Revealing hereditary variation of winter hardiness in cereals

A set of cereal crops and differentiating cultivars was shown to be of utility for identifying the major abiotic factors that limit the survival of winter crops in the cold season of a particular year. With this approach, the season was identified (1997-1998, Belgorod) when the survival of cereals depended on the tolerance to anaerobiosis rather than on the frost resistance. Differentiation of common wheat cultivars with respect to this property was attributed to a locus designated Win1 (Winter hardiness 1) and localized 3.2-5.8% recombination away from the B1 (awnlessness) gene. Winter barley (cultivar Odesskii 165) displayed the highest tolerance to anaerobiosis in the cold season; low and intermediate tolerance was established for winter durum wheat (cultivar Alyi Parus) and winter common wheat, respectively. Frost resistance and winter hardiness type 1 proved to be determined by different genetic systems, which showed no statistical association. Correlation analysis revealed significant positive associations of frost resistance in the field (1996-1997, Belgorod) with productivity, sedimentation index, plant height, and vegetation period in wheat. Statistical analysis associated frost resistance with gliadin-coding alleles of homeologous chromosomes 1 and 6 of the A, B, and D wheat genomes.     

Effect of the 5R(5A) Alien Chromosome Substitution on the Growth Habit and Winter Hardiness of Wheat

The growth habit, ear emergence time, and frost tolerance of wheat/rye substitution lines have been studied in cultivars Rang and Mironovskaya Krupnozernaya whose chromosome 5A is substituted with chromosome 5R of Onkhoyskaya rye. Hybrid analysis has demonstrated that the spring habit of the recipient cultivars Rang and Mironovskaya Krupnozernaya is controlled by dominant gene Vrn-A1 located in chromosome 5A. Onokhoyskaya rye has a dominant gene for the spring habit (Sp1) located in chromosome 5R. It has been found that the resultant 5R(5A) alien-substitution lines have a winter type of development and ears do not emerge during summer in plants sown in spring. The change in growth habit has been shown to be related to the absence of the rye Sp1 gene expression in the substitution lines. The winter hardiness of winter 5R(5A) alien-substitution lines has been studied under the environmental conditions of Novosibirsk. Testing the lines in the first winter demonstrated that their winter survival is 20–27%. The possible presence of the frost resistance gene homeoallelic to the known genes Fr1 and Fr2 of the common wheat located on chromosomes 5A and 5D, respectively, is discussed.     

The relationship between vernalization requirement and frost tolerance in substitution lines of wheat

Two sets of wheat (Triticum aestivum L.) substitution lines for the homoeologous group 5 chromosomes, 5A, 5B and 5D, carrying vernalization genes (Vrn-A1, Vrn-B1, Vrn-D1) were used to study the relationship between vernalization requirement and winter survival, with respect to the induction and maintenance of frost tolerance. Substitution lines carrying dominant Vrn loci substituted from the spring cultivars Zlatka (5A), Chinese Spring (5D) and the alternative cultivar eská Pesívka (5B) into three different winter wheat backgrounds, Vala, Koútka and Zdar, showed lower winter survival by 20, 36, and 41 % for substitutions of 5B, 5A and 5D, respectively, compared to the original winter cultivars. Reciprocal substitution lines between two winter cultivars Mironovskaya 808 and Bezostaya 1 carrying different recessive alleles, vrn-A1, vrn-B1, vrn-D1, did not exhibit a modified induction of frost tolerance, but the duration of good frost tolerance, as well as the ability to survive the whole winter, was changed. In accordance with the model suggesting that genes for vernalization act as a master switch regulating the duration of frost tolerance, substitutions of homoeologous group 5 chromosomes induced, at first, frost tolerance at a level equal to the parental cultivar, and then, relative to the different extent of saturation of vernalization requirement, they gradually lost both frost tolerance and their ability to re-induce significant frost tolerance with a drop in temperature following warm periods in the winter.     

Accumulation of Dehydrins and ABA-Inducible Proteins in Wheat Seedlings during Low-Temperature Acclimation

Using one-dimensional SDS-PAGE and immunochemical methods, we detected the presence and estimated the content of dehydrins and ABA-inducible (RAB) polypeptides in etiolated seedlings of four spring and three winter wheat (Triticum aestivum L.) cultivars differing in frost hardiness. We hardened three-day-old seedlings at 4°C for nine days or grew them at 22°C for a day (control seedlings). We established that heat-stable cold-regulated (COR) polypeptides with mol wts of 209, 196, 169, 66, 50, and 41 kD, which are characteristic of hardened wheat seedlings, were homologous to polypeptides from a dehydrin family and polypeptides with mol wts of 209, 196, 66, 50, and 41 kD were immunologically related to RAB-proteins. We supposed that these COR polypeptides were involved in the prevention of local protein dehydration and denaturation during hypothermia. Analysis of the relative content of COR proteins revealed a close correlation between the cultivar frost hardiness and the concentration of these proteins. It seems evident that different accumulation of dehydrins and RAB polypeptides in different cultivars of a single species is one of the causes for different plant frost hardiness.     

Inheritance of frost resistance and winter hardiness in distant hybrids of wheat and amphiploids

The data on inheritance of frost resistance and winter hardiness of bread wheat lines obtained as a result of distant hybridization of wheat-rye and wheat-elymus amphiploids with durum and bread wheat were presented. It was shown that selection of the donors of valuable traits is sensible to make in later progenies of hybrids (F6-F7). So, it is possible to obtain the new initial breeding material for winter bread wheat selection with high frost tolerance, winter hardiness and early maturity. Hypotheses explaining the high frost resistance of hybrids are presented. The crosses of the octoploid amphiploids with durum wheat are more preferable for the alien traits introgression into wheat than the crosses with bread wheat.     

Liming and deep ripping responses for a range of field crops

Grain yields were measured over 2 seasons from a range of field crops following liming and deep ripping an acid and compacted soil in north-eastern Victoria. Lime (2.5 t ha^–1) substantially reduced the level of exchangeable Al and exchangeable Mn whilst raising soil pH by about 1.0 unit. The crops grown were 7 cultivars of wheat and one cultivar each of triticale, oats, barley, rapeseed, safflower, field pea, chick pea and lupins. With the exception of lupin, liming the soil increased (p=0.05) the grain yield of all crops and cultivars. With the wheat cultivars there were 2 distinct groups with different tolerance to soil acidity. Wheat, oats, triticale and lupins had higher absolute yields than the other crops. Safflower and chick pea had very low yields without soil amendment. The magnitude of the lime response did not differ between the wheat cultivars (17%) or between any of the crop species (range 9–29%). Deep ripping the soil to break a hard compacted layer resulted in more yield for all the cereals and safflower. The results demonstrate the importance of using crops with tolerance to acid soil conditions as well as gains that can be obtained with ameliorating identifiable soil problems.     

Formation of phenolic compounds in various cultivars of wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.)

The formation of soluble phenolic compounds, including flavonols, was studied in winter (Erythrospermum , Lutescens 230, and R 47-28) and spring cultivars (Lada) of wheat (Triticum aestivum L.). The contents of soluble phenolic compounds and flavonols were 1.8–2.6 and 0.5–1.3 mg/g fresh weight, respectively. These results illustrate the similarity of phenol metabolism in leaves of winter and spring wheat cultivars. The exception was the cultivar R 47-28 that accumulated the maximum amount of phenolic compounds (e.g., flavonols). In this cultivar the ratio of flavonols reached 50% of total soluble phenol content. In other cultivars, this parameter did not exceed 25–35%. The data indicate that the cultivar R 47-28 differs from other wheat cultivars in metabolism of phenolic compounds. The observed differences are probably related to genetic modifications of the cultivar R 47-28 during selection.Translated from Prikladnaya Biokhimiya i Mikrobiologiya, Vol. 41, No. 1, 2005, pp. 113–116.Original Russian Text Copyright © 2005 by Zagoskina, Olenichenko, Chzhou Yunvei, Zhivukhina.     

Effect of the 5R(5A) alien chromosome substitution on the growth habit and winter hardiness of wheat

The growth habit, ear emergence time, and frost tolerance of wheat/rye substitution lines have been studied in cultivars Rang and Mironovskaya Krupnozernaya whose chromosome 5A is substituted with chromosome 5R of Onkhoyskaya rye. Hybrid analysis has demonstrated that the spring habit of the recipient cultivars Rang and Mironovskaya Krupnozernaya is controlled by dominant gene Vrn-A1 located in chromosome 5A. Onokhoyskaya rye has a dominant gene for the spring habit (Sp1) located in chromosome 5R. It has been found that the resultant 5R(5A) alien-substitution lines have a winter type of development and ears do not emerge during summer in plants sown in spring. The change in growth habit has been shown to be related to the absence of the rye Spl gene expression in the substitution lines. The winter hardiness of winter 5R(5A) alien-substitution lines has been studied under the environmental conditions of Novosibirsk. Testing the lines in the first winter demonstrated that their winter survival is 20-27%. The possible presence of the frost resistance gene homeoallelic to the known genes Fr1 and Fr2 of the common wheat located on chromosomes 5A and 5D, respectively, is discussed.     

Copy number variations of CBF genes at the Fr‐A2 locus are essential components of winter hardiness in wheat

Winter hardiness is important for the adaptation of wheat to the harsh winter conditions in temperate regions and is thus also an important breeding goal. Here, we employed a panel of 407 European winter wheat cultivars to dissect the genetic architecture of winter hardiness. We show that copy number variation (CNV) of CBF (C‐repeat Binding Factor) genes at the Fr‐A2 locus is the essential component for winter survival, with CBF‐A14 CNV being the most likely causal polymorphism, accounting for 24.3% of the genotypic variance. Genome‐wide association mapping identified several markers in the Fr‐A2 chromosomal region, which even after accounting for the effects of CBF‐A14 copy number explained approximately 15% of the genotypic variance. This suggests that additional, as yet undiscovered, polymorphisms are present at the Fr‐A2 locus. Furthermore, CNV of Vrn‐A1 explained an additional 3.0% of the genotypic variance. The allele frequencies of all loci associated with winter hardiness were found to show geographic patterns consistent with their role in adaptation. Collectively, our results from the candidate gene analysis, association mapping and genome‐wide prediction show that winter hardiness in wheat is a quantitative trait, but with a major contribution of the Fr‐A2 locus.     

Relationship between frost tolerance and sugar concentration of various bryophytes in summer and winter

Summary Frost resistance, measured via the photosynthetic capacity after freeze-thaw treatment, and concentrations of sucrose, glucose and fructose of thalli of seven species of Bryidae and one species of Marchantiidae were determined from January to March and June to September, respectively. A distinct increase in cold tolerance from summer to winter was found in Polytrichum formosum Hedw., Atrichum undulatum (Hedw.) P. Beauv., Plagiomnium undulatum (Hedw.) Kop., Plagiomnium affine (Funck) Kop., Mnium hornum Hedw. and Pellia epiphylla (L.) Corda. While the frost resistance of the musci differed in summer and winter by 15° to more than 25° C, the hardening capacity of the thalloid liverwort was comparably low. Except in Mnium hornum, the increase in frost hardiness was accompanied by rise of the sucrose concentration in the cells, but insignificant changes in glucose and fructose contents. In contrast, Brachythecium rutabulum (Hedw.) B.S.G. and Hypnum cupressiforme Hedw. already exhibited high frost tolerances in summer, which coincided with high sucrose levels in the tissue, comparable to those found in other musci during the winter. Highly frost-resistant musci had total sugar concentrations around 90–140 mM, of which at least 80% and often more than 90% was sucrose. Artificial degradation of sucrose during exposure of mosses to higher temperatures resulted in a decline in cold hardiness. The results signify that the concentration of sugars, mainly of sucrose, may be important for the frost tolerance of bryophytes.     

Does the lack of vernalization requirement interfere with winter survival of oilseed rape plants?

Recent studies (Rapacz 1999) have shown that cultivars of spring-type oilseed rape are able to cold-acclimate to the level comparable with winter cultivars, but only after prehardening which results both in the increase of photosynthetic activity and in growth cessation. It is commonly known that under field conditions spring-type cultivars could not survive winter. Present studies were undertaken to explain the reasons for low winter hardiness of spring type rape plants. Six cultivars of spring and two of winter rape were sown in the open-air vegetation room at the end of August. The obtained results indicate that the degree of frost damage in spring-type plants increased in the course of winter and this increase was parallel to elongation of generative shoots observed after periods of warming. Each spring cultivar was completely killed by frost just after its generative shoot reached 15–20 cm, irrespective of its frost resistance level, determined previously under laboratory conditions. In the case of winter cultivars survival rate was consistent with laboratory-estimated frost resistance. It is suggested that spring rape could not survive winter because of its limited ability to prevent shoot elongation during winter at temperatures slightly above 0 °C. It was also found that less efficient photosynthetic electron transport in autumn was observed in these spring cultivars in which the elongation of generative shoots was observed already during the first warm break in winter.     

Impact of intercropping aphid-resistant wheat cultivars withoilseed rape on wheat aphid (Sitobion avenae) and its natural enemies

The effects of intercropping of wheat cultivars and oilseed rape on the densities of wheat aphid, Sitobion avenae, and their arthropod natural enemies were evaluated. Three winter wheat cultivars with different resistant levels to S. avenae were used: ‘KOK’ (high resistance), ‘Xiaobaidongmai’ (low resistance) and ‘Hongmanghong’ (susceptible). The results showed that the densities of S. avenae were significantly higher on the monoculture pattern than on either the 8-2 intercropping pattern (eight rows of wheat with two rows of oilseed rape) or the 8-4 intercropping pattern (eight rows of wheat with four rows of oilseed rape). The mean number of predators and the mummy rates of S. avenae were significantly higher in two intercropping patterns than those in the monoculture pattern. The densities of S. avenae, ladybeetles, and mummy rate of S. avenae were significantly different among different wheat cultivars. The highest densities of S. avenae and ladybeetles were found on wheat cultivar Hongmanghong. The lowest densities of S. avenae associated with high mummy rate of S. avenae were found on wheat cultivar Xiaobaidongmai. The results showed that wheat-oilseed rape intercropping conserved more predators and parasitoids than in wheat monoculture fields, and partial resistance of wheat cultivar Xiaobaidongmai had complementary or even synergistic effects on parasitoid of S. avenae.     

Assessing cultivar resistance to Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae) using a phenotyping method under semi‐field conditions

The orange wheat blossom midge, Sitodiplosis mosellana (Géhin), can significantly reduce wheat yield. Growing resistant wheat cultivars is an effective way of managing this pest. The assessment of cultivar resistance in field trials is difficult because of unequal pressure of S. mosellana caused by differences in cultivar heading dates relative to the flight period of S. mosellana adult females and huge variations of egg laying conditions from 1 day to another. To overcome these hurdles and to expose all cultivars homogeneously to the pest, an assessment method of cultivar resistance was developed under semi‐field conditions. In 2015, the resistance of 64 winter wheat cultivars to S. mosellana was assessed. Few or no larvae developed in the ears of resistant cultivars, but in susceptible cultivars, large numbers of larvae developed. Seventeen cultivars proved to be resistant, whereas 47 were susceptible. The identification of new resistant cultivars offers more opportunities to manage S. mosellana. The phenotyping method is easy, cheap, efficient and reliable. It can be used to guide the breeding of new resistant wheat cultivars. Using specific midge populations, this method could also be used in research on new resistance mechanisms in winter wheat or in other cereal species.     

Carry-over effects of ozone and water stress on leaf phenological characteristics and bud frost hardiness of <Emphasis Type="Italic">Fagus crenata</Emphasis> seedlings

We examined the carry-over effects of ozone (O₃) and/or water stress on leaf phenological characteristics and bud frost hardiness of Fagus crenata seedlings. Three-year-old seedlings were exposed to charcoal-filtered air or 60 nl l^–1 O₃, 7 h a day, from May to October 1999 in naturally-lit growth chambers. Half of the seedlings in each gas treatment received 250 ml of water at 3-day intervals (well-watered treatment), while the rest received 175 ml of water at the same intervals (water-stressed treatment). All the seedlings were moved from the growth chambers to an experimental field on October 1999, and grown until April 2000 under field conditions. The exposure to O₃ during the growing season induced early leaf fall and reduction in leaf non-structural carbohydrates concentrations in the early autumn, as well as resulting in late bud break and reduction in the number of leaves per bud in the following spring. However, O₃ did not affect bud frost hardiness in the following winter. On the contrary, water stress did not affect leaf phenological characteristics, leaf and bud non-structural carbohydrates concentrations and bud frost hardiness. There were no significant synergistic or antagonistic effects of O₃ and water stress on leaf phenological characteristics, concentrations of leaf and bud non-structural carbohydrates and bud frost hardiness of the seedlings. These results show that the carry-over effects of O₃ can be found on the phenological characteristics and leaf non-structural carbohydrates concentrations, although there are almost no carry-over effects of water stress on phenological characteristics and winter hardiness of the seedlings.     

Introgression of an intermediate <Emphasis Type="Italic">VRNH1</Emphasis> allele in barley (<Emphasis Type="Italic">Hordeum vulgare</Emphasis> L.) leads to reduced vernalization requirement without affecting freezing tolerance

The process of vernalization is mainly controlled by two genes in winter barley (Hordeum vulgare L.), VRNH1 and VRNH2. A recessive allele at VRNH1 and a dominant allele at VRNH2 must be present to induce a vernalization requirement. In addition, this process is usually associated with greater low-temperature tolerance. Spanish barleys originated in areas with mild winters and display a reduced vernalization requirement compared with standard winter cultivars. The objective of this study was to investigate the genetic origin of this reduced vernalization requirement and its effect on frost tolerance. We introgressed the regions of a typical Spanish barley line that carry VRNH1 and VRNH2 into a winter cultivar, Plaisant, using marker-assisted backcrossing. We present the results of a set of 12 lines introgressed with all four possible combinations of VRNH1 and VRNH2, which were evaluated for vernalization requirement and frost tolerance. The reduced vernalization requirement of the Spanish parent was confirmed, and was found to be due completely to the effect of the VRNH1 region. The backcross lines showed no decline in frost tolerance compared with that of the recurrent parent unless they carried an extra segment of chromosome 5H. This extra segment, a carryover of the backcross process, apparently contained the well-known frost tolerance quantitative trait locus Fr-H2. We demonstrate that it is possible to manipulate the vernalization requirement with only minor effects on frost tolerance. This finding opens the path to creating new types of barley cultivars that are better suited to specific environments, especially in a climate-change scenario.     

Electrophysiological Investigation of Frost Resistance in Plants: 3. Critical Points Detected on the Freezing of Winter Wheat

Winter wheat (Triticum aestivum L.) seedlings of three cultivars differing in frost resistance were used to study cooling-induced changes in the bioelectric potential. Measurements were performed with nonfreezing graphite–glycerol electrodes in the regime of monitoring. Upon a gradual change in air temperature from 20 to –15°C at the rates of 20 and 2°C/h, the bioelectric potential underwent abrupt transitions at certain moments, indicating changes in the physiological condition of plants. The time required for the achievement of these critical states, as well as the survival of plants after thawing, depended both on the temperature and the cooling rate. Apparently, these characteristics were related to the dynamics of phase transitions of water. Cultivar-specific features were manifested in the different abilities of plants to maintain free water in a supercooled state. It is supposed that the critical points are related to the cold resistance of colloid systems and to the temperature lethal for plants.     

Fusarium Head Blight of Common Polish Winter Wheat Cultivars – Comparison of Effects of Fusarium avenaceum and Fusarium culmorum on Yield Components

The effects of Fusarium avenaceum and Fusarium culmorum on the reduction in yield components, after independent inoculation of 14 winter wheat cultivars, were investigated. Single isolates of F. avenaceum and F. culmorum were independently used in inoculations of winter wheat heads. Reductions in the following yield traits: 1000‐kernel weight (TKW), the weight (WKH) and number (NKH) of kernels per head after inoculation were analysed statistically. The results indicate differences between both pathogens in their effects on yield traits. The statistical calculations were performed using analysis of variance (a three‐factor experiment) for particular yield trait reductions and multivariate analysis of variance for the yield trait reductions jointly. Almost all of the univariate and multivariate hypotheses concerning no differences between pathogens (F. culmorum, F. avenaceum), climatic conditions (years) and cultivars as well as hypotheses concerning no interactions between factors (pathogens, years, cultivars) were rejected at least at P= 0.05 significance level. The reduction of yield traits indicated individual reactions of the tested winter wheat cultivars to different pathogens. Among the tested traits the highest influence on the rejection of the hypothesis concerning the equivalence of F. avenaceum and F. culmorum was observed for TKW and WKH. The effect of the pathogen on yield reduction was greater for F. avenaceum than for F. culmorum during 1996 and 1997. A comparison of the cultivars indicated that the Begra cultivar showed the highest tolerance to inoculation with both Fusarium pathogens. Moreover, this genotype as well as several others showed lower tolerance to F. avenaceum rather than to F. culmorum, whereas Elena was the only cultivar with the opposite tendency.     

Tolerance to manganese toxicity among cultivars of lucerne (Medicago sativa L.)

Two sand culture experiments were carried out to identify commercial cultivars of lucerne or alfalfa (Medicago sativa L.) which contain elite, Mn-tolerant plants for use in a selection programme to increase the acid-soil tolerance of this perennial legume. Differences in Mn tolerance, both within and between cultivars, were observed when a range of cultivars were exposed to regular waterings with dilute nutrient solution containing 20 or 25 mg Mn L^–1. Under these moderately toxic regimes, the winter dormant cultivars Cimmaron and WL 318 were found to contain elite plants that had greater dry matter yields than their mean cultivar yield under non-toxic Mn conditions.Cultivars which contained elite, Mn-tolerant plants could not be identified by phenotypic characteristics such as their height or their toxicity symptom score, nor by their winter dormancy class. Possible reasons for the occurrence of elite plants in these cultivars are discussed. The elite, high yielding Mn-tolerant plants could not be identified from the other plants within their cultivar population by their Mn toxicity symptoms nor by their height.     

Differences in the effects of alleles of the genes Vrd1 and Ppd-D1 with respect to winter hardiness, frost tolerance and yield in winter wheat

The influence of allelic differences between the genes Vrd1 and Ppd-D1 and their interaction with respect to winter hardiness, frost tolerance, and yield and the components of the yield in recombinant-inbred F5 lines of Odesskaya 16/Bezostaya 1 is investigated. From 9 to 15% of the differences with respect to winter hardiness and frost tolerance in the recombinant-inbred lines are attributable to alternative alleles of the Vrd1 gene and 10–16% to the alternative alleles of the Ppd-D1 gene. Interaction between the alleles vrd1 and Ppd-D1a promotes the formation of the greatest winter hardiness and frost tolerance in tillered plants throughout winter. At the same time, a reliable increase in the time to heading and height of the plants as well as a tendency towards reduced yield of grain in lines with the genotype vrd1 vrd1 Ppd-D1a Ppd-D1a by comparison with lines with the genotype Vrd1 Vrd1 Ppd-D1a Ppd-D1a are discovered.     

Frost tolerance in winter wheat cultivars: different effects of chromosome 5A and association with microsatellite alleles

Frost tolerance of ten Bulgarian winter wheat (Triticum aestivum L.) cultivars (Milena, Pobeda, Sadovo-1, Enola, Kristal, Laska, Svilena, Russalka, No301 and Lozen) and five foreign cultivars (Mironovskaya 808, Bezostaya-1, Rannaya-12, Skorospelka-35 and Chinese Spring) was studied in two experimental seasons following natural cold acclimation and in one experiment carried out in controlled acclimation conditions. Considerable intercultivar variability in plant survival was observed after freezing at ?21 °C following sufficient cold acclimation, or at ?18 °C following insufficient or controlled acclimation. In seven cultivars, the effects of chromosome 5A on frost tolerance were investigated in their F₂ hybrids with chromosome 5A monosomic lines of cultivars with high, intermediate and low frost tolerance. The effects of chromosome 5A depended on the stress severity and the genetic background of the hybrids and varied even in cultivars of similar frost tolerance and vernalization requirements. Effects of other chromosomes besides 5A on frost tolerance were assumed. The analysis of six microsatellite loci located in the interval from centromere to Vrn-1 on of chromosomes 5AL, 5BL and 5DL showed that the major loci determining frost tolerance in Bulgarian winter wheats were Fr-A2 on chromosome 5AL, and, to a lesser extent, Fr-B1 on chromosome 5BL. A strong association of the 176 bp allele at locus wmc327 tightly linked to Fr-A2 with the elevated frost tolerance of cvs. Milena, Pobeda, Sadovo-1, Mironovskaya-808 and Bezostaya-1 was revealed. Relatively weaker association between frost tolerance and the presence of the 172 bp allele at locus Xgwm639 tightly linked to Fr-B1 was also observed.