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Vollmann, J., A. Damboeck, A. Eckl, H. Schrems, and P. Ruckenbauer. 1996. Improvement of Camelina sativa, an underexploited oilseed. p. 357-362. In: J. Janick (ed.), Progress in new crops. ASHS Press, Alexandria, VA.

Improvement of Camelina sativa, an Underexploited Oilseed

Johann Vollmann, Astrid Damboeck, Anna Eckl, Heinrich Schrems, and Peter Ruckenbauer

  1. MATERIALS AND METHODS
    1. Genetic Entries
    2. Performance Trials
    3. Selection for Large Seed Size
  2. RESULTS
    1. Environmental Effects
    2. Genotype Performance
    3. Selection for Seed Size
  3. DISCUSSION
  4. REFERENCES
  5. Table 1
  6. Table 2
  7. Fig. 1
  8. Fig. 2
  9. Fig. 3
  10. Fig. 4
  11. Fig. 5
  12. Fig. 6
Camelina [Camelina sativa (L.) Crtz., Brassicaceae], known as false flax or gold-of-pleasure is a spring-planted crop species. Although camelina has been cultivated in Europe since the Bronze Age (Schultze-Motel 1979), it is an underexploited oilseed crop at present. Recent interest in the species is mainly due to the demand for alternative low-input oilseed crops with the potential for a non-food utilization of the seed oil (Seehuber 1984; Putnam et al. 1993). Camelina oil has a unique fatty acid pattern and is characterized by a linolenic acid (C18:3) content of 30% to 40% and an eicosenic acid (C20:1) content of around 15%, with less than 4% erucic acid (Seehuber 1984; Marquard and Kuhlmann 1986; Budin et al. 1995), which suggests a utilization of the seed oil as a drying oil with environmentally safe painting and coating applications similarly to linseed oil (Luehs and Friedt, 1993). Moreover, a rather low content of glucosinolates has been found in camelina as compared to other brassicaceous species (Lange et al. 1995), which makes the utilization of meals easier.

Agronomic investigations of camelina have been carried out both in Europe (Zimmermann and Kuechler 1961; Marquard and Kuhlmann 1986) and North America (Plessers et al. 1962; Robinson 1987). Unique agronomic features such as the compatibility with reduced tillage and cover crops, competitiveness with weeds or winter surface seeding have been emphasized by Putnam et al. (1993) with regard to the suitability of camelina for sustainable agriculture systems. Furthermore, the species has a potential as a low-cost crop for green-manuring. Breeding research and genetic improvement of camelina have been initiated in Germany during the 1980s; apart from the collection and evaluation of germplasm (Seehuber 1984), agronomically advanced lines have been developed (Seehuber et al. 1987), which are available as base population for further improvement (Seehuber and Dambroth 1987).

In the present investigation, results from an agronomic evaluation of new lines of camelina are reported. The genotypes tested were derived from a recombination program, which mainly focused on the improvement of agronomic performance of camelina as an alternative and low-input oilseed crop for Central Europe.

MATERIALS AND METHODS

Genetic Entries

Camelina populations CA13X and CA2X were derived from crosses BGRC 51558 x BGRC 51572 and Voronezskij 339 x BGRC 51558, respectively. BGRC genotypes were obtained from the genetic resources collection of the FAL Institute of Agronomy (Braunschweig, Germany), Voronezskij 339 is an accession obtained from the N.I. Vavilov Institute (St. Petersburg, Russia). Segregating populations were advanced to the F4-generation by a bulk breeding method. In the F4, single plants were harvested separately and F4-derived lines were selected visually from F5-single row plots for further testing.

Performance Trials

Homozygous breeding lines from the populations described above were evaluated in 1993 (F4-6) and 1994 (F4-7) at the two Austrian locations Gross Enzersdorf (10 km east of Vienna, 48°12' N, 16°32' E) and Reichersberg (60 km west of Linz, 48°20' N, 13°20' E) in replicated field trials. Cv. Iwan (Saatbau Linz, Reichersberg, Austria) was used as a check cultivar. Plot size was 5 x 1.25 m in Gross Enzersdorf and 8 x 1.25 m in Reichersberg. Agronomic parameters were set as described by Seehuber et al. (1987). All experiments were arranged as lattice designs in two replications. As particular genotypes were discarded after the 1993 experiments due to the necessity of selection, a complete set of data was available for 10 genotypes from both locations and for both years for a combined analysis of variance. Another set of 32 genotypes was analyzed across 3 environments (Gross Enzersdorf 1993, 1994; Reichersberg 1994). In general, adjusted entry means from the lattice analysis were used for the combined analyses of variance; in the experiment at Gross Enzersdorf 1993, seed yield data were adjusted by a neighbor analysis procedure (Vollmann et al. 1996), which was most efficient in controlling the spatial variation present in the particular trial field. In order to identify genotypes superior to the check cultivar, LSI (= least significant increase, one-tailed t-statistic) was used as a statistical testing procedure (Petersen 1994). Oil content of seed was determined non-destructively by near-infrared reflectance spectroscopy (NIRS) and is reported in g kg-1 on a dry weight basis.

Selection for Large Seed Size

For an improvement of seed size (mass), sub-populations of crosses CA2X and CA13X were established by sieving out small fractions (< 0.1 %) of largest seeds from the F2- (CA2X-1S, CA13X-1S) or from both the F2- and F3-bulks (CA2X-2S, CA13X-2S). F4-derived lines of these sub-populations were evaluated for 1000-seed weight in the F5-generation using single row plots with two replications (Gross Enzersdorf 1992) and a selected number of large-seeded genotypes was tested for agronomic performance (Gross Enzersdorf 1993) as described above.

RESULTS

Environmental Effects

In the set of 10 genotypes of camelina evaluated in two locations for two years, both seed yield and oil content were highly influenced by year and location effects as well as by a highly significant year x location interaction. Genotype effects were also significant, but genotype x year and genotype x location interactions were of minor importance for seed yield and not significant for oil content indicating a similar response of the different genotypes to environmental changes. Seed yields were in the range of 1050 to 1700 kg ha-1 in 1993 and from 1450 up to 3250 kg ha-1 in 1994. In both locations, oil contents were high in 1993 (400 to 455 g kg-1) and clearly lower in 1994 (385 to 425 g kg-1), as shown in Fig. 1.

Genotype Performance

Genetic variation in different agronomic characters was highly significant (F-test) in the set of 32 genotypes tested across 3 environments (Gross Enzersdorf 1993, 1994; Reichersberg 1994). The check cultivar was significantly outyielded in both seed and oil yield by several of the new genotypes evaluated (Table 1), an improved oil content of seed was however found in only one genotype. In the populations investigated, seed yield and oil content were positively correlated (Fig. 2), whereas a tightly negative correlation was found between 1000-seed weight and oil content (Fig. 3); a negative correlation was also detected between 1000-seed weight and yield. For the genotypes listed in Table 1, estimates of heritability were rather high in characters such as oil content or 1000-seed weight and lower for plant height (Table 2).

In particular performance trials (Gross Enzersdorf 1993), spatial variation in the trial field affected oil content (apart from the influence on seed yield) in the range of -8 to +7 g kg-1 seed oil. A clear trend in variation of oil content was found using a neighbor analysis covariate (Fig. 4), which was also helpful in order to adjust individual plot values for field heterogeneity during analysis of variance (results not shown).

Selection for Seed Size

In population CA2X, seed size of F4-5-lines was clearly improved by sieving of F2- or F3-bulks and lines with a 1000-seed weight of up to 2 g were identified within sub-population CA2X-2S (Fig. 5), whereas 1000-seed weights of the respective parent genotypes were only 0.9 and 1.2 g. In population CA13X, selection response was less pronounced with respect to seed weight. In a preliminary assessment of agronomic performance of large-seeded genotypes (96 F4-6-lines, Gross Enzersdorf 1993), seed yield was positively affected by 1000-seed weights of up to 1.5 g, whereas seed yield was reduced in genotypes with larger seed size (Fig. 6). Moreover, seed size and oil content were negatively correlated, and large-seeded genotypes had a reduced number of seeds per pod, malformation of pods as well as higher lodging scores (data not presented).

DISCUSSION

A considerable agronomic potential has been detected in newly developed lines of camelina during the present study. Furthermore, strong year x location interactions for seed yield and oil content indicated that specific weather conditions within a location could modify performance considerably. In the 1993 experiments, a severe drought during the flowering phase limited plant development and yield potential at both locations, whereas sufficient rainfall during the seed filling period resulted in the subsequent expression of high oil contents (Fig. 1). In the 1994 experiments, water conditions were not limiting plant development throughout the growing season, which allowed seed yields of up to 3250 kg ha-1, whereas oil contents were lower as a response to the high yield potential. Similar ranges of seed yield and oil content have also been reported from experiments in Germany (Seehuber 1984; Seehuber et al. 1987), whereas both seed yield and oil content were lower in North American studies (Plessers et al. 1962; Robinson 1987; Putnam et al. 1993), which might partly be due to a lack of environmental adaptation. The strong influence of environmental conditions on seed yield has also been reported for other spring-sown oilseed crops (Diepenbrock et al. 1995).

Sufficient genetic variation was present within the germplasm available, which allowed the selection of lines with improved agronomic features (Table 1 and 2). A broad genetic variation and moderately high heritabilities of important agronomic characters have also been identified by Seehuber et al. (1987) investigating similar genetic materials. The positive correlation between seed yield and oil content indicates that a simultaneous improvement of both characters is possible. An improvement of seed oil content would be of particular interest to make camelina more competitive to other oilseed crops exhibiting higher oil contents (Plessers et al. 1962; Putnam et al. 1993). Screening of large numbers of entries for oil content can be accomplished easily by non-destructive techniques such as near-infrared reflectance spectroscopy or nuclear magnetic resonance (Thies and McGregor 1989); the presence of spatial field variations affecting oil content (Fig. 4) can however reduce the efficiency of selection if not controlled properly (Ball et al. 1993; Vollmann et al. 1996).

In camelina, improvement of seed size would be of interest for a rapid field emergence and crop establishment under less favorable growing conditions; moreover, solvent extraction of oil is generally more efficient with large-seeded cultivars. A considerable increase of 1000-seed weight of up to 2 g has been achieved during the present selection experiment, as compared to the unselected control population (Fig. 5) as well as to variation in seed size reported previously (Seehuber 1984; Seehuber et al. 1987; Putnam et al. 1993). However, the obtained improvement of 1000-seed weight seems to be of low immediate value due to the drastic reduction of both oil content and seed yield, which makes further cycles of recombination necessary. Within smaller ranges of seed size, a significant correlation betweeen seed size and oil content was not found in camelina (Seehuber 1984), whereas positive correlations between 1000-seed weight and oil content have been reported for particular crosses in oilseed rape (Engqvist and Becker 1993).

The results obtained from the present study suggest that a considerable agronomic potential is present in newly developed lines of camelina. However, high oil content and a specific fatty acid profile would be the key requirements to re-establish camelina as an industrial oilseed crop. These quality characters should therefore deserve most attention in future breeding programs.

REFERENCES

Table 1. Agronomic performance of 32 genotypes of camelina (mean values across 3 environments).

No. Genotype name Seed yield (kg ha-1) Oil content (g kg-1) Oil yield (kg ha-1) 1000-seed weight (g) Plant height (cm)
1 CA13X-11 2091 413.3 858 1.26 72.5
2 CA13X-17 2381 424.0 1002 1.21 70.0
3 CA13X-20 2032 425.7 861 1.16 64.2
4 CA13X-6 2143 427.4 911 1.16 71.7
5 CA13X-1S-9 2392 424.9 1011 1.13 79.2
6 CA13X-2S-23 1947 427.7 828 1.21 69.2
7 CA13X-2S-44 2210 423.1 927 1.19 75.0
8 CA13X-2S-96 2370 400.7 940 1.34 75.8
9 CA2X-2S-29 2040 405.1 820 1.28 70.8
10 Iwan (check) 2029 422.9 853 1.29 71.7
11 CA13X-13 1965 434.9 847 1.20 72.5
12 CA13X-1S-19 1951 411.6 797 1.28 78.3
13 CA13X-2S-17 1799 410.9 735 1.35 70.8
14 CA13X-2S-20 1818 404.0 731 1.43 76.7
15 CA13X-2S-22 1746 393.5 677 1.41 70.8
16 CA13X-2S-26 1904 415.0 783 1.24 74.2
17 CA13X-2S-29 2041 408.4 824 1.32 75.0
18 CA13X-2S-4 1692 414.3 698 1.31 70.0
19 CA13X-2S-53 1945 424.2 822 1.26 70.8
20 CA13X-2S-56 1746 423.1 733 1.22 67.5
21 CA13X-2S-6 1775 405.4 715 1.42 75.0
22 CA13X-2S-63 1898 415.2 786 1.40 71.7
23 CA13X-2S-69 1953 401.7 782 1.47 73.3
24 CA13X-2S-7 2025 411.7 828 1.34 73.3
25 CA13X-2S-75 2009 410.3 819 1.31 74.2
26 CA13X-2S-85 1821 410.4 747 1.33 70.8
27 CA13X-2S-95 1797 399.8 714 1.36 70.8
28 CA2X-1S-1 1622 383.5 617 1.68 72.5
29 CA2X-1S-14 1888 400.3 769 1.47 67.4
30 CA2X-2S-17 1663 381.8 633 1.62 72.5
31 CA2X-2S-20 1605 378.0 604 1.66 70.2
32 CA2X-2S-22 1733 388.1 661 1.57 72.5
Total mean 1939 410.0 792 1.34 72.0
LSD 0.05 215 8.8 88 0.06 5.0
LSI 0.05 183 7.5 75 0.05 4.5

Table 2. Estimates of heritability calculated from components of variance for different agronomic characters of camelina (32 genotypes tested in 3 environments).

Character Heritability (%)
Seed yield 86.5
Oil content 95.6
Oil yield 90.5
1000-seed weight 97.6
Plant height 62.5

Fig. 1. Oil content of a set of 10 genotypes of camelina as affected by environmental conditions (locations: GE = Gross Enzersdorf, RE = Reichersberg; years: 1993, 1994).
Fig. 2. Relationship between seed yield and oil content in 32 genotypes of camelina (genotype mean values across 3 environments).
Fig. 3. Relationship between 1000-seed weight and oil content in 32 genotypes of camelina (genotype mean values across 3 environments).
Fig. 4. Trends of oil content due to spatial variation in the trial field (Gross Enzersdorf 1993) as visualized by a neighbour analysis covariate (residual EW3).
Fig. 5. Distributions of seed size (1000-seed weight) in F4-5 lines of population CA2X. a: unselected control population (n = 25 lines); b: F2-bulk sieved for large-seededness (n = 25); c: both F2- and F3-bulks sieved (n = 100).
Fig. 6. Relationship between 1000-seed weight and seed yield in a set of 96 genotypes selected for large seed size (environment: Gross Enzersdorf 1993; regression line and coefficient of correlation according to 2nd order regressional function).
Last update August 21, 1997 aw