嫁接不同文冠果品种根际土壤的微生物生物量及酶活性

文冠果是重要的园林绿化和生物质能源植物,但大多处于野生和半野生状态,且产量较低。嫁接不仅可提高植物的产量、改良植物抗逆性能性状,也可影响根际土壤性质。目前对文冠果的大量研究主要集中在嫁接技术方面,但嫁接对土壤性质的影响鲜有报道。为探讨嫁接对土壤生物学性质变化的影响,比较了文冠果嫁接和未嫁接处理后根际土壤微生物生物量及酶活性的变化。在嫁接处理中,以北京昌平文冠果做砧木,分别采用辽宁阜新白花古树(LFB)、辽宁建平白花古树(LJB)、内蒙古赤峰红花古树(NCH)和内蒙古实生红花苗(NSH)4种不同品种的接穗进行嫁接。结果表明,与未嫁接的北京昌平文冠果(CK)相比,嫁接LFB、LJB、NCH和NSH 接穗1年后根际土壤的微生物生物量碳分别显著提高了62%、45%、91%和40%;而嫁接NCH、LFB和NSH的根际土壤微生物生物量氮比未嫁接的CK分别提高了140%、107%和56%。采用LFB和NCH嫁接可显著提高β-糖苷酶、几丁质酶、亮氨酸氨基肽酶和磷酸酶的活性,但显著降低了酚氧化酶的活性。β-糖苷酶、几丁质酶和亮氨酸肽酶活性的变化与微生物生物量、土壤溶解性有机碳和有机氮溶解性呈显著正相关。综合来看,采用辽宁阜新白花和内蒙古赤峰红花古树接穗嫁接北京昌平文冠果有利于根际土壤微生物生物量及酶活性的提高。 

Microbial biomass and enzyme activity of the ;rhizosphere soil under different grafted Xanthoceras sorbifolia cultivars

Xanthoceras sorbifolia is an important plant species for landscaping and energy use, but mostly grown in wild or semi-wild environment with low yield. Grafting can enhance crop yield and improve stress tolerance properties, and can also influence rhizosphere soil properties. Although lots of grafting techniques in X. sorbifolia have been reported so far, the impacts of grafting on soil properties have not been well documented. In order to understand whether grafting could improve soil biological properties or not, we assessed microbial biomasses and enzyme activities of rhizosphere soils under non-grafting and grafting treatments. X. sorbifolia scions of four different cultivars, i. e. wild white flower cultivar from Fuxin ( LFB) , Liaoning Province of northeastern China;wild white flower cultivar from Jianping ( LJB) , Liaoning Province;wild red flower cultivar from Chifeng ( NCH) , Inner Mongolia of northern China;and planted red flower seedling ( NSH) from Inner Mongolia were grafted onto X. sorbifolia rootstock from Changping, Beijing, respectively. Compared with the non-grafted ( CK) cultivar, the microbial biomass C of the rhizosphere soils under LFB, LJB, NCH and NSH were significantly increased by 62%,45%, 91% and 40%, whereas the microbial biomass N of the rhizosphere soils under NCH, LFB and NSH were significantly increased by 140%, 107% and 56%, respectively. In contrast with CK, the activities of β-glucosidase, glucosaminidase, leucine amino peptidase and phosphatases of rhizosphere soils under NCH, LFB and NSH were significantly increased, whereas the activity of phenol oxidase was markedly decreased. A significantly positive relationship was observed between the change of activities of glucosidase, glucosaminidase as well as leucine amino peptidase and microbial biomass, dissolved soil carbon and dissolved organic soil nitrogen. In summary, the white-flowered scions from Fuxin, Liaoning and red-flowered ones from Chifeng, Inner Mongolia grafted onto the rootstock from Changping, Beijing could improve microbial biomass and enzyme activities of rhizosphere soils.