Carbohydrate accumulation in the needles of Siberian stone pine seedlings

Abstract

The aim of the research presented is to study effects extracted from biologically active peat substances on carbohydrate accumulationprocesses. The study was carried out on 5-year-old Siberian stone pine seedlings grown in the nursery forest in the southern part of the Tomsk region. These seedlings were treated with a peat preparation, which was created in Tomsk. Four groups of experimental plants were organized on the analog principle. Each group consisted of 30 seedlings of average size and half of these seedlings were control. At the beginning of the vegetative season, a single treatment was applied to experimental plants with water solution peat preparation. The first group of plants was treated with a 0.1% solution; the dose was calculated by dry substance. For the second group, the dose was increased by 25%. For the third and fourth groups, the dose was decreased by 25% relative to the first group. Control plants were sprayed with water. Accumulation of carbohydrates and pigments as well as growth values in the 2-year- old needles were studied by standard methods. Glucose levels in the experimental plants existed within the limits 117-120%. On the whole, simple sugar quantity did not differs between experimental variants.Glucose synthesis was accompanied by changes in quantitative values of fructose. This, connected with glucose being a more stable compound, and compulsory conversion from glucose to labile form fructose was necessary. The amount of fructose in the experimental seedlings had a very wide range. This process was accompanied by shoot elongationin Siberian stone pine in the first year after treatment, with the fructose amount of 14% exceeding control values in the first and fourth group. Shoot growth was accompanied by increased fructose amount to 20% relative to control. A similar situation was observed afterwinter with respect to buds. Experimental plants dominated by number of buds. After the winter quiescent period, potential main budrealized as growth of shoot. Probably, fructose was used in the growth process of shoots and in the period when buds were laid. The fructosecontent in the seedling needle increased when the growth rate of above-ground shoots decreased. Sucrose is a universal source for synthesis of all organic compounds; it keeps it inert, and it is important when sucrose is transported through the plant vascular systems. Sucrose is a reserve carbohydrate. In the first variant, significant sucrose decrease compensated for increased fructose amount. Possibly, sucrose was used intensively, namely for growth processes of above-ground shoots, or atleast, none of the experimental variant sucrose amounts exceeded control values. Existence of a close connection was discovered between the content of chlorophyll and the amount of carbohydrate.Maximum amount of chlorophyll 'a' was displayed in the first group (529.32 μg/g damp weights vs. control 467.20 μg/g). Pigment is responsive to changes in environmental conditions, therefore it substantially determines growth and development processes of plants. It is necessary to note that pigment  amounts did not exceed the upper limit of physiological norms in all experimental groups. Changes were observed in needle length. This is connected with leaf apparatus treated plants. Opportunity was taken for extra concentrated sugars and other photosynthesis products in the needle. Thus, the natural growth regulator that the plant possessed had a prolonged effect and influence on physiological parameters of leaves such as carbohydrate accumulation. Correlation between photosynthetic pigments, carbohydrate accumulation, dynamic and growth processes was discovered.