplasts. The symptoms related to potassium deficiency were more severe in the transfusion parenchyma cells than in the mesophyll. The lowest level of potassium produced almost complete disorganization of the cellular structures in the transfusion parenchyma tissue, but severe changes were also seen in the mesophyll. The simulated acid rain treatment caused the formation of protrusions in the chloroplasts and an increase in irregularly shaped lipid structures in the cytoplasm throughout the mesophyll tissue, but no clear symptoms were observed inside the bundle sheath. In general, the changes caused by acid rain in the chloroplasts were slight and did not cause serious disorganization of these organelles. When the seedlings were exposed to combination treatment, the typical symptoms of both exposures were observable. The results suggest that the stresses caused by potassium deficiency and short-term foliar acid rain treatment can be distinguished in the needle ultrastructure.





1994 ◽  
Vol 72 (1) ◽  
pp. 93-99 ◽  
Author(s):  
H. Ranta ◽  
S. Neuvonen ◽  
S. Kääriäinen ◽  
S. Vesanto

The frequency of endophytic microfungi was measured from current-year shoots of Scots pine trees growing in Harjavalta, a heavily polluted area in western Finland. The copper (Cu) and (Ni) concentrations in bark plus phloem and needles of the same trees were measured. The frequency of isolates of endophytic taxa were either negatively (Hormonema sp. 2 and Sterile sp. 1) or positively (Hormonema sp. 1, BL132) correlated with the Cu and Ni concentration of bark plus phloem. Isolates of the most common endophytic taxa and the pathogenic Gremmeniella abietina from Harjavalta were grown in vitro in different levels of Cu (0.6 – 126 μg/mL) and Ni (0.3 – 50 μg/mL) separately and in combination. This experiment included also isolates of G. abietina and Hormonema sp. 1 from the northern (unpolluted) area. The concentrations of Cu and Ni that reduced the linear growth to 50% of control were estimated. The endophyte taxa with positively correlated frequency with increasing concentration of Cu and Ni in the shoots were able to withstand elevated levels of Cu and Ni in vitro. Compared with most of the other fungi, G. abietina isolates were particularly sensitive to addition of Ni. No evidence for intraspecific adaptation of G. abietina and Hormonema sp. 1 to Cu and Ni was found. Key words: endophyte, Gremmeniella, heavy metal, Hormonema, Scots pine.



1996 ◽  
Vol 92 (3) ◽  
pp. 315-321 ◽  
Author(s):  
Pavel Shumejko ◽  
Vladimir Ossipov ◽  
Seppo Neuvonen


1991 ◽  
Vol 69 (2) ◽  
pp. 412-419 ◽  
Author(s):  
Minna Turunen ◽  
Satu Huttunen

The long-term effects of simulated acid rain treatment (pH 4 and pH 3) on the physicochemical characteristics of the needle surfaces in a natural stand of Scots pine was investigated in the extreme north of Finland during the period 1985–1988. By the end of this period, the pH 3 treated pines had received a sulphur load of 7.48 g m−2 and a nitrogen load of 2.62 g m−2, and the pH 4 treated pines a sulphur load of 1.23 g m−2 and a nitrogen load of 0.43 g m−2 in addition to ambient deposition. No visible symptoms of acid rain injury were observed in the needles, but their growth was significantly reduced. Delayed development of the epistomatal waxes and four types of deformed stomatal complex, namely narrow, half-formed, occluded, and double-sized, were found by scanning electron microscopy. The total number of deformed stomatal complexes in the pH 4 treated pine needles was over 50% greater than in dry control specimens and over 70% greater than in water controls. The rapid erosion of young, undeveloped waxes increased needle wettability (11%) significantly, but the quantity of chloroform-soluble waxes had decreased only slightly. The effects of acid rain on the epicuticular waxes were accentuated during unfavourable growing seasons with reduced effective temperature sums. Key words: acid rain, Scots pine, epicuticular wax, wettability.





2013 ◽  
Vol 48 (2) ◽  
pp. 160-167
Author(s):  
Song Liying ◽  
Ke Zhanhong ◽  
Sun Lanlan ◽  
Peng Changlian


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