Performance of j2uazifop-butyl against Elymus repens

The effects of irrigation, four fertiliser rates, fungicide, insecticide + molluscicide, and nematicide treatments were tested on an Italian ryegrass sward sown in May 1983, in a multi-factorial experiment that allowed treatment interactions to be examined. Pests and fungal diseases were monitored over a 2-yr period. No recognised grassland insect pests or slugs were found in the seedbed but there were an estimated 17 300 plant parasitic nematodes/litre soil. Other, non-pest invertebrate populations, e.g. earthworms, were not assessed. In the first year yields were increased most by irrigation. There were also large yield responses to fertiliser over the range 50–900 kg N/ha/yr. Responses to pesticide application were relatively small. However, there were significant yield responses in the first year to nematicide and to insecticide + molluscicide treatments. Yields in the second year were affected more by increased fertiliser use than by irrigation; increases after pesticide use were similar to the previous year, and there was also a small but significant yield gain over untreated plots at the second harvest from those treated with fungicide. Interactions between main factors occurred in both years, affecting yields and nematode abundance. Nematode numbers were decreased in both years where the larger, compared to the smaller fertiliser applications had been made. In the first year these differences were only apparent on irrigated plots. It was concluded that, in this trial, irrigation had the greatest effect on yields of spring-sown ryegrass during its establishment year but that increasing fertiliser rates had a greater effect the year after; that fungi had had little effect on ryegrass yields, and that nematodes were more important pests than insects during establishment but insects were more important subsequently.     

The seasonal response of Italian and hybrid ryegrasses to the control of frit fly, Oscinella frit

In years of relatively high frit fly activity the control of all generations produced increases averaging 0×44 t d.m. ha^-1 in annual yield of Italian and hybrid ryegrass. A cutting programme designed to make the sward especially vulnerable to frit fly attack did not increase the total annual effect of pesticide treatment but accentuated the periods at which damage occurred. The annual yield increase was almost entirely obtainable by controlling the second and third frit fly generations, but even one treatment for this purpose was of doubtful economic justification. The prospect of augmenting the response to control of later-occurring pests, such as leatherjackets or eriophyid mites, by including the part of the frit fly response which is recoverable by the same treatment, was a more probable justification for pesticide usage. There was some evidence that a Westerwold and a hybrid cultivar suffered more damage than an Italian ryegrass cultivar, but pesticide treatment did not improve the persistence of any cultivar.     

A field study of the pattern of local spread of ryegrass mosaic virus in mown grassland

In a field experiment at Hurley, small areas of old ryegrass sward, known to be infected with ryegrass mosaic virus (RMV) were partially surrounded by newly-sown Italian ryegrass. The experiment was harvested by mowing on five occasions. Samples of Italian ryegrass taken when it was 11 months old showed a very marked increase in the levels of RMV close to the areas of old sward. Thus, 84% of the Italian ryegrass plants bordering the old sward to the north contained RMV, compared with 63% of plants only 2.7 m away. The corresponding values to the south were 68% and 39%. The much higher values encountered to the north are presumed to be caused by the movement of the mite vector of RMV (Abacarus hystrix) in relation to the prevailing wind. Two different mowers were used, a rotary mower and a reciprocating knife mower. We could demonstrate no increase in the level of RMV as a result of mowing from the infected sward and on to the new sowing and could demonstrate no difference in the infection levels as a result of using the different mowers. We conclude that in mown swards migration by the mite is responsible for all or nearly all of very local spread of RMV.     

Growth of zinnia,Italian ryegrass,and alfalfa and their remediation effects in diesel oil-contaminated soils

Abstract

Our objective in this study was to compare the growth of zinnia, Italian ryegrass, and alfalfa, and their remediation effects in oil-contaminated soils. The soils were prepared by mixing 2, 4, or 8% diesel oil by weight with soil. The plant height and dry weights of shoots and roots were highest for zinnia in the 2 and 4% oil treatments, and highest for Italian ryegrass in the 8% oil treatment. The reduction ratios in soil total petroleum hydrocarbons concentration (TPH) for 3 plants were lower in the 4 and 8% oil treatments than those in the 2% treatment. The reduction ratios for Italian ryegrass and zinnia contaminated with 2, 4, and 8% diesel oil treatments were significantly higher than those for alfalfa and the non-cultivation treatment at 45?days after sowing, and there were no significant differences in reduction ratios between Italian ryegrass and zinnia. The reduction ratio of soil TPH concentration brought about by zinnia was also comparable to that of Italian ryegrass. Therefore, we conclude that zinnia shows growth and remediation effects that are equivalent to those of Italian ryegrass, in soils contaminated with less than 8% oil.     

Construction of a primary RH panel of Italian ryegrass genome via UV-induced protoplast fusion

Symmetric and asymmetric somatic hybrids were produced via protoplast fusion between common wheat ( TRITICUM AESTIVUM L.) cv. "Jinan 177" and Italian ryegrass ( LOLIUM MULTIFLORUM Lam.). The ryegrass without or with UV irradiation was used as a donor, providing a small amount of chromatin. In these somatic hybrids, most ryegrass chromosomes have been confirmed preferential elimination and the somatic hybrid calli and plants showed wheat-like morphology. Some of the hybrid lines were used for the analysis of distribution and heredity of donor DNA in the hybrid genome and the possibility of establishing a radiation hybrid (RH) panel of the ryegrass in the present experiment. These hybrids, subcultured for two and three years, retained the ryegrass DNA examined by RFLP and GISH analysis, respectively. Distribution of the ryegrass DNA in the wheat genomes of 20 single-cell individuals, randomly selected from hybrid cell lines produced, were analyzed by 21 ryegrass genome specific SSR markers. The average frequencies of molecular marker retention in symmetric hybrid lines (UV 0), as well as asymmetric hybrid lines from UV 30 s and 1 min were 10.88, 15.48 and 33.86, respectively. It was suggested that the UV dose increased the introgression of donor DNA into wheat genome. The ryegrass SSR fragments in most asymmetric hybrid cell lines remained stable over a period of 2 approximately 3 years. This revealed that those asymmetric somatic hybrids are suitable for the introgression of ryegrass DNA into wheat, and for RH panel and RH mapping.     

The effect of frit fly (Oscinella frit) control measures on the establishment of seedling ryegrass (Lolium spp.)

In four experiments from 1981 to 1983 August-sown perennial (Lolium perenne) and Italian (L. multiflorum) ryegrass were exposed to frit fly attack by oviposition on the seedlings. Responses to pesticide treatment were detected at autumn harvests. Even at low sowing rates pesticide application did not ultimately establish a better sward and, owing to a tendency towards spring reversal of autumn yield responses, even temporary returns were negligible. As frit fly numbers were unusually low the autumn response to pesticide was sufficient to suggest that frit fly is always likely to be an influential factor in ryegrass sown in early August in this area. Later sowings are less likely to be affected. The yield response was related to the numbers of adult flies present 2–7 wk after sowing. Neither grass species was consistently more affected than the other. Additional seed (compared with a sowing rate below normal commercial rates) and the inclusion of fertiliser at sowing also gave only small temporary returns and failed to establish a better sward. It is suggested that routine protection against frit fly attack is of at least equal value to the other two variables in an early August sowing.     

Selection of perennial and Italian ryegrass plants resistant to ryegrass mosaic virus

Perennial ryegrass plants collected from fields and Italian ryegrass plants grown from seed were selected for resistance to infection by ryegrass mosaic virus (RMV) by repeated manual inoculation. Two of 108 perennial ryegrass plants and one of 150 Italian ryegrass plants were symptomless after seven and nine inoculations respectively. These three plants were propagated vegetatively. Plants of the two perennial ryegrass clones showed no symptoms after further manual inoculations with the initial isolate of RMV, or with an inoculum from infected plants collected from several fields, or after inoculation by viruliferous mites. Electron microscopy and back tests indicated that the plants were virus free. Some plants of the selected Italian ryegrass clone became infected after a further inoculation with mites or sap, but fewer than similarly inoculated unselected plants.     

高温高湿条件下意大利黑麦草青贮技术研究

研究以水田冬闲期栽培的意大利黑麦草(Lolium multiflorum)为材料,结合常规的青贮方法进行了小规模控制实验,试验设计了隔水(将青贮过程中产生的渗出液排出)和不隔水,以及不同添加物的青贮处理.青贮结束后,对青贮黑麦草的品质和营养价值进行评定,探讨不同处理对黑麦草青贮的作用效果,以及南方高温高湿条件下青贮黑麦草的合理方法和最佳条件.结果发现,对黑麦草进行隔水添加乳酸的青贮处理从感观评定、pH值和营养成分的分析结果来看,都在一定程度上优于其他处理,由此可以认为隔水添加乳酸的处理相对实现了较稳定和较优质的青贮.     

Construction of a high-density linkage map of Italian ryegrass (Lolium multiflorum Lam) using restriction fragment length polymorphism, amplified fragment length polymorphism, and telomeric repeat associated sequence markers.

To construct a high-density molecular linkage map of Italian ryegrass (Lolium multiflorum Lam), we used a two-way pseudo-testcross F1 population consisting of 82 individuals to analyze three types of markers: restriction fragment length polymorphism markers, which we detected by using genomic probes from Italian ryegrass as well as heterologous anchor probes from other species belonging to the Poaceae family, amplified fragment length polymorphism markers, which we detected by using PstI/MseI primer combinations, and telomeric repeat associated sequence markers. Of the restriction fragment length polymorphism probes that we generated from a PstI genomic library, 74% (239 of 323) of randomly selected probes detected hybridization patterns consistent with single-copy or low-copy genetic locus status in the screening. The 385 (mostly restriction fragment length polymorphism) markers that we selected from the 1226 original markers were grouped into seven linkage groups. The maps cover 1244.4 cM, with an average of 3.7 cM between markers. This information will prove useful for gene targeting, quantitative trait loci mapping, and marker-assisted selection in Italian ryegrass.     

Development and implementation of a multiplexed single nucleotide polymorphism genotyping tool for differentiation of ryegrass species and cultivars

Perennial ryegrass (Lolium perenne L.) and Italian ryegrass (Lolium multiflorum Lam.) are important temperate forage grasses which are closely related, generating fertile interspecific hybrids. All groups are represented by multiple cultivars in the commercial pasture seeds market. Due to the close taxonomic relationship between the two species, differentiation based on morphophysiological criteria is not always readily achievable. In addition, an obligate outbreeding reproductive habit produces high levels of individual heterozygosity and intrapopulation diversity, which presents problems for discrimination between cultivars. Molecular genetic marker polymorphism provides an effective means of addressing these challenges. An iterative process of resequencing from loci distributed across the perennial ryegrass genome was used to identify single nucleotide polymorphism (SNP) markers, which were then validated and formatted in a highly multiplexed (384-plex) assay system. SNP genotyping was then performed across samples of 48–192 individuals from a total of 27 ryegrass cultivars (19 of perennial ryegrass, seven of Italian ryegrass and one hybrid cultivar). SNP markers from perennial ryegrass exhibited a high level of transfer to Italian ryegrass. Data analysis permitted quantification of intra- and inter-species diversity, as well as discrimination between cultivars within each species, including diploid and autotetraploid cultivars of perennial ryegrass. Lower levels of SNP-based diversity were detected in Italian ryegrass than in perennial ryegrass. A neighbour-joining tree based on genetic distance analysis located a hybrid cultivar to an intermediate position between the two species-specific cultivar groups. The resulting catalogue of ryegrass cultivars will provide support for the processes of cultivar accreditation and quality assurance.     

Enhanced resistance to four species of Clypeorrhynchan pests in Neotyphodium uncinatum infected Italian ryegrass

Particular alkaloids produced by Neotyphodium endophytes show toxicity to invertebrates. Italian ryegrass (Lolium multiflorum Lamarck) cultivars and strains that are symbiotic with Neotyphodium endophytes have been recently established in Japan. N. uncinatum-infected Italian ryegrass lines accumulate N-formylloline, a type of loline alkaloid (1-aminopyrrolizidine) showing neurotoxicity to herbivorous insects. This study investigated the toxicity of N-formylloline and resistance of N. uncinatum-infected Italian ryegrass to vascular-sap feeding Clypeorrhynchan pests. When four vascular-sap feeding insects: Laodelphax striatellus (Fallén) (Homoptera: Delphacidae), Sogatella furcifera (Horváth) (Homoptera: Delphacidae), Cicadulina bipunctata (Melichar) (Homoptera: Cicadellidae), and Nephotettix cincticeps (Uhler) (Homoptera: Cicadellidae) fed on N. uncinatum-infected Italian ryegrass, significant decreases in survival rate were observed for three phloem-sap feeders but not for a xylem-sap feeder, N. cincticeps. This result suggests an uneven distribution of N-formylloline among plant tissues. A potency assay for N-formylloline using a Parafilm feeding sachet and a quantitative analysis of N-formylloline in plant showed a concentration-dependent lethal effect of N-formylloline on all four tested vascular-sap feeders. Our results strongly suggest that N. uncinatum-infected plants can control some Clypeorrhynchan pests in crop fields.     

QTL mapping of resistance to gray leaf spot in ryegrass

Gray leaf spot (GLS) is a serious fungal disease caused by Magnaporthe grisea, recently reported on perennial ryegrass (Lolium perenne L.), an important turfgrass and forage species. This fungus also causes rice blast and many other grass diseases. Rice blast is usually controlled by host resistance, but durability of resistance is a problem. Little GLS resistance has been reported in perennial ryegrass. However, greenhouse inoculations in our lab using one ryegrass isolate and one rice-infecting lab strain suggest presence of partial resistance. A high density linkage map of a three generation Italian × perennial ryegrass mapping population was used to identify quantitative trait loci (QTL) for GLS resistance. Potential QTL of varying effect were detected on four linkage groups, and resistance to the ryegrass isolate and the lab strain appeared to be controlled by different QTL. Of three potential QTL detected using the ryegrass isolate, the one with strongest effect for resistance was located on linkage group 3 of the MFB parent, explaining between 20% and 37% of the phenotypic variance depending on experiment. Another QTL was detected on linkage group 6 of the MFA parent, explaining between 5% and 10% of the phenotypic variance. The two QTL with strongest effect for resistance to the lab strain were located on linkage groups MFA 2 and MFB 4, each explaining about 10% of the phenotypic variance. Further, the QTL on linkage groups 3 and 4 appear syntenic to blast resistance loci in rice. This work will likely benefit users and growers of perennial ryegrass, by setting the stage for improvement of GLS resistance in perennial ryegrass through marker-assisted selection.     

The range of mobility of the non‐cellulosic polysaccharides is similar in primary cell walls with different polysaccharide compositions

The molecular mobility of the non‐cellulosic polysaccharides in hydrated primary cell walls of three monocotyledons (Italian ryegrass, pineapple and onion) and one dicotyledon (cabbage) was studied using solid‐state ¹³C NMR spectroscopy. These cell walls were chosen as they have different non‐cellulosic polysaccharide compositions. By exploiting proton rotating‐frame and spin‐spin relaxation time constants three different cell wall domains which responded to cross‐polarization experiments were identified. Most of the non‐cellulosic polysaccharides occupied a mobile domain (C), but some occupied a partly rigid domain (B). Crystalline cellulose occupied a highly rigid domain (A). In the cell walls of Italian ryegrass and pineapple, domain C contained mainly glucuronoarabinoxylans and small amounts of rhamnogalacturonans; domain B contained small amounts of xyloglucans and galacturonans. However, in the cell walls of onion and cabbage, domain C contained mainly rhamnogalacturonans with galactans (in onion) or arabinans (in cabbage) as side chains; domain B contained galacturonans and xyloglucans. Single‐pulse excitation was used on Italian ryegrass and cabbage cell walls to reveal signals from a highly mobile fourth domain (D). In Italian ryegrass cell walls domain D contained glucuronoarabinoxylans and small amounts of rhamnogalacturonan, whereas in cabbage cell walls it contained arabinan side chains of rhamnogalacturonans. A novel feature of the research was the use of solid‐state ¹³C NMR spectroscopy to examine the molecular mobilities of the polysaccharides in monocotyledon cell walls that contain glucuronoarabinoxylans.     

Transfer of polygenic resistance to ryegrass mosaic virus from perennial to Italian ryegrass by backcrossing

Polygenic resistance to ryegrass mosaic virus (RMV) was transferred from perennial to Italian ryegrass cv. Tribune by repeated cycles of backcrossing, polycrossing and selection. The resulting synthetic variety (Bb 2113) was highly resistant to infection by RMV whereas the Italian ryegrass cultivars Tribune, RvP, Bartolini, Augusta, Wilo and Dalita all were highly susceptible. Leaf width and length of Bb 2113 was similar to that of cv. Tribune and, like Tribune, Bb 2113 had awned florets. In a field trial, Bb 2113 had a similar persistency rating and number of inflorescences in the regrowth to cv. Tribune but produced 11% less dry matter. The results emphasise the need for a more efficient means of transferring small numbers of genes from one species of Lolium to another than backcrossing provides.     

Tolerance to ryegrass mosaic virus, its assessment and effect on yield

Symptom severity of eighteen populations of Italian ryegrass infected artificially in the glasshouse and naturally in the field with ryegrass mosaic virus (RMV) was strongly correlated. A smaller proportion of plants of the more tolerant populations showed symptoms in the field, but this was probably due to an association of tolerance with increasing incidence of symptomless infection rather than with resistance to infection. Under sward conditions, the yield of a sensitive genotype was reduced by 27% and that of two more tolerant ones by 15 and 13 %. The percentage dry matter yield loss of the most sensitive genotype was similar in all cuts, despite the appearance of extensive necrosis at the time of one cut. With the more tolerant genotype the yield loss varied from 7 to 25 % according to cut. Over the period of the experiment RMV infection did not increase plant mortality.     

The effect of replacing potassium by sodium on cation uptake and transport to the shoots in four legumes and Italian ryegrass

White clover, red clover, lucerne, sainfoin and Italian ryegrass were grown in a series of culture solutions in which 0, 25, 50, 75 and 100% of the potassium was replaced by sodium. In the shoots, the potassium: sodium ratios indicated selectivity for potassium which decreased in the order: sainfoin>lucerne>red clover>white clover > Italian ryegrass. In the roots only sainfoin showed selectivity for potassium: with the other species the ratio of potassium to sodium in the roots was similar to that in the other species the ratio of potassium to sodium in the roots was similar to that in the culture solution. All species showed selective transport of potassium to the shoots in preference to sodium: this was least in Italian ryegrass and white clover and greatest in sainfoin, which in contrast to other species also showed restricted transport of potassium to the shoots. Replacement of potassium by sodium slightly increased the magnesium concentration in the shoots but had no effect on the calcium concentration.     

Changes in Dry Matter, Carbohydrate and Seed Yield Resulting from Lodging in Three Temperate Grass Species

The adverse effect of lodging on grass seed yield may be attributed,in part, to assimilate limitation during the seed filling period.This investigation examined plant dry matter assimilate partitioningand seed yield as affected by lodging in three species thatare closely related but phenotypically different: tall fescue(Festuca arundinacea Schreber.), Italian ryegrass (Lolium multiflorumLam.), and perennial ryegrass (L. perenne L.). Studies wereperformed in field plots at Corvallis, Oregon, USA. Seed yieldcomponents (seed number per inflorescence, seed yield per inflorescence,and single seed mass) and leaf, stem (lower, middle, and peduncle)and seed inflorescence dry mass were measured just prior toanthesis to seed maturity. Dry mass and water soluble carbohydrates(WSC) were determined for shoot components. The reduction indry mass and WSC in leaves and stem components following anthesiswas often greater in lodged plants compared to upright plants.The relatively low seed yield depression in lodged tall fescuesuggested a higher compensation potential for partitioning reserveassimilate from leaves and stems to support seed growth anddevelopment. This potential does not appear to be present tothe same degree in Italian ryegrass and to an even lesser extentin perennial ryegrass. These findings suggest that the potentialto compensate for reduced assimilate supply during the periodof high assimilate demand by seeds may be attributed, in part,to the total assimilate reserve accumulated prior to photoassimilatereduction caused by the lodged condition. Copyright 2000 Annalsof Botany Company Tall fescue, Festuca arundinacea Schreber., Italian ryegrass, Lolium multiflorum Lam., perennial ryegrass, L. perenne L., assimilate partitioning, source–sink     

Development of simple sequence repeat (SSR) markers and construction of an SSR-based linkage map in Italian ryegrass (Lolium multiflorum Lam.)

In order to develop simple sequence repeat (SSR) markers in Italian ryegrass, we constructed a genomic library enriched for (CA)n-containing SSR repeats. A total of 1,544 clones were sequenced, of which 1,044 (67.6%) contained SSR motifs, and 395 unique clones were chosen for primer design. Three hundred and fifty-seven of these clones amplified products of the expected size in both parents of a two-way pseudo-testcross F₁ mapping population, and 260 primer pairs detected genetic polymorphism in the F₁ population. Genetic loci detected by a total of 218 primer pairs were assigned to locations on seven linkage groups, representing the seven chromosomes of the haploid Italian ryegrass karyotype. The SSR markers covered 887.8 cM of the female map and 795.8 cM of the male map. The average distance between two flanking SSR markers was 3.2 cM. The SSR markers developed in this study will be useful in cultivar discrimination, linkage analysis, and marker-assisted selection of Italian ryegrass and closely related species.Electronic Supplementary Material Supplementary material is available for this article at and is accessible for authorized users.     

Metal accumulation in Lolium perenne and Brassica napus as affected by application of chitosans

The effects of chitosan, a fishery waste-based material, and its derivative glutaraldehyde cross-linked chitosan (chitosan-GLA) on metal uptake by Lolium perenne (perennial ryegrass) and Brassica napus (rapeseed) were studied in a greenhouse pot experiment. Metal uptake by perennial ryegrass was highly dependent on the rate of addition of the chitosans. Low application rate (1% w/w) enhanced metal uptake, whereas 10% (w/w) addition decreased metal uptake. It was estimated that chitosan 1% (w/w) treatment could assist perennial ryegrass to remove approximately 3.2 kg Zn/ha and 0.29 kg Pb/ha. For rapeseed, metal uptake was decreased at all rates of application of chitosans. The ammonium acetate extractable metals in soil decreased following application of chitosans and plant growth.