Type Rapeseed Research Articles

A Tourist-like MITE insertion in the upstream region of the BnFLC.A10 gene is associated with vernalization requirement in rapeseed (Brassica napus L.)

BackgroundRapeseed (Brassica napus L.) has spring and winter genotypes adapted to different growing seasons. Winter genotypes do not flower before the onset of winter, thus leading to a longer vegetative growth period that promotes the accumulation and allocation of more resources to seed production. The development of winter genotypes enabled the rapeseed to spread rapidly from southern to northern Europe and other temperate regions of the world. The molecular basis underlying the evolutionary transition from spring- to winter- type rapeseed is not known, however, and needs to be elucidated.ResultsWe fine-mapped the spring environment specific quantitative trait locus (QTL) for flowering time, qFT10-4,in a doubled haploid (DH) mapping population of rapeseed derived from a cross between Tapidor (winter-type) and Ningyou7 (semi-winter) and delimited the qFT10-4 to an 80-kb region on chromosome A10 of B. napus. The BnFLC.A10 gene, an ortholog of FLOWERING LOCUS C (FLC) in Arabidopsis, was cloned from the QTL. We identified 12 polymorphic sites between BnFLC.A10 parental alleles of the TN-DH population in the upstream region and in intron 1. Expression of both BnFLC.A10 alleles decreased during vernalization, but decreased more slowly in the winter parent Tapidor. Haplotyping and association analysis showed that one of the polymorphic sites upstream of BnFLC.A10 is strongly associated with the vernalization requirement of rapeseed (r2 = 0.93, χ2 = 0.50). This polymorphic site is derived from a Tourist-like miniature inverted-repeat transposable element (MITE) insertion/deletion in the upstream region of BnFLC.A10. The MITE sequence was not present in the BnFLC.A10 gene in spring-type rapeseed, nor in ancestral ‘A’ genome species B. rapa genotypes. Our results suggest that the insertion may have occurred in winter rapeseed after B. napus speciation.ConclusionsOur findings strongly suggest that (i) BnFLC.A10 is the gene underlying qFT10-4, the QTL for phenotypic diversity of flowering time in the TN-DH population, (ii) the allelic diversity caused by MITE insertion/deletion upstream of BnFLC.A10 is one of the major causes of differentiation of winter and spring genotypes in rapeseed and (iii) winter rapeseed has evolved from spring genotypes through selection pressure at the BnFLC.A10 locus, enabling expanded cultivation of rapeseed along the route of Brassica domestication.

Genetic dissection of intersubgenomic heterosis in Brassica napus carrying genomic components of B. rapa

Although strong intersubgenomic heterosis for seed production has been observed between “natural” domesticated Brassica napus (rapeseed, AACC) and a new type of rapeseed into which subgenomic components of Brassica rapa (AA) have been introgressed, the molecular genetic mechanism of this intersubgenomic heterosis is not understood. In this study, a recombinant inbred line population of new type rapeseed derived from a cross between B. napus and B. rapa, together with a population from a backcross with the parental line of B. napus, was used to identify single-locus quantitative trait locus (QTL) and interacting QTL pairs for yield and nine yield-related traits. More than half of single-locus QTLs and interacting QTL pairs detected were involved with the novel alleles induced by the introgression of B. rapa. The alleles directly from B. rapa A genome played a secondary role in contributing to intersubgenomic heterosis. Allelic and nonallelic interactions of both novel alleles generated by B. rapa introgression and the alleles directly from B. rapa A genome contributed to the intersubgenomic heterosis between “natural” domesticated rapeseed and new type rapeseed into which B. rapa had been introgressed. Six loci for fixed heterosis were identified and their possible applications are also discussed.

Introgression of genomic components from Chinese Brassica rapa contributes to widening the genetic diversity in rapeseed (B. napus L.), with emphasis on the evolution of Chinese rapeseed

In spite of its short history of being an oil crop in China, the Chinese semi-winter rapeseed (Brassica napus L., 2n = 38, AACC) has been improved rapidly by intentional introgression of genomic components from Chinese B. rapa (2n = 20, AA). As a result, the Chinese semi-winter rapeseed has diversified genetically from the spring and winter rapeseed grown in the other regions such as Europe and North America. The objectives of this study were to investigate the roles of the introgression of the genomic components from the Chinese B. rapa in widening the genetic diversity of rapeseed and to verify the role of this introgression in the evolution of the Chinese rapeseed. Ten lines of the new type of rapeseed, which were produced by introgression of Chinese B. rapa to Chinese normal rapeseed, were compared for genetic diversity using amplified fragment length polymorphism (AFLP) with three groups of 35 lines of the normal rapeseed, including 9 semi-winter rapeseed lines from China, 9 winter rapeseed lines from Europe and 17 spring rapeseed lines from Northern Europe, Canada and Australia. Analysis of 799 polymorphic fragments revealed that within the groups, the new type rapeseed had the highest genetic diversity, followed by the semi-winter normal rapeseed from China. Spring and winter rapeseed had the lowest genetic diversity. Among the groups, the new type rapeseed group had the largest average genetic distance to the other three groups. Principal component analysis and cluster analysis, however, could not separate the new type rapeseed group from Chinese normal rapeseed group. Our data suggested that the introgression of Chinese B. rapa could significantly diversify the genetic basis of the rapeseed and play an important role in the evolution of Chinese rapeseed. The use of new genetic variation for the exploitation of heterosis in Brassica hybrid breeding is discussed.

Changes in Erucic Acid Concentration of Rape Seeds in Advanced Generations

This study was carried out to determine the extend of changes in erucic acid concentration of rapeseeds which were grown in Carsamba and Bafra Plains of Central Blacksea Region. In addition to field experiments, the same experiment was conducted in the greenhouse to avoid polen transfer from other sources. The first material used was 00 type rapeseed cultivars. In order to ensure a good result, the experiment sites were selected based on the intensity of other Brassica species (B. oleracea, B. rapa, B. nigra). The harvested rape seeds was the seed material of following year. Erucic acid content was measured for seeds obtained each year. The erucic acid content for three genarations showed that it was much lower than the limits for health (0.04 %).

High-protein fraction of 00 type rapeseed meal in broiler nutrition

High-protein fraction of 00 type rapeseed meal in broiler nutrition

Fatty Acid Composition of Rapeseed Oils of Japanese Old Type Varieties.

Rapeseed oils from Japanese old type rapeseed varieties are rich in erucic acid. Rapeseed oil with high erucic acid content is said to be harmful in nutrition. Therefore, rapeseeds with low content or whithout erucid acid have been developed in Japan and many countries of the world. The fatty acid composition of rapeseeds of Japanese old type varieties was examined. Main fatty acid composition of Towada rapeseeds grown in Aomori prefecture in 1982 was as follows: Oleic acid, 16%; linoleic acid, 13%; linolenic acid, 8%; icosenoic acid, 10% and erucic acid, 45%. The fatty acid composition of the same rapeseeds in the same area in 1983 was similar to that in the previous year. The fatty acid composition of Oomi rapeseeds grown in Kagoshima prefecture in 1982 was similar to that in Aomori prefecture in same year. Of the twelve old type varieties of rapeseeds which were grown in Iwate prefecture, eleven contained erucic acid in seeds oils at levels ranging from 42 to 49% and oleic acid from 11 to 17%. There was a negative correlation between percentages of erucic and oleic acids. There was a linear relationship (r=0.795) (1) between oleic (Y) and erucic (X) acids percentage, except for 'Aomori-1'.Y=(-0.7246X)+47.24(1)There was also a linear relationship (r=0.847) (2) between percentages of oleic (Y) and erucic (X) acids in all rapeseeds analyzed and reported data.Y=(-0.4348X)+34.25(2)

Nitrogen Solubility as a Means of Estimating the Gross Protein Value of Rapeseed Meal

INTRODUCTIONSTUDIES on the nutritive value of rapeseed meal have shown that different samples vary in quality according to variety of seed from which the meal is produced and the amount of heat used during expeller processing of the seed (Clandinin et at., 1959). Samples of high quality had amino acid patterns similar to that of soybean meal but those of lower quality were lower in lysine content (Clandinin, 1967).Since rapeseed meals may vary greatly in quality, the present study was undertaken to assess the validity of some laboratory tests of protein evaluation as compared to biological assay, in the hope that a simple physical technique could be used to correlate nitrogen solubility with protein quality in rapeseed meal.EXPERIMENTALTen samples of rapeseed meal (R.S.M.) were obtained from solvent, prepress-solvent and expeller processing plants. Some of the meals were prepared from B. campestris type rapeseed, while others were…

GROWTH DEPRESSING FACTORS IN RAPESEED OIL MEAL: V. THE EFFECTS OF MYROSINASE ACTIVITY ON THE TOXICITY OF THE MEAL

A study was made of the effects of adding 0.1 per cent myrosinase (a thioglucoside-splitting enzyme) to mouse diets containing Swedish or Polish type rapeseed oil meal and hot water-treated fractions of the meal. The latter were devoid of active enzyme but contained known quantities of the thioglucosides, precursors of the toxic isothiocyanates (I) and thiooxazolidones (T).Hot water extraction of the meals resulted in about 20 per cent of the dry matter being extracted and in significant alteration in the proportions and amounts of I and T.The addition of myrosinase to untreated rapeseed oil meals failed to increase the toxicity, presumably because there was already sufficient enzyme in the meals to reduce gains to about 25 per cent of normal. Addition of enzyme to the extracted residue (containing about one-third of the original thioglucosides of the meal) also failed to increase the toxicity. Enzyme addition to diets containing the water-soluble components resulted in significant growth depression but the full potential toxicity was not obtained.It is concluded that the enzyme myrosinase is an important factor affecting the toxicity of rapeseed oil meal in animal feeding, although conditions for its optimum activity were not achieved in this experiment where semi-purified enzyme was employed as a dietary supplement.

RAPESEED OIL MEAL AS A PROTEIN SUPPLEMENT FOR SWINE AND RATS: I. RATE OF GAIN, EFFICIENCY OF FOOD UTILIZATION, CARCASS CHARACTERISTICS AND THYROID ACTIVITY

Diets containing 0, 2 or 10 per cent expeller extracted Argentine type rapeseed oil meal were fed to swine from 3 weeks of age to market weight averaging 195 lb., and to albino rats from 3 weeks to 6 months of age. The 10 per cent level of the meal depressed the rate of liveweight gain and in some cases reduced efficiency of food utilization in both species. Food consumption was not adversely influenced by the levels of meal used in these diets. Total weight, histological sectioning and I131 turnover rate of the thyroid gland indicated hypertrophy and other abnormalities of the gland in the animals fed 10 per cent meal. The 2 per cent level of meal did not exert consistent effects on the criteria measured. Female rats were more susceptible than males to the effects of the meal on rate of gain, but ovariectomy of females appeared to reduce this susceptibility. The nutritional quality of the diet fed to rats tended to alter the response to toxicity of the meal. Swine carcass characteristics were not markedly affected by rapeseed oil meal in the ration.

RAPESEED OIL MEAL AS A PROTEIN SUPPLEMENT FOR SWINE AND RATS: II. ENERGY AND NITROGEN DIGESTIBILITY AND NITROGEN RETENTION

Energy and nitrogen digestibility and nitrogen retention studies are reported for pigs averaging 7, 28 and 62 kg. in weight and for 4- and 6-weeks-old albino rats fed diets containing 0, 2 or 10 per cent expeller extracted Argentine type rapeseed oil meal. The 10 per cent level of the meal depressed apparent digestibility of dry matter, energy and nitrogen with significant effects occurring only in rats. The 2 per cent level of the meal had no significant effect on digestibility. Retention of digestible nitrogen was not altered by the level of rapeseed oil meal in the diet. As indicated by digestibility studies, female rats were more susceptible than males to the presence of rapeseed oil meal in the diet. There were a number of interactions between rapeseed oil meal level and the type of diet fed to rats suggesting that the energy and protein levels of the diet may influence the effect that this meal has on apparent digestibilities of dry matter, energy and nitrogen.