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During significant time, the use of bean-rhizobial systems and development of effective, competitive microbial preparations have been an integral part of organic farming. Also, in intensive technologies, only due to such ones, it is possible without reducing the achieved level of agricultural production to reduce its cost, harmful effects on the environment and at the same time to achieve ecological purity of products selection of highly effective strains that have adapted to local soil and climatic conditions and acquired resistance to nutrients and plant protection is the most promising strategy to increase the effectiveness of microbial inoculants. The aim of this work was to select highly effective strains that have adapted to local soil and climatic conditions and have become resistant to nutrients and plant protection and are the most promising for improving the effectiveness of microbial inoculants. Field researches were conducted in the research fields of the Skvyra Research Station of Organic Production of the Institute of Agroecology and Environmental Management of NAAS (Ukraine, Kyiv region, Skvyra) during 2020–2021. Nitrogen-fixing activity of root nodules was determined by acetylene method. The gas mixture was analyzed on an «Agilent 6850 chromatograph». The paper presents the results of research to establish the effectiveness of new strains of inoculants on crops of legumes: soybean of Moravia variety and peas of Starter variety in the Kyiv region, Skvyra Research Station of Organic Production of the Institute of Agroecology and Environmental Management of NAAS. The significant effect of new rhizobia strains for inoculation of legumes on phenological indicators and yield of these crops in the conditions of intensive technologies was shown. The competitiveness of strains is controlled by both internal determinants — genotype of the microorganism, and external factors such as symbiont plant physiology, exposure to abiotic factors, tolerance to pesticides and agrochemicals used in crop production technologies. It has been shown that the use for inoculation of soybean strain B. japonicum EL 35 and for inoculation of peas strain R. leguminosarum bv. viciae PS 12 stimulate the development of plants during their growing season and allow to obtain symbiotic systems with a high level of nitrogen fixation, as a result of which we can increase the yield of legumes from 16 to 20%., Уже багато років застосування бобово-ризобіальних систем та розробка ефективних, конкурентоспроможних мікробних препаратів є невід’ємною частиною органічного землеробства. Бобові культури потребують багато азоту для утворення бульбочок та подальшого синтезу білків. Доступний азот у ґрунті можна отримати з добрив та результатів фіксації вільного азоту ризобіями. Бобові рослини здатні використовувати N2 з повітря у результаті симбіозу із бульбочковими бактеріями. Внесені органічні речо- вини також можуть бути використані бобовими рослинами як макроелементи незамін- ні для рослин, які ризобії використовують як джерело енергії. Метою цього дослідження було дослідити органічні добрива на основі симбіотичних бактерій, які впливають на ріст і врожайність сої та гороху. Польові випробування проводили на дослідних полях Сквирської дослідної станції органічного виробництва Інституту агроекології і при- родокористування НААН (Україна, Київська обл., м. Сквира) впродовж 2020–2021 рр. Культуру як швидкорослих бульбочкових бактерій R. leguminosarum bv. vicіae, так і повільнорослих бактерій B. japonicum вирощували на манітно-дріжджовому середо- вищі впродовж 7 діб при 26–28 °С. Азотофіксувальну активність кореневих бульбо- чок визначали ацетиленовим методом. У роботі наведено результати досліджень зі встановлення ефективності застосування нових штамів інокулянтів на посівах бобових культур сої сорту Моравія та гороху сорту Стартер в умовах Київської обл., Сквирської дослідної станції органічного виробництва Інституту агроекології і при- родокористування НААН. Було показано значний вплив нових штамів ризобій для іно- куляції бобових культур на фенологічні показники та врожайність цих культур в умовах інтенсивних технологій. Встановлено позитивний ефект використання цих штамів на посівах бобових в умовах інтенсивних технологій вирощування сільськогосподарських культур у Правобережному Лісостепу України. Продемонстровано, що інокуляція бобових штамами B. japonicum EL 35 та R. leguminosarum bv. vicіae PS 12 стимулює розвиток рослин упродовж їх вегетації та дає змогу отримати ефективні симбіотичні системи з високим рівнем азотофіксації, внаслідок якої можна одержати збільшення врожайності бобових культур від 16,2 до 20,4%.

Данная работа посвящена изучению устойчивости ÐºÐ»ÑƒÐ±ÐµÐ½ÑŒÐºÐ¾Ð²Ñ‹Ñ Ð±Ð°ÐºÑ‚ÐµÑ€Ð¸Ð¹Â B. japonicum шт. 634б и B. japonicum шт. Н9 под действием Ð¿ÐµÑÑ‚Ð¸Ñ†Ð¸Ð´Ð½Ñ‹Ñ Ð¿Ñ€Ð¾Ñ‚Ñ€Ð°Ð²Ð¸Ñ‚ÐµÐ»ÐµÐ¹, а также влияния защитного биопротектора на выживаемость микроорганизмов. Задачи исследования – определить выживаемость ÐºÐ»ÑƒÐ±ÐµÐ½ÑŒÐºÐ¾Ð²Ñ‹Ñ Ð±Ð°ÐºÑ‚ÐµÑ€Ð¸Ð¹Â Bradyrhizobium japonicum шт. 634б под действием Ñ Ð¸Ð¼Ð¸Ñ‡ÐµÑÐºÐ¸Ñ Ð¿ÐµÑÑ‚Ð¸Ñ†Ð¸Ð´Ð½Ñ‹Ñ Ð¿Ñ€Ð¾Ñ‚Ñ€Ð°Ð²Ð¸Ñ‚ÐµÐ»ÐµÐ¹, исследовать выживаемость ÐºÐ»ÑƒÐ±ÐµÐ½ÑŒÐºÐ¾Ð²Ñ‹Ñ Ð±Ð°ÐºÑ‚ÐµÑ€Ð¸Ð¹Â Bradyrhizobium japonicum шт. H9 под действием Ñ Ð¸Ð¼Ð¸Ñ‡ÐµÑÐºÐ¸Ñ Ð¿ÐµÑÑ‚Ð¸Ñ†Ð¸Ð´Ð½Ñ‹Ñ Ð¿Ñ€Ð¾Ñ‚Ñ€Ð°Ð²Ð¸Ñ‚ÐµÐ»ÐµÐ¹, изучить влияние защитного биополимера на выживаемость ризобий, выявить наиболее жизнеспособный штамм к действию пестицидов. Объект исследования – инокулянты на основе штаммов Bradyrhizobium japonicum 634б и Bradyrhizobium japonicum H9 из ведомственной коллекции микроорганизмов ÑÐµÐ»ÑŒÑÐºÐ¾Ñ Ð¾Ð·ÑÐ¹ÑÑ‚Ð²ÐµÐ½Ð½Ð¾Ð³Ð¾ назначения Всероссийского научно-исследовательского института ÑÐµÐ»ÑŒÑÐºÐ¾Ñ Ð¾Ð·ÑÐ¹ÑÑ‚Ð²ÐµÐ½Ð½Ð¾Ð¹ микробиологии.Работа выполнена на базе ВНИИСХМ. Методами исследования являлись получение посевного материала, проведение посевов 10-ÐºÑ€Ð°Ñ‚Ð½Ñ‹Ñ Ñ€Ð°Ð·Ð²ÐµÐ´ÐµÐ½Ð¸Ð¹ на чашки Петри. По результатам работы была определена выживаемость Bradyrhizobium japonicum шт. 634б и Bradyrhizobium japonicum шт. Н9 под действием Ð¿ÐµÑÑ‚Ð¸Ñ†Ð¸Ð´Ð½Ñ‹Ñ Ð¿Ñ€Ð¾Ñ‚Ñ€Ð°Ð²Ð¸Ñ‚ÐµÐ»ÐµÐ¹, был выявлен наиболее устойчивый штамм к токсическому действию пестицидов, была зафиксирована эффективность защитного биополимера под воздействием протравителей., Work is devoted to the study of the responsiveness of nodule bacteria B. japonicum strain 634b and B. japonicum strain H9 under the action of pesticides, as well as the effect of a bioprotector on the survival of microorganisms. The tasks of the study: to determine the survival rate of nodule bacteria Bradyrhizobium japonicum strain 634b under the influence of chemical pesticides, to investigate the survival of nodule bacteria Bradyrhizobium japonicum strain H9 under the action of chemical pesticides, to study the effect of a protective biopolymer on the survival of rhizobia, to identify the most viable strain to the action of pesticides. The objects of the study are inoculants based on strains of Bradyrhizobium japonicum 634b and Bradyrhizobium japonicum H9 from the departmental collection of agricultural microorganisms of the All-Russian Research Institute of Agricultural Microbiology. The work was carried out on the basis of All-Russian Research Institute of Agricultural Microbiology, St. Petersburg.The research methods were obtaining seed material, carrying out crops of 10-fold dilutions on Petri dishes. Based on the results of the work, the survival rate of Bradyrhizobium japonicum strain 634b and strain H9 under the action of pesticide protectants, the most resistant strain to the toxic effects of pesticides was identified, the effectiveness of the protective biopolymer under the influence of protectants was recorded. Â

Исследования проводили с целью подбора оптимального углевода для культивирования и отбора чистых культур ризобий сои Bradyrhizobium japonicum (Jordan, 1982) и Sinorhizobium fredii (Scholia, Elkan, 1984), усваивающих широкий спектр источников углеродного питания. В лабораторных условиях изучали интенсивность роста коллекционных штаммов ризобий сои (91 штамм) на питательной среде № 79 с различными углеводами (мальтоза, глюкоза, сахароза, лактоза). На 7-е сутки роста 85 % штаммов B. japonicum на питательной среде без дополнительного источника углерода, показали скудный рост штриха чистой культуры, 9 % - умеренный. При добавлении мальтозы, глюкозы, сахарозы, маннита интенсивность роста бактериальной массы изучаемых штаммов увеличивалась. Количество штаммов B. japonicum, давших умеренный и хороший рост чистой культуры при добавлении этих компонентов в питательную среду, варьировало от 38 % (сахароза) до 60 % (маннит). Лучший рост чистых культур B. japonicum отмечен в вариантах с маннитом и глюкозой. Среда с добавлением лактозы для B. japonicum наименее удачна: 77 % исследуемых штаммов показали скудный рост, 15 % - не дали роста. При этом 75 % штаммов S. fredii на аналогичной питательной среде показали обильный и хороший рост чистой культуры. Штаммы быстрорастущего вида практически не росли на питательной среде без углевода, но показали интенсивный рост бактериальной массы со всеми испытываемыми источниками углеродного питания. Наибольшее количество штаммов S. fredii с обильным и хорошим ростом (82 %) отмечено в вариантах с добавлением маннита и сахарозы. Выявлено 4 штамма B. japonicum и 23 штамма S. fredii, хорошо усваивающих все испытываемые источники углеродного питания (маннит, мальтоза, глюкоза, сахароза, лактоза).

Los suelos agrícolas destinados al cultivo de especies vegetales de ciclo corto, carecen de materia orgánica por efecto del excesivo empleo de agroquímicos, estos fertilizantes edáficos de origen químico ocasionan cambios en la estructura y la biodiversidad del suelo. La incorporación de rizobacterias en la agricultura permite mejorar la productividad de cultivos de leguminosas por la formación de un complejo de simbiosis rhizobio-planta que permite la fijación de nitrógeno. El objetivo del presente trabajo fue evaluar el efecto de Bradyrhizobium japonicum, Pseudomonas veronii R4 y Pseudomonas fluorescens CHA0 para promover el desarrollo e incremento de productividad en tres variedades de soja: ICA-P34; INIAP-308; INIAP-307. A los 7 y 30 días se evaluó el desarrollo radicular y formación de nódulos, por co-inoculación de rizobacterias y sin inoculantes, también se determinó el rendimiento en kgha-1. En condiciones in vitro se incrementó el tejido radicular con 5, 3 y 9 cm de largo, por B. japonicum en ICA-P34, INIAP-308 y INIAP-307. En plántulas se observó raíces de 21 y 20 cm en INIAP-307 con P. veronii R4 y P. fluorescens CHA0. Inoculando las tres variedades con B. japonicum, se obtuvo 10, 14 y 10 nódulos por planta, cuando se aplicó Pseudomonas spp no existió formación de nódulos. El rendimiento de granos por hectárea fue 3700, 2890 y 3929 kgha-1, con B. japonicum, sin inoculo bacteriano los rendimientos disminuyen a 2006, 1611 y 1842 kgha-1. B. japonicum coloniza el sistema radicular influyendo con cambios morfológicos y fisiológicos, que positivamente incrementa el rendimiento en semillas de soja.

Submitted by Luiz Gustavo Moretti de Souza null (souzamoretti@gmail.com) on 2016-08-12T18:15:48Z No. of bitstreams: 1 Dissertação_LuizGustavoMorettideSouza_UNESP-AGRISUS_Projeto1505.15.pdf: 2329991 bytes, checksum: 01526a8579b5a8f61bca11230302583d (MD5) Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-08-15T14:51:13Z (GMT) No. of bitstreams: 1 souza_lgm_me_ilha.pdf: 2329991 bytes, checksum: 01526a8579b5a8f61bca11230302583d (MD5) Made available in DSpace on 2016-08-15T14:51:13Z (GMT). No. of bitstreams: 1 souza_lgm_me_ilha.pdf: 2329991 bytes, checksum: 01526a8579b5a8f61bca11230302583d (MD5) Previous issue date: 2016-07-14 Agricultura Sustentável (AGRISUS) Simbioses, da mesma forma que a maioria das interações patogênicas, são caracterizadas pela sua complexidade e especificidade. Esses processos são de enorme importância para a produtividade global na agricultura e fornecem modelos para estudos fundamentais dos sistemas da planta e do microrganismo. O presente trabalho visou avaliar a influência de diferentes palhadas e de inoculações suplementares em cobertura na nodulação por Bradyrhizobium japonicum e Bradyrhizobium elkanii no desenvolvimento e produtividade na cultura da soja. Os experimentos foram conduzidos na FEPE/UNESP, em área irrigada e de sequeiro, em delineamento em blocos casualizados, em um esquema fatorial 3 x 5, com quatro repetições para as avaliações na palhada das culturas antecessoras, ou seja, três culturas (Zea mays, Urochloa ruziziensis e Crotalaria spectabilis) e cinco épocas de coleta da palhada (0; 25; 50; 75 e 100 dias após o manejo). E um esquema fatorial, 3 x 8 x 4, com três repetições, para as avaliações na cultura da soja, ou seja, três culturas antecessoras, e, dois tratamentos controle (testemunha; 200 kg ha-1 N) + seis de inoculação [inoculação via semente (IVS); IVS + V1; IVS + V3; IVS + V6; IVS + R1 e IVS + R3], e avaliação da nodulação em quatro estádios (V4, R2, R4 e R6). Os restos culturais de Z. mays e de U. ruzizensis proporcionam maior cobertura do solo e acúmulo de nitrogênio na palhada em área irrigada, sendo que em área de sequeiro, foi a cultura da C. spectabilis que proporcionou maior matéria seca e acúmulo de nitrogênio na palha. Em ambas as áreas as gramíneas proporcionam maior permanência da palhada em função de suas maiores relações C/N. As inoculações suplementares não interferem no estado nutricional e nos atributos biométricos da soja em nenhuma área experimental de estudo. Os tratamentos em combinação com inoculações suplementares não diferem da inoculação padrão (via semente) para as variáveis analisadas em área de sequeiro, possivelmente pela ausência de lâmina de irrigação ou precipitação, inviabilizando a infecção pela bactéria. A nodulação em área irrigada é beneficiada sob palhada de U. ruziziensis e C. spectabilis, e as inoculações em cobertura nos estádios vegetativos e em reprodutivo (R1), com aplicação de lâmina de 10 mm de irrigação após inoculação em cobertura, proporcionam maior nodulação e produtividade na cultura da soja. Esses resultados indicam que a soja mantém a capacidade de formação de nódulos durante todo o ciclo vegetativo e parte do ciclo reprodutivo, inclusive respondendo à inoculações. Symbiosis, likewise mostly of the pathogenic interactions, it is characterized by its complexity and specificity. These processes are greatly important to the global productivity in agriculture and provide models for fundamental studies of plant and microorganism systems. This study aimed to evaluate the influence of different crop residues as well as supplementary spray inoculations in coverage on the nodulation of Bradyrhizobium japonicum and Bradyrhizobium elkanii and on the soybean development and yield. The experiment was conducted at FEPE / UNESP, in a randomized block design and factorial 3 x 5, with four repetitions for the evaluation on the previous crop stover, that is, three crops (Zea mays, Urochloa ruziziensis in Crotalaria spectabilis) and five straw sampling dates (0; 25; 50; 75 and 100 days after the treatment). Also, a factorial 3 x 8 x 4, with three repetitions for the evaluations on the soybean crop, being three previous crops and two control treatments (control; 200 kg ha-1 N) + six inoculations treatments [seed inoculation (IVS); IVS + V1 stage; IVS + V3 stage; IVS + V6 stage; IVS + R1 stage; IVS + R3 stage] and the nodulation evaluation in four stages (V4, R2, R4 and R6). The crop residue of Z. mays and U. ruziziensis provided greater soil coverage and N accumulation in the straw in irrigated area. However, in the dryland area the crop residue of C. spectabilis was the one that provided more dry matter and N accumulation in the straw. In both areas the grass crops provide greater permanence of the straw in function of its higher C/N relation. The supplementary inoculations do not interfere in the nutritional state and in the crop biometric parameters in none of the experimental areas of this study. The treatments in combination with the supplementary inoculations do not differ from the standard inoculation (seed inoculation) for the variables analysed in the dryland area, possibly due to the absence of the irrigation or rainfall, preventing infection by the bacterium. The nodulation in the irrigated area is benefited under U. ruziziensis and C. spectabilis straw, and the inoculations in coverage at the vegetative and reproductive stages (R1), under irrigation depth of 10 mm after inoculating in coverage, provide greater soybean nodulation and crop yield. These results indicate that soybean maintain its capacity of nodule formation during all the vegetative cycle and part of the reproductive cycle, responding, as well, to supplementary inoculations. AGRISUS: 1505-15

For many years, the lancelet Branchiostoma belcheri had been considered a widely distributed species throughout the West Pacific Ocean. Several recent studies divided it into two separate species based on significant morphological and genetic divergence. However, this taxonomic subdivision has not yet been fully accepted by the scientific community. In order to further clarify the taxonomic status of the West Pacific lancelets, we present here complete mitochondrial genomes (mitogenomes) of two species and compare them at both genomic and phylogenetic levels. These comparisons reveal a significant genetic differentiation and show a deep phylogenetic division. Moreover, to get more insights into the phylogeography of this species complex, we sampled lancelets from Qingdao and Maoming (China) and sequenced their 12S rRNA gene, then combined the data with those from Xiamen and Japan lancelets for phylogenetic analysis. The results were consistent with our previous identification and proved that the lancelets distributed in Qingdao and Japan as well as B.japonicum in Xiamen waters belong to the same species, and those in Maoming and B. belcheri in Xiamen waters are different. Finally, we discuss the implications of these findings on the distribution of lancelets in the West Pacific Ocean.

Istraživanja koja su imala za cilj utvrđivanje utjecaja gnojidbe dušikom, inokulacije sjemena kvržičnim bakterijama B. japonicum i mikoriznim gljivama roda Glomus na elemente prinosa soje, provedena su tijekom 2006. i 2007. godine na močvarnom glejnom tlu. Postavljanje pokusa izvedeno je po potpuno slučajnom planu u 4 ponavljanja i 16 varijanti različitih po inokulaciji sjemena, gnojidbi dušikom (20 i 60 kg/ha) i fosforom (40 i 80 kg/ha). Najbolji rezultati svih istraživanih parametara: prosječni prinos zrna (4, 07 t/ha), sadržaj bjelančevina u zrnu (40, 25%), prosječna suha masa kvržica (0, 442 g/biljci), prosječni broj spora po gramu tla (9, 54) dobiveni su kombiniranom inokulacijom sjemena soje kvržičnim bakterijama i mikoriznim gljivama.

O cultivo sucessivo de soja inoculada numa mesma área proporcionou a adaptação de uma população de rizóbios, que podem não ser tão eficientes quanto à capacidade de fixação de N2, mas apresentam alta competitividade, dificultando a introdução de novas estirpes mais eficientes. Com a finalidade de avaliar o desempenho simbiótico (eficiência e competitividade) de variantes espontâneos isolados de estirpes de B. japonicum (SEMIA 5079 e SEMIA 5080) e B. elkanii (SEMIA 587 e SEMIA 5019), realizou-se um experimento em casa de vegetação onde os variantes foram inoculados isoladamente e em diferentes combinações entre os variantes e uma estirpe comprovadamente mais competitiva (SEMIA 587 ou SEMIA 5019) a partir da adição de inóculos mistos (1/1; v/v) no cultivar de soja BR-16. Por meio da avaliação das variáveis analisadas (nodulação, produção de matéria de seca da parte aérea, N total acumulado na parte aérea e ocupação nodular), foi possível constatar que o determinante da maior eficiência em tratamentos co-inoculados não foi a ocupação nodular de determinada estirpe ou variante presente no inóculo, mas, sim, o tipo de interação (sinérgica ou antagônica) predominante no tratamento co-inoculado e que é possível selecionar variantes eficientes e competitivos para a cultura da soja a partir de estirpes parentais que já apresentam características desejáveis para utilização em inoculantes comerciais. The continuous cultivation of inoculated soybean in the same area can determine the soil colonization with a rhizobia population presenting low nitrogen fixation effectiveness. This fact can be a problem for the establishment of a more effective population. A greenhouse experiment was carried out to evaluate the symbiotic effectiveness and competitiveness of spontaneous mutants isolated from B. japonicum (SEMIA 5079 and SEMIA 5080) and B. elkanii (SEMIA 587 and SEMIA 5019) strains. The soybean biovar BR 16 was inoculated with the same proportion of inoculants (1:1; v/v) containing just one of the spontaneous mutants or in different combinations among them in comparison to a competitive strain (SEMIA 587 and 5019). Through the evaluation of nodulation, dry weight yields of plants, total N in plant and nodules occupancy, its was verified that the determinant factor for microorganisms symbiotic effectiveness in co-inoculated treatments was the synergism and the antagonistic interaction and not the nodule occupancy. It was also possible to select effective an competitive spontaneous mutants for soybean from parental strains recommended for commercial inoculants.

The aim of this investigation was to identify and to characterize indigenous Bradyrhizobium japonicum strains isolated from different soil types in eastern Croatia which are regularly used for agricultural production. The actual composition and genetic diversity of natural field population were studied using RAPD fingerprinting. Total genomic DNAs from 19 field isolates and two reference strains from commercial inoculant were amplified using six different 10-mer primers. Characteristic and informative band patterns were obtained for all strains analyzed. RAPD profiles revealed that indigenous B. japonicum strains were predominant in field population. Only a few isolates corresponded to inoculant strain. One soil sample contain both indigenous and inoculant strains while the others contain exclusively indigenous bradyrhizobia. Among indigenous B. japonicum strains several distinct groups can be determined.

Uspješnost predsjetvene bakterizacije sjemena soje vrlo često ovisi o visokokompetitivnim autohtonim sojevima B. japonicum koji se nalaze u tlima povoljnih fiz. kemijskih karakteristika. U cilju rješavanja ovog problema, a s namjerom da se izvrši selekcija učinkovitih sojeva B. japonicum izoliranih iz tala Slavonije, od kojih je pripravljen inokulum za predsjetvenu bakterizaciju sjemena, korišteni su autohtoni, genetski diferencirani sojevi S3; S4; S9 i S14 te referentni soj 344 iz kolekcije Zavoda za mikrobioogiju. Za genetsku diferencijaciju sojeva primijenjena je RAPD analiza. Kako je poznato da je za učinkovitost simbioznog vezivanja molekularnog dušika vrlo značajan odnos između kultivara soje i soja B. japonicum, u ovom pokusu istraživana je kompatibilnost između navedenih sojeva B. japonicum i sorti Nada i Tisa iz selekcije Polj. Instituta Osijek. Ova istraživanja su provedena u poljskim pokusima sa slučajnim bloknim rasporedom na pedosistematskoj jedinici eutrični kambisol, okusnog polja P.I. Osijek. Rezultati istraživanja su pokazali različitu učinkovitost pojedinih autohtonih izolata sojeva B. japonicum kako u odnosu na nebakteriziranu kontrolnu varijantu tako i na referntni soj 344. Međutim, Bakterizacija sjemena soje novim izolatima B. japonicum (S3;S4;S9 i S14) iskazala je pozitivan učinak iako ne uvijek i statistički značajan na visinu biljke, broj plodnih etaža po biljci, masu tisuću zrna (g) kao i na prinos oba istraživana kultivara soje Nada i Tisa.

Prisutnost adaptiranih, visoko kompetitivnih autohtonih sojeva Bradyrhizobium japonicum u tlu često može ograničiti uspjeh predsjetvene bakterizacije soje čak i sa visoko učinkovitim komercijalnim sojevima. Iz različitih tipova tala Slavonije izolirani su i genetski diferencirani, primjenom RAPD metode, autohtoni sojevi B. japonicum. Glavni cilj ovih istraživanja je selekcija najučinkovitijih autohtonih izolata sojinih mikrosimbionata te utvrđivanje kompatibilnosti sorta x soj. Najučinkovitiji sojevi, istovremeno prilagođeni uvjetima određenog lokaliteta, koristit će se za pripremu kvalitetnijeg komercijalnog preparata za predsjetvenu bakterizaciju soje. Tijekom dvogodišnjeg istraživanja, putem poljskih pokusa u Osijeku, ispitivana je simbiozna učinkovitost osam autohtonih izolata i referentnog soja D344 kao i njihova kompatibilnost sa sortama soje Nada i Tisa. U obje godine istraživanja utvrđene su signifikantno niže vrijednosti za broj i masu suhe tvari kvržica na nebakteriziranim, kontrolnim varijantama u odnosu na varijante bakterizirane autohtonim izolatima kao i referentnim sojem D344 dok između autohtonih sojeva nisu utvrđene statistički opravdane razlike. U prvoj godini istraživanja utvrđen je statistički opravdan utjecaj sorte na broj i masu suhe tvari kvržica s time da je na korijenu soje sorte Tise utvrđen signifikantno veći broj i masa suhe tvari kvržica u odnosu na sortu Nada. Bakterizacija svim ispitivanim sojevima B. japonicum je uzrokovala signifikantno povećanje prinosa soje u obje godine istraživanja. Međutim, za razliku od broja i mase suhe tvari kvržica, i između pojedinih sojeva B. japonicum utvrđene su statistički opravdane razlike. Najviši prinosi postignuti su uz primjenu autohtonih sojeva S4, S12 i S9 koji su na osnovi rezultata RAPD metode svrstani u zasebnu i izdvojenu grupu kvržćičnih bakterija. Također je utvrđen statistički opravdan utjecaj sorte na postignute prinose. Rezultati istraživanja jasno pokazuju značenje izbora soja B. japonicum za predsjetvenu bakterizaciju sjemena u cilju što uspješnije i ekonomičnije proizvodnje soje.

The 13 isolates of B. japonicum, obtained from different soil types in western Croatia, and two reference strains from commercial inoculant were analysed. Several methods for strain identification were used: biochemical tests, intrinsic antibiotic resistance, SDS-PAGE of total cell proteins and RAPD analysis. RAPD analysis was the most sensitive and the most reliable for B. japonicum strain identification. RAPD profiles revealed that all field isolates essentially differed from inoculant strains and so can be regarded as indigenous strains for that area. Among natural B. japonicum population two highly divergent groups were determined. Strains S4, S9 and S12 differed significantly from all other isolates and represent a very distinct and separate group of bradyrhizobia. A greenhouse pot experiment was designed to evaluate the symbiotic efficiency and the compatibility of B. japonicum strains with two soybean cultivars. All strains nodulated both soybean cultvars. Indigenous strains showed higher ineffectiveness in respect to inoculant strains. The results indicate that the inoculant strain possesing hydrogenase (S2) and indigenous strains S9, S12 and S4 can be characterized as the most efficient of all strains tested.

In this study the symbiotic interactive effect of different Bradyrhizobium japonicum strains with six soybean cultivars were evaluated under fi eld conditions. The rhizobial strains ASR011, USDA123 and CB1809 respectively showed hostcultivar specifi city with JS335, Lee and Bragg. B. japonicum ASR011 recorded the highest nodulation and nitrogenase activity with all the studied cultivars. Generally, plants inoculated with strain ASR011 produced higher plant dry matter accumulation and seed yield over all other cultivars. On the basis of analysis of correlation coeffi cients, it was found that plant dry matter accumulation emerged as best criterion for selection of most effective legume-Rhizobium associations for given physical and biological conditions.