基于GGE-biplot的大豆根瘤菌抗逆性资源筛选

为了准确评价大豆根瘤菌在干旱及酸碱环境中的稳定性和适应性,采用GGE双标图对黑龙江省不同生态区分离、鉴定、纯化的7个大豆根瘤菌菌株分别进行耐旱性、耐酸碱性能力分析评价。结果表明:各供试菌株随着PEG6000浓度的增加,菌株生长量均呈现逐渐下降的趋势。GGE双标图分析表明,耐旱性强且稳定性较好的菌株为111-1;供试菌株在耐酸碱性上均有较大优势,菌株在pH3.0和pH12.0的环境条件下均能缓慢生长,并且均在pH9.0的环境条件下生长量最大。GGE双标图分析得出,耐酸性强且稳定性较好的菌株为112-2,耐碱性强且稳定性较好的菌株为111-3。该结果对适于黑龙江地区不同环境条件下大豆根瘤菌的应用具有重要的指导意义。     

哈茨木霉T2-16发酵产物对豇豆土著根瘤菌的多样性及其抗逆性影响的研究

研究了哈茨木霉T2-16在改良后的GPF培养基中培养所获得的发酵产物,对豇豆根瘤菌菌株耐逆性及对抗生素抗性等多个表型性状的影响。结果表明,经该发酵产物处理后,供试的一些根瘤菌菌株的耐高温、耐盐碱能力有所提高,对一些抗生素的抗性也有一定的增加,显示了木霉发酵产物在提高土著根瘤菌固氮活性方面的潜能。     

豆科树种根瘤菌共生体系研究进展

本文根据国内外有关豆科树种根瘤菌共生固氮研究现状,结合作者几年来的工作,对豆科树种的结瘤情况进行综述;对绝大多数苏木亚科树种既不结瘤,又不固氮的原因,以及豆科树种根瘤菌的分类地位和这一共生体系的其他性状,也进行了扼要的评述。     

Cultivar × rhizobial strain interactions in peas with respect to early symbiosis, nodule initiation and N uptake

Sixteen pea cultivars differing in their phenotypic characteristics were studied in order to characterize the cultivars' variability in symbiotic characters using three Rhizobium leguminosarum biovar viceae strains. The peas did not show any cultivar × strain interactions with the rhizobial strains used with respect to root hair infection frequency or day of nodule initiation. Three cultivars had high root hair infection frequencies, and five had only a few infected root hairs. Four of five leafless/semi-leafless varieties investigated and one cultivar with normal leaves formed nodules quickly, whereas three varieties with normal leaves formed nodules slowly. Ten of the cultivars showed cultivar × strain interactions with respect to N uptake, indicating that the performance of the N2-fixing symbioses depends on the rhizobial partner. Six cultivars showed cultivar × strain interactions with respect to dry matter production and the nodule proportion of the dry matter. Of the cultivars investigated, we conclude that some of the leafless/semi-leafless varieties (‘Capella’, ‘Filby’ and ‘Solara’) are suitable for inclusion in a future breeding programme, since these cultivars combined several important symbiotic characters.     

Nodulation Status and Nitrogenase Activity of Some Legume Tree Species in Bangladesh

Summary

A study was conducted to observe the nodulation status and measure nitrogenase activity of some important legume tree species in nursery. Of the thirteen species surveyed eight belong to Mimoceae, two Papilionaceae and three Caesalpiniaceae. All the species in Mimo-ceae and Papilionaceae were found nodulated whereas all the members of Caesalpiniaceae were non-nodulated. Among nodulated seedlings, highest number of nodules per seedling was recorded in Leucaena leucocephala (82) followed by Acacia auriculiformis (55), Acacia mangium (52), Albizia lebbeck (46), A. procera (41), Dalbergia sissoo (32) and Acacia catechu (29). Nitrogenase activity was highest in L. leucocephla (4913.59 nmole C₂H₄ h^?1) followed by Albizia procera (2080 nmole C₂H₄ h^?1). Seedling height, nodule fresh weight, root fresh weight and nitrogenase activity (per nodule per h, per gram nodule fresh weight per h, per gram root fresh weight per h and per gram root dry weight per h) were also highest in L. leucocephala.     

不同生态区若干典型作物土壤中紫花苜蓿土著根瘤菌分布状况

采用根瘤菌接种技术可以保证苜蓿成功建植、提高苜蓿产量和改善苜蓿品质,有关效果受施用区土著茵影响较大。应用MPN法对我国多种土壤进行苜蓿土著菌分布状况研究,结果表明：除个别土壤外,苜蓿土著菌数量为30～3OOO个／g;黄土高原典型作物土壤中根瘤菌数量为2.5万～45万个／g。可见,在典型作物地土壤及有关土壤类型区,土著菌数量较低,根瘤菌接种技术是此类地区发展苜蓿种植的重要技术。     

我国部分地区土壤杆菌的数值分类及DNA同源性分析

 本研究对我国42株土壤杆菌待测菌株和28株参比菌进行了数值分类和DNA同源性分析,结果将41株土壤杆菌与2株根瘤菌分在3个土壤杆菌种内,其中23株来自内蒙等地葡萄的菌株分在葡萄土壤杆菌种内,10株来自山东等地樱桃、桃树的菌株为发根土壤杆菌,8株来自4个地区4种植物的菌株及分自宁夏刺果甘草的2株根瘤菌菌株参比菌分在根癌土壤杆菌种内。1株土壤杆菌和1株根瘤菌的分类地位有待进一步研究。     

新疆根瘤菌抗逆性研究

利用根瘤菌-豆科植物共生体固氮是我国农业的传统经验,也是现代农业体系中维持土壤碳氮平衡的一个重要环节,培肥改土的有效途径。然而,根瘤菌-豆科植物共生体只是“固氮潜力”,并不能代表固氮能力。就根瘤菌来说,它的活动还要受到周围环境的影响,所以开发逆性环境中的根瘤菌资源并研究其抗逆特性是提高根瘤菌-豆科植物共生体固氮能力的关键。新疆干旱区环境特殊,豆科植物在农牧业生产、药材生产、土壤改良、防风固沙中起着重要作用,我们从1983年开始,对新疆境内不同生态环境中的根瘤菌资源进行了比较全面的     

Effect of salt stress on interaction between lentil (Lens culinaris) genotypes and Rhizobium spp. strains: symbiotic N2 fixation in normal and sodic soils

 Following screening, selection, characterization and examination of their symbiotic N₂ fixation, only two Rhizobium strains (ND-16 and TAL-1860) and four lentil genotypes (DLG-103, LC-50, LC-53 and Sehore 74-3) were found to be suited to sodic soils. Interactions between salt-tolerant lentil genotypes and Rhizobium strains were found to be significant, and resulted in greater nodulation, N₂ fixation (nitrogenase activity), total nitrogen, plant height, root length and grain yield in sodic soils under field conditions compared to uninoculated controls. Significantly more nodulation, nitrogenase activity, glutamine synthetase (GS) and NADH-dependent glutamate synthase (NADH-GOGAT) activities were found in normal soil as compared to the soil supplemented with 4% and 8% NaCl. Salt stress inhibited nitrogenase, GS and NADH-GOGAT activities. However, nitrogenase activity in nodules was more sensitive to salt stress than GS and NADH-GOGAT activities (NH₄ ⁺ assimilation). The relevance of these findings for salt-tolerant symbionts is discussed. Received: 14 November 1997     

Efficiency of N2 fixation in Vicia faba L. in combination with different Rhizobium leguminosarum strains

The efficiency of symbiotic dinitrogen (N₂) fixation in Vicia faba L. in combination with 3 different Rhizobium leguminosarum strains was studied in a pot experiment during vegetative and reproductive growth. The objective of the experiments was to assess variability among Rhizobium strains inoculated on single legume species and determine possible reasons for observed variations. Dry matter formation, N₂ fixation and the carbon (C) costs of N₂ fixation were determined in comparison with nodule free plants grown with urea. Nodule number and the capacity of different respiratory chains in the nodules were also measured. The plants inoculated with the Rhizobium strain A 37 formed less dry matter and fixed less N compared to the other two Rhizobium strains (Vic 1 and A 150). This coincided with a lower number of nodules and higher C costs of N₂ fixation. The C costs for N₂ fixation were in all cases significantly lower during reproductive growth compared to vegetative growth. Neither the latter nor the differences in C expenditure for N₂ fixation between the Rhizobium strains could be explained in terms of differences or shifts in the capacity of different respiratory chains in the nodules.