This study investigates the inheritance pattern of petalous and apetalous traits in yellow sarson (Brassica rapa var yellow sarson) and its significance for breeding efforts. Utilizing three crucial crosses between petalous (Pant Sweta, Pant Girija, YSH0401) and ‘apetalous’ parents, we observed the absence of apetalous plants in the F1 generation, indicating dominant inheritance of petalous plants. The F2 generation consistently displayed a 3:1 ratio of petalous to apetalous plants, confirming the dominance of the petalous trait. Chi-squared tests on each generation supported this conclusion. Backcrosses with petalous parents yielded no fruit, reinforcing the dominance of the petalous trait. Chi-squared tests on these backcrosses further confirmed the dominance inheritance pattern. Conversely, backcrosses with apetalous parents consistently exhibited a 1:1 ratio, highlighting the recessive nature of the apetalous trait. The study underscores the importance of understanding the inheritance pattern of petalous and apetalous traits in B. rapa var yellow sarson crop, as it has implications for breeding goals. Knowledge on trait inheritance can guide future breeding strategies, facilitating the transfer of the apetalous trait as needed. This study provides valuable insights for genetic investigations and breeding initiatives in B. rapa var yellow sarson.

Crop germplasm conserved in genebanks, are a fundamental resource of genetic diversity for crop improvement activities, underpinning future food security and sustainable agricultural practices. However, taxonomic errors in genebank germplasm (due to misclassification, contamination and poor data collation) restrict the effective use of this material for correct purpose. Earlier studies investigating species genetic diversity using genebank germplasm, have shown varying levels of taxonomic error within the Brassica species. In response to this reported taxonomic error of global collections, together with the availability of a multiplex PCR (MPCR) marker, targeting the specific chromosomes (A, B and C) of the six Brassica species in U's triangle, this study was undertaken to confirm the taxonomic identity of accessions within the Australian Grains Genebank's (AGG) long-term Brassica collection. A total of 5161 accessions were analysed with MPCR for taxonomic identification, of which, 4842 (93.8%) were confirmed to be consistent (correct) with their labelled taxonomy, while the remaining 319 (6.2%) were identified as taxonomically inconsistent (in-error). Through the evaluation of earlier regeneration and original seed of the error accessions with MPCR, we determined that 80.9% of the taxonomic errors were traced back to the original seed, while 19.1% of errors were the result of genebank seed regeneration handling practices. Results from this study directly enhance information of the AGG Brassica collection and shape directions for distribution, acquisition and regeneration practices within the AGG and potentially other global genebanks, which will facilitate in a more effective use of these valuable genetic resources by researchers and breeders.

Seeds are notoriously high in polyphenols and polysaccharides, which reduce RNA quality and yield, and interfere with downstream applications. We present simple modifications to a rapid RNA extraction protocol for use with seeds. The inclusion of polyethylene glycol in place of polyvinylpyrrolidone reduced polyphenol and polysaccharide contamination. In addition, replacing NaCl with KCl improved the RNA yield from Arabidopsis seeds still bound by mucilage. On extraction of Arabidopsis seed recovered from field soils clean RNA pellets with no accompanying gelatinous matrix (polysaccharide) were seen, with A260/230 ratios greater than 1.8 confirming the lack of polysaccharide carry-over. When Brassica oleracea and Sinapis arvensis seeds were extracted, 260/230 ratios greater than 1.8 were seen. RNA yields in excess of 10 µg per 100 mg seed suitable for RT-QPCR were obtained.

With the recent confirmation of protoporphyrinogen oxidase (PPO)-resistant Palmer amaranth in the US South, concern is increasing about the sustainability of weed management in cotton production systems. Cover crops can help to alleviate this problem, as they can suppress weed emergence via allelochemicals and/or a physical residue barrier. Field experiments were conducted in 2014 and 2015 at the Arkansas Agricultural Research and Extension Center to evaluate various cover crops for suppressing weed emergence and protecting cotton yield. In both years, cereal rye and wheat had the highest biomass production, whereas the amount of biomass present in spring did not differ among the remaining cover crops. All cover crops initially diminished Palmer amaranth emergence. However, cereal rye provided the greatest suppression, with 83% less emergence than in no cover crop plots. Physical suppression of Palmer amaranth and other weeds with cereal residues is probably the greatest contributor to reducing weed emergence. Seed cotton yield in the legume and rapeseed cover crop plots were similar when compared with the no cover crop treatment. The seed cotton yield collected from cereal cover crop plots was lower than from other treatments due to decreased cotton stand.

The target site of glyphosate [N-(phosphonomethyl)glycine] inhibition in plants and bacteria is 5-enolpyruvylshikimate 3-phosphate (EPSP) synthase. Our strategy for developing glyphosate-resistant crops has been to genetically engineer plants with a gene that codes for EPSP synthase with low sensitivity in glyphosate. We cloned such a gene from the aroA locus of a glyphosate-resistant mutagenized strain of Salmonella typhimurium. The enzyme encoded by this gene has a single amino acid change resulting in lower affinity for glyphosate and higher affinity for substrates than either plant or wild-type bacterial counterpart. A chimaeric gene containing the mutant aroA gene behind the octopine synthase promoter was constructed and integrated into Agrobacterium T-DNA vectors. Analysis of gall tissue from Brassica campestris L. (turnip rape) infected with A. tumefaciens K12 containing this chimaera showed mRNA and protein expressed from the bacterial gene; 50% of the total EPSP synthase activity present had kinetic properties of the mutant bacterial enzyme. Tobacco (Nicotiana tabacum L. ‘Xanthi′) plants have been regenerated from cocultivation with A. rhizogenes containing the same construct; analysis indicates expression of the gene and enhanced tolerance to glyphosate.

Weeds often limit productivity of organic cropping systems. Radish is a fast-growing, potentially allelopathic cover crop that has the potential to improve weed management in organic systems. To evaluate the effect of radish on density, cover, and biomass of weeds in organically managed corn, 2-yr field experiments were conducted over 4 site years. Four cover-crop planting treatments (fall-only, spring-only, fall + spring, and no cover) were tested in factorial with three cultivation treatments (standard [three to four passes], false seedbed [standard with a false seedbed], and reduced [two passes]). All plots were tilled before planting. Shoot biomass averaged 3,057 kg ha−1 for fall-seeded radish and 385 kg ha−1 for spring-seeded radish. Radish cover crops generally did not improve management of weeds during the corn growing season. However, in the absence of a false seedbed, fall-seeded radish reduced field pennycress density from 9 to < 1 plant m−2 and horseweed density from 6 to 2 plants m−2 in spring in site years where these weeds were present. Fall-seeded radish also reduced cover of summer annual weeds during the fall cover-crop growing season from 4 to 0% in 1 site year, preventing these weeds from setting seed. Radish cover crops did not affect corn grain yield.

Brassica species have an economic and medicinal importance. Estimation of the amount and distribution of genetic diversity within Brassica species is essential for establishing efficient management, conservation and breeding practices. This review discusses the taxonomy, gene pool, and Brassica-derived phytochemicals and their nutraceutical importance. It also surveys the recently advanced studies of the genetic diversity and phylogenetic studies of Brassica species at the level of morphological, cytological, biochemical and molecular markers that have proven to be useful for evaluating the genetic variation, taxonomic relationships and species identity, and could be useful for improving Brassica crops through future promising breeding programmes.

Terminal-repeat retrotransposon in miniature (TRIM) elements are a miniature form of retrotransposons and play an important role in genome organization. The Cassandra TRIM family has been identified in over 50 plant species, including both monocots and dicots. Cassandra elements carry an independently transcribed 5S RNA sequence in their terminal repeat regions, which is unique compared with other TRIM families. Although the existence of Cassandra elements has been documented in many plants, much work remains to characterize Cassandra family members and elucidate their distribution. In this study, we comparatively analysed the Cassandra family members in the Brassica oleracea, B. rapa and Arabidopsis thaliana genomes. A total of 602, 451 and 173 members, of which 130, 60 and 9 were relatively intact, were identified from the B. oleracea, B. rapa and A. thaliana genomes, respectively. Most of the Cassandra elements (1120/1226) were found in intergenic spaces, but 106 elements were inserted in genic regions such as introns, exons and untranslated regions. Our comparative analysis of the Cassandra family members in A. thaliana, B. rapa and B. oleracea reveals that some Cassandra elements have been commonly retained during the last 20 million years in three species and some elements have been uniquely evolved in Brassica species. This study promotes our understanding of the role and utility of Cassandra elements in the evolution of the Brassicaceae family.

The most common way to test seed quality is to use a simple and reliable but time- and space-consuming germination test. In this paper we present a fast and simple method to analyse cabbage seed deterioration by measuring ethanol production from partially imbibed seeds. The method uses a modified breath analyser and is simple compared to gas chromatographic or enzymatic procedures. A modified method using elevated temperatures (40°C instead of 20°C) shortened the assay time and improved its sensitivity. The analysis showed an inverse correlation between ethanol production and seed quality (e.g. the final percentages or speed of germination and the number of normal seedlings). The increase in ethanol production was observed when cabbage seeds were deteriorated by storage under ambient conditions or hot water treatments, both of which reduced the number of normal seedlings. Premature seeds produced more ethanol upon imbibition than mature seeds. Ethanol production occurred simultaneously with oxygen consumption, indicating that lack of oxygen is not the major trigger for ethanol production.

The isolation of viable egg cells of rape (Brassica napus L.) has been achieved from microdissected ovules. The non-gametic cells of the embryo sac, synergids and central cells have also been isolated. Their morphology corresponded to that of these cells in situ, making a discrimination from isolated sporophytic cells possible. Two hours after isolation the egg cells were still viable. Viable egg cells have been reproducibly isolated with afrequency of 25% per dissected ovule.

The rate of oxygen consumption by cabbage seeds increased on imbibition and there was a further sharp increase on germination. This was delayed in artificially aged seeds of low vigour. The increases in oxygen consumption reflect the increased oxidation of carbohydrates via respiratory pathways. The activities of key regulatory enzymes of glycolysis and the oxidative pentose phosphate pathway were measured in aged and unaged seed lots of cabbage. Differences in the activities of glucose 6-phosphate dehydrogenase and pyrophosphate:fructose 6-phosphate 1-phosphotransferase were correlated with the rate of germination (T50) in seed lots with large differences in seed vigour induced experimentally by artificial aging. However, the activities of these enzymes could not be used to distinguish between untreated seed lots which had smaller vigour differences apparent only under stress. The enzymes are presumably not controlling and determining seed vigour, but merely reflecting actual seed performance under the current conditions.

Seeds of the Brussels sprouts cultivar Asmer Aries and the cauliflower cultivar Hipop were subjected to ageing at 20% moisture content and 45°C for 24 or 30 h, respectively; all seeds retained high germination after ageing. Aerated hydration of unaged and aged seeds of both cultivars for 4–8 h at a range of temperatures (10–30°C), followed by drying, resulted in improved performance, except that germination percentage and rate of cauliflower were lower at 10°C. Thus, all treated seeds showed greater germination rate and seedling root length than the control, which may have resulted from the advancement of the process of germination. The deleterious effect of aerated hydration at 10°C on cauliflower could be explained by damage due to rapid imbibition; seeds that had imbibed slowly to close to full imbibition (41% moisture content) before aerated hydration showed no decrease in germination. The improvement of aged seeds after aerated hydration was also revealed by higher germination after the controlled-deterioration test, which indicated less deterioration in treated seeds. Furthermore, the optimum improvements for all seeds were observed at 25°C and were greater when the water was aerated than non-aerated. These observations indicate the activation of metabolic repair processes during aerated hydration, leading to a reversal of the deterioration sustained during ageing.

Ageing causes a delay in the onset of DNA replication in seeds. Aerated hydration for 8 h, a treatment to invigorate seeds, resulted in a reduction of about 12 h in the time difference in the onset of DNA synthesis between unaged and aged embryos of brassica seed. This effect is consistent with a recovery process occurring during aerated hydration of the seed involving the repair of accumulated DNA damage. The occurrence of hydroxyurea-resistant 3H-thymidine incorporation in aged Brussels sprouts embryos during the period 16–32 h from the start of hydration supports this interpretation.

When strong directional selection acts on a trait, the spatial distribution of phenotypes may reflect effects of selection, as well as the spread of favoured genotypes by gene flow. Here we investigate the relative impact of these factors by assessing resistance to synthetic pyrethroids in a 12-year study of diamondback moth, Plutella xylostella, from southern Australia. We estimated resistance levels in populations from brassicaceous weeds, canola, forage crops and vegetables. Differences in resistance among local populations sampled repeatedly were stable over several years. Levels were lowest in samples from weeds and highest in vegetables. Resistance in canola samples increased over time as insecticide use increased. There was no evidence that selection in one area influenced resistance in adjacent areas. Microsatellite variation from 13 populations showed a low level of genetic variation among populations, with an AMOVA indicating that population only accounted for 0.25% of the molecular variation. This compared to an estimate of 13.8% of variation accounted for by the resistance trait. Results suggest that local selection rather than gene flow of resistance alleles dictated variation in resistance across populations. Therefore, regional resistance management strategies may not limit resistance evolution.

The protective effects of brassica vegetables against cancer may be partly related to their glucosinolate content. Glucosinolates are hydrolysed by plant myrosinase following damage of plant tissue. Isothiocyanates are one of the main groups of metabolites of glucosinolates and are implicated in the preventive effect against cancer. During cooking of brassica the glucosinolate–myrosinase system may be modified as a result of inactivation of plant myrosinase, loss of enzymic cofactors such as epithiospecifier protein, thermal breakdown and/or leaching of glucosinolates and their metabolites or volatilisation of metabolites. Cooking brassica affects the site of release of breakdown products of glucosinolates, which is the upper gastrointestinal tract following consumption of raw brassica containing active plant myrosinase. After consumption of cooked brassica devoid of plant myrosinase glucosinolates are hydrolysed in the colon under the action of the resident microflora. Feeding trials with human subjects have shown that hydrolysis of glucosinolates and absorption of isothiocyanates are greater following ingestion of raw brassica with active plant myrosinase than after consumption of the cooked plant with denatured myrosinase. The digestive fate of glucosinolates may be further influenced by the extent of cell rupture during ingestion, gastrointestinal transit time, meal composition, individual genotype and differences in colonic microflora. These sources of variation may partly explain the weak epidemiological evidence relating consumption of brassica to prevention against cancer. An understanding of the biochemical changes occurring during cooking and ingestion of brassica may help in the design of more robust epidemiological studies to better evaluate the protective effects of brassica against cancer.

Vavilov (1935) described China as the earliest and largest independent centre of origin of cultivated plants. Gansu Province occupies the geographic centre of China. With an area of 454,000 km2, latitudes ranging from 32°3′N to 42°57′N and elevations varying from 500 to 6200 m, the province has an extremely diverse climate and topography. Stretching 1653 km along the ancient Silk Road, Gansu also has a long history of agriculture (6000 years) and for centuries was exposed to dynamic cultural exchanges between the East and the West. The unique combination of these conditions allowed rapeseed to be introduced from Europe and the Middle East, to evolve over a long time of cultivation and to diversify to adapt to many types of ecological conditions and cropping systems in Gansu. Currently, rich genetic resources exist in Gansu for Brassica rapa, B. juncea, B. chinensis and Eruca sativa. Eight landraces are described to demonstrate the diversity of rapeseed genetic resources in Gansu. It is generally recognized that B. chinensis originated in China. Information provided in this paper suggests that Gansu and its adjacent regions could also be a centre of diversity for B. rapa and B. juncea.

Repeated monitoring for escaped transgenic crop plants is sometimes necessary, especially in cases when the crop has not been approved for release into the environment. Transgenic oilseed rape (Brassica napus) was detected along roadsides in central Japan in a previous study. The goal of the current study was to monitor the distribution of transgenic oilseed rape and occurrence of hybridization of transgenic B. napus with feral populations of its closely related species (B. rapa and B. juncea) in the west of Japan in 2005. The progenies of 50 B. napus, 82 B. rapa and 283 B. juncea maternal plants from 95 sampling sites in seven port areas were screened for herbicide-resistance. Transgenic herbicide-resistant seeds were detected from 12 B. napus maternal plants growing at seven sampling sites in two port areas. A portion of the progeny from two transgenic B. napus plants had both glyphosate-resistance and glufosinate-resistance transgenes. Therefore, two types of transgenic B. napus plants are likely to have outcrossed with each other, since the double-herbicide-resistant transgenic strain of oilseed rape has not been developed intentionally for commercial purposes. As found in the previous study, no transgenic seeds were detected from B. rapa or B. juncea, and more extensive sampling is needed to determine whether introgression into these wild species has occurred.

An investigation was carried out to monitor the escape and spread of oilseed rape (Brassica napus) transgenic plants and the introgression of transgenes to its closely related feral species in Japan. We screened a total of about 7500 feral B. napus, 300 B. rapa, and 5800 B. juncea seedlings from maternal plants in 143 locations at several ports, roadsides, and riverbanks. The presence of glufosinate-resistance or glyphosate-resistance transgenes in these seedlings was confirmed by means of herbicide treatments and also immunochemical and DNA analyses. B. napus plants with herbicide-resistant transgenic seeds were found at five of six major ports and along two of four sampled roadsides in the Kanto District. Transgenic oilseed rape plants have not been commercially cultivated in Japan, suggesting that the transgenes would probably have come from imported transgenic seeds that were spilled during transportation to oilseed processing facilities. No transgenes were detected in seeds collected from B. napus plants growing along riverbanks in the Kanto District or in seeds from closely related species (B. rapa and B. juncea). To our knowledge, this is the first published example of feral, transgenic populations occurring in a nation where the transgenic crop has not been cultivated commercially.