BioMatNet Item: AIR3-CT94-2324 - Coordinated Improvement of Castor Oil Productivity and Quality for New Potential European Markets

AIR3-CT94-2324
Coordinated Improvement of Castor Oil Productivity and Quality for New Potential European Markets

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AIR Cluster IV - Oils and Fats : Paints/Coatings/Plastics : Plant Genetics : Starch : Sugar : Vegetable Oil/Fat

	Proposal No:	AIR3-CT94-2324
	Date Prepared:	September 1999
	Source:	Progress report April 1998

Progress report April 1998

Introduction

The castor project aims at improving by agronomic and genetic means the productivity and the technological quality of castor crops grown in European seeking new high value added outlets in the oleo chemical field in order to improve the economics of a future European castor production chain.

Objectives

The scientific general objectives of the project were grouped within a series of tasks as follows:

Task 1. Plant physiology

To observe the response of castor to different light irradiance and water stresses in terms of photosynthesis and especially stomata behaviour and to identify the preferential flows of the carbon assimilates produced by the plant during the flowering and the gain filling periods.
To look for genetic variability as regard photosynthesis performances.

Task 2. Improvement of the quality by agronomic methods

To evaluate the agronomic and technological performances of the pre saleable castor hybrids in the four countries participating in the network: France, Greece, Italy and Spain.
To confirm the response of castor to the water feeding and the best irrigation strategy.
To confirm the suitability of new seed coatings, to look for other active ingredients against Alternaria ricini and for methods to rank the genotypes according to their susceptibility.
To assess the bio-ecology and the damages of the Empoasca spp. and to make the third year survey of the insects and of the natural enemies in the European castor crops.

Task 3. Improvement of the quality by genetic methods

To (re-evaluate for sexual characters the Fl and the segregating generations F2, BCIF and F3 of crosses involving all forms of sexual expressions and determinate the genetic basis.
To evaluate the Fl, BCIFI and F2 of reciprocal crosses between high and low selections for oil content.
To analyse for ricinoleic content reciprocal crosses between high and low selections and to search for additional genetic variability for technological characters.
To continue the creation and the evaluation of new male and male sterile sensitive lines and to produce new experimental hybrids for both irrigated and rain-fed conditions.

Task 4. Seeking of new castor oil based products

To look for more reliable and cost-effective physical deacidification (distillation) and dewatering processes allowing such refined castor oil to be used as polyol for sophisticated polyurethane dispersions, including laboratory and preindustrial tests.
To improve the isolation method of the promising neutral surfactant from castor undecylenic acid and glucosamine and to check their ecotoxicological properties.
To set up the synthesis of quaternary cationic surfactants derived from glycolic acid and fatty acids of several oils.
To evaluate the toxicological properties of the ricinobetaines and their suitability as amphoteric surfactant for cosmetic formulations and for applications in textile area.
To transfer the synthesis of polyhydroxylated alpha-monoglycerides of fatty acids of castor oil from small scale to pre-pilot stage and to assess their rheological and surfactant properties.

Results

In 1997, eight trials designed in randomised complete blocks and including six common pre saleable hybrids (5 of the 6 present in 1996) were established under irrigation in different pedo-climatic conditions of the four countries. All hybrids displayed suitable first raceme insertion height, total height and moderate vegetative development for mechanical harvesting. Exceptional mean yield and seed quality over location and varieties was reached in 1997 mostly thanks to more favourable climatic conditions (especially in Spain), demonstrating definitively the good potential of castor if accurate practices are applied and suitable water feeding and sufficient temperatures are available. However, as in 1996 wide variations were noted between locations for seed production (4 t/ha in Greece and 2,7 t/ha in the most northern area of France on superficial soils).

In seven trials, significant differences between cultivars were also observed for seed production (between 3 and 3.4 t/ha) and for oil content (from 49,3 % for the control Pronto to 54,2 % for HD912). H 526 and HD912 were confirmed to rank the best (1.8 t of oil /ha that is 120 % of the control) thanks to both higher seed productivity and oil contents, showing the outstanding genetic progresses achieved in few years, breeding castor specially for European conditions. Contrary to the last year, no relationship has been established between TSW (thousand seeds weigh) and yield while number of seeds/m² has been confirmed as a determinant yield component.

Three experiments designed in split-plots were carried using different watering strategies: rain-fed, full irrigation restrictive irrigation.. Two genotypes were used: Pronto and a mid-late dwarf hybrid HD912. In the Spanish trial, soil water content was periodically measured with neutron probe and actual ET was calculated for each treatment. The dynamic water balance through the cycle and the crop function has been estimated and the global response of castor to water feeding confirmed. rain-fed productivity varied sharply among locations from 0.76 t/ha in Greece to 19.6t/ha in Spain, outlining the differences in environmental conditions between the locations and the extreme variability of castor yields while cultivated in rain alone. The relationship between yield and water/ETP ratio showed that maximum yield is reached under full irrigation (3.2t/ha in average over varieties and locations) and that productivity is decreased by 20 % to 2.5t/ha using a restrictive water feeding (50% of the crop demand). Finally the best irrigation strategy should consist in providing about 75% of the crop demand, starting water supply just before or during the flowering period.

As in 1996, a strong correlation was found between the yield and the number of seeds/m², confirming that irrigation allows a better fructification of the first raceme and the growth of secondary racemes as well as a great number of full filled capsules/raceme. Contrary to 1996, oil content was significantly affected by the water supply. The harvest index (0,35 to 0,45 depending on the locations) was stable between treatments for each location, confirming the well-oriented use of water by the plant. These results indicate that Castor must be cultivated under irrigation in the south of Europe and that water use can be oriented for the seed production.

Considerable attention was paid to means of controlling Alternaria ricini, the most troublesome fungus for Castor in Europe. A guide was prepared by a pathologist and sent to each partner to facilitate the disease detection in a network trial. Castor crops surveys confirmed Alternaria as a major pathogenic agent even if other fungi are present and must not be neglected, as is the case for Macrophomina phaseolina and Phoma (especially for seed multiplication). On the basis of previous years results all seeds were treated with Germipro. No particular problem was observed and a lower level of Alternaria, than in 1996, was reported - but no significant difference was observed between treated and untreated variety trials. Tebuconazole - which was found in 1996 to be more efficient than iprodione - was also tested as coating product (Raxil) and aerial treatment in open fields and no injurious effect was noticed. As far as other active ingredients are concerned, triticonazole showed a more durable efficiency (no restart of fungi growth after inhibition) in the laboratory and a lack of phytotoxicity in small plots trials (in spite of a little reduction of the hypocothyle length) to be further verified.

The feasibility of using a lab test (root inoculation and length of the hypocotyle-as indicator) to classify at the seedling stage the genotypes according to their resistance (horizontal type) against Alternaria was verified and used as routine. Observations made in the nurseries suggested that resistance against Alternaria ricini should exist.

As far as insects were concerned, the work was focused on Empoasca. Survey of the fauna in the castor crops confirmed it as an "insectary plant" providing both food (extra-floral nectaries) and resting sites. The most common phytophagous insects were again Empoasca, (Cicadellidae), Aphis fabae (Aphidae), Thrips tabaci and Lygus spp (Miridae). In addition to Empoasca, Lygus should not be neglected because even at low density it can cause serious damages (death of the apical meristem). Same generic predators (12 species) were identified and Anagrus atomus (Mymaridae) was confirmed to an effective eggs parasitoid, especially of Empoasca.

Insect density was found to be location dependent, reflecting ecological conditions, in terms of distribution of the insects. Insecticide application proved to be efficient and significant difference in oil content, TSW, seed yield appeared between treated and untreated variety trials in Spain, demonstrating the potential economic importance of this pest. The existence of variable susceptibility according the genotypes was also suggested in these trials.

Twelve crosses among the initial group of 19 crosses which involved all the identified phenotypic were selected to go on within the study of improving quality by genetic methods. . So, parents, Fl, F2 and BCIFI (6938 plants) of these crosses were evaluated for sexual expression three times during the reproductive period. Heterogeneity of the parental genotypes was confirmed, amplifying the difficulty of this very complicated issue. Useful information for breeders was however obtained from the first analysis of the data. The female lines probably carry different genes of femaleness, dominant (F) and recessive (a), the sensitive reference line CNES I being maybe Aa and Ff. The dominance of interspersed over femaleness was confirmed as well as the dominance of the interspersed type I over the type II. Complying with the literature the observed segregation suggested that there should be two Id (interspersed) genes at two independent loci.

The genetic experiments on oil content carried out confirmed that oil content in castor seed is controlled by the genotype of the plant (maternal or sporophytic control) similarly to most oilseed crops and that high content is dominant over the low one even if some cytoplasmic influences could be envisaged. So, in the F2 of the reciprocal crosses transgressive segregations were found which would be useful in selection process. As regards ricinoleic content, the Fl and Fl reciprocal of crosses between low and high selections, as well as the analyses of selfed and open-pollinated seeds coming from the same plant: the control of ricinoleic content should be maternal, allowing selection of this character on open-pollinated plants. It was observed that temperature during the grain filling phase could have an influence on the ricinoleic content, low temperatures favouring higher ricinoleic contents which is in agreement with the results obtained within the agronomic network (the highest contents often occurring in France).

Several nurseries were planted. In particular 153 male lines selected in 1996 for European conditions and still in fixing progress were selfed and observed for a comprehensive set of agronomic traits. Some of these males were also evaluated for combining ability with two sensitive and one genetic female testers (60 tested hybrids). From this test, 5 male lines were selected for further breeding works. With respect to the breeding of new sensitive female lines, the test cross evaluated in 1997 showed that some families reach the productivity of the controls but none was better. Trials involving the 'most promising hybrids gave encouraging results of the variety trial performance in rain-fed trials, where all the hybrids selected on their better drought tolerance yielded better than the controls.

Work on product development was concentrated on testing additional physical refining methods on castor oil at lab and pre- industrial levels, in order to get a castor oil displaying the water content and acid value (without decreasing hydroxyl value) required to be used as polyps in sophisticated polyurethane formulations. None of the methods which were tested at large-scale in 1997 gave completely satisfactory results on both technical (any origin) and press oils (high quality). However from the experiments, some methods can be selected for further investigations and scaling-up: short path and other forms of evaporators (thin film, fat-film), deacidification with adsorbents for soap with subsequent dewatering as well as their combination.

The production of the ricinobetaine at the industrial scale was investigated and several lots were prepared to supply the cosmetic industry. The bioecotoxicological tests demonstrated the anti-microbial activity of the castorbetaine to be similar to those of the competing coco and lauric betaines. Ricinobetaines were successfully incorporated in formulations for shampoo, bath foam and personal care detergents, confirming that they have equivalent chemical-physical properties to the currently marketed betaines. Great gelling, viscosity and emulsifying properties can be outlined but difference in performance is not high enough to lead the users to switch from the current betaines to the more expansive ricinobetaines (due to the higher cost of the ricinoleic acid). Other arguments are therefore to be developed to introduce this ingredient into the market. Use as surfactant during the humid phase of the textile process was proved to be possible but the castorbetaines price is definitively excessive to allow their introduction into this application. To conclude the ricinobetaines are ready to be marketed.

Other activities were focused on the transfer from small scale to pre pilot scale of the synthesis method of the polyhydroxymonoglycerides from pure alpha-monoglyceride (MG) and on assessment of their surfactant and rheological properties. Encouraging conversion rates (88 % in the final compound) and yields (55 %) were obtained. The dihydroxyMG derived from ricinoicic acid expressed both good surfactant (at theinterface oil/water but not at the interface oil/air) and thickening properties meanwhile the trihydroxyMC showed outstanding thickening properties, leading to envisage possible applications for these compounds as texturing agent in cosmetic formulations. Presence of several hydroxyl group in theses molecules allows also their use as polyol in the polyurethane production. Speciality surfactants based on undecylenic acid (obtained from the castor oil by steam cracking) as sugar or starch derivatives that could enter into personal care formulations, were also investigated. Neutral surfactants derived from glucosamine and castor undecylenic acid were investigated as hair care products. Purified compounds were submitted to additional toxicological tests. Formulation works have been stopped until the results will be available. A patent was requested in France (against alopecia).

Synthesis of quternary surfactant compounds from glycolic acid and fatty chains of variable length for skin care produced a range of anionic surfactants derived from glycolic acid, which gives softness and brightness. Focus was put on establishing the operating conditions of the route (4 steps). A set of homologues derivatives displaying a high purity (>96%) have been obtained at the 2-20g scale and chemical-physical characterisation as well as the preliminary ecotoxicological tests are under way.