Wild Soybean Basis Of Physiological Studies

The difference of salt tolerance between G. soja and G. max was compared. The results showed that the salt tolerance of G. soja was higher than G. max both in the seed germinating stage and in the seedling stage.Glycine soja plants were treated with different salinity conditions. The shape and distribution of the attachments on the surface of stalk and leaf of G. soja plants were observed by SEM, and among which the ultrastructure of glandular hairs was observed by TEM; The Na+ and Cl" content in the secretion of the leaf surface and inside the leaf of G. soja plants under different treatments were determined; The Na+, K+, Cl" relative content in glandular cells, epidermal cells and mesophyllous cells of leaf of G. soja plants under different salinity were determined by X-ray microanalysis. Results show: There are only glandular hairs and epidermal hairs among the surface attachments of leaves and stalks of G. soja plants. The glandular hairs of G. soja plants were similar in shape to some salt glands of Gramineae halophytes, and they attached to the vein on the leaf surface of G. soja plants; and the cell structure of the glandular hairs took on the characteristics of common salt glands, such as big vacuoles, dense cytoplasm, a great deal of mitochondria, chloroplast, plasmodesmi and thicker cell walls etc; The results of Na+ and Cl" content in the leaf secretion and inside leaf show that the glandular hairs of G. soja plants executed a salt-secretion function, and when treated with a salt gland inhibitor its salt-secretion was inhibited and meanwhile Na+ and Cl" accumulated inside the leaf of G. soja plants; The results of Na+, K+, Cl" relative content by X-ray microanalysis under different salinity proved that the three cells of the glandular hairs of G. soja plants possessed strong competence of Na+, Cl" accumulation, and by the Na+, Cl" accumulation and secretion of the leaf glandular hairs, lower Na+, Cl" and higher K+ relative content were maintained in the epidermal cells and mesophyllous cells of leaf. In all, the glandular hairs were the salt gland of G. soja plants, and no the kind of "salt glands" of G. soja plants as Lu et al reported were found. The physiological function of the salt gland of G. soja was also to regulate the salt content in plant, and to keep natural function not to be affected by salt.In contrast with the G. max (Ludou2 from Shandong), the water content, osmotic potential, osmotica (including organic and inorganic osmotica) of G. soja plants under different salinity were determined. The results were shown as follows: (1) under salinity condition, G. soja plants could maintain higher osmotic adjust ability than G. max plants, and the leaf water content of G. soja plants was also higher than that of G. max plants. (2) under conditions of the same NaCl concentration, the Na*/K+ ratio of G. soja plant leaves was smaller than that of G. max. (3) under lower salinity condition, K+ was the main inorganic osmotica of G. soja, but Na+ was the main inorganic osmotica of G. max; under higher salinity condition, K+ was still the important parts in the osmotic adjustment of G. soja, but K+ was replaced completely by Na+ as the main inorganic osmotica of G. max. (4) compared with the different organic osmotica content under salinity condition, the contributions of amino acids and organic acids of G. soja to the osmotic adjustment was bigger than G. max; theIVcontributions of soluble sugar of G. max to the osmotic adjustment was bigger than G. soja. The above results indicated that G. soja could adapt to salinity condition by osmotic adjustment better than G. max.The seedlings of G. soja and G. max were treated with 100 mmol/L NaCl and 300 mmol/L NaCl for 72h, and the plasma membrane permeability of leaves, O2 and MDA content of leaves and roots were determined, and the activities of SOD, POD, APX were also determined. The results were shown as follows: (1) Under light salt stress condition, the plasma membrane permeability, O2 and MDA content of G. soja did not change distinctly...