Ecotypic variation of water-soluble carbohydrate concentration and winter hardiness in cocksfoot (Dactylis glomerata L.)

The variation of the water-soluble carbohydrate (WSC) concentration in foliage and stubble and winter hardiness among cocksfoot (Dactylis glomerata L.) ecotypes originated from diverse countries were studied in the field in order to find a breeding material for the improvement of WSC. The total WSC concentration of foliage was found to be highest in Japanese cultivars and lowest in ecotypes from northern Europe in summer and autumn. The variation of fructan concentration in stubble among ecotypes was larger than the variation of mono and disaccharide concentrations in stubble and that of total WSC concentration in foliage in both winters over which this study was conducted. The total WSC and fructan concentrations in the stubble of ecotypes from Spain and southern Europe, derived from the Mediterranean region, were highest in summer. Ecotypes from Japan showed the highest concentration of total WSC in stubble, and were especially high in fructan concentration in autumn. Ecotypes from France, central Europe and central Asia, like Japanese cultivars, also showed a high fructan concentration. The latitude of origin was negatively correlated with WSC concentration and plant vigor in autumn. The altitude of origin was negatively correlated with plant vigor in autumn and positively correlated with fructan concentration in stubble, winter hardiness and snow endurance. Typhula snow blight resistance was related with the amount of the increase in fructan in the plants and with their growth habits in autumn. The fructan concentration of foliage and stubble in autumn was found to be closely related with winter hardiness in cocksfoot ecotypes. A breeding material which has a high WSC concentration in the foliage could not be found among the ecotypes in this study. However, some ecotypes that showed disease resistance, good winter hardiness and plant vigor would be useful as breeding materials for Hokkaido.     

Effects of introgressions from <Emphasis Type="Italic">Festuca pratensis</Emphasis> on winter hardiness of <Emphasis Type="Italic">Lolium perenne</Emphasis>

Previous studies reported that some genotypes with introgressed Festuca chromosome segment(s) in Lolium genome showed enhanced winter hardiness compared to Lolium. The aim of this study was to search comprehensively for the Festuca pratensis chromosome regions affecting winter hardiness-related traits when introgressed into the Lolium perenne genome. Association between F. pratensis introgression and winter hardiness-related traits (fall and winter hardiness indexes, early-spring dry matter yield, and freezing tolerance) were screened in the diploid introgression populations (n = 203) that had some F. pratensis chromosome segments introgressed. Eighty-four intron markers corresponding to unique rice genes randomly distributed across the genome were used for genotyping. Winter hardiness of almost all plants in the introgression populations was lower than that of the F. pratensis and triploid hybrid parents, but the average was higher than that of L. perenne. A significant positive effect of F. pratensis introgression on early-spring dry matter yield was detected on chromosome 7. This quantitative trait locus (QTL) was confirmed by linkage analysis using a backcross population with F. pratensis introgression in the target region of chromosome 7. However, the contribution of the newly identified QTL was rather small (6.7–9.6%), suggesting that superior winter hardiness of F. pratensis compared to L. perenne is conferred by multiple small-effect QTLs. We also detected a previously unreported negative effect of Festuca introgression on winter hardiness. Newly obtained QTL information in this study would contribute to the design of Festuca/Lolium hybrid breeding.     

Heading behaviour in Japan of Turkish populations of cocksfoot,Dactylis glomerata L.

Summary Ninety-nine populations of cocksfoot collected throughout Turkey were examined for heading behaviour at Sapporo, Japan. In some populations, all the plants produced heads in the year of sowing or in the aftermath of the next year. Much of the Turkish populations, even from the mountainous regions with severe winters, is also distinct in heading behaviour in autumn from the north European types, which fail to head in the year of sowing. This behaviour is related to winter temperatures of the place of origin, with the milder winter tending to result in a higher heading rate. Date of heading is also influenced by the climatic factors of the habitat, especially by the length of the growing period between winter and summer dormancies. Turkish populations provided useful material for the study of flowering habit.     

Introgression of low temperature tolerance and red rot resistance from Erianthus in sugarcane

Eighteen clones involving Erianthus, as one of the parents, were evaluated in a randomised block design under sub-tropical conditions of Karnal (Haryana, India). Fifteen characters, which contribute towards stalk yield and juice-quality, were studied. The growth of these clones was monitored during peak winter months of December and January. Significant variability existed among the clones for all the traits studied, except for pol % in juice at 10-month crop age, indicating potentiality of the clones to select desirable types. Nine clones showed significant increase in stalk length during winter months over the better standard Co 1148. Whereas 6 clones developed more number of leaves than Co 1148. Both these characters showed high genetic variability, high heritability and hence, high expected genetic gain. Path analysis revealed that these traits contributed about 16%, 5% and 4% to the total genetic variability in juice quality traits (pol % and CCS %), stalk yield and CCS yield, respectively. Growth in winter months has resulted in an increase in stalk yield and CCS yield. This may help in reducing the yield gap between tropical and sub-tropical regions. Majority of clones showed resistance to red rot disease (major disease of sugarcane in sub-tropical region). Hence, hybridization of Erianthus with sugarcane has resulted in introgression of genes for cold tolerance and red rot resistance. As Erianthus is known for its hardiness, resistance, of these clones, to other abiotic and biotic stresses is to be ascertained. This revised version was published online in August 2006 with corrections to the Cover Date.     

Relationship between vernalization requirement and winter hardiness in doubled haploids of barley

Summary Progeny lines of chromosome-doubled haploids from crosses between one winter and four spring barley varieties were analysed for winter hardiness and vernalization requirement in the field. About one quarter or less of the offspring lines required vernalization under field conditions showing that winter versus spring habit of growth is controlled by at least two pairs of genes. The vernalization requirement could be measured quantitatively by testing a few plants in a greenhouse after artificial cold treatment during germination. The individual winter lines tested required from two to seven weeks of vernalization in order to flower as early as possible. The cold treatment had no effect on the time of flowering in the spring lines.Winter hardiness varied from zero to 100% plant survival in the field. The majority of the lines requiring vernalization survived better than 90% and the survival of the rest was at least 60%. The winter survival of the spring lines varied from zero per cent (about one third of the lines) to 100%. Hence, it is possible to obtain lines of good winter hardiness without requirements for cold treatment. Conversely, a selection for vernalization requirement has a positive effect on winter hardiness.     

Assessment of perennial ryegrass (Lolium perenne L.) for breeding. II. Components of winter hardiness

Summary When breeding for good winter hardiness a broad range of adaptations must be considered. Such a multitrait approach requires some understanding of physiological and genetical relationships between relevant traits.Fourteen winter related characters were measured on field grown plants from 86 perennial ryegrass accessions originating from a wide range of climates. Genetic components of variance and covariance were extracted from the data and a principal components analysis carried out. The first three independent components accounted for 80% of the variance represented by the genetic correlations and were broadly identified as winter growth, winter hardiness and early spring activity factors. None of the accessions exhibited a combination of extreme winter growth and winter hardiness although several with excellent winter hardiness showed better than average winter growth. Amounts of water soluble carbohydrate maintained through the winter appeared important for good survival.It was concluded that a selection index approach may prove useful in future breeding programmes as further information concerning physiological relationships becomes available.     

Relationship between cold resistance,heading traits and ear primordia development of wheat cultivars

Summary For breeding early heading wheat cultivars with resistance to frost damage which are well adapted to dry areas of West Asia and North Africa, the relationships between winter hardiness, ear primordia development and heading traits, i.e. veernalization requirement, photoperiodic response and narrow-sense earliness, were assessed using a total of 30 genotypes of wheat (Triticum aestivum L.) grown in an experiment in Syria. The results of artificial freezing tests indicated that cultivars with good winter hardiness were to be found only in the winter wheat cultivars which required 50 or more days of vernalization treatment. These winter wheat cultivars did not initiate internode elongation without vernalization even at 95 days after planting. Thus their ear primordia were still underground and were protected from frost injury at this stage. Photoperiodic response and narrow-sense earliness were not associated with winter hardiness and earliness of internode elongation, but were related to the number of days to heading after planting. This indicated the possibility for breeding early heading cultivars with winter hardiness and tiller frost avoidance by combining high vernalization requirement, short narrow-sense earliness and neutral response to photoperiod.     

Genetic variation in cocksfoot (Dactylis glomerata L.) populations for mottle virus resistance

Summary Highly significant and continuous variation in the degree of injury due to cocksfoot mottle virus (CfMV) infection was found among clones of 7 cocksfoot (Dactylis glomerata L.) populations, taken at random among surviving plants in 9 year old swards. Broad sense heritabilities for CfMV injury ranged from 0.52 to 0.91 within populations, and genotypic correlations between CfMV injury and total DM-yield ranged from –0.46 to –0.88. The relationship between CfMV injury and DM-yield could be described by a second degree curve. CfMV injury was to some extent genotypically correlated in the positive direction with crude protein content and digestibility, and negatively with crude fiber content, especially in the first cut. Artificial infection of plants from the original populations with CfMV in a simulated sward experiment, did not reveal any significant differences between populations in tolerance towards CfMV infection. Infection caused a 54.5% increase in the number of dead plants per plot, relative to uninfected plots, but only a 4.5% reduction in dry matter yield. There is a clear tendency that synthetic populations selected for high yield are less tolerant towards CfMV infection than unselected or low yielding populations. The resistance found in these cocksfoot populations is a sort of tolerance, and the results indicate that the level of tolerance can be increased by selection.     

Field performance of natural narrow-leafed lupin from the northwestern Spain

Summary Narrow-leafed lupin or lupine (Lupinus angustifolius L.) is one of the three species of the genus Lupinus that grows naturally in Galicia (northwestern Spain). In this region, with more than one million of cattle heads, almost 20% of Spanish total, there is no cultivation of any protein legume for feed. Lupins are widely used as a source of protein and energy in livestock feed and would contribute to the supply of vegetable protein at low cost. A 2-year study of natural narrow-leafed lupin germplasm was conducted under winter Mediterranean conditions in northwestern Spain. Fifty-nine wild populations and two cultivars developed in Poland were evaluated for major morphological, phenological, and agronomical characteristics. The objectives were to assess the agronomic potential of this germplasm for the future production and breeding, and to know the relationships among populations studied. Lupin populations showed significant differences for most of the traits studied. Genotype × environment interaction was significant for plant height, green and dry mass, pod length, seeds per pod, seed length and width, and water permeability of seed coat, indicating that some genotypes were better fitted to a specific environment than others. Three narrow-leafed lupin populations (LUP-0098, LUP-0138 and LUP-0200) were identified with suitable agronomical characteristics for their possible future cultivation in the region and breeding purposes. The accession LUP-0138 presented the best behaviour for seed production. These results open the way for the winter narrow-leafed lupin to become a promising crop in the future for the northwestern Spain.     

Field Evaluation of Cocksfoot,Tall Fescue and Phalaris for Dry Marginal Environments of South‐Eastern Australia. 2. Persistence

Perennial grasses provide forage and environmental benefits in the agricultural systems of southern Australia, but persistent cultivars are lacking for the lower rainfall inland margins (<600 mm average annual rainfall). Potential new cultivars of cocksfoot (Dactylis glomerata L.), tall fescue (Festuca arundinacea Schreb. = syn. Lolium arundinaceum (Schreb.) Darbysh.) and phalaris (Phalaris aquatica L.) have been developed in response to this need. These and older cultivars were evaluated for persistence at five sites in south‐eastern Australia from 2009 to 2013. A wide range in rainfall was experienced, but survival was principally reduced by a severe spring–summer–autumn drought in the final year in which all species began to decline in persistence once the spring 2012 to autumn 2013 cumulative climatic moisture deficit became higher than about 700 mm and declined very severely at deficits over 1000 mm. The highly summer‐dormant cocksfoot ssp. hispanica control cultivar Kasbah showed outstanding survival of this event in the cropping zone of southern New South Wales, but not at the drier of two sites with acidic soils in central Victorian where all cocksfoot cultivars showed similar survival. Potential new summer‐active tall fescue cultivars survived well at the higher rainfall Victorian site and under high rainfall in northern NSW. All tall fescue cultivars experienced high mortality during a period of high moisture stress in the spring of the establishment year in southern NSW, but the Mediterranean cultivar Grasslands Flecha MaxP gradually recovered. Differences among phalaris cultivars were not large with new cultivars of North African origin being marginally more persistent at the drier site in southern NSW. Comparisons with results from the Mediterranean Basin are discussed. Although there was no clear evidence of differences in persistence between the new and old cultivars, some of the new cultivars were considered to show potential for commercial release.     

Agronomic and quality effects in winter wheat of a gene conditioning resistance to wheat streak mosaic virus

Wheat streak mosaic virus (WSMV) is one of the most important diseases limiting winter wheat (Triticum aestivum L.) production in the western Great Plains of North America. There is no known effective WSMV resistance within the primary gene pool of wheat. However, a resistance gene (Wsm1) has been transferred to wheat from a perennial relative, intermediate wheat-grass [Thinopyrum intermedium (Host) Barkworth & DR Dewey]. Nebraska-adapted winter wheat lines carrying Wsm1 were used to characterize the effects of this alien introgression on agronomic and quality traits. Sister-lines from six breeding populations were evaluated under virus-free conditions, and under a naturally occurring viral infection. In uninfected locations, no significant difference for grain yield was detected between resistant (R) and susceptible (S) lines, when averaged over populations, but resistant lines had significantly higher test weights. Within populations, significantly higher grain yield was observed only in population 1, while significantly higher test weights occurred in populations 1, 2, 5 and 6. At the infected location, resistant lines were significantly higher in yield in five of six populations. In two of six populations, susceptible lines were significantly higher in bread loaf volume and bake mix time, while in the remaining populations, no significant quality differences were observed. As the Wsm1 gene provided yield advantages under viral infection, and there was no yield detriment in the absence of the virus, its deployment in hard winter wheat cultivars merits consideration.Joint contribution of the United States Department of Agriculture, Agricultural Research Service and the Department of Agronomy, University of Nebraska-Lincoln as Journal Series Paper No. 15066. Mention of firm names or trade products does not imply that they are endorsed or recommended by the USDA or the University of Nebraska over other firms or products not mentioned.     

Winter hardiness in trench celery

A total of 51 red and white commercial varieties of trench celery were grown and examined for winter hardiness at the National Vegetable Research Station. Although some plants of most varieties survived the winter, none showed a commercially useful degree of winter hardiness, in that none were marketable after moderate frost. The red varieties had a significantly better survival than the white varieties. In the first season, single plant selections were made from the varieties having both the highest percentage of winter survival and the best agronomic characters. Although some of the progenies derived from these selected plants by self-pollination showed a small increase in winter survival as compared with their parent varieties when both were grown in the second season, no plants of these progenies were sufficiently hardy to remain marketable after moderate frost. It was concluded that none of the varieties tested showed any promise as a source of winter hardiness to be used in a breeding programme, and that selection for one generation from within these varieties did not improve winter hardiness to a useful extent.     

Third supplementary list of wheat varieties classified according to their genotype for hybrid necrosis

Summary New data about the geographical distribution of necrosis genes support the previous conclusion, viz. the Old World can be divided by a rough line running through the Mediterranean and Black Sea countries to Lake Baikal and from these to northern Japan. The Ne ₁-area lies south and east and the Ne ₂ area north and west of this line. There are indications that Ne ₁-carrying wheat varieties exist in the Leningrad district.The third supplement contains 441 varieties and selections of which the genotype for hybrid necrosis is given. The total number of tested varieties etc. is now 1150.     

Winter hardiness in marginal populations of timothy

Summary A comprehensive collection of local fodder grass populations was carried out in the northern regions of Norway in 1972 and 1973. The main purpose was to find ecotypes with extreme winter hardiness. This paper gives results from experiments carried out with some of the timothy populations collected.After testing in dense stand a few of the most promising populations were selected for investigation of genetic variation within populations by growing in duplicate blocs of 100 clones from randomly selected plants. Twenty-two clones were selected from each of six populations and planted in separate isolated polycross fields. During 1986 to 1990 the half-sib families from these polycrosses were grown in two series of experiments laid out at two locations, Tromsø and Alta.Significant genetic variations were found for winter hardiness within all six populations tested, as well as interaction between families and locations, while the interaction effects between families and years were small and insignificant in all cases.Winter hardiness was strongly genotypically correlated in the positive direction with visually estimated general performance, but not correlated with digestibility.     

Genetic variation in a Norwegian germplasm collection of white clover (Trifolium repens L.)

Genetic variation and genotype × environment interactions for important agronomic characters were estimated for eleven Norwegian populations of white clover (Trifolium repens L.), originating from between 58^°52′N and 69^°30′N latitude, and from altitudes of 10 to 450 m a.s.l. The populations were evaluated in monoculture clonal field plots for two years at two locations in Norway. The medium-leaved Danish cultivar Milkanova was also included in the experiment as a standard market cultivar. Considerable variation between populations was observed for winter survival, spring growth, morphological characteristics, dry matter yield, general performance, earliness and seed yield. Winter survival, measured as plant cover after two years, was significantly different at the two locations. All the populations had sufficient winter survival at the southern, continental highland site (61^°07′N).At the northern coastal location (69^°30′N),where the winter climate is unstable with physical stresses such as frost, ice-encasement and water-logging frequently occurring, only the northernmost, coastal populations showed sufficient winter survival. Highly significant interactions were found between populations and locations, and between populations and years for all characters measured at both locations and in both years, respectively. Interaction effects between populations, locations and years were significant only for leaflet length. The largest leaf lamina's were observed in the most southern populations. However, genotypes possessing relatively long leaflets were also found in the northernmost populations, although at low frequencies. In general, the populations originating from the northernmost locations had lower biomass production, and were smaller-leaved, more prostrate and exhibited shorter internodes and stolons compared to the populations from South and Middle Norway. These populations also initiated inflorescences earliest, and were among the lowest seed yielding populations. Otherwise, no clear clinal variation in growth characteristics was observed which could be related to the latitude or altitude of origin of the populations. This revised version was published online in July 2006 with corrections to the Cover Date.     

Field Evaluation of Cocksfoot,Tall Fescue and Phalaris for Dry Marginal Environments of South‐Eastern Australia. 1. Establishment and Herbage Production

Newly developed candidate cultivars of cocksfoot (Dactylis glomerata L.), phalaris (Phalaris aquatica L.) and tall fescue (Festuca arundinacea Schreb. = syn. L. arundinaceum (Schreb) Darbysh.) were evaluated over four years for persistence and productivity against current commercial cultivars in small plots at five locations selected for lower and less reliable rainfall and difficult soils (low pH and high Al) in south‐eastern Australia known to be marginally too dry for these grass species. The five locations were ‐ representing summer dominant rainfall, Inverell, in northern New South Wales (NSW); ‐ representing uniform rainfall; Trungley Hall, (medium rainfall), and Beckom (lower rainfall) both in southern NSW; and; representing a winter dominant pattern ‐ Eversley, (higher rainfall), and Bealiba, (lower rainfall), in central Victoria. The objective was to determine if the new candidate cultivars were more likely to persist and to be productive than current commercial cultivars. The study showed that most phalaris and cocksfoot treatments were highly productive in high rainfall years at one or both sites in southern NSW. However, all treatments had become much less productive by the end of the experimental period due to plant loss under hot, dry conditions in the final summer. At Bealiba in central Victoria, cocksfoot was the most productive species with several cocksfoot treatments of both subsp. hispanica and subsp. glomerata still present at the final harvest despite a hot and dry final summer‐autumn. Tall fescue was the most productive species in the two higher rainfall environments (Inverell, Eversley) although most treatments of all species performed well at those sites. Continental tall fescues were more productive on average than Mediterranean tall fescues at the strongly acidic Eversley site. As a result of this work, two of the new cocksfoot candidates (Moroccan Fine and AVH48 Selection) and one of the tall fescue candidates (Summer Active 1) have been licensed for commercial development and release.     

Abscisic acid response to water status in Dactylis glomerata differs with expression of summer dormancy

Summer dormancy confers superior drought survival in cool-season perennial grasses and is likely to be of increasing importance as climate change proceeds although relatively little is known about this trait. This paper explores the relationship between the level of abscisic acid (ABA), the expression of summer dormancy and the onset and relief of water deficit in cool-season perennial grasses. Three cultivars of Dactylis glomerata L. (cocksfoot) known to differ in expression of summer dormancy were grown in the field over summer and in the glasshouse over winter under water deficit or full irrigation. Hydration and osmotic potentials of basal tissues were measured to assess the level of water deficit, and endogenous ABA was determined in the tissues by monoclonal immunoassay analysis. In a winter trial, higher contents of ABA were present when plant water deficits became greater so that there were no differences between the cultivars in the concentrations of ABA observed. In a summer trial a short period of waterlogging caused water status to increase in all cultivars, although in the maritime cultivar Oasis this was also associated with a rise in ABA contents. In contrast, in the summer-dormant cultivar Kasbah, only low ABA concentrations were observed throughout the entire period whether waterlogged or in drying soil. Heightened ABA levels are not induced by water deficit when summer dormancy is expressed in Dactylis glomerata. This contrasted with those cultivars unable to express summer dormancy where particularly in early summer severe water deficit was associated with heightened ABA levels.     

Winter Hardiness, Frost Resistance and Vernalization Requirement of European Winter Oilseed Rape (Brassica napus var. oleifera) Cultivars within the Last 20 Years

Cultivars of European winter oilseed rape cultivated in the second half of the 1970s and in the mid-1990s were screened for their winter hardiness, frost resistance and vernalization requirement. A strong correlation between winter hardiness and frost resistance in both groups of rape has been noticed. Among oilseed rapes cultivated in the late 1970s, low erucic acid and particularly double zero cultivars were less winter hard than high erucic acid cultivars. Double zero cultivars were characterized by lower frost resistance and lower vernalization requirement. A significant correlation between vernalization requirement and both frost resistance and field survival has also been shown. Frost resistance of the 1990s (double zero) cultivars was higher than that of double low cultivars from the late 1970s. Their vernalization requirement was still small and did not correlate with either frost resistance or winter hardiness. It was concluded that reduction in the content of glucosinolates in the 1970s involved decrease in winter hardiness and vernalization requirement of cultivars. During the following 20 years winter hardiness of double low cultivars has been improved, but vernalization requirements have not changed. As a result no correlation between winter hardiness and vernalization requirement in contemporary canola cultivars has been observed.     

Alien introgression of spring habit dominant genes into bread wheat

Summary Alien dominant genes of spring habit were introgressed into bread wheat. The introgression was undertaken by simple crossing of winter bread wheat to related spring species or genera, followed by backcrossing to winter bread wheat, and did not involve the use of the ph mutants or embryo culture. The introgressed genes were located mostly on chromosomes of homoeologous group 5, and were allelic to the known Vrn genes in bread wheat. Nevertheless three groups of lines were discovered with the genes possibly located on other chromosomes. These genes were non-allelic to each other and to known Vrn genes and were designated Vrn6 ^Sc , Vrn7 ^Sc (introgressed from Secale cereale) and Vrn8 ^Ts (from Triticum sphaerococcum).     

Relevance of Osmotic and Frost Protecting Compounds for the Winter Hardiness of Autumn Sown Sugar Beet

The cultivation of autumn sown sugar beet (winter beet) is supposed to result in a marked yield increase compared with spring sown sugar beet. Although the importance of the growth stage reached before winter for the survival of autumn sown sugar beet has already been shown, it is not clear to which extent osmotic and potentially frost protecting compounds may contribute to winter hardiness. The study thus aimed to analyse the acclimatization process of sugar beet to low temperatures and to identify compounds which are important for survival of frost. Field trials with autumn sown sugar beet were conducted at eleven environments in Germany from 2009/10 to 2012/13, which were accompanied by greenhouse experiments with controlled temperature regimes. In the field trials, the survival rates after winter varied from 0 % to 99 %, but only in four environments differences between the five genotypes occurred. During acclimatization, betaine, glutamine, proline and raffinose were markedly accumulated and osmolality was enhanced. In particular betaine, amino acids and osmolality showed a positive correlation to the survival rate and were thus identified as potentially frost protecting substances for sugar beet. In contrast, raffinose and proline seem to act rather as stress indicators as they were negatively related to survival. Possible frost protecting substances were identified which can be used in breeding to improve the winter hardiness of sugar beet.