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Heat stress, especially during the reproductive stage, has been exacerbated by changing climatic conditions, resulting in reduced seed yield in crops like Indian mustard. In the present study, 154 genotypes of Indian mustard were used to find novel SSR marker-based associations for seed yield and physiological traits by linkage disequilibrium. Extensive phenotyping of 154 genotypes for seed yield and various physiological traits was done for two consecutive years (2020–2021 and 2021–2022) in timely and late-sown environments. Out of 237 SSR markers, a total of 111 polymorphic markers containing 312 alleles were used for analysis. Two different models, i.e., general linear model (GLM) and mixed linear model (MLM), were used to detect the significant marker–trait associations for timely and late-sown environment separately. A total of 12 and 10 MTAs were found to be associated under timely and late-sown conditions with seed yield and physiological traits using MLM model. Out of these promising MTAs identified in the present study, five SSRs were specifically detected only in late-sown environments which meant that these specific genomic regions and QTLs were associated under terminal heat conditions. This is the first report on the identification of marker-trait associations for physiological traits under terminal heat stress conditions. It may be possible to develop the molecular markers for significant SSRs after due validation. The findings contribute to our understanding of the genetic basis of heat tolerance and provide valuable information for breeding programs aiming to improve crop productivity under heat stress conditions. [ABSTRACT FROM AUTHOR]

The beneficial effects of endophytes on plant growth, development and yield are well known. Modulating plant growth-promoting substances and ameliorating biotic and abiotic stresses are some of the key mechanisms that are deployed by endophytes to facilitate host growth and defence. However, the understanding of the plant's genome response to their presence is still limited. Therefore, this study provides an insight into the microbiome of B. juncea seeds as well as leaves, and its impact on plant growth and development. It also correlates their presence with the changes in plant. Removal of seed-borne culturable endophytes resulted in trade-off of accelerated growth with decreased biomass. 16S metagenomics revealed that bacterial endophyte diversity and density varied with stage of the plant. We found that 22 endophytic genera including Enterococcus, Halobacteroides, Planktothrix and Streptomyces were observed irrespective of Bavistin treatment and age of the plant. Removal of culturable endophytes also led to downregulation of crucial genes involved in growth, photosynthesis (Photosystem I assembly protein, Photosystem II reaction center protein and Rubisco), transport (nitrate transporter; NRT) and regulation of plant hormones (auxin homeostasis and signalling; CYP83A1) in B. juncea. To the best of our knowledge, this is the first report of the response of plant' transcriptome to changes in endophyte composition indicating a strong possibility of host gene regulation by the endophytic partner. The exact mechanism of the same needs to be further explored. [ABSTRACT FROM AUTHOR]

Background: Researchers in Indian mustard have made minimal progress in breaking the yield barrier due to limited genetic resources. To increase productivity, a combination of molecular markers and morphological features is advised to boost productivity. The purpose of current work is to characterise polymorphic SSR markers, determine genotype variability, identify suitable parents for hybridization and understand key yield factors. Methods: In 2020-21, twenty-eight Indian mustard varieties and advance breeding materials were evaluated at Ramakrishna Mission Vivekananda Educational and Research Institute's experimental field in Narendrapur, West Bengal, using statistical techniques to assess genetic estimates and molecular diversity using twenty identified polymorphic SSR primers out of thirty tested primers. Result: The study found that the number of siliqua per plant and primary and secondary branches are crucial yield components determined by correlation and path analysis. The high heritability of ten traits was observed. Genotypes were divided into four clusters with both Mahalanobis's D2 and molecular diversity analysis, with 1000 seed weight and plant height showing the highest degree of divergence. But the composition of genotypes varied in two types of clusters. Ra1F09 and Ra2B02, SSR markers, showed greater PIC values and heterozygosity among the twenty polymorphic SSR primers. Hybridization between PM25 and high oil content genotypes from cluster I, such as Sanjukta Asech and Kranti, is proposed to produce segregants with high yield, oil content and early maturity. [ABSTRACT FROM AUTHOR]

Background Results Conclusion Brassica juncea L. (family Brassicaceae) or Indian mustard is a fast‐growing oilseed crop. Climate changes mean that it is very important to evaluate the effects of salinity stress on B. juncea. The aim of this study was therefore to show the metabolic effect of salinity stress on shoots and roots using two cultivation models – hydroponic and microplot – in different cultivars, including RH‐725 and RH‐761. Salinity levels of 5, 7.5, and 10 dS m⁻¹ were investigated, and compared with a control of 0 dS m⁻¹, using untargeted metabolomics with gas chromatography–mass spectrometry (GC–MS) post‐silylation, focusing on metabolic markers such as proline and glycine‐betaine.A total of 56 metabolites were identified, with the most prevalent classes belonging to sugars (8), followed by organic acids (13), amino acids (11), and fatty acids/esters (11). Shoots were found to have a higher sugar content than roots. Increases in unsaturated fatty acids were also associated with salinity stress, compared with a decrease in saturated fatty acids. Absolute levels of proline and glycine‐betaine correlated with salinity stress, with the largest increases detected in shoots grown under hydroponic conditions, particularly for the RH‐761 cultivar. Multivariate data analyses revealed that roots were more affected than shoots, regardless of cultivation model.These findings might explain the different metabolic behavior of B. juncea's roots and shoots under various levels of salinity, associated with higher levels of free sugars in shoots and lipids in roots. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

In order to maximize yield of Indian mustard (Brassica juncea (L.) Czernj. & Cosson) by optimizing sowing dates and nutrient management, a field experiment was conducted at Rajasthan Agricultural Research Institute, Jaipur, India during 3 consecutive rabi seasons (2012–13 to 2014–15). The experiment was laid out in a split plot design with four replications. The two main plot treatments comprised date of sowing (D1: IV week of October; D2: II week of November) and four sub-plot treatments comprised nutrient applications (T1: RD-N40P60K40; T2: RD-N40P60K40+RDgypsum250; T3: RD-N40P60K40+RDgypsum250+Zn and T4: RD-N40P60K40+RDgypsum250+Zn + Fe). Result showed that the seed germination, seedling growth and seedling vigor index were better in D1 sowing over D2 sowing under control as well treated conditions. Chlorophyll content increased with the application of sulfur, zinc and iron during both the sowings, with greater magnitude in D2 sowing. Seed yield and its contributing factors viz. days to flowering, plant height, shoot length, leaf area; primary branches per plant, number and length of siliqua were significantly and variably affected by different nutrient combinations. Application of T3 significantly enhanced the seed and biological yield (23.13 and 74.03 q ha−1) (16.35% and 20.63%) over T1, respectively, and T3 was statistically at par with T4. T3 also provided the highest benefit:cost (B:C) ratio (2.14) and net returns (₹ 38168 ha−1). Thus, sowing of Indian mustard in the month of October and application of RD-N40P60K40+RDgypsum250+Zn (T3) is recommended to maximize its seed yield along with higher B:C ratio and returns under semi-arid conditions of India. [ABSTRACT FROM AUTHOR]

Global warming delays the harvest of kharif crops, which delay the subsequent sowing of Indian mustard, especially in northwestern India and also causes dry winters that exacerbate challenges for the timely sowing of rabi-crops. To check this, a field experiment was conducted during the Rabi-seasons of 2018–19 and 2019–20 to assess the influence of sowing dates, irrigation, and fertilizer levels under late-sown conditions. A split-plot design was used with two sowing dates, two irrigation levels and four fertilizer levels (87.5%, 100%, 112.5% and 125% RDF; Recommended-fertilizers-dose). Crop sown in the 4th week of November significantly reduced seed (46.79 and 38.77%) and stover yield (43.72 and 41.62%) as compared to the 2nd week of November sowing during 2018–19 and 2019–20, respectively. Uptake of NPK by seed and stover was higher with the 2nd week of November sowing. The 2nd week of November sowing resulted in significant increase in water productivity by 63.72% and Benefit cost ratio (B:C) by 75.45% over the 4th week of November sowing. Irrigation at flowering stage increased the seed yield, water productivity and B:C by 11.94%, 1.72% and 9.17%, respectively, as compared to No post-sown irrigation. The biological yield of the Indian mustard increased with every increase in fertilizer doses but the response was significant up to 112.5% RDF (90 kg N, 33.75 kg P2O5 and 22.5 kg K2O ha−1). Application of 112.5% RDF increased the seed, stover yield, water productivity and B:C by 16.17%, 9.29%, 15.66% and 11.27%, respectively, over 87.5% RDF. [ABSTRACT FROM AUTHOR]

Abstract Indian mustard (Brassica juncea; Brassicaceae) is an edible, oilseeds-yielding crop widely consumed as a food spice owing to its richness in nutrients with several health benefits. The current study aims to dissect the B. juncea metabolome heterogeneity among its different organs including leaf, stem, flower, and seed. Moreover, assessing the metabolome differences between two different varieties RH-725 and RH-761 grown at the same conditions. Gas chromatography-mass spectrometry (GC–MS) post-silylation was used to dissect the composition of nutrient metabolites coupled to multivariate data analysis. Variation in sulphur aglycones was measured using headspace-solid phase-microextraction HS-SPME coupled to GC–MS. A total of 101 nutrient metabolites were identified with the abundance of sugars represented by monosaccharides in all organs, except for seeds which were enriched in disaccharides (sucrose). α-Linolenic acid was detected as a marker fatty acid in leaf from RH-725 at 12.5 µg/mg. Malic acid was detected as a significant variant metabolite between the two varieties as detected in the leaf from the RH-725 variety at ca. 128.2 µg/mg compared to traces in RH-761. 7 Volatile sulphur compounds were detected at comparable levels in RH-725 and RH-761, with 3-butenyl isothiocyanate was the most abundant at 0.8–2 ng/mg.

The present investigation was undertaken to study the residual heterosis in F2 and F3 populations of Indian mustard [Brassica juncea (L.) Czern & Coss.]. The study material included eight parents and the 28 crosses of Indian mustard in two generations, namely F2 and F3. The experiment was conducted over two years at Uttar Banga Krishi Viswavidyalaya, Cooch Behar, West Bengal, during Rabi season 2020-21 and 2021-22. Out of the 28 crosses, three crosses namely, Npj-194 × DRMR-15-16, Npj-194 × RW- 85-59 (Sarma) and Npj-194 × SKJM-05 were found to show significantly positive residual standard heterosis over the standard variety (SKJM-05) for both the characters siliquae per plant and seed yield per plant. This provides us evidence that by improving siliquae per plant, the character seed yield per plant can be improved. The promising cross populations which have shown significant standard heterosis for seed yield in F2 and F3, can be utilized for the development of hybrid varieties, which would be very much beneficial to the marginal farmers of our country as they would be able to use the F2 and F3 seeds of the hybrid varieties without any compromise with seed yield. [ABSTRACT FROM AUTHOR]

Indian mustard (Brassica juncea; Brassicaceae) is an edible, oilseeds-yielding crop widely consumed as a food spice owing to its richness in nutrients with several health benefits. The current study aims to dissect the B. juncea metabolome heterogeneity among its different organs including leaf, stem, flower, and seed. Moreover, assessing the metabolome differences between two different varieties RH-725 and RH-761 grown at the same conditions. Gas chromatography-mass spectrometry (GC–MS) post-silylation was used to dissect the composition of nutrient metabolites coupled to multivariate data analysis. Variation in sulphur aglycones was measured using headspace-solid phase-microextraction HS-SPME coupled to GC–MS. A total of 101 nutrient metabolites were identified with the abundance of sugars represented by monosaccharides in all organs, except for seeds which were enriched in disaccharides (sucrose). α-Linolenic acid was detected as a marker fatty acid in leaf from RH-725 at 12.5 µg/mg. Malic acid was detected as a significant variant metabolite between the two varieties as detected in the leaf from the RH-725 variety at ca. 128.2 µg/mg compared to traces in RH-761. 7 Volatile sulphur compounds were detected at comparable levels in RH-725 and RH-761, with 3-butenyl isothiocyanate was the most abundant at 0.8–2 ng/mg. [ABSTRACT FROM AUTHOR]

Indian mustard is an important oilseed crop in India. The productivity of Indian mustard needs to be increased in marginal environments such as in arid and semi‐arid areas to boost production. For this, identification of promising genotypes with high yield and quality under arid and semi‐arid climate is required. In this study, 65 genotypes of Indian mustard were evaluated in Augmented Randomized Block Design in the Purulia district of West Bengal, a mustard growing zone characterized by red laterite soil and semi‐arid climate. Considerable variation was observed between the genotypes for most characters such as number of seeds per siliqua (coefficient of variation [CV] 7.39%), followed by days to first flowering (CV 6.9%) and total number of siliquae (CV 6.43%), respectively. However, variation was less for days to maturity and quality parameters. Strong positive correlations were observed between many traits such as number of branches and number of siliquae on branches (0.82), number of branches and siliquae per plant (0.73), number of branches and yield per plant (0.72), number of siliquae on branches and siliquae per plant (0.91), number of siliquae on branches and seed yield per plant (0.76). Relatively strong negative correlation was observed only between oil and glucosinolate content (−0.60). Most of the traits showed high heritability along with high genetic advance over mean. Principal component analysis and cluster analysis classified the genotypes into six clusters. Based on yield, its components, and other quality parameters, promising genotypes such as Pusa Mahak, Narendra Ageti Rai 4, and JM‐1 were identified. These genotypes may be targeted for further genetic improvement or be incorporated in breeding programmes for developing high‐yielding mustard varieties for arid and semi‐arid climate. [ABSTRACT FROM AUTHOR]

Indian mustard (Brassica juncea) is an important contributor towards edible oil supply in India. Traditional Indian mustard varieties contain high proportion of 18C polyunsaturated fatty acids (linoleic and linolenic acids) and large amounts of long-chain monounsaturated FAs, mainly erucic acid, in seeds. Oleate desaturase (FAD2) regulates the composition of 18C PUFAs in cellular membranes and TAG in seed oil. The present study was conducted to gain insight into the allelic diversity of the FAD2 gene in Indian mustard. Analyses of cloned FAD2 genes of three Indian mustard varieties revealed a novel FAD2 gene that has a longer ORF (1167 bp) owing to insertions and several SNPs across its length that distinguish it from the more prevalent native FAD2 gene. Overall, the Indian mustard varieties possess three FAD2 alleles, but there is limited nucleotide diversity among members of each FAD2 type across varieties, suggesting narrow genetic diversity among the varieties examined. [ABSTRACT FROM AUTHOR]

This article presents the findings of a study on the breeding of Indian Mustard, specifically focusing on heterosis and combining ability for seed yield and its component traits. The researchers evaluated 12 advanced lines/varieties of Indian Mustard and found significant differences among the treatments for various traits. Certain lines and cross combinations were identified as good combiners and showed high heterosis. The study provides valuable information for breeding programs aimed at improving seed yield and its component traits in Indian Mustard. [Extracted from the article]

Background: Drought is one of the important abiotic stresses that can significantly reduce crop yields. In India, about 24% of Brassica juncea (Indian mustard) cultivation is taken up under rainfed conditions, leading to low yields due to moisture deficit stress. Hence, there is an urgent need to improve the productivity of mustard under drought conditions. In the present study, a set of 87 B. carinata-derived B. juncea introgression lines (ILs) was developed with the goal of creating drought-tolerant genotypes. Method: The experiment followed the augmented randomized complete block design with four blocks and three checks. ILs were evaluated for seed yield and its contributing traits under both rainfed and irrigated conditions in three different environments created by manipulating locations and years. To identify novel genes and alleles imparting drought tolerance, Quantitative Trait Loci (QTL) analysis was carried out. Genotyping-by-Sequencing (GBS) approach was used to construct the linkage map. Results: The linkage map consisted of 5,165 SNP markers distributed across 18 chromosomes and spanning a distance of 1,671.87 cM. On average, there was a 3.09 cM gap between adjoining markers. A total of 29 additive QTLs were identified for drought tolerance; among these, 17 (58.6% of total QTLs detected) were contributed by B. carinata (BC 4), suggesting a greater contribution of B. carinata towards improving drought tolerance in the ILs. Out of 17 QTLs, 11 (64.7%) were located on the B genome, indicating more introgression segments on the B genome of B. juncea. Eight QTL hotspots, containing two or more QTLs, governing seed yield contributing traits, water use efficiency, and drought tolerance under moisture deficit stress conditions were identified. Seventeen candidate genes related to biotic and abiotic stresses, viz., SOS2, SOS2 like, NPR1, FAE1-KCS, HOT5, DNAJA1, NIA1, BRI1, RF21, ycf2, WRKY33, PAL, SAMS2, orf147, MAPK3, WRR1 and SUS, were reported in the genomic regions of identified QTLs. Conclusions: The significance of B. carinata in improving drought tolerance and WUE by introducing genomic segments in Indian mustard is well demonstrated. The findings also provide valuable insights into the genetic basis of drought tolerance in mustard and pave the way for the development of drought-tolerant varieties. [ABSTRACT FROM AUTHOR]

The presented study assessed 27 Indian mustard (Brassica juncea [L.] Czern & Coss) genotypes for 13 quantitative and one biochemical trait by a PCA-dependent multivariate analysis, which split the total divergence into 14 accountable principal components among them. The first five PCs, which showed an Eigenvalue of more than one, contributed significantly to about 76.35% of the total divergence. Interpretation of the PCA-Biplot declared that the genotypes, namely, two and 11, mostly subsidized the overall variance, which is about 20% and 17%, respectively. The study of the bar plot of contribution percentage presented relevance with the PCA-biplot study, which again indicated the significance of genotypes two and 11 in total variance. The biplot analysis revealed that traits, NSB and SYP, contribute appreciably to the variation of the genotypes placed in the second coordinate, showing a detrimental interference with PC 1 and positive interference with PC 2. Likewise, in the third coordinate, traits, such as LMS, influenced the variance of the genotypes of that coordinate. The percentage contribution study for features in the first and second PCs revealed that characteristics, such as, LMS, PH, NSMS, BYP, NSS, and SYP participated prominently to accelerate the total variance. This research work can be a groundwork for further crop improvement featuring the studied materials. [ABSTRACT FROM AUTHOR]

Lead (Pb) is one of the most toxic elements on earth. The harmful effects of Pb at higher concentrations were seen on plant vegetation because plants are directly exposed towards it. Indian mustard, a well-known hyperaccumulator plant is the most promising crop for the environment, engaged in a variety of scenarios for ecological cleanup. In the present study, we used ethylene diamine tetraacetic acid (EDTA), a chelating agent that is of remarkable efficiency. The pot experiments were conducted in soil pretreated with 1000 mgkg-1 Pb with different concentrations of EDTA (2-10 mmol). All the growth parameters were reduced significantly in the plants treated with Pb and EDTA, however, a non-significant effect was observed in 5 mmol EDTA compared to Pb alone treatment. Photosynthetic pigments yield, nitrate reductase activity and NPK content were affected negatively; in contrast, superoxide dismutase and catalase activity was increased in Pb and Pb+EDTA treated in both the varieties. The Pb accumulation was elevated significantly by the augmentation of 5 mmol EDTA in both varieties. Accumulation of Pb in the shoot was higher in PM 25 than in P. Vijay, whereas root Pb accumulation showed the opposite, i.e., more Pb in roots of P. Vijay than PM 25. Moreover, The Pb accumulation per plant was observed more in P. Vijay as compared to PM 25. Hence, the present study implies that the augmentation of Pb-polluted soil with EDTA works well while dealing with B. juncea assisted phytoremediation and P. Vijay to be a stronger variety than PM 25. Further, 5 mmol of EDTA was optimum for phytoremediation of the soil polluted with up to 1000 mg Pb kg-1 soil. [ABSTRACT FROM AUTHOR]

This article presents a study conducted on the genetic variability of Indian mustard genotypes in Northern Karnataka, India. The study evaluated the variability in eight genotypes of Indian mustard and recorded observations for 12 different traits. The study found that certain traits, such as the number of secondary branches and racemes per plant, exhibited high genetic variability and potential for improvement. The genotypes TM-210, TM-136, and KMR (E) 16-11 showed superior performance in terms of yield across all locations. The study suggests combining hybridization and recombination to enhance diversity and improve selection programs. [Extracted from the article]

Due to ongoing human activities, heavy metals are heavily accumulated in the soil. This leads to an increase in the discharge and the quick spread of heavy metal pollution in human settlements and natural habitats, having a disastrous effect on agricultural products. The current experiment was planned to evaluate the effect of lead-tolerant-plant-growth-promoting rhizobacteria (LTPGPR) on growth, yield, antioxidant activities, physiology, and lead uptake in the root, shoot, and seed of Indian mustard (Brassica juncea) in lead-amended soil. Three pre-isolated well-characterized lead-tolerant rhizobacterial strains—S10, S5, and S2—were used to inoculate seeds of Indian mustard grown at three different levels of lead (300 mg kg−1, 600 mg kg−1, 900 mg kg−1) contaminated soil. The experiment was designed following a completely randomized design (CRD) under factorial arrangements. Lead nitrate was used as a source of lead contamination. At harvesting, data regarding growth, physiology, yield per plant, antioxidant activities, malondialdehyde and proline content, and lead uptake in the root, shoot, and seed of Indian mustard were recorded. Results demonstrated that lead contamination at all levels significantly reduced the plant growth, yield, and physiological processes. Plants inoculated with lead-tolerant rhizobacteria showed a significant improvement in plant growth, yield, antioxidant activities, and physiological attributes and cause a valuable reduction in the malondialdehyde contents of Indian mustard in lead-contaminated soil. Moreover, plants inoculated with lead-tolerant rhizobacteria also showed an increment in lead uptake in the vegetative parts and a significant reduction of lead contents in the seed of Indian mustard. [ABSTRACT FROM AUTHOR]

Brassica juncea and B. napus species are predominantly self-pollinated. Parchment paper or muslin cloth bags are used for controlled selfed or cross-seed production. We evaluated three non-woven synthetic pollination control bags (PCBs) for two years as replacement for the commonly used PCBs. The new synthetic PCBs were fully pollen proof since the molecular marker analysis of the random seeds set on two cytoplasmic male sterile (CMS) lines isolated with PCBs were all maternally originated. DWB03 bags returned 47% significantly more seeds per bud than the parchment paper bags. Larger DWB03 bags showed 38% higher mean seed yield (g/plant) than the muslin cloth bags. Re-used DWB03 bags were statistically on par with new bags for the seed yield per plant. On average, DWB03 bags produced 57% more hybrid seed set on CMS lines than the muslin cloth bags. The micro-climate in DWB03 bags appeared to be more conducive for good seed set as compared to the outside and muslin cloth bags. Non-woven PCBs offer better options for replacing paper or muslin cloth bags in the breeding of Brassicas. [ABSTRACT FROM AUTHOR]

One of the consequences of mining is the release of heavy metals into the environment, especially water bodies. Phytoremediation of areas contaminated by heavy metals using Vetiver grass and Indian mustard is cost-effective and environmentally friendly. This study aimed at enhancing remediation of heavy metal contaminated water through the simultaneous hybrid application of clay minerals (attapulgite and bentonite) and Vetiver grass or Indian mustard. A 21-day greenhouse experiment was carried out to investigate the effectiveness of the clay minerals to improve heavy metal phytoremediation. The highest accumulation of aluminium (Al) by Vetiver grass was 371.8 mg/kg in the BT2.5VT treatment, while for Mn, the highest accumulation of 34.71 mg/kg was observed in the AT1VT treatment. However, Indian mustard showed no significant uptake of heavy metals, but suffered heavy metal toxicity despite the addition of clay minerals. From this study, it was evident that bentonite added at 2.5% (w/v) could improve the phytoremediation capacity of Vetiver grass for Al and Mn polluted water. The current laboratory-scale findings provided a basis for field trials earmarked for remediation in a post-mining coal environment in South Africa. This remediation approach can also be adopted in other places. [ABSTRACT FROM AUTHOR]

Background: Indian mustard is an important oilseed crop which occupies premier position in Indian agriculture. Developing high yielding genotypes is a major breeding objective in Indian mustard. Present study was conducted at Experimental Farm of Ranaghat, Nadia, West Bengal, during 2017 to 2019. Methods: Line x tester analysis of seven lines and five testers was carried out to identify the high heterotic crosses and their relationship in terms of GCA and SCA in Indian mustard. The parents and F1 hybrids were evaluated in RBD with three replications. Result: The analysis of variances revealed significant differences of genotypes for all characters studied, indicating sufficient genetic variability for the characters. The estimates of SCA variances were higher than GCA variance the characters indicating that dominance variance was more than the additive variance. The ratio of variance due to general and specific combining ability was less than unity for all the traits that indicated the non-additive gene action was predominant over additive gene action. Five lines, viz. PM 24, PM 25, PM 30, Pusa Agrani, JD-6 and one tester, Pusa Bold were deemed to be the good general combiner for seed yield and yield attributing traits. On the basis of high heterosis over mid parent as well as better parent and significant SCA effects for seed yield per plant and its component traits, hybrids namely, JD-6 x Pusa Bold, PM 30 x Seeta, PM 25 x Pusa Bold, PM 24 x Kranti and PM 22 x Sarama were found to be very promising for further exploitation in breeding program. [ABSTRACT FROM AUTHOR]

• Heat map and PCA biplot identifies two ideotypes with regard to N allocation. • Higher root biomass and volume helps to absorb nutrients more efficiently. • The activity of NR from pre-anthesis and post-anthesis is correlated with the final seed products, such as oil content. • Rise in NiR activity during post-anthesis correlated with N assimilation for seed component storage, particularly proteins, which aligns with the rising seed N content at this stage. • N -allocation follows the pattern: seed > siliquae husk > stover > root. The study explores the effect of varying levels of nitrogen (N) application on N allocation in Indian mustard (Brassica juncea) genotypes from vegetative to the generative phases. The use of a heat map and PCA biplot analysis identifies two distinct sets of ideotypes. The first set is represented by genotype IC212031 having "Stay-green" phenotype with effective N regulating enzymes, high N uptake (NUpt) and better root development. The second set of ideotype is represented by HB9902 having delayed flowering phenology phases. The study highlights the relevance of Nitrate reductase (NR) in the final oil buildup in seeds (r = 0.5, p = 0.09). The considerable rise in NR activity from pre-anthesis to post-anthesis stages translates to higher seed storage compounds such as oil (r =−0.65, p = 0.03). And the developed prediction models confirmed the significance of these stages (pre-anthesis and post-anthesis) in the accumulation of seed storage components with emphasis on oil content. Similarly, this prediction model helps us to study the cause and effect relationship between various factors and oil content. The notable rise in Nitrite reductase (NiR) activity during the post-anthesis phase suggests its role in assimilating N for the storage of seed components, most likely proteins. Further, the inverse relationship between seed N (−0.53, p = 0.09) and oil content (−0.65, p = 0.03) confirmed that at the post anthesis stage the allocation of N towards precursor carbon compounds happens, which in turn forms either proteins or lipids. This becomes a critical factor in determining the final composition of the seed. Irrespective of N treatment and genotype, the N allocation follows the pattern: seed > siliquae husk > stover > root. However, higher N application rates primarily result in increased NUpt, but not necessarily improve utilisation. Overall, the study highlights the roles of root characteristics, N metabolising enzymes, and flowering phenology in enhancing N allocation and seed production in Indian mustard offering valuable insights for breeding strategies to enhance seed yield, oil content and nutrient efficiency in oilseed crops. [Display omitted] [ABSTRACT FROM AUTHOR]

Acid phosphatases (Apases) are an important group of enzymes that hydrolyze soil and plant phosphoesters and anhydrides to release Pi (inorganic phosphate) for plant acquisition. Their activity is strongly correlated to the phosphorus use efficiency (PUE) of plants. Indian mustard (Brassica juncea L. Czern & Coss) is a major oilseed crop that also provides protein for the animal feed industry. It exhibits low PUE. Understanding the genetics of PUE and its component traits, especially Apase activity, will help to reduce Pi fertilizer application in the crop. In the present study, we evaluated 280 genotypes of the diversity fixed foundation set of Indian mustard for Apase activity in the root (RApase) and leaf (LApase) tissues at three- low (5μM), normal (250μM) and high (1mM) Pi levels in a hydroponic system. Substantial effects of genotype and Pi level were observed for Apase activity in both tissues of the evaluated lines. Low Pi stress induced higher mean RApase and LApase activities. However, mean LApase activity was relatively more than mean RApase at all three Pi levels. JM06016, IM70 and Kranti were identified as promising genotypes with higher LApase activity and increased R/S at low Pi. Genome-wide association study revealed 10 and 4 genomic regions associated with RApase and LApase, respectively. Annotation of genomic regions in the vicinity of peak associated SNPs allowed prediction of 15 candidates, including genes encoding different family members of the acid phosphatase such as PAP10 (purple acid phosphatase 10), PAP16, PNP (polynucleotide phosphorylase) and AT5G51260 (HAD superfamily gene, subfamily IIIB acid phosphatase) genes. Our studies provide an understanding of molecular mechanism of the Apase response of B. juncea at varying Pi levels. The identified SNPs and candidate genes will support marker-assisted breeding program for improving PUE in Indian mustard. This will redeem the crop with enhanced productivity under restricted Pi reserves and degrading agro-environments. [ABSTRACT FROM AUTHOR]

Elevated temperature is one of the major production constraints of Indian mustard. The present study was aimed to estimate variations in phenology, yield attributes and seed yield under elevated temperature (ET) in temperature gradient tunnels (TGT) and open field for heat tolerance. Fourteen genotypes consisting of introgression lines and the mustard varieties were sown in TGT and open field for two consecutive winter seasons (2017-2019). The phenophases were shortened due to elevated temperature in TGT as compared to control except physiological maturity which was trailed by 17-18 days during both the years. Temperature affect was most severe on siliqua formation and seed filling. Among growth parameters only length of main shoot suffered reduction whereas yield contributing parameters like siliqua on main shoot, siliquae plant-1, seeds siliqua-1 and 1000 seed weight along with biomass, seed yield and harvest index suffered significant decline in TGT. Average temperature had positive correlation with all phenological parameters except flowering completion, growth parameters except number of primary and secondary branches while yield attributes only with 1000 seed weight, biomass and seed yield under TGT. Interestingly, number of primary branches had significant negative correlation with average temperature under both control (r=-0.59*) and TGT (-0.61*). Phenological traits had strong relationship with seed yield under TGT. However, seed yield had strong relationship with growth parameters, yield attributes under control except for number of primary branches. Biomass had strong relationship with seed yield under both TGT (R²= 0.51) and control (R²= 0.43). Two years testing revealed introgression lines (JA24 and JA53) and varieties (JD6 and Giriraj) tolerant to heat stress. [ABSTRACT FROM AUTHOR]

Seed coat colour is an important trait in Indian mustard. Breeding for seed coat colour needs precise knowledge of mode of inheritance and markers linked to it. The present study was focussed on genetics and development of functional markers for seed coat colour. F1s (direct and reciprocal) and F2 populations were developed by crossing two contrasting parents for seed coat colour (DRMRIJ-31, brown seeded and RLC-3, yellow seeded). Phenotypic results have shown that the seed coat colour trait was under the influence of maternal effect and controlled by digenic-duplicate gene action. Further, Bju.TT8 homologs of both parents (DRMRIJ-31 and RLC-3) were cloned and sequenced. Sequencing results of Bju.TT8 homologs revealed that in RLC-3, gene Bju.ATT8 had an insertion of 1279bp in the 7th exon; whereas, gene Bju.BTT8 had an SNP (C→T) in the 7th exon. These two mutations were found to be associated with yellow seed coat colour. Using sequence information, functional markers were developed for both Bju.TT8 homologs, validated on F2 population and were found highly reliable with no recombination between the markers and the phenotype. Further, these markers were subjected to a germplasm assembly of Indian mustard, and their allelic combination for the seed coat colour genes has been elucidated. The comparative genomics of TT8 genes revealed high degree of similarity between and across the Brassica species, and the respective diploid progenitors in tetraploid Brassica species are the possible donors of TT8 homologs. This study will help in the markerassisted breeding for seed coat colour, and aid in understanding seed coat colour genetics more precisely. [ABSTRACT FROM AUTHOR]

Contamination of soils with cadmium (Cd) and lead (Pb) poses serious threat to the environment as well as human health via their entry in the food web. Exploration of the viable remedial measures has become inevitable to prevent their entry into the food chain. Thus, the present screen house study was undertaken to evaluate the effect of rice residue biochar on bioavailability to Indian mustard (Brassica juncea (L.) Czern) in a loamy sand soil spiked with four levels of Cd and Pb varying from 0 to 40 mg kg-1 and 0 to 200 mg kg-1 soil, respectively. The soil of the metal treated pots was further amended with four rates (0, 1%, 2% and 4%, w/w) of rice residue biochar. Crop was grown for 60 days with recommended doses of nitrogen and phosphorus. Addition of biochar up to 2% increased the above ground biomass of Indian mustard but decreased with application @ 4% as compared to unamended soil. Application of biochar significantly reduced the accumulation of Cd and Pb by the crop with increasing rates of its application. The ameliorative efficiency of biochar for Pb was more as compared to Cd. It was concluded that rice residue biochar has the potential to curtail the solubility, availability and translocation of Pb and Cd to Indian mustard. [ABSTRACT FROM AUTHOR]

A screen house experiment was conducted to study the effect of rice residue biochar (0, 0.5, 1 and 2 % w/w) on the bioavailability and accumulation of Cd by Indian mustard (Brassica juncea) in a loamy sand soil spiked with three levels each of Cd (0, 10 & 25 mg Kg-1 soil) and Pb (0, 25 & 50 mg Kg-1 soil) in all possible combinations. Immobilization of Cd by rice residue biochar was assessed by DTPA-extractable Cd in soil and Cd concentrations in shoots of Indian mustard. Mean DTPA-Cd after harvest of crop decreased with increasing rates of applied rice residue biochar. Addition of biochar at its highest level of 2% decreased the mean DTPA-Cd in soil and its concentrations in plant by 59% and 36% over control, respectively. Biochar addition increased dry matter yield (DMY) of Indian mustard and a maximum increase of 18% over control was observed at a level of 1%. However, DMY decreased by 19% with addition of biochar at 2%. It was concluded that rice residue biochar can be used as an amendment for amelioration of Cd contaminated sites as its concentration in plants decreased with increasing levels of biochar application. [ABSTRACT FROM AUTHOR]

In the present study, a set of 36 Indian mustard genotypes were evaluated in three replications for twelve agromorphological traits. D² analysis was done to study the diversity pattern which enabled the grouping of genotypes into 11 clusters. Cluster I was the largest (D²=7.53) comprising of 20 genotypes followed by cluster II (D²=7.20) of 7 genotypes, while other 9 clusters contained one genotype each. Estimates of average inter cluster distance revealed that clusters IX and XI were most divergent (D²=118.49) followed by clusters V and XI (D²=88.48). Hence, crossing between genotypes Pusa Agrani × Rohini (cluster IX × cluster XI); PM-28 × Rohini (cluster V × cluster XI) may yields a considerable amount of heterosis in F1 generation. Days to maturity (31.9 %) had the highest contribution, followed by seed yield per plant (25.4 %), days to 50% flowering (13.33 %), beak length (7.30 %) and 1000 seed weight (6.67 %) towards the observed genetic diversity. Selection for divergent parents based on concerned traits could enhance the development of transgressive segregants with increased vigor in Indian mustard. [ABSTRACT FROM AUTHOR]

Tocopherol is vital for the nutritional value and stability of Indian mustard (Brassica juncea L. Czern and Coss) oil; nonetheless, the lack of information on genetic control is hampering its improvement. In this study, six populations (P1, P2, F1, F2, BC1P1, and BC1P2) of RLC3 × NPJ203 were evaluated in a family block design to evaluate the inheritance pattern, gene effects, and various other genetic parameters of tocopherol content (α, γ, and total), using generation mean analysis. The comparison of direct and reciprocal crosses indicated that the tocopherol content was not influenced by maternal inheritance. Negative directional heterosis showed that ATC, GTC, and TTC are governed by recessive genes. Potence ratio and degree of dominance highlighted an over-dominance type of gene interaction for GTC and TTC, whereas ATC was governed by epistatic interactions. Furthermore, the six-parameter model revealed a duplicate gene action for α-tocopherol content. Broad and narrow sense heritability coupled with genetic advances were high. [ABSTRACT FROM AUTHOR]

Forty-day-old Brassica juncea (var. Pusa Jai Kisan) plants were exposed to arsenic (As, 250 µM Na2HAsO4·7H2O) stress. The ameliorative role of ferrous sulfate (2 mM, FeSO4·7H2O, herein FeSO4) was evaluated at 7 days after treatment (7 DAT) and 14 DAT. Whereas, As induced high magnitude oxidative stress, FeSO4 limited it. In general, As decreased the growth and photosynthetic parameters less when in the presence of FeSO4. Furthermore, components of the antioxidant system operated in better coordination with FeSO4. Contents of non-protein thiols and phytochelatins were higher with the supply of FeSO4. Blue-Native polyacrylamide gel electrophoresis revealed an As-induced decrease in almost every multi-protein-pigment complex (MPC), and an increase in PSII subcomplex, LHCII monomers and free proteins. FeSO4 supplication helped in the retention of a better stoichiometry of light-harvesting complexes and stabilized every MPC, including supra-molecular complexes, PSI/PSII core dimer/ATP Synthase, Cytochrome b6/f dimer and LHCII dimer. FeSO4 strengthened the plant defence, perhaps by channelizing iron (Fe) and sulfur (S) to biosynthetic and anabolic pathways. Such metabolism could improve levels of antioxidant enzymes, and the contents of glutathione, and phytochelatins. Important key support might be extended to the chloroplast through better supply of Fe-S clusters. Therefore, our results suggest the importance of both iron and sulfur to combat As-induced stress in the Indian mustard plant at biochemical and molecular levels through enhanced antioxidant potential and proteomic adjustments in the photosynthetic apparatus. [ABSTRACT FROM AUTHOR]

Rapeseed-mustard is one of the most important oilseed crops and providing a major source of edible oil in the world besides having other economic importance like leafy vegetables, ornamentals, and hedge crops. However, the genetic diversity present in the Brassica gene pool has not been investigated in detail. To address this problem, a study was conducted on 76 genotypes of B. juncea including cultivars, exotic lines, registered genetic stocks, advanced breeding lines, and germplasm lines. The genetic diversity was analyzed with the help of 50 polymorphic SSR and EST-SSR markers. For these genotype-marker combinations, a total of 126 alleles were amplified. All the genotypes were grouped into 5 clusters based on their dissimilarity matrix. Population structure analysis grouped the genotypes in 8 clusters and various degrees of admixture was also observed. The grouping of the genotypes appears effective as per their pedigree. The marker data was found more accurate to characterize the diversity and study the population structure than the quantitative trait data. The results of the present investigation will provide useful information for the identification of important alleles for future studies and pave the way to enhance genetic gains in Indian mustard. [ABSTRACT FROM AUTHOR]

Heavy metal pollution in the environment compromises environmental quality and human health. Phytoremediation is an innovative, green, and affordable technique that uses plants for the removal of contaminants from soil and water. Finding suitable plants that can adequately remove heavy metals from both soil and water has been a research hotspot in recent years, and there has been a rapid development in research on the use of high biomass producing crops for this purpose. Vetiver grass and Indian mustard have emerged as plants that are effective for phytoremediation and can serve other purposes during and after their use in phytoremediation. These plants are applicable in many areas because they can tolerate varied climatic conditions, thrive on degraded lands and contaminated water bodies, are easy to cultivate, and produce high biomass. This review article evaluates the phytoremediation potential of vetiver grass and Indian mustard by providing a synthesis of studies that have investigated their use for this purpose. The review considered research articles from the past 21 years and highlights the status and possible advancements in the efficient use of these plants for the remediation of heavy metal–contaminated sites. This work is of importance because phytoremediation is still undergoing immense research to promote its applicability and acceptability. Thus, it gives information on two important plants that are very useful for phytoremediation. [ABSTRACT FROM AUTHOR]

In present endeavors, the genetic diversity and Bayesian structure of 88 genotypes of Indian mustard procured from four different centers viz., ICAR-DRMR Bharatpur, ICAR-IARI New Delhi, CCS HAU Hisar and PAU Ludhiana were studied using 59 genomic SSR markers, and their genetic liaison was explored. A total of 209 repeatable alleles were detected by 59 SSR markers in a size range of 50-1000 bp with maximum (7) fragments intensified by BG6, BG32, BG46 and BG71 markers. The average value of PIC and the mean expected heterozygosity (He) value from all the polymorphic primers were 0.49 and 0.56, respectively, which is an indicative of the presence of ample amount of genetic diversity among Indian mustard genotypes. All the 88 genotypes were grouped into four distinct clusters based on Jaccard's dissimilarity coefficients and UNJ (Unweighted Neighbour Joining) methods, however, three subpopulations were predicted by bayesian structure analysis at delK = 3. The PCoA (Principal Coordinate Analysis) revealed 20.95% and 10.85% of variation, respectively, with 31.80% of cumulative variation. The present work indicates the presence of considerable genetic diversity among the Indian mustard genotypes, which could be used in future breeding programmes for developing mustard cultivars and germplasm management purposes. [ABSTRACT FROM AUTHOR]

It is known that auxin and nitric oxide have the ability to ameliorate various abiotic stresses in plants individually. However, their interactive effects on the stress generated by salt in plants are not reported yet. Therefore, the present study was conducted to explore the effectiveness of sodium nitroprusside (SNP), a donor of nitric oxide and IAA (Indole acetic acid) individually and in combination on the photosynthetic efficiency, antioxidative enzyme activities, and plant biomass under salt stress. Twenty-five-day-old plants were exposed to SNP and IAA individually and in combination for 5 days continuously, and it was found that both SNP and IAA showed almost similar response at 30 and 45 days of old plants and increased studied parameters over their respective controls. However, the interactive effect of both SNP and IAA excelled over the individual response of SNP and IAA. On the other hand, the presence of salt in soil significantly decreased the parameters studied. Furthermore, stress generated by NaCl was overcome by the exogenous application of SNP, IAA alone as well as in combination at both the stages of samplings. However, the combination of IAA and SNP was more effective at 45 DAS where the value of plant biomass and photosynthetic efficiency was more in comparison to control plants. The level of antioxidant enzymes and proline was further enhanced by SNP and IAA and maximum values were reported in the plants received both SNP and IAA under NaCl stress. This enhanced antioxidant system and proline accumulation could ameliorate the stress induced by NaCl in plants that was reflected by the improved plant biomass, and photosynthetic efficiency in comparison to control plants. [ABSTRACT FROM AUTHOR]

In the present study, line× tester analysis was carried out at Castor-Mustard Research Station, S. D. Agricultural University, Sardarkrushinagar, Gujarat, India during rabi 2018-19 (October 2018 to February 2019) in order to estimate all three types of heterosis (relative heterosis, heterobeltiosis and economic heterosis) for identification of superior cross combinations of Indian mustard [Brassica juncea (L.) Czern&Coss]. Thirty-five hybrids along with five CMS lines, seven testers and check GDM 4 were evaluated for ten different traits. The F1 generation of all the crosses exhibited fertility restoration with pollen fertility except F1 crosses with Vardan, Rohini and SKM 319 fertile line (0%). The remaining crosses exhibited pollen fertility ranging from 68.26% (Kranti×SKM 303) to 85.17% (Kranti×Mori 'R' 1-18). The analysis of variance for parents, hybrids and parents vs. hybrids revealed that mean sum of squares of parents were highly significant for majority of the characters except days to maturity. Whereas, hybrids differed highly significant for all the characters. Comparison of mean squares due to parents vs. hybrids was found significant for almost all the characters except number of seeds siliqua-1 and oil content. This indicates that considerable amount of genetic variability present among the parents and hybrids for all the characters studied. On the basis of per se performance, three hybrids viz., Kranti×Mori 'R' 1-18, SKM 9928×PusaAgrani and SKM 9928×Mori 'R' 1-18 were foundpromising for seed yield plant-1 over the standard check GDM 4. With respect to heterosis, one of the hybrid Kranti×Mori 'R' 1-18 (17.85 %)manifested significant and positive standard heterosis for seed yield plant-1. [ABSTRACT FROM AUTHOR]

Genetic divergence using D² statistics was assessed for 13 different traits in a collection of 75 exotic and indigenous Indian mustard lines at CCS HAU Hisar. Based on genetic diversity, all were grouped into 15 clusters, of which cluster I had the maximum of 46 genotypes, followed by cluster V (8 genotypes), cluster III (7 genotypes) and cluster XII (3 genotypes). The remaining 11 clusters, i.e., cluster II, cluster IV, cluster VI, cluster VII, cluster VIII, cluster IX, cluster X, cluster XI, cluster XIII, cluster XIV and cluster XV, had only one genotype each. Cluster XII showed the maximum intra-cluster distance (15.51), while the maximum inter-cluster distance between cluster XII and cluster XV was observed (38.15). The maximum contribution to genetic divergence was recorded for the trait 1000-seed weight (33.26%) followed by days to 50 per cent flowering (26.09%), oil content (23.93%), days to maturity (26.09%) and seed yield per plant (% ). The genotypes IC-570302, IC-520747, IC-122427, EC-766480, RH 0749, EC-766040 and IC-470935, were observed promising for most of the important yield traits based upon high cluster means. The use of these genotypes was suggested in the crossing programme for further improvement in Indian mustard. [ABSTRACT FROM AUTHOR]

Line × tester analysis was carried out to estimate combining ability of Ogura CMS based hybrids in Indian mustard [Brassica juncea (L.) Czern & Coss.]. For this, 50 hybrids were developed by crossing five Ogura CMS lines with ten restorers according to the Line x Tester mating design. A total of 65 genotypes including 50 hybrids and 15 parents were evaluated during Rabi, 2017-18. Analysis of variance revealed significant differences among lines and crosses for most of the traits. The value of σ2 SCA/σ2 GCA was found less than one, for most of the traits indicating a major role of non-additive gene action in the expression of characters. Line RH 0555-OA and tester IOR-12 were found to be good general combiners possessing highly significant and positive gca effects for seed yield and component traits. The cross RH 0630-OA × IOR-12 had expressed the highly significant and positive sca effects for seed yield per plant. Other crosses such as RH 8812-OA × IOR-3, RH 0749-OA × IOR-6, RH 0749-OA × IOR-22, RH 0749-OA × IOR-18 and RH 0630-OA × IOR-11 had exhibited significant sca effects for different yield related characters in Indian mustard. [ABSTRACT FROM AUTHOR]

Background: Climatic variations such as drought have high level of impingement on the yield of rain-fed crops like mustard. A drought is an extended period of months or years when region notes a deficiency in its water availability. Water stress causes heavy yield losses in Indian mustard (17-94%). Low water availability during stem elongation, flowering and pod development causes reduction of pods per plant leading to reduction in grain yield. Very meagre efforts have been made towards improving drought tolerance of this crop. Hence there is an urgent need for, development of water use efficient genotypes. Drought Susceptibility Index (DSI) is a measure of drought, based on loss of yield under drought conditions in comparison to the yield under normal conditions. It expresses the separate effects of yield potential and drought susceptibility on yields under drought. In these terms, lower DSI is considered synonymous with higher drought tolerance. In view of above facts, present study is aimed at investigating the effects of drought on yield attributing traits with, the objective of identifying Indian mustard genotypes and their hybrids which can withstand water stress with minimum loss in yield. Methods: Nine Indian mustard genotypes and their F1s were evaluated under irrigated and rainfed conditions to study the effect of drought by calculating DSI, on yield and yield traits and to characterize their relative tolerance against drought at the Agriculture Research Farm, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi during Rabi 2017-18 season. Observations were made for different yield and yield related traits. Result: Genotype RB-50 was found as tolerant for seed yield per plant with DSI 0.38 while hybrids RB-50xRH-749 and RB-50xGiriraj were exhibiting tolerant DSI values for siliqua per plant, 1000 seed weight, seed yield per plant and oil content. These parents and F1s would serve as useful donors and hybrids respectively, in mustard breeding programmes for improving drought tolerance. [ABSTRACT FROM AUTHOR]

In this study, we investigate the release of melanoidin-like product (MLP) from hybrid silica xerogels to control the quantity of MLP in the medium for lead phytoextraction. In the preparation of the hybrid organic–inorganic xerogels with MLP, tetraethoxysilane (TEOS), methyltriethoxysilane (MTES), propyltriethoxysilane (PTES), and 3-aminopropyltriethoxysilane (APTES) were used as precursors. The experimental results suggest that the release of MLP can be easily controlled by partially substituting TEOS with the organosilanes. The addition of the organosilanes lowered the release rate of MLP in the following order of xerogels: TEOS, MTES/TEOS, PTES/TEOS, and APTES/TEOS. Furthermore, a novel phytoextraction of lead through the Indian mustard was conducted using the MLP-doped TEOS xerogel. Results show that the addition of TEOS xerogel did not have any influence on the growth of the mustard, whereas the lead uptake significantly increased in a nutrition medium with 1-mM Pb(NO3)2. In conclusion, the beneficial effect of the MLP-doped TEOS xerogel on lead phytoextraction was confirmed. [ABSTRACT FROM AUTHOR]

Forty five genotypes of Indian mustard [Brassica juncea (L.) Czern and Coss] were evaluated for seed yield and quality traits in Randomized Block Design with four replications during the Rabi, 2019-2020. The analysis of variance revealed that the mean sum of squares due to genotypes was significant for all the eighteen characters studied indicating the presence of variability for all the traits among the genotypes under study. Low difference between genotypic and phenotypic variances revealed that the contribution of genotypic variance to total variance was more for all the traits except days to maturity and plant height. The high values of genotypic and phenotypic coefficient of variation for the number of branches per plant, seed yield per plant, myristic acid, palmitic acid and stearic acid which indicated the potential variability available for these traits. The high heritability estimates obtained in conjunction with high genetic advance were observed for the number of branches per plant, the number of siliquae per plant, seeds per siliqua, length of siliqua, 1000-seed weight, seed yield per plant, myristic acid, palmitic acid, stearic acid, linoleic acid, linolenic acid and glucosinolate suggesting the predominant role of additive gene action for their expression. Association analysis between seed yield per plant and other seventeen characters revealed significantly positive correlation of seed yield per plant with the number of siliquae per plant, seeds per siliqua, length of siliquam, myristic acid and erucic acid. Path analysis revealed positive direct effects of the number of siliquae per plant and seeds per siliqua towards seed yield per plant while myristic acid, the number of branches per plant had a positive indirect effect on seed yield per plant via the number of siliquae per plant suggesting that the selection for such traits would be more effective for improving seed yield in Indian mustard. [ABSTRACT FROM AUTHOR]

Heat stress at the seedling stage can increase mortality and has become an increasing threat for Indian mustard cultivation. Indian mustard is being predominantly grown under a rainfed ecosystem. In this context, the selection of heat tolerant genotypes may be one of the panaceas. Hence, this study was planned to evolve, evaluate and identify some of the promising early maturing heat stress tolerant from a pool of advanced breeding lines, to be used as probable donors for transferring heat tolerance. For this purpose, heat stress was imposed on 10 Indian mustard advanced breeding lines at the seedling period. The mean performance of the ten advanced breeding lines of Indian mustard with respect to morphophysiology revealed that the genotype DRMRHT-13-13-5-4 recorded earliest in maturity (117.5 days), high oil content (43.14 %) and seed yield of 3182.82 (kg/ha) which was 19.75 per cent higher seed yield over best check NPJ-112 under heat stress conditions. Similarly, the genotype DRMRHT-13-13-5-6 also recorded early in maturity (118.5 days), oil content (42.18%) and seed yield of 2964.92 (kg/ha) which was 11.55 per cent higher seed yield over the best check NPJ-112. There was a positive correlation between relative water content and membrane stability index (r=0.945) but both of these traits were negatively associated with excised-leaf water loss. Cluster survey classified 10 advanced breeding lines in five divergent groups. The tree diagram revealed abundant diversity between the Indian mustard genotypes for different characters and some magnitude of a consortium between different clusters. Based on the higher membrane stability index, water retention capacity of leaves, relative water content, minimum excised-leaf water loss and seed yield, advanced breeding lines DRMRHT-13-13-5-4 and DRMRHT-13-13-5-6 were identified as early in maturity and heat tolerant at a seedling stage which could be used in breeding programmes. [ABSTRACT FROM AUTHOR]

A screenhouse experiment was conducted to study the effect of four rates of rice straw biochar (0, 1, 2 and 4%) on the bioavailability and accumulation of cadmium (Cd) by Indian mustard (Brassica juncea) in sewage water irrigated soil artificially spiked with Cd. Immobilization of Cd by rice straw biochar was assessed on the basis of DTPA-extractable Cd in soil and its content in shoots of Indian mustard. The results revealed a linear decrease in DTPA-Cd with the addition of rice straw biochar. Addition of biochar at the highest level (4%) decreased the mean Cd content in soil and in plant by 38.1 and 60.1%, respectively. Biochar addition increased dry matter yield (DMY) of Indian mustard and maximum yield increase of 19.3% was observed at 2% addition. The increase in DMY was decreased to 2.6% at 4% addition of biochar. The study indicated that rice straw biochar can be used as a remediation measure for contaminated sites and may prove to be a viable option for managing agricultural residues. [ABSTRACT FROM AUTHOR]

Genetic diversity in crop species plays an important role for breeding new cultivars than existing ones in available germplasm. Therefore, 50 Indian mustard genotypes evaluated for the extent of diversity for utilization in breeding program. The data recorded on thirteen characters were subjected to analysis of variance and dispersion revealed significant differences. D2 analysis was conducted to measure the genetic diversity among the genotypes. The genotypes were grouped in 9 clusters using Tocher's method. Intra-cluster distance was maximum for cluster V followed by cluster IV. The highest inter cluster distance was observed between the cluster VII and IX followed by VII and VIII and the lowest between cluster I and III. The characteristics such as oil content, test weight and number of siliquae per plant contributed greatest towards the divergence in the mustard genotypes. The genotypes RC 502 and RC 510 of cluster VII constitute high cluster mean for number of siliquae per plant, number of secondary branches per plant along with earliness in flowering; the genotype RC 524 of cluster IX for high oil yield along with early maturity and genotype RC 535 of cluster VIII for high seed yield per plant and test weight. These genotypes could be considered as best parents and can be utilized in the hybridization programme in different combinations for selection of transgressive segregants and high heterotic response to get maximum yield alongwith early maturity and high oil content. [ABSTRACT FROM AUTHOR]

Levels of arsenic (As), chromium (Cr), and copper (Cu) are increasing in the soils worldwide. Such contaminants cause toxicity in the plant systems which adversely affects growth and productivity. The objective of the present investigation was to elucidate individual and combined effects of As, Cr, and Cu (100 μM each) stress in metal hyper-accumulator plant Indian mustard (Brassica juncea L.), exposed for a week. The highest accumulation was in the roots and in decreasing order viz. Cu > As > Cr. The magnitude of oxidative stress was maximal in combined stress, followed by As, Cr, and then Cu stress. Glutathione in conjunction with glutathione reductase, glutathione peroxidase, and glutathione S-transferase increased in all set of stress treatments, notably when exposed to Cr alone. In addition, the level of sulfur-rich compounds like cysteine, phytochelatins, and non-protein thiols increased under each stress indicating efficient coupling of the enzyme system and sulfur-containing compounds during stress conditions. The highest tolerance or growth index of plants was recorded for Cu. Protein profiling of leaf tissues showed modulation of protein patterns in each stress. Mediator of RNA polymerase II transcription subunit 1 isoform X1, RuBisCO (large subunit), and ribosomal protein S3 proteins were more abundant under Cr and Cu stress. Zinc finger A20/AN1 domain-containing stress-associated protein 5–like protein was more abundant under Cu stress. HSP (15.7 kDa) and autophagy protein 5–like were in higher abundance under As and combined stress. Our results suggest that Indian mustard has a differential mode of defense against a particular stressor at the level of protein expression profile. [ABSTRACT FROM AUTHOR]

Nine Indian mustard genotypes including standard check, RB-50 and their hybrids were sown under timely sown irrigated condition to study the extent of relative, heterobeltiosis and standard heterosis for seed yield and its components. The analysis of variance revealed that considerable genetic variation existed among the parents and hybrids for most of the traits under study. RB-50×Kranti showed positive and significant value for all the three types of heterosis for 1000 seed weight. Rh-119×Giriraj, RGN-298×RH-749, RGN-298×Giriraj, Vardan×RH-749 and Vardan×Giriraj showed standard heterosis for seed yield per plant as well as number of primary and secondary branches. The cross combinations Vardan×Giriraj, RGN-298×RH-749, RGN-298×Giriraj, Vardan×RH-749 and Vardan×RGN-73 were identified on the basis of standard heterosis alogwith per se performance for seed yield per plant which, could be exploited for getting transgressive segregants in the subsequent generation for developing high yielding varieties. [ABSTRACT FROM AUTHOR]

Indian mustard (Brassica juncea) is a major source of vegetable oil in the Indian subcontinent. The seed cake left after the oil extraction is used as livestock feed. We examined the genetic architecture of oil, protein, and glucosinolates by conducting a genome-wide association study (GWAS), using an association panel comprising 92 diverse genotypes. We conducted trait phenotyping over 2 years at two levels of nitrogen (N) application. Genotyping by sequencing was used to identify 66,835 loci, covering 18 chromosomes. Genetic diversity and phenotypic variations were high for the studied traits. Trait performances were stable when averaged over years and N levels. However, individual performances differed. General and mixed linear models were used to estimate the association between the SNP markers and the seed quality traits. Population structure, principal components (PCs) analysis, and discriminant analysis of principal components (DAPCs) were included as covariates to overcome the bias due to the population stratification. We identified 16, 23, and 27 loci associated with oil, protein, and glucosinolates, respectively. We also established LD patterns and haplotype structures for the candidate genes. The average block sizes were larger on A-genome chromosomes as compared to the B- genome chromosomes. Genetic associations differed over N levels. However, meta-analysis of GWAS datasets not only improved the power to recognize associations but also helped to identify common SNPs for oil and protein contents. Annotation of the genomic region around the identified SNPs led to the prediction of 21 orthologs of the functional candidate genes related to the biosynthesis of oil, protein, and glucosinolates. Notable among these are: LACS5 (A09), FAD6 (B05), ASN1 (A06), GTR2 (A06), CYP81G1 (B06), and MYB44 (B06). The identified loci will be very useful for marker-aided breeding for seed quality modifications in B. juncea. [ABSTRACT FROM AUTHOR]