| Ziziphus jujuba Mill. is a typical combination of economic and ornamental fruit trees, belongs to Rhamnaceae. Though it has a broad prospect for development and production requirements, its seedling production still lags behind demand. Cuttage as a kind of simple, efficient and economical asexual reproduction technology which is suitable for mass production. The rooting experiments on softwood cuttings of Z. jujuba Mill. as the plant materials were treated by the different exogenous hormones, simultaneously carried on the fumble to the cuttage technology pattern, and took root the mechanism to its cuttage to conduct the research. The main results are as follows:(1) Cutting propagation experiments showed that both cuttings of secondary and bearing shoots, the main influential factor was exogenous hormone type on softwood cutting. The best root growth promoting agent was IBA+NAA(1:1), IB A followed, and NAA was the poorest. Concentration effect was significant on softwood cutting, but far less than hormone type, the rooting effect of adopting "IBA+NAA (1:1) with 500mg/L" is the best, and the rooting effect of adopting "IBA or NAA with 1500mg/L" is the better. The treatment time had a little bit of influence with rooting of softwood cutting, in particular, dipping time of 5-30s had a better rate than delaying treatment time. Experiments showed that secondary shoots cuttings’ rooting effect was better than other cuttings’. Therefore, under this experimental condition, the rooting effect was the best which used the softwood cuttings of secondary shoots as the plant materials and IBA+NAA (1:1) to dip time of 5-30s with 500mg/L as the hormones. The high rooting rate reached to 91.1%, the average number of roots was reached to 5.38, the average length and width of roots was reached to 36.06mm and 1.27mm.(2) Regularly the morphological changes observed that Z. jujuba Mill, root belong to rooting types of callus in cut surface was primary and in the cortex was secondary; The cuttings can be divided into five periods: "visible early callus", "callus formation", "callus swelled and adventitious root formation"," callus rooting "," root elongation".(3) By studying the dynamic changes of the nutrient content in different parts of Z. jujuba Mill. cuttings with exogenous hormone treatments, it was found that the correlation between the consumption of soluble sugar and protein appears to be positive with rooting rate. It could accelerate the process of nutrient metabolism and ensure the rooting quality with different hormone treatments, they had the same tendency during rooting, and the peak valley was appeared in callus formation, and the rooting effect of adopting "IBA+NAA (1:1) with 500mg/L" is the best. Leaf apex and leaf base can also be affected the phloem of nutrients in the period of adventitious root formation, especially the activities of leaf apex, leaf apex are viewed as a major venue for producing soluble sugar to promote the formation of callus and adventitious roots to some extent.(4) By studying the dynamic changes of the endogenous hormones in different parts of Z. Jujuba Mill. cuttings with exogenous hormone treatments, it was found that the correlation between the content of IAA and IAA/ABA appears to be positive, however, contents of the ABA, ZR, GA have a negative correlation with rooting rate in the phloem of cuttings. Different exogenous hormones could increase the contents of IAA, IAA/ABA, and decrease the contents of ABA, ZR and GA during the rooting. All of them were good for developing adventitious roots, and the rooting effect of adopting "IBA+NAA (1:1) with 500mg/L" is the best. Leaf apex and leaf base can also be affected the phloem of endogenous hormones in the period of adventitious root formation, especially the activities of leaf apex, leaf apex are viewed as a major venue for producing IAA, GA to regulate the balance of adventitious roots with phloem to some extent. |
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