Breeding prospects of
Lunaria annua
L.
H.D. Mastebroek *, H.J.P. Marvin
Centre for Plant Breeding and Reproduction Research,CPRO-DLO,PO Box16,6700AA Wageningen,The Netherlands
Accepted 8 October 1999
Abstract
Lunaria annuais a biennial cruciferous oil seed crop. The seeds contain 30 – 35% oil, which consists of 67% long chain fatty acids (44% erucic acid, C22:1, and 23% nervonic acid, C24:1). The oil is suitable as lubricant. In addition, recent developments indicate that nervonic acid may be used as raw material for the production of a medicine against multiple sclerosis. The biennial character ofLunariais a main constraint for an economically feasible production of
Lunaria oil. The crop has to be sown early in the summer to achieve vigorous plant development required for vernalization during the winter. It would be a great advance whenLunariacould be sown later in the summer after an early harvested crop. From 1993, breeding research inLunariahas been performed at CPRO-DLO, Wageningen, The Netherlands. A collection of 76 accessions was maintained and evaluated for agronomic performance. In 1995, a selection of 24 accessions were sown at four sowing dates, from end June until end of August and in 1996, 12 promising accessions were sown again at 15 and 30 July. Three accessions showed suitability for delayed sowing until beginning of August. Delay in sowing time caused also delay of flowering and seed ripening. Seed yield amounted to 1200 kg/ha in 1996 and 1700 kg/ha in 1997. Seed oil content varied from 30 – 38%. Severe infection ofAlbugo candida
andAlternariaoccurred and might have reduced seed yield in both years. Most accessions sustained severe winter frost of−17°C very well. It is concluded that within the evaluated gene pool promising variation is available to select for ability for late sowing, to improve the disease resistance and to increase seed yield and seed oil content. © 2000 Elsevier Science B.V. All rights reserved.
Keywords:Lunaria annua; Vernalization; Seed yield; Seed oil content;Albugo candida;Alternaria
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1. Introduction
Lunaria annuais a biennial cruciferous oil seed crop.Lunariais grown as an ornamental plant in many temperate countries of Europe and
North-ern America, but originates from south eastNorth-ern Europe and western Asia (Baily, 1949). In orna-mental gardens, plants shed their seeds late in autumn and seeds germinate in the very early spring. During the first year after germination plants stay in a vegetative stage until early spring the next year. During spring the plants become reproductive and flower in April and May. Flow-ers are mainly violet, but also plants with white or purple flowers occur. After a reasonable long
* Corresponding author. Tel.:+31-317-477036; fax:+ 31-317-418094.
E-mail address:h.d.mastebroek@cpro.wag-ur.nl (H.D. Mas-tebroek)
flowering period disk shaped pods are produced containing six to ten flat seeds. The seeds are rather heavy with a thousand seed weight of 15 – 20 g. At the end of the summer, when the seeds are ripe, the pods discolour to pale white. After removal of the outer layer of the pods a silver coloured false septum remains which repre-sents the ornamental value. The crop can easily be threshed and harvested with a combine-harvester. The seeds contain 30 – 35% oil, which consists of 67% long chain fatty acids (44% erucic acid, C22:1, and 23% nervonic acid, C24:1) (Nicholls, 1996). The oil is suitable as a lubricant (Meier zu Beerentrup and Ro¨bbelen, 1987; Van Soest, 1994). Recently, nervonic acid is investigated as a raw material for the production of a medicine against multiple sclerosis (Nicholls, 1996).
The biennial character of Lunaria is a main constraint for an economical feasible cultivation. Because of a long juvenile phase, Lunaria has to be sown early in the summer to achieve vigorous plant development required for vernalization dur-ing the winter (Pierik, 1967). Furthermore, seed yields between 1000 and 2000 kg/ha with oil content of approximately 30% are low for a crop that needs a growing period of two years. There-fore, it would be a great advance when Lunaria
could be sown later in the summer after an early harvested crop. For that purpose, CPRO-DLO has investigated 76 Lunariaaccessions.
2. Material and methods
In 1993 and 1994, 76 accessions of Lunaria annua L. were grown individually in plots sepa-rated by cereals. In October 1993, 50 seeds per accession were sown in a glasshouse in pots and three months after emergence moved to a cooled growing chamber for vernalization. Temperature in the glasshouse was 15°C and in the growing chamber 5°C. Artificial illumination was given during 14 h per day. At the end of April, after 10 weeks of vernalization, plants were transplanted to the field. During the season date of flowering, plant habit and infection of diseases were scored. Plants were harvested manually, as soon as seeds were ripe and threshed after artificial drying.
In 1995, 24 accessions were selected on the basis of disease resistance and agronomic performance in isolated plots in 1994. The accessions were sown on 23 June, 13 July and 8 and 29 August 1995 in three replicates in fertile clay soil at the CPRO-DLO experimental farm, in Lelystad, the Netherlands. The plots were sown at a seed rate of 2 g per m2 (approximately 100 seeds) and with a row distance of 50 cm. On 23 June, plots were sown mechanically and composed of three rows of 8 m length. On the other sowing dates, plots were sown manually and composed of one row of 2 m. During the growing season, plant development and disease infection were monitored. The plots were harvested with a combine harvester. The three first sown trials were harvested on 23 Au-gust and on 4 and 19 September 1996, respec-tively. The seed bearing plants in the plots, sown on 29 August 1995, were harvested manually at beginning of October. After harvest, the seeds were dried and cleaned and seed yield, thousand seed weight and oil content were determined.
In 1996, twelve accessions were sown on 15 and 30 July. The location and trial lay out were simi-lar to the first sown trial in 1995. Ten accessions were selected on the basis of their suitability for later sowing shown in the previous trials and two accessions, known from large-scale practical ex-periments, were added as standards. During the growing season, plant development and disease infection were scored. Both trials were harvested on 14 and 25 August 1997, respectively. After drying and cleaning of the seeds, seed yield, thou-sand seed weight, oil content and fatty acid com-position were determined.
3. Results and discussion
In 1994, plants developed well and were flower-ing the entire month of June. From early June onwards, severe infection of Albugo candida and slight infection of Alternaria spp. occurred. The final plant height varied from 35 to 100 cm.
From emergence onwards, plant development differed between accessions. Counts of number of leaves on 21 November showed clear differences between accessions and between sowing times. Delay in sowing resulted also in delay of initial flowering and ripening and therefore delay in harvest time. In the latest sown trial of 29 August plants were rarely flowering. The sowing date of 8 August was clearly discriminating between acces-sions with a high and a moderate vernalization requirement. Three accessions did not flower at all. The data obtained from these three accessions have been excluded from Table 1. The percentage
of flowering plants in the remaining accessions varied from 10 to 100%. Ten accessions exceeded 80% flowering plants and were selected for further evaluation during the growing season of 1996/ 1997.
Two accessions suffered during the winter from severe frost of−17°C, which caused a severe re-duction in soil cover of the first sown trial. Signifi-cant difference was found for plant health before the winter, some accessions showed very healthy leaves without disease symptoms whilst other showed many brown spots. The moderate and negative correlation between plant health before
Table 1
Variation for agronomic characteristics among 24Lunariaaccessions sown on 23 June, 13 July and 8 August 1995a
Sowing date
Characteristic Observation date Mean Range LSD (0.05)
1.9 10.7–19.3
15.7 21 November
23 June Number of leaves/plant
14.0 10.0–16.0
Plant healthb 23 June 21 November
6.7 5.0–9.0
13 July 1.7
8 August 6.5 3.7–8.3 1.2
27.8 17.3–100
66.9
Soil cover (%) 23 June 24 May
13 July 91.9 68.3–100 25.0
8 August 78.8 10.0–100 31.0
23 June 3 May
Plant development stagec 50.5 43.7–55.0 2.6
13 July 24 May 58.5 45.3–62.3 4.8
4.4
Plant height (cm) 23 June 11 June 96.4 65.6–110.6 15.7
70.0–113.3
99.7 19.4
13 July
Alternariainfectiond 23 June 11 July 5.0 2.9–8.3 2.5
23 June 11 July
Albugo candidainfectiond 4.3 2.2–7.2 2.0
2.3–7.7 2.8
5.3 13 July
3.3
8 August 1.0–8.3 2.2
6.3 3.0–9.0
Disease infection hullsd 23 June 26 July 2.3
6.0
13 July 3.9–8.3 2.8
322 46–1212
523 Seed yield (kg/ha) 23 June 23 Auguste
13 July 4 Septembere 839 280–1837 575
546 220–1287
608 19 Septembere
8 August
Thousand seed weight (g) 23 June 17.5 14.7–21.1 1.8
13 July 17.8 14.8–22.0 2.3
15.6 13.5–17.3 1.8 8 August
1.2
23 June 34.1–37.8
Seed oil content (%) 35.9
aResults of 21 accessions.
b1, Leaves severely spotted; 9, leaves without disease symptoms.
cPlant development stage: 41, flower buds just visible; 49, flower stalks extended; 51, first flowers visible; 59, full bloom; 61, first
pods developed; 61, pod development completed.
Table 2
Results of the best performing accession ofLunariain comparison to the variation for agronomic characteristics among 12Lunaria accessions sown on 15 and 30 July, 1996
Observation date
Characteristic Sowing date Access. 883158 Mean Range LSD (0.05)
10 December 7.0
Plant healtha 15 July 5.6 1.0–9.0 0.9
30 July 5.7 5.2 1.0–9.0 1.0
10 December 91.7 76.0
15 July 53.3–91.7
Soil cover (%) 7.6
63.3 56.1 30.0–76.7
30 July 11.4
17 March 30.0 17.6
15 July 1.0–30.0
Soil cover (%) 2.3
30.0 20.9 1.0–30.0 4.2
30 July
15 May 59.0 54.3
15 July 50.3–59.0
Plant developmentb 1.7
30 July 12 June 65.7 58.8 51.0–65.7 1.6
15 July
Plant height (cm) 10 July 100 89.3 70.0–106.7 6.7
110 98.5
30 July 78.0–11.7 5.5
15 July
Alternariainfectionc 3 July 6.3 5.7 2.3–9.0 2.5
3.7 4.7
30 July 2.3–9.0 1.5
10 July 3.0 4.2
Albugo candidainfectionc 15 July 1.0–9.0 3.0
7.0 4.7
30 July 1.0–9.0 3.0
Disease infection hullsc 15 July 10 July 7.0 7.3 4.3–9.0 1.6
4.3 5.2
30 July 1.7–9.0 2.0
15 July
Seed yield (kg/ha) 14 Augustd 1700 624 90–1700 197
30 July 25 Augustd 1570 476 43–1570 108
16.5 14.9
15 July 13.8–17.0
Thousand seed weight (g) 0.8
30 July 16.0 14.5 12.5–16.5 1.0
34.3 32.1
15 July 28.0–34.9
Seed oil content (%) 1.2
33.7 30.7 27.5–33.7
30 July 1.2
46.7 46.5
15 July 43.3–48.2
Erucic acid content oil 1.6
30 July 46.5 45.6 42.9–48.6 1.6
22.6 23.7
15 July 20.2–27.0
Nervonic acid content oil 1.8
22.5 24.6 20.1–27.6 1.8 30 July
a1, Leaves severely spotted; 9, leaves without disease symptoms.
bPlant development stage: 41, flower buds just visible; 49, flower stalks extended; 51, first flowers visible; 59, full bloom; 61, first
pods developed; 61, pod development completed.
c1, no symptoms; 9, severe infection. dHarvest date.
the winter and degree of infection by Albugo candida(r= −0.60) after sowing on 23 June sug-gests that the brown spots could have been due to
Albugo candida infection. During the summer of 1996, severe infection of Alternaria and Albugo candida occurred. Alternaria infection was more severe in the first sown trial and hardly occurred in the trials sown in August. The infection of
Albugo candidawas more severe in the trial sown on 13 July 1995.
The highest seed yield and thousand seed weight were observed in the trial sown on 13 July. However, due to the small area of the plots, seed yield data suffered from large random variation. Seed yield determined in the first sown trial
showed significant correlation with soil cover in spring, plant height and early flowering (r=0.74, 0.62 and 0. 63, respectively). A negative correla-tion was found between seed yield and the degree of disease infection of the hulls (r= −0.62). The correlations in the second sown trial showed a similar pattern but were somewhat lower.
The results obtained in the trials sown on 15 and 30 July 1996 are presented in Table 2. In this table also the results of the best performing acces-sion CPRO 883158 have been included. Signifi-cant variation was observed for each characteristic.
acces-sions suffered severely from frost and only some plants were left. In these two accessions soil cover was low through the further growing season and the same was found for seed yield. The percentage of flowering plants observed in the trial sown on 30 July 1996 was similar to that found in the trial sown on 8 August 1995. Only two accessions reached 100% flowering. As in 1996, it was shown also in 1997 that later sowing delayed initial flow-ering and ripening.
Severe infection ofAlternariaoccurred in 1997, which was higher than in 1996. Especially the hulls were severely infected. However, Albugo candida infection was lower in 1997. The harvest was earlier in 1997, probably due to higher tem-peratures during the summer. The mean seed yield was more or less similar to that in 1996. Seed yield obtained in the trial sown on 15 July 1996 showed a high and significant correlation with soil cover in spring (r=0.81), early flowering (r= 0.85), plant height (r=0.85), thousand seed weight (r=0.72) and oil content (r=0.73). The correlations with seed yield were somewhat lower in the trial sown on 30 July 1996 but still signifi-cant. In this trial seed yield showed a high correla-tion with percentage flowering plants (r=0.85). The best yielding accession CPRO 883158 ex-ceeded in both trials the trial mean for plant health before winter, soil cover, early flowering, plant height, seed yield, thousand seed weight and seed oil content. The level of disease infection of CPRO 883158 was similar to the trial mean. The seed yield of CPRO 883158 corresponds with seed yield results obtained in Southern England (Cro-mack, 1998).
Seed oil content determined in the first sown trials varied between 34 and 38% in 1996 and between 28 and 35% in 1997. These results corre-spond with values found by Prince and Rothfus (1984) and by Cromack (1998).
4. Conclusions
The best performing Lunariaaccession showed a high seed yield when sown mid July and a moderate seed yield when sown end of July. How-ever, within the investigated gene pool no acces-sions were found suitable for sowing end of August. Later sowing than mid July led to lower seed yields and later harvest dates evidently due to delayed and reduced flowering.
Reasonable levels of disease resistance were found and it is expected that seed yield can be increased when the disease resistance level of highly productive genotypes is improved.
The observed variation for seed oil content and fatty acid composition is promising for further enhancement of these characteristics by breeding and selection.
References
Baily, L.H., 1949. Manual of Cultifated Plants. Macmillan, New York, p. 443.
Cromack, H.T.H., 1998. The effect of sowing date on the growth and production of Lunaria annua in Southern England. Ind. Crops Prod. 7, 217 – 221.
Meier zu Beerentrup, H., Ro¨bbelen, G., 1987. Screening for European production of oilseeds with unusual fatty acids. Angew. Botanik 61, 287 – 303.
Nicholls, F.H., 1996. New crops in the UK: from concept to bottom line profits. In: Janick, J. (Ed.), Progress in New Crops. ASHS Press, Alexandria, VA.
Prince, L.H., Rothfus, J.A., 1984. Development of new crops for industrial raw materials. J. Am. Oil Chem. Soc. 61, 281 – 289.
Van Soest, L.J.M., 1994. Alternative crop developments in the Netherlands. Alternative Oilseed and Fibre Crops for Cool and Wet Regions of Europe. Proceedings of a Workshop, 7 – 8 April 1994 at Wageningen, the Netherlands, pp. 14 – 20.
Pierik, R.L.M., 1967. Regeneration, vernalisation and flower-ing in Lunaria annua L. In vivo and in vitro. Meded. Landb. Hogesch. Wageningen 67 (6), 1 – 71.
