Estimates of genotypic and yearly variations on fruit quality and functional traits for tetraploid table grape breeding

We estimated genetic and environmental variance components for fruit quality traits (cluster weight, berry weight, soluble solids content, total sugar content, sugar composition, free acid content, total amino acid content, amino acid composition), and a functional trait (gamma-aminobutyric acid (GABA) content) of three commercial tetraploid table grape cultivars (Kyoho, Pione, Suiho) grown in Japan over three successive years. ANOVA showed that the effect of genotype was significant (P < 0.05) for all traits except soluble solids content and total sugar content. The effect of the year was significant for all traits except amino acid composition (γ ratio) and GABA content. The variance of genotype (σ _g ²) was highest for γ ratio (63.6%), high in sugar composition (α ratio, 60.3%) and GABA content (58.8%), and negligible for soluble solids content (0.0%) and total sugar content (0.0%). The variance of among years (σ _y ²) was very high in soluble solids content (82.8%), high in total sugar content (60.2%) and negligibly small in γ ratio (8.7%) and GABA content (6.4%). Some effects of genotype × year interaction, among vines within genotypes, and vine × year interaction were statistically significant, but these components were negligibly small. Except for soluble solids content and total sugar content, significant varietal differences in the traits were recorded. Variance estimates for each trait provides useful information for optimal yearly repetition to effectively discriminate genetic differences in fruit quality and functional traits for improving future tetraploid table grape breeding programs.     

Resveratrol production potential of grape flowers and green berries to screen genotypes for gray mold and powdery mildew resistance

The ability of grape cultivars to produce resveratrol in response to UV radiation is associated with their resistance to fungal pathogens. In this study, we evaluated the UV-induced resveratrol production potential of grape flowers and green berries of 72 grape genotypes. Their ability to produce resveratrol in response to UV radiation was used to establish a selection criterion for screening genotypes for resistance to gray mold and powdery mildew. We quantified resveratrol in grape flower extracts from pre-bloom and early bloom flowers after exposure to UV radiation. There was a strong negative correlation between UV-induced resveratrol production and susceptibility to Botrytis infection. The grape genotype was considered to be susceptible to gray mold when the resveratrol content of whole flower clusters was less than 10 μg g⁻¹ FW after the UV treatment. We determined resveratrol production in response to UV radiation in whole grape berries from 0 to 30 days after full bloom. The ability to produce resveratrol in response to UV increased by 8- to 20-times during this period, depending on the genotype. At 30 days after full bloom, Vitis vinifera genotypes generally had low levels of resveratrol (<50 μg g⁻¹ FW), while interspecific hybrids, especially the North American cultivars, had high levels (>50 μg g⁻¹ FW). There were clear varietal differences in resistance to Erysiphe (powdery mildew) infection. Susceptibility to Erysiphe infection was strongly negatively correlated with UV-induced resveratrol production.     

An investigation to estimate genetic parameters in CSIRO's table grape breeding program. 2. Quality characteristics

Genetic parameters for table grape quality characteristics, including ripening date, berry size (weight, width and length) and uniformity, seediness, ^°Brix, acidity and the ratio of ^°Brix and acidity, were estimated based on two seasons' evaluations. Data were collected from a total of 5039 vines in 1999 and 1848 vines in 2000 and individual vine mixed models using the restricted maximum likelihood approach were used to account for all pedigree information. The results showed that quality characteristics were generally under strong additive genetic control; narrow-sense heritability estimates were 0.35 for ripening date, 0.63 for berry weight, 0.69 for berry width, 0.68 for berry length, 0.58 for seediness, 0.48 for ^°Brix, 0.36 for acidity and 0.10 for the ratio of ^°Brix and acidity. Berry size components (berry weight, width and length) were correlated strongly and positively with each other (r _g = 0.88 ∼ 0.96), and correlated negatively with ^°Brix and acidity (–0.19 ∼ –0.62), but positively with the ratio of ^°Brix: acidity (0.05 ∼ 0.33). ^°Brix was also favourably associated with acidity (0.41). Vine vigour was associated with ^°Brix (–0.05) and acidity (0.30) without an unfavourable impact on berry size. Thus, low vigour vines may potentially produce high quality table grapes. Ripening date was generally independent of most quality characteristics. Heritability estimates derived from seedless and seeded populations were similar to each other and mirrored the estimates for the combined population. The implications of these estimates for table grape breeding are discussed. This revised version was published online in August 2006 with corrections to the Cover Date.     

Preharvest applications of growth regulators and their effect on postharvest quality of table grapes during cold storage

Over 54,600 ha of table grapes (Vitis vinifera), mainly cvs. ‘Thompson Seedless’, ‘Flame Seedless’ and ‘Redglobe’, are planted in Chile. Almost the entire production is exported to the USA, Europe, Asia, or one of several Latin American countries, which typically requires 15–40 d of maritime transportation. During this period, several physical, physiological, and pathological factors cause table grape deterioration. Because berry size is the main quality factor in international markets, farmers often overuse the growth regulators, gibberellic acid (GA₃) and forchlorfenuron (CPPU), in an effort to increase berry size. We examined the effect of preharvest growth regulators on seedless (‘Thompson Seedless’, and ‘Ruby Seedless’) and seeded (‘Redglobe’) table grape cultivars during cold (0 °C) storage plus a shelf life period of 3 d at 20 °C. The overuse of GA₃, eight instead of two GA₃ applications on Thompson Seedless, and the use of one GA₃ application on Redglobe and ‘Ruby Seedless’, increased berry pedicel thickness and lowered cuticle content but induced shatter and predisposed grapes to gray mold caused by Botrytis cinerea. In contrast, CPPU increased berry pedicel thickness and cuticle content but did not increase shatter or gray mold incidence. Clusters that were subjected to overuse of combined GA₃ and CPPU were highly sensitive to shatter, had the thickest pedicel, and developed a high gray mold incidence during cold storage. Hairline, a fine cracking developed during cold storage, was induced on ‘Thompson Seedless’ and ‘Ruby Seedless’ by growth regulators, but no hairline occurred on ‘Redglobe’ table grapes. Therefore, berry quality during cold storage is greatly influenced by growth regulator management in the vineyard.     

Inheritance of taste characters and fruit size and number in a diploid Actinidia chinensis (kiwifruit) population

We investigated the variability and inheritance of taste components and fruit size and number in a seedling population of diploid Actinidia chinensisPlanch. We found significant variation in all characters measured. Narrow-sense heritability estimates were high for vitamin C content, titratable acidity (TA), soluble solids content (SSC), fruit weight and dry matter content (DM), but low for glucose content, quinic acid content, and fruit number per vine. The genetic correlations between sugars (except myo-inositol), acids (except quinic acid), TA, vitamin C content, SSC and DM tended to be positive and moderate to high. However, correlations between these characters and fruit weight tended to be negative and moderate to high. The standardised coefficients () of multiple regression showed that SSC was highly dependent on the levels of fructose content, sucrose content and TA. Estimates of relative selection efficiencies (E) suggested that selection using SSC could be an efficient and convenient alternative to direct selection for improvement of sugar levels in kiwifruit. However, selection strategies based on SSC need to take account of its moderate negative correlation with fruit weight. Male and female parents useful for improving acid and sugar composition and fruit size were identified. One family was outstanding, as it combined large fruit size with high levels of SSC and DM.     

架式与负载量对晚红葡萄果实品质的影响

以三年生晚红葡萄为试验材料,研究了不同架式及负载量对果实品质的影响。结果表明:立体棚架栽培的果实单粒重、可溶性固形物含量、固酸比等品质指标均高于平棚架和篱架,总酸含量低于二者;立体棚架叶片净光合速率(Pn)极显著高于棚架和篱架(P0.01),并且叶片Pn与果实单粒重、总糖含量呈显著正相关。单粒重与总糖、固酸比呈极显著正相关,与总酸呈显著负相关。总糖与固酸比呈极显著正相关。总酸与固酸比呈极显著负相关。立体棚架保留8～10个/m2新梢对其光能利用和果实品质较适宜。     

Variation in endosperm protein composition and technological quality properties in durum wheat

Durum wheat quality is controlled by endosperm protein content and composition. Electrophoretic, protein content and SDS sedimentation analyses were carried out on a large collection of accessions of durum wheat from Turkey, and compared with Italian cultivars. A number of patterns were detected, resulting from the combination of different alleles at genomes A and B, and new allelic variants were identified. Genotypes with the same allele at Gli-B1 showed inconsistencies in the comparison of low molecular weight glutenin subunits (LMW-GS), suggesting caution in considering γ-gliadins as genetic markers for pasta quality. Variation in protein content and SDS sedimentation values was wider in the Turkish material than in the Italian cultivars, the values of which were in line with cultivars from Australia, Canada, France, and the USA. A substantial amount of the variation in gluten properties was explained in terms of protein composition, with LMW-GS making the largest contribution. Reversed phase high performance liquid chromatography (RP-HPLC) analyses were carried out on two biotypes of the Italian cultivar Lira that differ at the Gli-B1/Glu-B3 loci (Lira 42 has γ-42, LMW-1, and poor quality; whereas Lira 45 has γ-45, LMW-2, and good quality). The results indicated that differences in quality may be due to: 1) the absolute amount of LMW glutenins which was greater in LMW-2; 2) the relative predominance of LMW-s type and LMW-m type subunits in Lira 45 glutenins which act as polymer chain extenders; and 3) the higher proportion of the α-type and γ-type glutenin subunits, in Lira 42 glutenins, which have an additional (nine) cysteine residue in the N-terminal region and act as glutenin chain terminators. The conclusion reached was that breeding for quality should consider selection for LMW-GS and against α-type and γ-type glutenin subunits. This revised version was published online in August 2006 with corrections to the Cover Date.     

Inheritance of long chain fatty acid content in rapeseed (Brassica napus L.)

A large industrial oil market has recently developed for high erucic acid (>500 g kg⁻¹) rape (Brassica napus L.) cultivars. This research was conducted to: (i) determine genetic effects for five fatty acids, (ii) determine if maternal effects influence fatty acid content of progeny, and (iii) estimate correlations among fatty acid contents in hybrid progeny. Lines with very high erucic acid content and very low erucic acid content were used to develop eight generations to estimate additive, dominance, and epistatic effects for fatty acid content using Generation Means Analyses. Mean oleic, linoleic, linolenic, eicosenoic and erucic acid content differed among generations and additive genetic effects were important for control of all five fatty acids, contributing from 84% to 97% of the total sums of squares for each fatty acid. Epistasis was observed in the inheritance of eicosenoic acid. Maternal effects were not detected.     

Flavan-3-ols and procyanidins in grape seeds: biodiversity and relationships among wild and cultivated vines

Flavan-3-ol monomers and polymers composition of seeds from wild (17) and autochthonous (8) Vitis vinifera grapes growing in northern Tunisia were evaluated. Wild grape seeds were spherical with a small beak and relatively a high seed/berry ratio (~ 18.1%w/w). Local cultivars developed pyriform-shaped seeds with a well-developed beak representing on average 2.2% of total weight of the berry. Flavanol concentrations ranged between 40.9 and 67.5 mg/g FW in seeds from wild accessions and between 48.9 and 96.7 mg/g FW in seeds from cultivated grapes. Differences between accessions were highly significant (p < 0.01) and seeds from cultivar ‘Boukhasla’ showed the highest polyphenols content. Among flavan-3-ol monomers, (+)-catechin was predominant for all ecotypes and generally their abundance was: (+)-catechin (Cat) > (?)-epicatechin (Ec) > (?)-epicatechin-3-O-gallate (EcG). The Cat/Ec ratio was approximately 1.7 for wild grapes while it was about 2.5 for cultivated grapes. Procyanidins in wild seeds differed from cultivated ones by a lower mDP and higher proportions of galloylated derivatives, likely to affect fruit bitterness and astringency. (?)-epicatechin was the main extension subunit in grape seed procyanidins, reaching on average 52% in wild and 58% in cultivated seeds. Hierarchical cluster analysis based on seeds morphometry and procyanidin profile indicated close proximity between some wild and cultivated grapes suggesting that some cultivars derived from ancestral events of local domestication or cross hybridization with native wild plants.     

Relationship between sensory and NIR spectroscopy in consumer preference of table grape (cv Italia)

A combination of near infrared spectroscopy (NIR) instrumental measurements and sensory analysis was investigated to predict solids soluble content (SSC, assessed as Brix) and to classify preference in table grape cv Italia. SSC was monitored in each berry of whole bunches in order to evaluate intra-bunch distribution and variability. NIR spectra were recorded in the spectral region 12,000–4000 cm⁻¹ (833–2500 nm) using a set of 682 berries. The Partial Least Square (PLS) model based on cross-validation provided acceptable value for the main statistical parameters (coefficient of determination of cross-validation, r²: 0.85; standard error of cross-validation, SECV: 1.08; residual predictive deviation, RPD: 2.6) and was confirmed by external validation performed with 115 independent berries (coefficient of determination of prediction, r_p²: 0.82; standard error of prediction, SEP: 0.83). For consumer testing, the selected PLS model was used to predict the Brix value in 400 berries and Discriminant Analysis (DA) was then carried out to classify berries in terms of preference by relating NIR data to consumer judgment. The three defined preference clusters of berries were fully classified obtaining 100% membership. In cross-validation the value decreased especially for class 1 (78.5%) and 3 (75%) whereas class 2 obtained comparable values (98.7%). According to our results, NIR technology appears to be a promising technique for predicting SSC and obtaining information with regard to consumer preference in ‘Italia’ table grape for application of efficient and low cost on-line instruments in the fruit industry.     

Utilization of genetic resources for the introduction and adaptation of exotic vegetable crops: The case of pepino (Solanum muricatum)

Summary Pepino (Solanum muricatum), a vegetatively propagated plant from the Andean region used for its edible fruits, has been identified as a potential crop for greenhouse cultivation in Mediterranean regions. However, attempts for introducing it have been unsuccessful, either because of the low yield, poor fruit quality, or both. Screening of germplasm under Mediterranean conditions showed that sources of variation for high yield existed in the cultivated genepool and that wild species S. caripense and S. tabanoense could contribute to a considerable improvement of soluble solids content (SSC) of pepino. Progenies obtained after crossing genetically distant (AFLP-based) parental clones were heterotic for yield, and allowed the selection of clones with an improved combination of yield and SSC. As a result of this intraspecific programme, two new improved cultivars (‘Turia’ and ‘Valencia’), which outperform the rest of cultivars available, have been selected for cultivation in Mediterranean conditions. The interspecific programme involved the selection of clones with high yield and SSC in backcross generations. The results show that introgression of genes from the wild species can contribute to improve the SSC of pepino. The backcross programme is in an advanced stage and new cultivars derived from the interspecific crosses are expected to be released in a near future. New prospects for the future in pepino breeding include the genetic transformation, the establishment of a genetic map, and the use of the genomic information from related Solanaceae important crops. All the information obtained is illustrative for the breeding for adaptation of vegetatively propagated crops.     

Wild relatives can contribute to the improvement of fruit quality in pepino (Solanum muricatum)

Narrow intraspecific variation for sugar content in pepino (Solanum muricatum Aiton) hinders the development of new pepino cultivars with improved fruit quality. However, some wild related species have high soluble solids concentration (SSC) and titratable acidity (TA). Generation means analysis was used to estimate genetic parameters for SSC, TA and ascorbic acid concentration (AAC) in two families of interspecific crosses between a S. muricatum parent (Sm-32) and one accession of each of the wild species Solanum caripense (Sc-4) and Solanum tabanoense (St-1). In both families, the additive effect [d] was the only significant parameter for SSC, the alleles of wild species contributing positively to increasing SSC values. For TA, genetic effects associated with additivity [d] and dominance [h] were detected in both families. Additionally, in Sm-32 × Sc-4 nonallelic interactions associated with dominance ([j] and [l]) were significant. For this trait, alleles from the wild species contribute additively to a high value of the character, but are recessive to those of the cultivated S. muricatum. No genetic variation was found for AAC. Broad-sense heritabilities for SSC and TA were intermediate (0.40 to 0.50). Positive significant genetic correlations (around 0.68 in both families) were found between SSC and TA. The results obtained in backcrosses of interspecific hybrids to S. muricatum, together with the estimates of genetic advance after selection, indicate that recovery of individuals with higher SSC and TA and adequate SSC/TA ratio can be achieved in a few backcrosses. In conclusion, this work indicates that wild species S. caripense and S. tabanoense are worthy sources of variation for improving pepino fruit quality. This revised version was published online in July 2006 with corrections to the Cover Date.     

葡萄品种资源果实重要经济性状分析

对郑州果树研究所国家葡萄种质圃内的主要葡萄栽培品种的果穗和浆果的主要经济性状进行了鉴定评价。结果表明,在葡萄果穗形状、果穗大小、果粒形状、果粒大小、果粒重量、可溶性总糖含量、总酸含量、果实颜色、果肉硬度和香味等方面均存在丰富的遗传多样性。在丰富的多样性中,具有圆锥形、圆形和短椭圆形果粒、软肉、无香味的品种最多,其它穗形、果形、硬度和特殊香味特征均是葡萄的遗传变异中人为选择的结果。     

Oil content, tocopherol composition and fatty acid patterns of the seeds of 51 Cannabis sativa L. genotypes

The oil content, the tocopherol composition, the plastochromanol-8 (P-8) content and the fatty acid composition (19 fatty acids) of the seed of 51 hemp (Cannabis sativa L.) genotypes were studied in the 2000 and 2001 seasons. The oil content of the hemp seed ranged from 26.25% (w/w) to 37.50%. Analysis of variance revealed significant effects of genotype, year and of the interaction (genotype × year) on the oil content. The oil contents of the 51 genotypes in 2000 and 2001 were correlated (r = 0.37**) and averaged 33.19 ± 1.45% in 2000 and 31.21 ± 0.96% in 2001. The -tocopherol, -tocopherol, -tocopherol, P-8- and -tocopherol contents of the 51 genotypes averaged 21.68 ± 3.19, 1.82 ± 0.49, 1.20 ± 0.40, 0.18 ± 0.07 and 0.16 ± 0.04 mg 100g^–1 of seeds, respectively (2000 and 2001 data pooled). Hierarchical clustering of the fatty acid data did not group the hemp genotypes according to their geographic origin. The -linolenic acid yield of hemp (3–30 kg ha^–1) was similar to the -linolenic acid yield of plant species that are currently used as sources of -linolenic acid (borage (19–30 kg ha^–1), evening primrose (7–30 kg ha^–1)). The linoleic acid yield of hemp (129–326 kg ha^–1) was similar to flax (102–250 kg ha^–1), but less than in sunflower (868–1320 kg ha^–1). Significant positive correlations were detected between some fatty acids and some tocopherols. Even though the average content of P-8 in hemp seeds was only 1/120^th of the average -tocopherol content, P-8 content was more closely correlated with the unsaturated fatty acid content than -tocopherol or any other tocopherol fraction. The average broad-sense heritabilities of the oil content, the antioxidants (tocopherols and P-8) and the fatty acids were 0.53, 0.14 and 0.23, respectively. The genotypes Fibrimon 56, P57, Juso 31, GB29, Beniko, P60, FxT, Félina 34, Ramo and GB18 were capable of producing the largest amounts of high quality hemp oil.     

Development of SNP assays associated with oleic acid QTLs in N00-3350 soybean

Increasing the amount of oleic acid in soybean oil would reduce the need for hydrogenation, a process that creates unhealthy trans fatty acids. A previous study mapped six oleic acid quantitative trait loci (QTLs) from N00-3350 (~550 g kg⁻¹ oleic acid) on soybean chromosomes (Gm) 5, 17, 18, and 19, which corresponds to linkage groups (LG) A1, D2, G, and L, respectively. The objectives of this study were to develop high throughput assays to detect single nucleotide polymorphism (SNP) markers associated with these oleic acid QTLs. Several candidate genes that are putatively responsible for the oleic acid phenotype in N00-3350 were identified by BLAST searches against the soybean genomic assembly using the sequences of fatty acid synthesis genes from soybean and Arabidopsis. Putative accC-2 and KAS I genes were located in the region of the cqOle-001 on Gm05 (LG-A1). A putative KAS I gene was located in the region of the cqOle-003 on Gm18 (LG-G) and a putative accB-1 gene was located in the region of the cqOle-004 on Gm18 (LG-G). These fatty acid candidate genes and sequence-tagged sites were used to identify SNPs between N00-3350 and ‘Boggs’. Based on these SNPs, seven SimpleProbe probes for melting curve analysis were developed to rapidly identify the alleles from the mid-oleic acid soybean line N00-3350 at the desired loci. These assays provide a high-throughput and rapid SNP genotyping method which can be used to accelerate the development of mid-oleic acid content soybean cultivars.     

Genome composition of ‘Elatior’-begonias hybrids analyzed by genomic in situ hybridisation

Interspecific hybridization of various tuberous Begonia species hybrids with Begonia socotrana results in so-called ‘Elatior’-begonias hybrids (B. × hiemalis Fotsch). In our study, genomic in situ hybridization (GISH) has been employed to assess the genome composition in eleven ‘Elatior’-begonias hybrids and their ancestor genotypes. Genomic DNA of tuberous Begonia was sonicated to 1–10-kb fragments, labelled by nick translation with digoxigenin-11-dUTP and used as a probe whereas B. socotrana DNA was autoclaved to 100 bp fragments and used as block. The genome of tuberous Begonia was clearly pronounced in ‘Elatior’-begonias when the probe concentration was ~3.75 ng/μl (150 ng/slide), with 30 times the excess of B. socotrana blocking DNA and stringency of post hybridization washings at 73% (0.1× SSC at 42°C). In ‘Elatior’-begonias hybrids GISH distinguished two groups comprising short (0.6–1.03 μm in length) and relatively longer chromosomes (1.87–3.88 μm) which represent B. socotrana and tuberous Begonia genomes, respectively. The number of chromosomes derived from tuberous Begonia ranged from 14 to 56 and for B. socotrana from 7 to 28 which suggest the presence of different ploidy levels in analyzed ‘Elatior’-begonia hybrids. Intergenomic recombination has not been detected through GISH in hybrids analyzed. Genomic in situ hybridization turned out to be useful to identify the genome constitution of ‘Elatior’-begonia hybrids and thus gain an insight into the origins of these cultivars. This knowledge on the ploidy level and genome composition is essential for further progress in breeding Begonias.     

Mineral bioavailability in grains of Pakistani bread wheat declines from old to current cultivars

Estimating variation in grain mineral concentration and bioavailability in relation to grain yield and the year of cultivar release is important for breeding wheat with increased content of bioavailable minerals. The grain yield and yield components, grain phytate concentration, and concentration and bioavailability of minerals (zinc Zn, iron Fe and calcium Ca) in wheat grains were estimated in 40 wheat cultivars released in Punjab (Pakistan) during the last five decades. Mean grain Zn and Ca concentrations in current-cultivars were significantly lower (≥14%) than in obsolete cultivars released during the Green Revolution (1965–1976). Much of this variation was related to increased grain weight in current-cultivars. There was a positive correlation among minerals (r = 0.39 or higher, n = 40) and minerals with phytate in wheat grains (r = 0.38 or higher, n = 40). The tested cultivars varied widely in grain yield and grain phytate-to-mineral molar ratios (phytate:mineral). Compared to obsolete cultivars, the current-cultivars had a higher phytate:mineral ratio in grains, indicating poor bioavailability of minerals to humans. The study revealed a non-significant relationship between grain yield and phytate:mineral ratios in grains. Therefore, breeding for lower phytate:mineral ratios in wheat grains can ensure increased mineral bioavailability without significant reduction in the yield potential. Future breeding should be focused on developing new genotypes suitable for mineral biofortification and with increased mineral bioavailability in grains.     

刺葡萄的品质分析及加工性能研究

选取湖南省几个有代表性产地所生产的刺葡萄进行了品质分析,对其加工特性进行了讨论。结果表明,刺葡萄主要成分的平均含量为:总糖13.21%,总酸0.35%,糖酸比37.8,抗坏血酸21.92m g/100g,单宁0.04%,蛋白质0.88%,果胶0.81%和纤维素0.23%。从加工性能分析,刺葡萄是制造果汁的优良原料。     

Effect of hardening on frost tolerance and fatty acid composition of leaves and stems of a set of faba bean (<Emphasis Type="Italic">Vicia faba</Emphasis> L.) genotypes

Frost tolerance is a main component of winter-hardiness and improving it would promote faba bean (Vicia faba L.) cropping in cool-temperate regions. In many species, leaf fatty acid composition was found to be related to frost tolerance. The objective of this study was to determine, in a representative sample of genotypes, the effect of hardening on leaf and stem (1) frost tolerance and (2) fatty acid composition, and to seek correlations between them. First leaf, second leaf and stem of 31 faba bean genotypes were analyzed after hardening and without hardening. High frost tolerance of known winter genotypes and several experimental lines was shown. Hardening had a significant, positive effect on frost tolerance of all three organs. Stems were on average more frost tolerant than leaves. Hardening induced significant changes in the fatty acid composition: oleic acid decreased significantly in leaves by 3.24% and in stems by 1.77%, whereas linolenic acid increased in leaves by 6.28% and in stems by 9.06%. In stems, correlations between frost tolerance and fatty acid composition were not significant. Correlation coefficients strongly indicated that non-hardened oleic acid content, changes in oleic acid and in linoleic plus linolenic acid content in leaves partly explained their frost tolerance; 0.347 (P < 0.1) < |r| < 0.543 (P < 0.01). The results corroborate the importance of using genetic differences in the fatty acid metabolism in breeding grain legumes for frost tolerance.