茄子根际拮抗细菌的筛选鉴定及培养条件研究

【作者】 孙琛琛；

【导师】 杨峰山； 杜秉海；

【作者基本信息】 黑龙江大学 ， 微生物学， 2008， 硕士

【摘要】 茄子是人们喜爱而又熟悉的农作物之一,在全国拥有很大的种植面积,但近年来茄子病害的发生严重的影响了茄子的产量及质量,同时也造成了极大的经济损失。目前采取的防治措施主要依靠化学农药,但长期施用化学农药必将对环境造成污染。因此,生物防治在茄子的病害防治中就显得尤为重要。本实验筛得的拮抗细菌可以有效对抗几种茄子病害。从济宁接庄试验田健康茄子植株根际土壤中分离细菌,用平板对峙法经过初筛和复筛得到33株对茄子3种病原菌(茄子灰霉病,茄子枯叶病I,茄子枯叶病II)均有拮抗效果的细菌。根据这33株细菌抑菌效果的明显程度结合抑菌圈直径以及拮抗作用的稳定性、遗传性,最后保留3株拮抗菌。通过传统的形态学观察,生理生化鉴定及16S rDNA序列测序,将所测结果与EMBL/ BankIT/ DDBJ资料库中相关模式菌株的16S rDNA全序列进行聚类比较,得到系统发育树状图,综合鉴定结果为:Q47(1)、Q69为枯草芽孢杆菌,Q17(2)为短小芽孢杆菌。其中菌株Q47(1)的综合拮抗效果极其明显且作用稳定,并且它的抑菌谱非常广,可对除三种供试病原菌外的数10种植物病原菌均有极强的抑制作用,抑菌直径平均在10mm左右,是一株真正的具有广谱抑菌性质的优良拮抗菌,因此对Q47(1)的培养条件进行了初步研究。通过对Q47(1)的培养条件的研究表明:32℃,pH=7,持续光照、震荡培养72h为最适培养条件,此时菌体有最大生长量,通过研究其最适生长条件也为今后的发酵工作打下基础,提供有利依据。更多还原

【Abstract】 Eggplant is one of a favorite and familiar crops with people. It has a lot of area under cultivation in our country,but in recent years eggplant’s serious diseases has impacted it’s yield and quality ,also caused great economic losses. Therefore, we must take effective measures to carry out prevention. Control measures are being taken mainly rely on chemical pesticides,but the long-term application of pesticides on the environment will cause pollution. So,the biological control of disease on eggplant is particularly important. This experiment has screened antagonistic bacteria ,also they can make strong effect against several eggplant’s disease.Isolated bacteria from healthy eggplant’s rhizosphere soil of JiNing Jie village, with the preliminary-screening and again-screening of flat-screen , thirty-three stains remained,they have antagonistic effects against three kinds of eggplant’s pathogens (Botrytis cinerea、Alternaria spp. I、Alternaria spp. II). With inhibitory effect of the significant degree and the stability ,genetic factors ,finally three antagonistic bacteria was left. Through orthodox morphology characteristics,the physiocal and chemical experiments and 16S rDNA sequence identified ,take the results measured with model strain’s 16S rDNA sequence from EMBL / BankIT / DDBJ. Obtained develop-tree. The identification result is Q47 (1), Q69 was Bacillus subtilis, Q17 (2) was Brevibacillus pumilus.One strain Q47 (1), the integrated effect of antagonistic role is extremely clear and stable, and it’s a very wide spectrum of antimicrobial, it can antagonize three supplied pathogenic bacteria , also can antagonize several other plants’pathogenic bacteria , antagonistic-rings can achieve more than ten millimeters average. It’s a genuine antagoristic bacteria which has broad bacteriostasis. Thus, following research is intensive for it’s preliminary culture condition. The research of culture condition about strain Q47(1) indicates us : 32℃,pH=7, keep on illuminating ,shake culture seveny-two hours is the optimal culture condition,in this period the strain has the largest yield . The research of optimal culture condition can provide advantageous accord and also make foundations for ulterior ferment works .更多还原