Studies On Morphological Anatomical Characteristic Of Root Crown And Regular Of Matter Accumulation In Melilotoides Ruthenica And Cold Resistance

The trial on comparison of cold resistance of Melilotoides was done in the greenhouse and the forage experimental station of Inner Mongolia Agricultural University in 2005 to 2006. In order to compare the difference of cold resistance and reveal the mechanism of cold resistance of all materials, the morpha and physiological index that are relative to cold resistance of three Melilotoides were mensurated in seed germinating and seedling and adult period compared with two alfalfa, which offers basis for identification and breeding of Melilotoides cold resistance .1,The indexes that are relate to cold resistance of three Melilotoides were mensurated in seed germinating and seedling period, which was synthetically appraised with membership functional value of cold resistance. The results showed: five materials of cold resistance is accordant in seed germinating and seedling period, Melilotodes ruthenica (L.) Sojak of wildness >Melilotodes ruthenica (L.) Sojak cv.zhilixing>Melilotodes ruthenica (L.) Sojak. of prematurity germination rate and germination index and vigor index and relative vigor index in seed germinating period are better the cold resistance indexes, but the relative vigor can much more reflect cold resistance.2,Root crown buried depth of Melilotodes of growth five years is deepest, which is 7.7 to 8.3cm. Root crown buried depth of Melilotodes ruthenica (L.) Sojak of prematurity is lowest, which is 5.0 to 6.5cm.Root crown buried depth of Melilotodes ruthenica (L.) Sojak cv.zhilixing is between them. Root crown buried depth of Melilotodes of growth five years is deeper than that of triennial Melilotodes in different growth number of years of Melilotodes.3,The dissolubility sugar content and the dissolubility protein content of Melilotodes in the root crown decreases a little from branching period to budding period. The dissolubility sugar content increases and the dissolubility protein content continues decreasing from flowering period to podding period, but the extent of increase and decrease is much little. The dissolubility sugar content and the dissolubility protein content rapidly increases from pod maturity period to overwintering before , which is the ability of increased plant overwintering and the exhibition of improving cold resistance.4,The exterior of root system of Melilotodes in adult period mostly covers a flat thick"velamen"in the course of growth and development. The polysaccharide in the interior of root system lies in secondary phloem and secondary xylem and xylem ray ,which distributes uniformity. The exterior of root system of alfalfa in adult period hasn't velamen. The polysaccharide in the interior of root system lies in partial secondary phloem and xylem ray of secondary xylem, which doesn't distribute uniformity. This is a kind of morphological characteristic that Melilotodes adapts cold.5,Based on American Barnes(1991) method to confirm the fall dormancy, the fall dormancy of Melilotodes is ranked grade1.