scholarly journals Development of a Yellow-Seeded Stable Allohexaploid Brassica Through Inter-Generic Somatic Hybridization With a High Degree of Fertility and Resistance to Sclerotinia sclerotiorum

2020 ◽  
Vol 11 ◽  
Author(s):  
Preetesh Kumari ◽  
Kaushal Pratap Singh ◽  
Sundip Kumar ◽  
Devendra Kumar Yadava

The Brassica coenospeceis have treasure troves of genes that could be beneficial if introgressed into cultivated Brassicas to combat the current conditions of climate change. Introducing genetic variability through plant speciation with polyploidization is well documented, where ploidy augmentation of inter-generic allohexaploids using somatic hybridization has significantly contributed to genetic base broadening. Sinapis alba is a member of the Brassicaceae family that possesses valuable genes, including genes conferring resistance to Sclerotinia sclerotiorum, Alternaria brassicae, pod shattering, heat, and drought stress. This work aimed to synthesize stable allohexaploid (AABBSS) Brassica while incorporating the yellow-seed trait and resistance to S. sclerotiorum stem rot. The two fertile and stable allohexaploids were developed by polyethylene glycol mediated protoplast fusions between Brassica juncea (AABB) and S. alba (SS) and named as JS1 and JS2. These symmetric hybrids (2n = 60) were validated using morphological and molecular cytology techniques and were found to be stable over consecutive generations. The complete chromosome constitution of the three genomes was determined through genomic in situ hybridization of mitotic cells probed with S. alba genomic DNA labeled with fluorescein isothiocyanate. These two allohexaploids showed 24 hybridization signals demonstrating the presence of complete diploid chromosomes from S. alba and 36 chromosomes from B. juncea. The meiotic pollen mother cell showed 30 bivalent sets of all the 60 chromosomes and none of univalent or trivalent observed during meiosis. Moreover, the backcross progeny 1 plant revealed 12 hybridization signals out of a total of 48 chromosome counts. Proper pairing and separation were recorded at the meiotic metaphase and anaphase, which proved the stability of the allohexaploid and their backcross progeny. When screening, the allohexaploid (JS2) of B. juncea and S. alba displayed a high degree of resistance to S. sclerotiorum rot along with a half-yellow and half-brown (mosaic) seed coat color, while the B. juncea and S. alba allohexaplopid1 (JS1) displayed a yellow seed coat color with the same degree of resistance to Sclerotinia rot.

2020 ◽  
Author(s):  
Zhen Huang ◽  
Yang Wang ◽  
Hong Lu ◽  
Xiang Liu ◽  
Lu Liu ◽  
...  

Abstract BackgroundYellow seed breeding is an effective method to improve the oil content in rapeseed. Yellow seed coat color formation is influenced by various factors, and no clear mechanisms are known. In this study, Bulked segregant RNA-Seq (BSR-Seq) of BC9 population of Wuqi mustard (yellow seed) and Wugong mustard (brown seed) was used to identity the candidate genes controlling the yellow seed color in Brassica juncea L.ResultsYellow seed coat color gene was mapped to chromosome A09, and differentially expressed genes (DEGs) between brown and yellow bulks enriched in the flavonoid pathway. A significant correlation between the expression of BjF3H and BjTT5 and the content of the seed coat color related indexes was identified. Two intron polymorphism (IP) markers linked to the target gene were developed around BjF3H. Therefore, BjF3H was considered as the candidate gene. The BjF3H coding sequences (CDS) of Wuqi mustard and Wugong mustard are 1071-1077bp, encoding protein of 356-358 amino acids. One amino acid change (254, F/V) was identified in the conserved domain. This mutation site was detected in four Brassica rapa (B. rapa) and six Brassica juncea (B. juncea) lines, but not in Brassica napus (B. napus).ConclusionsThe results indicated BjF3H is a candidate gene that related to yellow seed coat color formation in Brassica juncea and provided a comprehensive understanding of the yellow seed coat color mechanism.


2021 ◽  
Author(s):  
Zhicheng Hu ◽  
Xueyin Shi ◽  
Xuemiao Chen ◽  
Jing Zheng ◽  
Aiai Zhang ◽  
...  

Abstract Seed coat color is related to flavonoid content which is closely related to seed dormancy. According to the genetic analysis of a six-generation population derived from two parents (IC2508 with a yellow seed coat and IC2518 with a brown seed coat), we discovered that the yellow seed coat trait in melon was controlled by a single dominant gene, named CmBS-1. Bulked segregant analysis sequencing (BSA-Seq) revealed that the gene was located at 11,860,000–15,890,000 bp (4.03 Mb) on Chr 6. The F2 population was genotyped using insertion-deletions (InDels), from which cleaved amplified polymorphic sequence (dCAPS) markers were derived to construct a genetic map. The gene was then fine-mapped to a 233.98 kb region containing 12 genes. Based on gene sequence analysis with two parents, we found that the MELO3C019554 gene encoding a homeobox protein (PHD transcription factor) had a nonsynonymous single nucleotide polymorphism (SNP) mutation in the coding sequence (CDS), and the SNP mutation resulted in the conversion of an amino acid (A→T) at residue 534. In addition, MELO3C019554 exhibited lower relative expression levels in the yellow seed coat than in the brown seed coat. Furthermore, we found that MELO3C019554 was related to 12 flavonoid metabolites. Thus, we predicted that MELO3C019554 is a candidate gene controlling seed coat color in melon. The study lays a foundation for further cloning projects and functional analysis of this gene, as well as marker-assisted selection breeding.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10770
Author(s):  
Yanjing Ren ◽  
Ning Zhang ◽  
Ru Li ◽  
Xiaomin Ma ◽  
Lugang Zhang

Background Seed coat color is an important horticultural trait in Brassica crops, which is divided into two categories: brown/black and yellow. Seeds with yellow seed coat color have higher oil quality, higher protein content and lower fiber content. Yellow seed coat color is therefore considered a desirable trait in hybrid breeding of Brassica rapa, Brassica juncea and Brassica napus. Methods Comprehensive analysis of the abundance transcripts for seed coat color at three development stages by RNA-sequencing (RNA-seq) and corresponding flavonoids compounds by liquid chromatography-tandem mass spectrometry (LC-MS/MS) were carried out in B. rapa. Results We identified 41,286 unigenes with 4,989 differentially expressed genes between brown seeds (B147) and yellow seeds (B80) at the same development stage. Kyoto Encyclopedia of Genes and Genomes enrichment analysis identified 19 unigenes associated with the phenylpropanoid, flavonoid, flavone and flavonol biosynthetic pathways as involved in seed coat color formation. Interestingly, expression levels of early biosynthetic genes (BrCHS, BrCHI, BrF3H, BrF3’H and BrFLS) in the flavonoid biosynthetic pathway were down-regulated while late biosynthetic genes (BrDFR, BrLDOX and BrBAN) were hardly or not expressed in seeds of B80. At the same time, BrTT8 and BrMYB5 were down-regulated in B80. Results of LC-MS also showed that epicatechin was not detected in seeds of B80. We validated the accuracy of our RNA-seq data by RT-qPCR of nine critical genes. Epicatechin was not detected in seeds of B80 by LC-MS/MS. Conclusions The expression levels of flavonoid biosynthetic pathway genes and the relative content of flavonoid biosynthetic pathway metabolites clearly explained yellow seed color formation in B. rapa. This study provides a foundation for further research on the molecular mechanism of seed coat color formation.


1979 ◽  
Vol 59 (3) ◽  
pp. 635-637 ◽  
Author(s):  
C. L. VERA ◽  
D. L. WOODS ◽  
R. K. DOWNEY

The genetics of seed coat color inheritance in Brassica juncea (L.) Coss. were studied. It was concluded that this character is controlled by two duplicate pairs of genes (R1, R2) for brown color, either of which can produce brown seed color when a single dominant allele is present. Yellow seed results when all alleles at both loci are recessive.


2021 ◽  
Vol 22 (6) ◽  
pp. 2972
Author(s):  
Yuzi Shi ◽  
Meng Zhang ◽  
Qin Shu ◽  
Wei Ma ◽  
Tingzhen Sun ◽  
...  

Seed coat color is an important agronomic trait of edible seed pumpkin in Cucurbita maxima. In this study, the development pattern of seed coat was detected in yellow and white seed coat accessions Wuminglv and Agol. Genetic analysis suggested that a single recessive gene white seed coat (wsc) is involved in seed coat color regulation in Cucurbita maxima. An F2 segregating population including 2798 plants was used for fine mapping and a candidate region containing nine genes was identified. Analysis of 54 inbred accessions revealed four main Insertion/Deletion sites in the promoter of CmaCh15G005270 encoding an MYB transcription factor were co-segregated with the phenotype of seed coat color. RNA-seq analysis and qRT-PCR revealed that some genes involved in phenylpropanoid/flavonoid metabolism pathway displayed remarkable distinction in Wuminglv and Agol during the seed coat development. The flanking InDel marker S1548 was developed to predict the seed coat color in the MAS breeding with an accuracy of 100%. The results may provide valuable information for further studies in seed coat color formation and structure development in Cucurbitaceae crops and help the molecular breeding of Cucurbita maxima.


2021 ◽  
Vol 62 (1) ◽  
Author(s):  
Yu-Lan Lin ◽  
Dong-Hong Wu ◽  
Cheng-Chieh Wu ◽  
Yung-Fen Huang

Abstract Background Weedy rice, a conspecific weedy counterpart of the cultivated rice (Oryza sativa L.), has been problematic in rice-production area worldwide. Although we started to know about the origin of some weedy traits for some rice-growing regions, an overall assessment of weedy trait-related loci was not yet available. On the other hand, the advances in sequencing technologies, together with community efforts, have made publicly available a large amount of genomic data. Given the availability of public data and the need of “weedy” allele mining for a better management of weedy rice, the objective of the present study was to explore the genetic architecture of weedy traits based on publicly available data, mainly from the 3000 Rice Genome Project (3K-RGP). Results Based on the results of population structure analysis, we have selected 1378 individuals from four sub-populations (aus, indica, temperate japonica, tropical japonica) without admixed genomic composition for genome-wide association analysis (GWAS). Five traits were investigated: awn color, seed shattering, seed threshability, seed coat color, and seedling height. GWAS was conducted for each sub-population × trait combination and we have identified 66 population-specific trait-associated SNPs. Eleven significant SNPs fell into an annotated gene and four other SNPs were close to a putative candidate gene (± 25 kb). SNPs located in or close to Rc were particularly predictive of the occurrence of seed coat color and our results showed that different sub-populations required different SNPs for a better seed coat color prediction. We compared the data of 3K-RGP to a publicly available weedy rice dataset. The profile of allele frequency, phenotype-genotype segregation of target SNP, as well as GWAS results for the presence and absence of awns diverged between the two sets of data. Conclusions The genotype of trait-associated SNPs identified in this study, especially those located in or close to Rc, can be developed to diagnostic SNPs to trace the origin of weedy trait occurred in the field. The difference of results from the two publicly available datasets used in this study emphasized the importance of laboratory experiments to confirm the allele mining results based on publicly available data.


Weed Science ◽  
2011 ◽  
Vol 59 (1) ◽  
pp. 61-67 ◽  
Author(s):  
Jody E. Dexter ◽  
Amit J. Jhala ◽  
Rong-Cai Yang ◽  
Melissa J. Hills ◽  
Randall J. Weselake ◽  
...  

Flax is a minor oilseed crop in Canada largely exported to the European Union for use as a source of industrial oil and feed ingredient. While flax could be genetically engineered (GE) to enhance nutritional value, the adoption of transgenic technologies threatens conventional flax market acceptability. Harvest seed loss of GE crops and the persistence of GE crop volunteers in the seed bank are major factors influencing transgene persistence. Ten commercial fields in Alberta, Canada, were sampled after harvesting conventional flax in 2006 and 2007, and flax seed density and viability were determined. Additionally, artificial seed banks were established at two locations in Alberta in 2005 and 2006 to quantify persistence of five conventional flax cultivars with variability in seed coat color (yellow or brown) and α-linolenic acid (ALA, 18:3cisΔ9,13,15) content (3 to 55%) at three soil depths (0, 3, or 10 cm). Harvest methods influenced seed loss and distribution, > 10-fold more seed was distributed beneath windrows than between them. Direct harvested fields had more uniform seed distribution but generally higher seed losses. The maximum yield loss was 44 kg ha−1or 2.3% of the estimated crop yield. Seed loss and the viability of flax seed were significantly influenced by year, presumably because weather conditions prior to harvest influenced the timing and type of harvest operations. In artificial seed bank studies, seed coat color or ALA content did not influence persistence. Flax seed viability rapidly declined in the year following burial with < 1% remaining midsummer in the year following burial but there were significant differences between years. In three of four locations, there was a trend of longer seed persistence at the deepest burial depth (10 cm). The current study predicts that seed-mediated gene flow may be a significant factor in transgene persistence and a source of adventitious presence.


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