Abstract:
That studying the mineral ion balance and stoichiometry characteristics of plants, can help us to understand the interaction between nutrients in plants, which plays an important role in the research of stress adaptations, mineral ion balance and related regulatory gene control networks of grassland plants. Based on different grassland types in Inner Mongolia,
Stipa Linn., as a representative of gramineous plants, was used to determine the content of 15 nutrients in the leaves of the grass (7 macro-elements C, N, P, K, Mg, Ca, S and 8 micro-elements B, Mn, Fe, Na, Zn, Cu, Ni, Mo), and the stoichiometric characteristics of these elements and the interactive relationship between the elements. The results showed that: There was similar pattern of macro- and micro-elements distribution in the leaves of
S. sareptanai,
S. grandis,
S. breviflora,and
S. tianschanica, and the mean content of these mineral elements showed the change of C>N>K>S>Mg>P>Ca>Na>Mn>Fe>Zn>Ni>Cu>B>Mo. Between the four
Stipa plants the content of P, K, Ca macro-elements and Mn, Fe and Mo micro-elements were significant different (
P<0.05), and other elements such as N, Mg, Cu, Ni, etc. did not show significant difference (
P>0.05). The correlation analysis of the elements of the four
Stipa plants showed that the coefficience of the nutrient elements was in a wide range of fluctuations, and the interrelationships between different elements were complex, among the 105 pairs of 15 nutrients, 25 pairs were significantly related (
P<0.05), accounting for 20%. The Principal Component Analysis (PCA) of the inter-relationship between various elements of the leaf could extract four principal component axes with large variation and high interpretation rate, and macro-elements and micro-elements exhibit differential clustering distribution in the principal component axes. The cluster analysis of various elements could classify the nutrients into two categories. The first category was a included in C, N, P, K, S, etc., which together determined the physiological and ecological processes of plant growth, development and reproduction. And the second category included macro-elements Mg, Ca and micro-elements B, Mn, Na, Fe, Cu, Ni, Mo, as a prosthetic group involved in electron transport and biochemical reactions, and plant growth and habitat adaptation.