Study On The Dynamic Of The Endogenesis Hormone Content For Root Of Different Fall Dormancy Alfalfa Cultivars

7 imported alfalfa varieties were studied in this report which belonged to 2,4,6,8 fall dormancy respectively. Using high-performance liquid chromatography (HPLC) determined the change of the endogenesis hormone, which contained GA3, IAA and ABA, in the alfalfa stem during of the cutting rootage process and the roots within the reviving, regeneration, dormancy process of different fall dormancy alfalfa varieties. This study provides a theoretical basis for exploring that endogenous hormones control the process of plant metabolism, growth and development. and how to properly use measures of growth substance.The result indicated:1. In alfalfa stem segments cutting during the rooting process, the peak of IAA content is consistent with the root primordium's; low level of GA3 content and a certain concentration in the ABA are impact to the formation of adventitious root. Under the conditions of temperature in 25℃and humidity 70 percent , there is no significant correlation between hormone changes and autumn dormancy in the rooting process of alfalfa stem segments cutting2. The revive process: the endogenesis hormone in the alfalfa varieties of the same level fall dormancy showed the consistent variety trend, whereas in that of the different level showed obvious difference. With a higher and a lower fall dormancy, the root GA3 contents were higher and lower according to the level of fall dormancy before the reviving. However, opposite to GA3, ABA content was higher in the lower fall dormancy varieties. IAA content in non- and semi-fall dormancy varieties was higher than fall dormancy varieties. ABA content in the roots of fall dormancy varieties consistently maintained a relative high level which was obviously higher than that of the non- and semi-fall dormancy varieties. GA3 content had double waves which obviously varied in short terms in the high level fall dormancy varieties. IAA content descended no matter what the level of the fall dormancy was.3. In the regeneration process, GA3 is the mainly endogenous hormone related by the fall dormancy of alfalfa. Before mowing alfalfa, GA3 content in the Cutting roots and the type of fall dormancy have no relevance. But after that, GA3 content in the Cutting roots is FD8≥FD6≥FD4≥FD2. Mowing three days later, GA3 content in the Cutting roots of non-fall and semi-fall dormancy are signific higher than of autumn varieties. IAA content have no relevance with fall dormancy. ABA content only in non-fall dormancy super-R13 and semi-fall dormancy Victoria were smaller than other varieties, in which without a significant difference..4. In the dormancy process, GA3 content in the Cutting roots is in a declining trend, at same time IAA and ABA is in an upward trend. When the daily minimum temperature between 0℃and 5℃time, the levels and changes of endogenous hormone have nothing to do with fall dormancy. However when the daily minimum temperature is below freezing point, GA3 content decrease extent in fall dormancy varieties is obviously larger than a semi- and non-fall dormancy variety, whereas ABA content increase extent in fall dormancy varieties is in the same way; IAA content change have no relevance with fall dormancy...