Oilseed Brassica Species Research Articles

Intergeneric hybridization between Erucastrum canariense and Brassica rapa. Genetic relatedness between E(C) and A genomes.

An intergeneric hybrid between a wild species, Erucastrum canariense (2n = 18; E(C)E(C)), and a cultivated oilseed brassica species, Brassica rapa (2n = 20; AA), was synthesized through ovary culture in White's basal medium supplemented with casein hydrolysate. Morphological, cytological and DNA-based analysis helped to establish the hybrid nature of the derived plants. Hybrid plants were morphologically intermediate between the two parents and were completely male, as well as female sterile. Cytological analysis revealed the occurrence of 19 I in about 38% of the PMCs investigated. However 1-8 bivalents/PMC were also observed, indicating a significant level of homology between the two genomes. Normal chromosome pairing and pollen fertility was restored following colchiploidy. The intergeneric amphiploid developed during the investigation can be used as a bridging species for the transfer of desirable genes from E(C) to cultivated genomes (especially A and C), and for resistance to Alternaria blight and mustard aphid. Under field conditions, the E. canariense intergeneric hybrid and the amphiploid appeared to be moderately resistant to Alternaria blight and also harboured a significantly lower population of mustard aphid than the cultivated B. rapa.

Use of Near Infrared Reflectance Spectroscopy to Screen Ethiopian Mustard for Seed Weight

AbstractNear infrared reflectance spectroscopy (NIRS) provides a method for the simultaneous measurement of multiple quality traits in oilseed Brassica species, such as oil, protein, glucosinolate, and chlorophyll content. The incorporation of new traits into NIRS analysis should increase the information obtained from analyzed samples with little additional effort. The objective of this study was to determine the potential use of NIRS to screen intact‐seed samples of Ethiopian mustard (Brassica carinata Braun) for 1000‐seed weight. A calibration equation for this trait developed in 1992 using modified partial squares (MPLS) regression was successively expanded with new samples from the 1993 and 1994 crops. The 3‐yr calibration showed an r2 of 0.86 in external validation, indicating the reliability of NIRS for screening Ethiopian mustard samples for seed weight. This method could be particularly useful in large breeding programs, as it is less time consuming and more cost effective than conventional methods.

Plant regeneration from peduncle segments of oil seed Brassica species: Influence of silver nitrate and silver thiosulfate

Cultured peduncle segments of B. juncea, B. campestris, B. napus, B. nigra and B. carinata produced shoot buds on Murashige and Skoog medium supplemented with benzyladenine and 1-naphthalene acetic acid. Supplementation of the media with 30 µm silver nitrate or silver thiosulfate enhanced the frequency of shoot regeneration. The regenerated shoots could be rooted at a frequency of 95% and transferred to soil where 75% survived and set seed.

Transfer of Brassica tournefortii (TT) genes to allotetraploid oilseed Brassica species (B. juncea AABB, B. napus AACC, B. carinata BBCC): homoeologous pairing is more pronounced in the three-genome hybrids (TACC, TBAA, TCAA, TCBB) as compared to allodiploids (TA, TB, TC)

Transfer of Brassica tournefortii (TT) genes to allotetraploid oilseed Brassica species (B. juncea AABB, B. napus AACC, B. carinata BBCC): homoeologous pairing is more pronounced in the three-genome hybrids (TACC, TBAA, TCAA, TCBB) as compared to allodiploids (TA, TB, TC)

Transfer of Brassica tournefartii (TT) genes to allotetraploid oilseed Brassica species (B. juncea AABB, B. napus AACC, B. carinata BBCC): homoeologous pairing is more pronounced in the three-genome hybrids (TACC, TBAA, TCAA, TCBB) as compared to allodiploids (TA, TB, TC)

For the transfer of genes from B. tournefortii (TT) to the allotetraploid oilseed brassicas, B. juncea AABB, B. carinata BBCC and B. napus AACC, B. tournefortii was first crossed with the three basic diploid species, B. campestris (AA), B. nigra (BE) and B. oleracea (CC), to produce the allodiploids TA, TB and TC. These were tetraploidized by colchicine treatment to produce the allotetraploids TTAA, TTBB and TTCC, which were further crossed with B. juncea and B. napus to produce three-genome hybrids with substitution-type genomic configurations: TACC, TBAA and TCAA. These hybrids along with another hybrid TCBB produced earlier, the three allodiploids, their allotetraploids and the four diploid parent species were studied for their male meiotic behaviour. The diploid parent and the allotetraploids (TTAA, TTBB and TTCC) showed regular meiosis although the pollen viability was generally low in the allotetraploids. In the allodiploids (TA, TB and TC) only some end-to-end associations were observed without any clearly discernible chiasmata or exchange points. Chromosomes involved in end-to-end associations were randomly distributed at the metaphase/anaphase-I stages. In contrast, the three-genome hybrids (TACC, TBAA, TCAA and TCBB) showed normal bivalents whose number exceeded the expected bivalent values. Bivalents arising out of homoeologous pairing were indistinguishable from normal pairs by their disjunction pattern but could be distinguished on the basis of the heteromorphy of the homoeologous chromosomes. The three-genome hybrids could be backcrossed to allotetraploid oilseed brassicas as they had some fertility. In contrast, the allodiploids could neither be selfed nor back-crossed. On the basis of their meiotic stability, in terms of more pronounced homoeologous pairing and fertility for backcrossing, the three-genome configurations provide the best possible situation for the introgression of alien genes from the secondary gene pool to the allotetraploid oilseed crops B. juncea, B. napus and B. carinata.

Seedling and adult plant evaluation of race variability in Leptosphaeria maculans on Brassica species in Australia

Seedling and adult plant studies were used to identify the race structure of Leptosphaeria maculans (the cause of blackleg) on oilseed Brassica species in Australia. Host-pathogen interactions using a set of 12 differential host lines identified 14 seedling relationship, however, between seedling and adult plant reactions to individual isolates, indicating that seedling and adult plant resistance are under different genetic control. While non-specific adult plant resistance was observed in the B. napus line Jet Neuf, host-pathogen interactions confirmed the existence of race-specific adult plant resistances in other differential lines.

Growth, development, and yield of three oilseed Brassica species in a water-limited environment

Representative lines of Brassica napus, B. campestris, and B. juncea were compared at East Beverley in the central wheatbelt of Western Australia on the basis of agronomic and physiological characters known to affect seed yield. Seed yield of B. juncea line 81794 was 32% higher than the locally adapted B. napus cv. Wesbrook (76 g/m2). Yields of B. napus cv. Eureka and the 2 B. campestris populations were not significantly different from Wesbrook and were lower than 81794. The higher yield of 81794 was due to higher dry matter production, particularly after first open flower. Yield superiority of 81794 was not associated with any single yield component. Under the water-stressed conditions of this experiment, seed yield had a strong positive correlation with dry matter production after first open flower. Differences in dry matter production during this period were due to variation in crop growth rates among the lines, not to variations in duration of the period. There was no relationship between flowering time and seed yield in this experiment, suggesting earlier reproductive development is not obligatory for high yield of oilseed Brassicas in low rainfall mediterranean environments. Total water use throughout the season differed little among populations, but there were differences in water use patterns over time. The greater rate of dry matter accumulation of 81794 is due to its ability to extract more water from the soil profile after anthesis; postanthesis water use of 81794 was 20% higher than that of Wesbrook. Water use efficiency of 81794 was also higher than that of Wesbrook, because soil evaporation comprised a smaller proportion of evapotranspiration. Further increases in seed yield of oilseed brassicas in this environment should be possible if higher postanthesis water use could be combined with lower soil evaporation and improved water use efficiency.

Response of oilseed Brassica cultivars to ozone

Cultivars of four oilseed Brassica species were exposed to acute levels of ozone (0.31 or 0.47 μL L−1) at the seedling stage. Brassica hitra ’BHL-926’ was the most sensitive to ozone followed by B. juncea ’Newton’ and B. rapa ’Torch.’ Brassica napus seedlings exhibited very little foliar injury (0 – 4%) after 24 h exposure to 0.31 μL L−1 ozone. Key words: Ozone, foliar injury, rapeseed, mustard

Application of the ideotype concept in breeding for higher yield in the oilseed brassicas

Approaches to yield-improvement breeding methodology which utilize information from biometrical genetic studies and from plant physiological studies aimed at developing ideotype models are reviewed here, with special emphasis on yield improvement in the oilseed brassicas. Major difficulties involved in yield-improvement programmes are the accurate selection of parents from which to generate superior breeding populations, and the selection of high-yielding genotypes from early-segregating generations. In both cases, the complex polygenic inheritance of yield and the magnitude of genotype × environment interactions affecting yield greatly reduce the chances of isolating superior genotypes. A wide array of biometrical procedures have been proposed in developing yield-improvement programmes. Some have been utilized successfully. However, their use in analyzing a character such as yield has been generally limited because of the need to conduct analyses with populations sown at much lower densities than commercial crops. Development of the ideotype concept has focussed the attention of plant physiologists on identification of simple morphological characters which have some influence on physiological processes determining the yield of the economic organs. Characters such as leaf inclination and leaf shape, for example, are often simply inherited and can greatly influence crop canopy structure and radiation interception. Such characters could be rapidly modified by selection to increase crop photosynthesis and yield. Ideotype definitions integrate information on these relationships and provide plant breeders with a clear blueprint of the characteristics of a high-yielding cultivar in a specified environment. Research with oilseed Brassica species in Western Australia and Tasmania has identified a number of highly heritable characters which provide a basic framework for the definition of a yield ideotype for spring rape ( B. napus). These include an optimal time of flowering, apetalous flowers and long upright pods to improve light penetration of the dense pod canopy, and pod shattering resistance to allow for direct harvesting of the crop. A major advantage in breeding for this ideotype is that genes for certain characters can be easily introgressed from the related species B. campestris and B. juncea. It is also possible, using microspore cultures, to generate large numbers of B. napus pure lines directly from plants selected in F2 populations on the basis of ideotype characteristics. This would allow for large-scale yield testing of selections within two to three years of making the original crosses.

Gene expression in Brassica tissues and species following heat shock

Several tissues from the three oilseed Brassica species have been analyzed for polypeptides synthesized in vivo and in vitro under control (23 °C) and heat-shock conditions. The various tissues have characteristically unique patterns of polypeptide synthesis, the general pattern being maintained following heat shock. In addition, all tissues exhibit synthesis of a set of qualitatively similar heat shock protein (HSP) that differ, however, in relative intensity among tissues. Synthesis of control polypeptides as well as high molecular-weight HSP is similar in hypocotyls of the three genomically interrelated species B. napus, B. campestris, and B. juncea; however, the three species exhibit variation in in vivo and in vitro synthesized polypeptides in the 18 000–27 000 molecular-weight region, with several prominent differences in the number and distribution of the major class of low molecular-weight (20 000) HSP. Several of the HSP appear to be unique to B. juncea and one is unique to B. napus. Immunochemical studies of in vitro synthesized Brassica polypeptides using antisera to maize HSP of molecular weight 18 000 substantiate the observed differences in synthesis of various members of the 20 000 molecular-weight HSP family among the three species, and indicate that the Brassica low molecular-weight HSP are immunologically similar to the small HSPs of other plants including maize, soybean, pea, and Arabidopsis.

Freezing Injury in Oilseed Brassica Species

Journal Article Freezing Injury in Oilseed Brassica Species Get access A. K. DHAWAN, A. K. DHAWAN Oilseeds Section, Haryana Agricultural UniversityHissar-125004, India Search for other works by this author on: Oxford Academic PubMed Google Scholar M. L. CHHABRA, M. L. CHHABRA Oilseeds Section, Haryana Agricultural UniversityHissar-125004, India Search for other works by this author on: Oxford Academic PubMed Google Scholar T. P. YADAVA T. P. YADAVA Oilseeds Section, Haryana Agricultural UniversityHissar-125004, India Search for other works by this author on: Oxford Academic PubMed Google Scholar Annals of Botany, Volume 51, Issue 5, May 1983, Pages 673–677, https://doi.org/10.1093/oxfordjournals.aob.a086514 Published: 01 May 1983 Article history Published: 01 May 1983 Accepted: 17 November 1992