【作者】 李霞；

【导师】 马永清；

【作者基本信息】 西北农林科技大学 ， 植物营养学， 2009， 硕士

【摘要】 本文在荒漠肉苁蓉的寄主梭梭苗龄、初植密度、肉苁蓉接种方式、立地条件以及水肥管理等完全一致的试验地内,对寄生和未寄生肉苁蓉的梭梭幼苗生长情况进行了连续定位观测,同时测定其生理指标,系统地研究了肉苁蓉寄生对寄主梭梭苗生长及生理特性的影响。本研究取得如下主要结果:1、不同植物生长调节剂处理对梭梭幼苗移栽成活率及肉苁蓉寄生情况的影响不同,其中用PDJ处理梭梭幼苗后,在梭梭接种成活率以及肉苁蓉寄生率、寄生数目、肉苁蓉大小等各方面都有促进作用,但对于提高梭梭幼苗移栽成活率无显著影响。而生根粉的处理对提高梭梭接种成活率有促进作用,但对肉苁蓉寄生有抑制作用。运用主成分分析的方法可得出PDJ处理的综合效果最好,其中高浓度PDJ处理效果较低浓度好,而生根粉的综合效果不及对照处理。因此可采用PDJ浸根的方法提高梭梭幼苗成活率及肉苁蓉寄生率。2、肉苁蓉寄生后,梭梭同化枝的绝对含水量及相对含水量均较未寄生梭梭的减小,且叶片保水力降低,而水分饱和亏较大。寄生肉苁蓉后,梭梭的蒸腾速率较未寄生的梭梭有所下降,寄生肉苁蓉的梭梭,树高、地径、冠幅及其新生枝生长量,普遍小于同时期未寄生肉苁蓉的梭梭。3、寄生和未寄生肉苁蓉的梭梭幼苗在测定时期内3种保护酶活性的变化趋势均为先升后降,而寄生肉苁蓉梭梭的保护酶活性在前期大于未寄生的梭梭。梭梭在被肉苁蓉寄生后,MDA含量显著增加,且梭梭体内的主要渗透调节物质可溶性蛋白质及脯氨酸含量均有不同程度的升高。寄生给寄主梭梭造成了胁迫的环境,对寄主保护酶系统及渗透调节系统产生了明显的伤害,并降低了寄主梭梭的抗旱性。4、肉苁蓉寄生后,寄主梭梭同化枝的氮元素含量显著低于未寄生的梭梭,磷元素和钾元素含量均高于未寄生的梭梭,但二者之间无显著差异。说明肉苁蓉的大量吸收氮素,直接导致了寄主梭梭体内氮元素含量的降低。肉苁蓉寄生后,梭梭同化枝磷、钾含量的提高,有助于提高梭梭同化枝的保水力,增强其抗逆性。寄生肉苁蓉梭梭的钙含量变化幅度较未寄生梭梭的大,且前者钙含量较后者稍低,寄生肉苁蓉的梭梭同化枝中镁含量显著高于未寄生梭梭。寄生和未寄生肉苁蓉梭梭同化枝内的锰、铜、锌含量间未有显著差异,铁含量存在显著差异,但寄生肉苁蓉梭梭同化枝中这四种微量元素含量均低于未寄生的梭梭。更多还原

【Abstract】 The growth situation of two kinds of Haloxylon ammodendron seedlings which were parasitized and unparasitized by Cistanche deserticola were studied under the experimental condition that seeding age, initial planting density, inoculation methods, site conditions and water management are fully consistent. The effect of C. deserticola parasitizing on the growth and physiological characters of H. ammodendron was measured based on the continuous located observation of growth and determination of physiological indicators. The main results of this experiment are as followed:1. Different plant growth regulators have different influence on the survival ratio of H. ammodendron and parasitic condition of C. deserticola. PDJ had promoting effect on the inoculating survival ratio of H. ammodendron and parasitic ratio, parasitic number and size of C. deserticola, while had no significant effect on the transplanting survival ratio. Rooting powder treatment can improve the inoculation survival ratio while had inhibition effect on the parasitism of C. deserticola. Principal component analysis shows that the comprehensive effect was the best with PDJ treatment, and high concentration PDJ has better effect than low concentration PDJ, while the rooting powder treatment was less effective than the control treatment. So rooting soaking with PDJ can be used to improve the surviving ratio of H. ammodendron seedling and parasitic ratio of C. deserticola.2. The tissue water content, relative water content and water retention capacity of H. ammodendron assimilating branches were decreased while the water saturation deficit was increased after parasitized by C. deserticola, which indicated that the parasitizing of C. deserticola lowered the drought-resistant ability of H. ammodendron. In addition the transpiration rate of H. ammodendron was decreased; it is possible that the parasitism of C. deserticola has influence on the stomatal regulation. The plant height, ground diameter and crown width were decreased after parasitized, the new branches growth was also reduced compared to the unparasitized H. ammodendron. Experimental results showed that the parasitizing of C. deserticola inhibited the growth of H. ammodendron, which may be caused by the excessive nutrient absorption of C. deserticola from the host plant.3. Three protective enzyme activities of both unparasitized and parasitized H. ammodendron assimilating branches firstly increased and then decreased during the whole determination period, and the protective enzyme activities of parasitized H. ammodendron were higher than the unparasitized plant in earlier stage. The content of MDA was significantly increased after parasitized by C. deserticola. In addition, the content of mainly osmotic adjustment substance such as soluble protein and free proline were increased in different degree while the soluble sugar content was decreased after parasitized. SOD and proline have high correlation with other indicators in the parasitized H. ammodendron, while there is less interaction in the physiological indicators of unparasitized H. ammodendron. The results showed that the stress and harmness environment was caused by the parasitizing of C. deserticola to the host plant, resulting in damage on protective enzyme system and osmotic adjustment system, and the parasitizing decreased the drought resistance of H. ammodendron too.4. The nitrogen content in assimilating branches of parasitized H. ammodendron was significantly lower than the unparasitized plant.While the phosphorus content and potassium content was higher after parasitized, without significant difference between them. The decrease of N content in H. ammodendron was directly caused by the absorption of large amount of N. The increase of P, K content in H. ammodendron will help to improve the water retention capacity and enhance the stress resistance. The change range of Ca content of parasitized H. ammodendron was bigger than the unparasitized, and the former was lower than the latter. The Mg content in assimilating branches of parasitized H. ammodendron was significantly higher than the unparasitized plant. No significant difference was found between the Mn, Cu, Zn content of parasitized and unparasitized H. ammodendron, and the Fe content between these two groups was significantly different. But these four trace elements content in the parasitized H. ammodendron were lower than the unparasitized plant.更多还原