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Porównując plony ziarna ze zdrowych i porażonych przez Cephalosporium gramineum pędów pszenicy ozimej uprawianej w monokulturze stwierdzono, że odmiana Kobra zareagowała na porażenie ponad 40% spadkiem plonu ziarna z kłosa, a w przypadku odmian Roma i Zyta spadki te były mniejsze i wynosiły odpowiednio 22% i 23%. Obniżki MTZ na skutek infekcji wahały się od 23% u odmiany Kobra do 17% i 15% u odmian Roma i Zyta. Ziarno pochodzące z pędów chorych zawierało nieznacznie więcej białka ogólnego niż ziarno pochodzące z pędów zdrowych. Nie stwierdzono obecności C. gramineum w ziarniakach z porażonych pędów badanych odmian pszenicy ozimej.
Soil samples collected from 80 locations in Poland were analysed for numbers of root-nodule bacteria (rhizobia) fixing N2 in symbiosis with leguminous crops. Basic chemical and physical properties of the examined soils were also determined and correlation coefficients between these properties and numbers of rhizobia in the soils were calculated. Soil populations of alfalfa and clover rhizobia were significantly and positively correlated with soil pH and clay contents in the soils while negative correlation coefficients between these parameters and populations of lupine rhizobia were shown.
Liquid media containing potato extract and 1% of glucose or sucrose were used to culture root-nodule bacteria (rhizobia) in shaken Erlenmeyer flasks. For comparison, these bacteria were also cultured in yeast extract-mannitol broth (YEMB) as a standard medium. Proliferation of rhizobia was monitored by measuring optical densities (OD₅₅₀) of the cultures and by plate counting of the viable cells (c.f.u) of the bacteria. In general, multiplication of the rhizobia in potato extract-glucose broth (PEGB) and potato extract-sucrose broth (PESB) was markedly faster, as indicated by higher values of OD₅₅₀, than in YEMB. The numbers of R. leguminosarum bv. vicae GGL and S.meliloti 330 in PEGB and PEGB were high and ranged from 1.2×10¹⁰ to 4.9×10¹⁰ mL⁻¹ after 48 h of incubation at 28°C. B. japonicum B3S culture in PEGB contained 6.4×10⁹ c.f.u. ml⁻¹ after 72 h of incubation. PEGB and YEMB cultures of the rhizobia were similar with respect to their beneficial effects on nodulation of the host-plants of these bacteria.
Two soils were kept moist at 4°C, -20°C or air-dried at 20-22°C and after one week, one month, two months and six months of storage at these conditions changes in soil populations of Rhizobium leguminosarum bv. trifolii (Rlt) and Rhizobium leguminosarum bv. \iciae (Rlv) were examined. In one air-dried soil (from Grabów) markedly lower numbers of both Rlt and Rlv., as compared to the refrigerated or frozen samples, were found already after 1 week of storage. In the case of the second soil (from Osiny) air-drying significantly reduced numbers of the rhizobia after 2 and 6 months of storage. The soil from Osiny contained higher amounts of C org, total N and clay than the Grabów soil. Both soils stored moist in a refrigerator (4°C) or frozen (-20°C) retained similar populations of the examined rhizobia throughout the entire storage period, indicating that soil freezing is not detrimental for the examined rhizobia.
In 2008 and 2009 the effect of two cultivation systems (conventional and ecological) on population of yeasts and mycelial fungi colonizing grain of two winter wheat cultivars (Bogatka and Legenda) was studied. In 2008 only grain of cv. Bogatka grown under the conventional system was colonized by significantly higher number of fungi than grain under the ecological system. In 2009 with frequent rainfall grain of both cultivars grown under the ecological system was colonized by a higher number of fungi as compared to the conventional system. In 2008 more isolates of Fusarium poae and F. sporotrichioides were obtained from grain grown under the conventional than under the ecological system, but in 2009 the opposite was generally true.
Using a sand pouch-plant infection method, populations of several species of root-nodule bacteria (rhizobia) were enumerated in eighty soils collected throughout Poland. Rhizobium leguminosarum bv. viciae (symbionts of pea, faba bean, vetch) and R. leguminosarum bv. trifolii (symbionts of clover) were detected in 77 and 76 soils, respectively. Most of these soils contained moderate and high numbers of these species of the rhizobia. Symbionts of beans, R. leguminosarum bv. phaseoli, were assessed in 76 soils; of this number 15 soils had no detectable populations of bean rhizobia and in 40 soils high or moderate numbers of these bacteria were found. Bradyrhizobium sp. (Lupinus), root-nodule bacteria of lupine and serradella, were absent in 19 soils, out of 80 tested, and 34 soils were colonised by high or moderate populations of bradyrhizobia. Sinorhizobium meliloti, rhizobia nodulating alfalfa, were sparse in the examined soils; with 56 soil containing no detectable numbers of S. meliloti and only 6 soils harbouring high or moderate populations of this species. The estimated numbers of the rhizobia in the studied soils were also related to some physical and chemical properties of these soils.
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