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.

(1). 98种白三叶草生态型主要采集自日本东北地区。鉴定了采集的白三叶草的一些性状的变异。(2)．根据施氮肥后固氮酶活性的变化规律，将白三叶草分为5个类型，即0型；活性无下降，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，固氮酶活性对施氮的反应在白三叶草中是不同的。(3)。白三叶草的过氧化物酶同工酶出现6条带。收集的白三叶草按条带图案的不同分为a、b、c、d型。 d型同工酶谱与0型固氮酶活性密切相关。(4)．在白三叶草和果园草混交草地中，施氮后对固氮酶活性的抑制作用较白三叶草草地减轻。这被认为是草类吸收土壤中硝态氮的结果。(5)。田间条件下，白三叶草表现出一年中的三个固氮酶活性高峰，即5月、7月和9-10月。活动的季节变化格局与平均气温、日照时数、降水量和土壤N%没有表现出显着的相关性。(6)。综上所述，存在着在富氮条件下表现出高固氮酶活性的白三叶草生态型，本次调查收集了14个这样的生态型，通过土壤氮素环境的改善，白三叶草的固氮酶活性将保持较高。与草种混合培养。