人工诱导桑树绿枝扦插皮孔生根机理的研究

【作者】 杜伟；

【导师】 程嘉翎；

【作者基本信息】 江苏科技大学 ， 特种经济动物饲养， 2010， 硕士

【摘要】 桑树是家蚕能够顺利完成其世代的唯一饲料来源,是蚕丝业的重要物质基础。研究适应性广、成活率高的桑苗快速繁育技术,使不同生态的蚕区能够快速繁育适宜本地的优良桑树品种苗木,实现桑园真正意义上的良种化,降低栽桑成本,提高桑园的质量和产量具有重要的现实意义。本研究应用程嘉翎研究员的发明专利“一种苗木的立体育苗方法及其产品”(申请号:200710132106.7)的相关技术进行桑树绿枝扦插育苗试验,首次较为系统地对桑树绿枝扦插皮孔生根的新机理进行了探讨,以期为进一步提高桑树扦插繁殖的成活率提供技术和理论依据。主要研究结论如下:(1)桑树绿枝扦插生根过程的解剖学研究发现:本试验扦插育苗形成的根绝大多数为不定根,探明其诱生根原基组织学上的起源是维管形成层。扦插后9天左右,幼小不定根从皮孔处和切口上方顶破皮层2种方式伸出皮层外。比原先用常规的绿枝扦插方法的愈伤组织生根时间要缩短4天左右,且株平均生根量达到30～40条,提高了2倍以上。(2)插穗的选择和扦插的时期对桑树绿枝扦插生根极为重要。5个桑树品种扦插生根效果比较,育711的生根效果最好,生根率为91.1%,株平均生根数为49.1条,其次为湖桑32号、选792、大10,湘7920的生根效果最差。湖桑32号和育711不同部位插穗和不同长度插穗生根率和根系数量,均为中部>下部>上部,15 cm>18 cm>12 cm。育711于7月20日和8月10日两次扦插的效果最好,生根率均超过90%,9月1日扦插生根率也有74.5%,所以7～9月份可连续进行2～3次扦插育苗。(3)对桑树绿枝扦插生理学基础研究表明:在插穗生根的进程中,可溶性蛋白和可溶性总糖含量在前期都有明显的下降;其后随着新陈代谢的加快,含量又有不同程度的升高;在根的伸长生长期,可溶性蛋白和可溶性总糖含量再度降低。吲哚乙酸氧化酶(IAAO),多酚氧化酶(PPO),过氧化物酶(POD)与扦插生根有密切关系。IAAO,PPO,POD与桑树扦插生根有密切关系。IAAO和POD均能氧化IAA,使IAA含量降低,有利于根的诱导;而POD活性提高又增强了插穗的抗逆性,对插穗生根有利。生根后期IAAO和POD活性又不同程度的降低,有利于IAA含量的积累,促进根的生长。不同部位绿枝插穗扦插后PPO活性先下降,然后又呈现上升趋势。酚类物质含量在插穗生根阶段降低,说明酚是生根过程中必须的物质,生根需要消耗一定的酚类物质。各生理指标与生根率的相关关系,在不同品种间和同一品种枝条不同部位间表现不同,有待于进一步的研究。更多还原

【Abstract】 Mulberry is the only source of feed for domesticated silkworm, Bombyx mori to live on, and is also the important material basis for sericulture. Therefore, the study on wide adaptability and high survival rate of mulberry fast propagation technique has important practical significance. That is, different ecological zones of sericulture can quickly breed fine varieties of mulberry saplings which are suitable for local conditions, to achieve a real sense of the mulberry varieties, to reduce the costs of the planting of mulberry, and to improve the quality and yield of mulberry.In this study, related technologies of Prof. Jia-Ling Cheng patent "a method and its seedling nursery three-dimensional product" (Application No.: 200710132106.7) is used to carry out the softwood cutting propagation test of mulberry, and for the first time, the new mechanism of softwood cutting lenticels-derived rooting has been discussed in a more systematic way, with a view to provide technical and theoretical basis for further improvement of the survival rate of cutting propagation of mulberry.The main findings are as follows:(1)The anatomical study on the process of softwood cutting rooting of mulberry found that: in this study, the roots formed by cutting propagation are mostly adventitious roots, and its root primordium induced histological origins on the vascular cambium cells. About 9 days after cutting, young adventitious roots knock out the cortex in two ways--from the lenticels department and the incision at the top. Compared with the conventional methods of softwood cuttings roots initialed from callus, the time of periderm-derived rooting shortened about 4 days, and amount of roots per cutting reached 30 to 40, with increase of 2 times.(2) The selection of cuttings and cutting time are very important for softwood cutting rooting of mulberry. Here is the comparison of the rooting results of 5 mulberry varieties. The rooting effect of yu711 is the best, rooting rate is 91.1% and the amount of roots per cutting is 49.1, followed by husang32, xuan792, da10. Xiang7920 is the worst among them. The rooting rate and root number of cuttings of husang32 and yu711 in different parts and with different lengths are the central part>lower part >upper part, 15cm>18cm>12cm.Yu711 used as experimental materials, the effect of cutting is the best on July 20th and August 10th, rooting rate is more than 90%, and 74.5% on September 1st. Therefore, the cutting propagation can be done 2 ~ 3 times continuously from July to September. (3) The research on the physiological basis of softwood cutting of mulberry showed that: in the process of cutting rooting, the contents of soluble protein and soluble sugar have a significant decrease in the earlier stage. Later, with the metabolism speeding up, there are varying degrees of increasing; however, in the period of root elongation growth, the contents of soluble protein and soluble sugar reduced again. IAAO, POD and PPO have a close connection with the cutting rooting of mulberry. IAAO and POD can both oxidize IAA, and then lower the levels of it, which is good for root induction. Meanwhile, the improvement of the activity of POD has also strengthened the resistance of cuttings, which is beneficial for cutting rooting. During the later part of rootage, the activities of IAAO and POD are reduced to varying degrees, which is beneficial to the accumulation of the content of IAA, promoting root elongation. PPO activity in softwood cuttings of different parts of bough presented downward first and then an upward trend after cutting. The reduction of the content of phenols compounds during the stage of cutting rooting indicates that they’re the necessary material for rooting. The correlation between the physiological indicators and the rooting rate in different mulberry varieties and different parts of bough in same variety to show distinct, expected to further research.更多还原