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在荒漠草原采用两因素完全随机区组设计,分析了不同载畜率下降水变化对植物物种多样性的影响。结果表明:(1)低载畜率放牧下增加50%的降水植物物种数最多,增加100%的降水反而降低了植物物种的多样性。(2)在低载畜率放牧下,减少50%降水Shannon-wiener指数显著低于自然降水、增加50%、100%降水(P0.05)。(3)中载畜率处理下,Margalef指数在减少50%降水下显著低于其他3个降水处理(P0.05)。(4)Pielou指数在中、高载畜率放牧处理下,减少50%降水显著低于增加50%降水(P0.05)。由上述结果可知,在中等载畜率放牧下减少降水有降低植物物种多样性的趋势。 相似文献
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通过Rusitec-s体外发酵系统研究不同粒度猫尾草对羔羊体外发酵参数与微生物数量的影响,选取6种不同粒度(1.00、2.36、3.35、4.75、8.00和12.50 mm)的猫尾草作为试验饲粮的纤维来源,按照猫尾草的粒度将试验分为6个处理组,每个处理4个重复,利用Rusitec-s型人工瘤胃模拟装置进行48 h体外发酵,测定养分降解率、发酵参数及发酵液中6种微生物菌群的拷贝数。结果表明:与其他处理组相比,2.36 mm组显著提高了体外中性洗涤纤维降解率(IVNDFD)、丁酸、异丁酸、戊酸、异戊酸摩尔比和溶纤维丁酸弧菌(B. f)数量(P<0.05),且显著降低总产甲烷菌(TMe)数量(P<0.05)。总菌(TB)与氨态氮(NH3-N)浓度、乙酸摩尔比呈正相关(R2=0.84,P=0.038;R2=0.88,P=0.021);B. f数量与丙酸摩尔比呈正相关(R2=0.82,P=0.045),且与pH呈负相关(R2=-0.98,P=0.001);TMe数量与体外粗蛋白质降解率(IVCP... 相似文献
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荧光假单胞菌岩藻多糖酶的生产和酶学性质研究 总被引:1,自引:1,他引:0
[目的]研究了荧光假单胞菌HNTO1液态发酵产岩藻多糖酶的条件,并对酶学性质进行初步探索。[方法]采用单因子试验。[结果]HNT01产酶的最适培养基组成为:海带粉2%、尿素2%、葡萄糖0.06%、磷酸氢二钾0.1%,发酵起始pH值6.0,250 ml三角瓶装液量为100 ml,30℃、160 r/min条件下培养76 h。该菌所产岩藻多糖酶最适反应温度为50℃,最适反应pH值为6.0。[结论]为进一步开发高附加值的褐藻类保健食品和医药产品提供必要的科学基础。 相似文献
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奶牛业产业化,是在建立社会主义市场经济体制过程中,畜牧业经营体制上的创新,也是建设发达的现代化奶牛业长期的战略举措。内蒙古呼伦贝尔盟按照产业化思路,大力发展奶牛业,初步形成了市场牵龙头,龙头带基地,基地连农户,服务一体化的奶牛产业化发展格局.1996年乳品加工业产值18297万元,年末良种及改良种乳用牛存栏289848头,其中可繁母牛占43%,鲜奶总产量19.48万吨,比上年分别增长52%、3.6%和7.1%。一、奶牛业产业化是实现奶牛业现代化的必由之路纵观世界发达国家奶业的发展过程,所走的都是产业化发展道路。其共同特点… 相似文献
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Four common inducers, salicylic acid (SA), 1-aminocyclopropane-1-carboxylic acid (ACC), benzothiadiazole (BTH) and methyl jasmonate (MeJA), were selected to evaluate the effects of inducers on the resistance of adzuki bean to rust by investigating urediospores germination and the adzuki bean resistance to Uromyces vignae. The results showed that four inducers had no effects on the urediospores germination. However, they can significantly induce adzuki bean resistance to U. vignae. Among these four inducers, 0.25 mg·mL-1 ACC can significantly reduce the disease index, which was 45.06% lower than the control. Aditionally, seedlings treated with ACC exhibited a typical "triple reaction", which indicated that this induced resistance may relate with the endogenous ethylene biosynthesis in adzuki bean. Then the adzuki bean seedlings were treated with an ethylene receptor inhibitor, 1-methylcyclopropene (1-MCP) alone or combined with ACC. The results showed that 1-MCP alone had no significant effect on the growth and rust resistance of adzuki bean. However, 1-MCP could eliminate the "triple reaction" and did not affect the induced resistance caused by ACC when it used combined with ACC. Results obtained in current study suggested that ACC can significantly induce the resistance of adzuki bean to the rust. Moreover, we speculate that ACC-induced rust resistance of adzuki bean may not depend on ethylene signaling pathway. 相似文献