生长调节剂及增产菌对稻田异养固氮的影响

The influence of Growth Reculator and YieldIncreasing Bacteria to the Heterotrophic Nitrogen Fixing in the Paddy Field

用赤霉素(GA_3)、多效唑(MET)、增产菌处理稻田及分离培养的固氮菌,观察了三者对乙炔还原活性(ARA)的影响。田间处理12g·hm^(-2)GA_3后1个月内,稻株茎基部、根系及根际土 ARA 均被提高。处理450ghm^(-2)MAT 后1个月内,茎基部 ARA 受抑,根系及根际土ARA 受促进。GA_3及 MET 处理后过1个月,各部位 ARA 逐渐接近对照。增产菌田间处理后,根系 ARA 先被促进,处理后约20天又下降,低于对照。根际土 ARA 处理后1个月内也被促进,随后接近对照。对分离培养的固氮处管时,MET 显著促进其 ARA(约5倍),GA_3微弱促进(约30%),增产菌则无促进作用。GA_3及 MET 对分离培养的固氮菌 ARA 的抑制浓度为80mg·kg^(-1)和2500mg·kg^(-1)远高于田间处理浓度。比较 GA_3、MET、增产菌对田间处理与分离培养菌处理结果认为三者对稻株 ARA 的影响是通过影响稻株代谢而起作用的。

To treat the paddy field and the isolated cultured nitrogen fixing bacteria with gibberellin(GA_3),MET and yield--increasing bacteria,the infl- uence of these three agents to the acetylene reduction activity (ARA) were observed.Within one month after the field treatment with 12g·hm^(-2) of GA,. The ARA of rice stem base,root system and rhizosphere soil were raised. Within one month after the treatment with 450g·hm^(-2) MET,the ARA of the stem base were inhited,and the ARA of the root system and the rhizosphe- re soil were improved.One month after the treatment with GA_s and MET,the ARA of each position gradually approached to that of check group.To treat the isolated and cultured nitrogen fixing bacteria,MET promoted obviously the ARA (about five—fold),GA_3 promoted slightly the ARA (about 30%) and the yield—increasing bacteria had no promotive on action.The inhibitory conc- entrations of GA_3 and MET to ARA of the isolated and cultured nitrogen fixing bacteria were 80 ppm and 2500ppm that was far higher than the treated concent- ration in the field.Commared the results of GAs,MET,and YIB to the field treatment and isolated and cultured bacteria treatment,we considered that the influence of all these three informations to the rice ARA is through the action of their influence to the metabolism of rice.