The evaluation of hop cultivars held in germplasm collection for their susceptibility to downy mildew and powdery mildew

W latach 2001-2003 badano podatność 44 odmian chmielu na mączniaka rzekomego i prawdziwego. Porażenie roślin oceniano w warunkach polowych na podstawie występowania objawów chorobowych na szyszkach w fazie dojrzałości technologicznej. Objawy mączniaka rzekomego i prawdziwego chmielu stwierdzono na większości badanych odmian, a ich nasilenie zależało od warunków pogody. Wśród testowanych odmian wydzielono grupy homogeniczne różniące się istotnie wrażliwością na badane choroby. Najmniej podatna na mączniaka rzekomego i prawdziwego chmielu okazała się angielska odmiana Wye Target.In the years 2001-2003, 44 hop cultivars were tested for downy mildew and powdery mildew resistance. The level of disease severity was determined in the field conditions by a number of infected cones at the technological maturity stage. The symptoms of studied diseases occurred in most hop cultivars and their severity depended on weather conditions. The groups of significantly different susceptibility to downy mildew and powdery mildew were distinguished among tested hop cultivars. The most resistant to both diseases appeared to be the English cultivar Wye Target

Immunodiagnosis of eyespot disease in winter wheat cultivated in different production systems

The aim of the study carried out in the years 2001-2003 was to determine the occurrence of Pseudocercosporella herpotrichoides in winter wheat cultivated in different production systems using traditional visible disease assessment and ELISA technique. Pathogen was detected by ELISA test in all years of the study and attained highest level in 2003. The greatest quantities of Pseudocercosporella herpotrichoides were observed in integrated system and monoculture and significantly lower in conventional production system.Celem badań prowadzonych w latach 2001-2003 było określenie występowania Pseudocercosporella herpotrichoides na pszenicy ozimej uprawianej w różnych systemach produkcji przy użyciu makroskopowej oceny mikologicznej i enzymoimmunologicznego testu ELISA. Przy użyciu testu ELISA stwierdzono, że grzyb występował we wszystkich latach badań. Największe nasilenie patogena obserwowano w 2003 roku. Najliczniejsze występowanie grzyba zaobserwowano w systemie integrowanym i monokulturze, istotnie niższe występowanie Pseudocercosporella herpotrichoides zanotowano w systemie konwencjonalnym. Odmiana Kobra okazała się bardziej podatna na łamliwość podstawy źdźbła niż odmiana Roma, co potwierdza zarówno test ELISA, jak i ocena makroskopowa

Genome size in Humulus lupulus L. and H. japonicus Siebold and Zucc. [Cannabaceae]

We analysed chromosome lengths, karyotype structure, and nuclear DNA content (flow cytometry) in diploid (2n=20) and triploid (2n=30) European H. lupulus var. lupulus, American H. lupulus var. neomexicanus (2n=20) and Japanese ornamental hop, H. japonicus (F/2n=16; M/2n=17). Diploid female representatives of H. lupulus var. lupulus and H. l. var. neomexicanus differed in total length of the basal chromosome set (23.16 µm and 25.99 µm, respectively) and nuclear 2C DNA amount (5.598 pg and 6.064 pg) but showed similar karyotype structure. No deviation from the additivity, both in chromosome length and 2C DNA amount was evidenced in triploid monoecious H. lupulus (2n=30, XXY). H. japonicus showed different karyotype structure, smaller basal chromosome set (F/18.04 µm, M/20.66 µm) and lower nuclear DNA amount (F/3.208 pg and M/3.522 pg). There are first evaluations of nuclear genome size in diploid, not commercial representative of European H. lupulus var. lupulus and American H. lupulus var. neomexicanus and first attempt to determine the absolute male and female genome size in two Humulus species

Aroma profile and bitter acid characterization of hop cones (Humulus lupulus L.) of five healthy and infected Polish cultivars

The characteristic hoppy aroma is directly correlated with the chemical composition of its volatile profile and essential oil. The aim of this work was to analyse the essential oils and volatile fractions of five popular Polish hop cultivars (Sybilla, Lubelski, Pulawski, Magnat and Marynka), healthy and infected by viruses and viroids by SPME and GC–MS. Hop fraction of hard resins and alpha- and beta acids were determined according to the official analytical method (modified Wöllmer method EBC 7.7 and HPLC method EBC 7.5, respectively). Hop Mosaic Virus (HpMV), Apple Mosaic Virus (ApMV), Hop Latent Viroid (HLVd) are commonly found in plants of all hop cultivars commercially produced in Poland. Monoterpenes hydrocarbons showed higher percentages in the aroma profile of infected cones (82.5%–94.3%) than in the healthy ones (81.1%–91.4%) and increased from the healthy to the infected plants, except for ‘Sybilla’ that had an opposite trend (from 90.1% in healthy to 77.9% in infected hop). Hydrogenated sesquiterpenes were the second main class of aroma constituents with major amount in healthy cones with the exception for ‘Sybilla’. Myrcene was always the most abundant chemical constituent in all the infected cultivars, except for ‘Sybilla’ (from 86.3% in infected to 74.6% in healthy plants), followed by α-humulene in four of the five cultivars except for ‘Marynka’ where (E)-β-farnesene showed higher amount. The EO yields related to the five healthy cultivars showed variations between 0.2% in ‘Lubelski’ up to 1.1% in ‘Marynka’ very similar to those observed in the five infected cultivars. Monoterpenes predominated over sesquiterpenes in healthy and infected ‘Sybilla’ and ‘Marynka’ EOs, while in healthy and infected ‘Lubelski’ and ‘Magnat’ prevailed an opposite trend. ‘Magnat’ is the only one cultivar that showed different amount of the two main classes of constituents between the healthy and infected plants (sesquiterpenes 64.6% in healthy cones and 50.5% of monoterpenes in the infected ones). Myrcene was the main constituent in all the infected EO samples (29.9%–67%), while α-humulene predominated only in three healthy cultivars (‘Lubelski’ ‘Pulawski’ and ‘Magnat’ with 34.2, 36.8, 31.0%, respectively). The content of bitter substances (α and β-acids as well as hard and soft resins) varied in healthy and infected hop plants and this behaviour was strongly dependent on the selected cultivars but differences between healthy and infected plants were not statistically significant. In conclusion virus/viroid infection seems not to interfere in a substantial way with the normal hop secondary metabolite biosynthesis, but only in the biomass yields

Characterisation of four popular Polish hop cultivars

Polish cultivars of hop (Humulus lupulus L.) are well known as aroma and bitter raw material in the brewing industry. To characterise four popular Polish hop cultivars, Lubelski (Lublin), Marynka, Sybilla and Iunga (also known as Junga), the essential oil profiles were determined by gas chromatography/flame ionisation detector (GC-FID) and gas chromatography/chemical ionisation mass spectrometry (GC-CIMS) and the alpha/beta acids amounts by high-performance liquid chromatography/diode array detector (HPLC-DAD) analysis. In addition, the multivariate statistical analysis of the volatile profiles was performed. The results obtained evidenced qualitative and quantitative differences between the four cultivars studied and the foreign hops described in the literature. Lubelski and Iunga showed the typical chemical profile of the fine-aroma and high-alpha cultivars, respectively. In Marynka and Sybilla, the average amounts of alpha acids were similar to the bitter hops, but with a volatile profile characteristics of the fine-aroma and aroma cultivars respectively. �� 2013 Institute of Food Science and Technology