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Investigation of white clover ecotypes showing high nitrogenase activity under an abundant nitrogen and applying them to mixed grassland.

富氮条件下高固氮酶活性白三叶草生态型的调查及其在混合草地上的应用

基本信息

批准号：
63560251
负责人：
SUGAWARA Kazuo
金额：
$ 1.02万
依托单位：
TOHOKU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1988
资助国家：
日本
起止时间：
1988 至 1989
项目状态：
已结题

项目摘要

(1). Ninety eight of white clover ecotypes were mainly collected from Tohoku district in Japan. The variations of some characteristics were identified among the collected white clovers.(2). From variation pattern of nitrogenase activity after an application of nitrogen fertilizer, white clovers were grouped into 5 types, i.e., 0 type; no decrease of activity, AA type: quick decrease and quick recovery, AB type: quick decrease and slow recovery, BA type: slow decrease and quick recovery, and BB type: slow decrease and slow recovery. Thus, the response of nitrogenase activity to the nitrogen application differs among white clovers.(3). The peroxidase isozyme of white clover appears in 6 bands. White clovers collected were grouped into a,b,c,d type by the different pattern of bands. The d type of isozyme pattern was closely related to 0 type of nitrogenase activity.(4). In the mixed grassland, white clover and orchard grass, the inhibition of nitrogenase activity after nitrogen application was reduced compared with white clover grassland. This is assumed as the result of the absorption of nitrate nitrogen in soil by grass species.(5). Under field condition, white clover shows the three peaks of nitrogenase activity in the year, May, July and September to October. The pattern of the seasonal variation of activity did not show significant correlation with mean temperature, sunshine hours and precipitation and N% in soil.(6). From the mentioned above, there are white clover ecotypes showing high nitrogenase activity under an abundant nitrogen and 14 of the ecotypes like that were collected in this investigation, and the nitrogenase activity of white clover will be kept higher by the improvement of nitrogen circumstance in soil with mixing culture with grass species.

（一）.白色三叶草生态型98个，主要采自日本东北地区。对采集的白色三叶草进行了部分性状的变异鉴定。（二）、根据施氮后固氮酶活性的变化规律，将白色三叶草分为5种类型，0型; AA型：下降快，恢复快，AB型：下降快，恢复慢，BA型：下降慢，恢复快，BB型：下降慢，恢复慢。因此，不同白色三叶草的固氮酶活性对施氮量的反应不同。（三）、白色三叶草的过氧化物酶同工酶有6条带。收集的白色三叶草根据带型的不同分为a、B、c、d型。d型同功酶谱与0型固氮酶活性关系密切。（四）、在白色三叶草和果园混播草地中，施氮后对固氮酶活性的抑制作用较白色三叶草草地有所减轻。这被认为是草吸收土壤中硝酸盐氮的结果。（五）、在田间条件下，白色三叶草的固氮酶活性在一年中的5月、7月和9 ~ 10月有三个高峰。活性的季节变化与平均气温、日照时数、降水量和土壤氮含量的相关性不显著。（六）、由此可见，白色三叶草在氮素充足的条件下表现出较高的固氮酶活性，本研究共收集到14个与之相似的生态型，通过与草种混栽改善土壤氮素环境，可使白色三叶草保持较高的固氮酶活性。