Mutant Trait Research Articles

A single-base deletion in exon 2 of Hd1 delineates monogenic recessive photoperiod insensitivity in aromatic Joha rice: a novel allele for seasonal adaptability

BackgroundAssam's aromatic Joha rice is a unique rice class famous for its aroma, taste, and nutritional benefits, which fetch high market prices in domestic and international markets. Joha landraces are inherently poor yielders due to their strong aroma and predominantly photoperiod sensitivity. Hybridization involving non-aromatic HYVs improves yield with concomitant loss of quality. In this context, mutation breeding, a sustainable approach where genetic mutations are induced to create desirable traits, often provides useful allelic variation in specific morpho-agronomic traits. The present study delves into the genetic characterization of a photoperiod-insensitive mutant. As part of our mutation breeding programme, this mutant was isolated from a gamma ray-induced M2 population of a Joha rice landrace, Kon Joha.ResultsThe mutant was unique, and a single recessive gene conditions the induced photoperiod insensitivity. Mutant gene tagging involved 402 SSR and InDel markers, and later polymorphic markers were used for bulk segregant analysis (BSA) in the F2 population of ‘mutant × Kalijeera (distant parent)’. BSA revealed an association between the SSR marker RM527 and this mutant trait. This marker is present on chromosome 6 of the rice genome. Using chromosome 6-specific SSR markers in polymorphic screening and BSA revealed another associated marker, RM19725, for the mutant trait. The genomic interval between RM527 and RM19725 harbors a photoperiod-insensitive gene, Hd1, on chromosome 6. Cloning and sequencing of Hd1 genomic fragments from the parents and mutants revealed a single-base deletion in exon 2, leading to a frameshift mutation in the Hd1 protein. This mutation in exon 2 leads to severe structural abnormalities in the CCT domain of the Hd1 protein that is critical for the interaction of the repressing complex with conserved response elements in the florigen gene under long-day conditions, thereby causing photoperiod insensitivity.ConclusionsThe mutant's pleasant aroma and other quality characteristics, comparable to those of the parent cultivar, hold significant promise. They expand its potential use in a structured breeding programme aimed at developing high-value aromatic Joha rice. This rice, resilient to winter- and summer-growing environments and with broad seasonal adaptability, could revolutionize the rice market. The practical value of our research is underscored by this exciting possibility.

An Ethyl Methanesulfonate-Induced GIF1 Splicing Site Mutation in Sesame Is Associated with Floral Malformation and Small Seed Size

Flower and inflorescence architecture play fundamental roles in crop seed formation and final yield. Sesame is an ancient oilseed crop. Exploring the genetic mechanisms of inflorescence architecture and developmental characteristics is necessary for high-yield breeding improvements for sesame and other crops. In this study, we performed a genetic analysis of the sesame mutant css1 with a malformed corolla and small seed size that was mutagenized by ethyl methanesulfonate (EMS) from the cultivar Yuzhi 11. Inheritance analysis of the cross derived from css1 mutant × Yuzhi 11 indicated that the mutant traits were controlled by a single recessive gene. Based on the genome resequencing of 48 F2 individuals and a genome-wide association study, we determined SNP9_15914090 with the lowest p value was associated with the split corolla and small seed size traits, which target gene Sigif1 (GRF-Interacting Factor 1). SiGIF1 contains four exons and encodes a coactivating transcription factor. Compared to the wild-type allelic gene SiGIF1, Sigif1 in the mutant css1 has a splice donor variant at the exon2 and intron2 junction, which results in incorrect transcript splicing with a 13 bp deletion in exon2. The expression profile indicated that SiGIF1 was highly expressed in the flower, ovary, and capsule but lowly expressed in the root, stem, and leaf tissues of the control. In summary, we identified a gene, SiGIF1, that regulates flower organs and seed size in sesame, which provides a molecular and genetic foundation for the high-yield breeding of sesame and other crops.

Identification and Gene Fine Mapping of the Bisexual Sterility Mutant Meiosis Abnormal Bisexual Sterility 1 in Rice.

Exploring the genes regulating rice fertility is of great value for studying the molecular mechanisms of rice reproductive development and production practices. In this study, we identified a sterile mutant from the mutant library induced by ethyl methanesulfonate (EMS), designated as meiosis abnormal bisexual sterility 1 (mabs1). The mabs1 mutant exhibits no phenotypic differences from the wild-type during the vegetative growth phase but shows complete sterility during the reproductive growth phase. Phenotypic observations revealed that both pollen and embryo sac fertility are lost in mabs1. Notably, in mabs1, the development of the anther inner and outer walls, tapetum degeneration, and callose synthesis and degradation all proceed normally, yet meiosis fails to form normal tetrads. Genetic analysis indicated that this mutant trait is controlled by a single recessive nuclear gene. By constructing a genetic segregation population, we successfully mapped the MABS1 gene to a 49 kb region between primer markers Y7 and Y9 on chromosome 1. Resequencing revealed a single-nucleotide substitution in the exon of the LOC_Os01g66170 gene, which resulted in a change from Valine to Isoleucine. Subsequent sequencing of this locus in both wild-type and mabs1 mutants confirmed this mutation. Therefore, we have identified the gene at LOC_Os01g66170 as a candidate for MABS1, a previously unreported novel gene involved in rice meiosis. Through RT-qPCR, we found that the expression levels of multiple meiosis-related genes were significantly changed in the mabs1 mutant. Therefore, we believe that MABS1 is also involved in the process of rice meiosis. This study lays the groundwork for a functional study of MABS1.

Natural variation of CT2 affects the embryo/kernel weight ratio in maize

Embryo size is a critical trait determining not only grain yield but also the nutrition of the maize kernel. Up to present, only a few genes have been characterized affecting the maize embryo/kernel ratio. Here, we identify 63 genes significantly associated with maize embryo/kernel weight ratio using a genome-wide association study (GWAS). The peak GWAS signal shows that the natural variation in Zea mays COMPACT PLANT2 (CT2), encoding the heterotrimeric G protein α subunit, is significantly associated with the Embryo/Kernel Weight Ratio (EKWR), Further analyses show that a missense mutation of CT2 decreases its enzyme activity and associates with EKWR. The function of CT2 on affecting embryo/kernel weight ratio is further validated by characterization of two ct2 mutants, for which EKWR is significantly decreased. Subsequently, the key downstream genes of CT2 are identified by combining the differential expression analysis (DEG) of the ct2 mutant and quantitative trait transcript analysis in the GWAS population. In addition, the allele frequency spectrum shows that CT2 was under selective pressure during maize domestication. This study provides important genetic insights into the natural variation of maize embryo/kernel weight ratio, which could be applied in future maize breeding programs to improve grain yield and nutritional content.

Identification and Fine Mapping of a Mutant pv‐nts Gene Responsible for Dwarf and Thin Stem of Snap Bean (Phaseolus vulgaris L.)

ABSTRACTPlant height is one of the most important traits in the breeding of snap bean, which determines the planting density and the resistance to failure, which in turn affects its yield and quality. Therefore, studying the molecular mechanism of plant height in snap bean is an important measure to realize the improvement of snap bean. We obtained a dwarf, thin‐stemmed mutant nts (normal to slim) from a dwarf variety of snap bean A18 via 60CO‐γ‐ray treatment. We conducted phenotypic observations, endogenous hormone content measurements and genetic analyses of the dwarfing thin‐stemmed mutant nts and explored gene localization and candidate gene screening for the mutant trait in snap bean. Compared with wild‐type A18, nts mutant exhibited various abnormal phenotypes such as dwarfing, reduced branching, thinner top stem, reduced plant width, reduced number of leaf area and thousand grain weight and increased content of hormones such as indole‐3‐acetic acid (IAA) in the top stem. Genetic analysis indicated that the mutant trait was controlled by a single recessive nuclear gene, and the mutant gene was named pv‐nts. pv‐nts was localized to a 361.1‐kb segment on chromosome 8 as revealed by bovine serum albumin (BSA) hybrid pool sequencing and simple sequence repeat (SSR) molecular markers. Phvul.008G106300 (encoding LAX2 protein) was identified as a candidate gene corresponding to pv‐nts via gene function annotation. Phvul.008G106300 was significantly upregulated in nts mutant compared with wild‐type A18, which was consistent with the results of endogenous IAA levels. Sequence analysis showed that the Phvul.008G106300 gene in nts had a base mutation that altered the protein structure, thus causing the dwarfed, thin‐stemmed phenotype of cauliflower. Taken together, these results contribute to a better understanding of the genetic basis of dwarfing traits in snap bean.

Modeling spatial evolution of multi-drug resistance under drug environmental gradients.

Multi-drug combinations to treat bacterial populations are at the forefront of approaches for infection control and prevention of antibiotic resistance. Although the evolution of antibiotic resistance has been theoretically studied with mathematical population dynamics models, extensions to spatial dynamics remain rare in the literature, including in particular spatial evolution of multi-drug resistance. In this study, we propose a reaction-diffusion system that describes the multi-drug evolution of bacteria based on a drug-concentration rescaling approach. We show how the resistance to drugs in space, and the consequent adaptation of growth rate, is governed by a Price equation with diffusion, integrating features of drug interactions and collateral resistances or sensitivities to the drugs. We study spatial versions of the model where the distribution of drugs is homogeneous across space, and where the drugs vary environmentally in a piecewise-constant, linear and nonlinear manner. Although in many evolution models, per capita growth rate is a natural surrogate for fitness, in spatially-extended, potentially heterogeneous habitats, fitness is an emergent property that potentially reflects additional complexities, from boundary conditions to the specific spatial variation of growth rates. Applying concepts from perturbation theory and reaction-diffusion equations, we propose an analytical metric for characterization of average mutant fitness in the spatial system based on the principal eigenvalue of our linear problem, λ1. This enables an accurate translation from drug spatial gradients and mutant antibiotic susceptibility traits to the relative advantage of each mutant across the environment. Our approach allows one to predict the precise outcomes of selection among mutants over space, ultimately from comparing their λ1 values, which encode a critical interplay between growth functions, movement traits, habitat size and boundary conditions. Such mathematical understanding opens new avenues for multi-drug therapeutic optimization.

Role of CES1 and ABCB1 Genetic Polymorphisms on Functional Response to Dabigatran in Patients with Atrial Fibrillation.

Background: Dabigatran etexilate is a pro-drug hydrolyzed into dabigatran by carboxylesterases (CES) and is a substrate of the P-Glycoprotein encoded by the adenosine-triphosphate-binding cassette sub-family B member (ABCB)1 genes. We evaluated the functional response to dabigatran according to different CES1 and ABCB1 single-nucleotide polymorphisms (SNPs) in patients with atrial fibrillation (AF). Methods: A total of 100 consecutive patients with AF taking dabigatran were enrolled by two Italian centers. A venous blood sample was drawn for genetic determinations, as well as a measurement of the diluted thrombin time (dTT) and drug plasma concentrations, at the trough and peak. The main objective was the relationship between the dTT values and CES1 rs2244613, CES1 rs8192935 and ABCB1 rs4148738 SNP while on two different dabigatran doses (110 and 150 mg BID). Results: A total of 43 patients were on a 110 mg dabigatran dose and 57 on 150 mg. The DTT values at the trough and at peak were not different among patients with different CES1 rs2244613 and CES1 rs8192935 genotypes, regardless of the dabigatran dose. In patients on 150 mg dabigatran, the dTT values at the trough were 77 (44-111) ng/mL in patients with the ABCB1 rs4148738 heterozygous CT genotype vs. 127 (85-147) ng/mL in the wild-type CC genotype vs. 110 (47-159) ng/mL in the mutant trait TT genotype (p = 0.048). In patients with the ABCB1 rs4148738 CT genotype, OR for having dTT values at a trough below the median was 3.21, 95% CI 1.04-9.88 (p = 0.042). Conclusions: ABCB1 rs4148738 CT heterozygous is associated with the reduced anticoagulant activity of dabigatran at the trough in patients receiving the higher dose regimen.

Ethyl Methanesulfonate Mutant Library Construction in Tartary Buckwheat with Agronomic Trait and Flavonoid Screening for Germplasm Innovation

As a nutrient-rich multigrain crop, buckwheat is a typical “medicinal food homology” crop that is rich in flavonoids, including rutin and various vitamins. It has positive anti-oxidant and anti-tumour properties and lowers blood pressure. However, due to strict self-crossing characteristics, slow progress has been made in Tartary buckwheat (TB) cross-breeding, resulting in the slow breeding of new varieties of new TB varieties, which has limited the improvement of yield and quality. Therefore, mutant breeding is a rapid and effective technique for broadening and innovating TB breeding. In recent years, improving qualities related to yield, lodging resistance, and stability have become key points in TB breeding. Based on the above findings, excellent, potentially valuable TB lines with rich phenotypes were obtained for the TB mutation library via ethyl methanesulfonate (EMS), laying a foundation for creating new TB germplasms. In this study, we systematically investigated more than 10 agronomic traits of JQ2 and JQ4 mutants, including plant type, leaf colour, grain type, grain colour, grain number per plant, grain length, grain width, grain weight per plant, and 1000-grain weight. The results show that the maximum number of grains per plant was 1956, the weight was 32.84 g, and the 1000-grain weight was 30.89 g. The maximum number of grains per JQ4 plant was 2308, and the weight was 44.82 g. The maximum 1000-grain weight was 24.7 g. Among the 295 JQ2 mutants and 153 JQ4 mutants, 10 flavonoids (orientin, morin, quercetin, kaempferol, luteolin, naringin, hesperetin, myricetin, hesperidin, and rutin) were detected with near infrared spectroscopy (NIR). The mutants were divided into five groups according to the flavonoid content of the JQ2 mutants, of which the first group included 31 individual lines. and the second to fifth groups included 70, 69, 72, and 53 lines, respectively. The JQ4 mutants were divided into four classes, of which 41, 50, 32, and 30 were individual lines, respectively, with the highest rutin content being 82.06 mg/g. In summary, through systematic analysis and screening of the agronomic traits and flavonoid contents of JQ2 and JQ4 mutant seeds, we obtained three lines with a high 1000-grain weight, including two JQ2 mutant lines (30.89 g) and one JQ4 mutant line, which reached 24.70 g and ten lines with high grain weight per plant. This included 8 JQ2 mutants and 2 JQ4 mutants, as well as 72 high-rutin mutants (including 31 lines from JQ2 and 41 lines from JQ4 mutants). These elite lines provide the material basis for creating TB germplasms with excellent qualities and cultivation characteristics.

Mutations in BrABCG26, encoding an ATP-binding cassette transporter, are responsible for male sterility in Chinese cabbage (Brassica rapa L. ssp. pekinensis).

The gene BrABCG26 responsible for male sterility of Chinese cabbage was confirmed by two allelic mutants. Male-sterile lines are an important way of heterosis utilization in Chinese cabbage. In this study, two allelic male-sterile mutants msm3-1 and msm3-2 were obtained from a Chinese cabbage double haploid (DH) line 'FT' by using EMS-mutagenesis. Compared to the wild-type 'FT,' the stamens of mutants were completely degenerated and had no pollen, and other characters had no obvious differences. Cytological observation revealed that the failure of vacuolation of the mononuclear microspore, accompanied by abnormal tapetal degradation, resulted in anther abortion in mutants. Genetic analysis showed thata recessive gene controlled the mutant trait. MutMap combined with kompetitive allele specific PCR genotyping analyses showed that BraA01g038270.3C, encoding a transporter ABCG26 that played a vital role in pollen wall formation, was the candidate gene for msm3-1, named BrABCG26. Compared with wild-type 'FT,' the mutations existed on the second exon (C to T) and the sixth exon (C to T) of BrABCG26 gene in mutants msm3-1 and msm3-2, leading to the loss-of-function truncated protein, which verified the BrABCG26 function in stamen development. Subcellular localization and expression pattern analysis indicated that BrABCG26 was localized in the nucleus and was expressed in all organs, with the highest expression in flower buds. Compared to the wild-type 'FT,' the expressions of BrABCG26 were significantly reduced in flower buds and anthers of mutants. Promoter activity analysis showed that a strong GUS signal was detected in flower buds. These results indicated that BrABCG26 is responsible for the male sterility of msm3 mutants in Chinese cabbage.

Above and belowground phenotypic response to exogenous auxin across Arabidopsis thaliana mutants and natural accessions varies from seedling to reproductive maturity.

Plant hormones influence phenology, development, and function of above and belowground plant structures. In seedlings, auxin influences the initiation and development of lateral roots and root systems. How auxin-related genes influence root initiation at early life stages has been investigated from numerous perspectives. There is a gap in our understanding of how these genes influence root size through the life cycle and in mature plants. Across development, the influence of a particular gene on plant phenotypes is partly regulated by the addition of a poly-A tail to mRNA transcripts via alternative polyadenylation (APA). Auxin related genes have documented variation in APA, with auxin itself contributing to APA site switches. Studies of the influence of exogenous auxin on natural plant accessions and mutants of auxin pathway gene families exhibiting variation in APA are required for a more complete understanding of genotype by development by hormone interactions in whole plant and fitness traits. We studied Arabidopsis thaliana homozygous mutant lines with inserts in auxin-related genes previously identified to exhibit variation in number of APA sites. Our growth chamber experiment included wildtype Col-0 controls, mutant lines, and natural accession phytometers. We applied exogenous auxin through the life cycle. We quantified belowground and aboveground phenotypes in 14 day old, 21 day old seedlings and plants at reproductive maturity. We contrasted root, rosette and flowering phenotypes across wildtype, auxin mutant, and natural accession lines, APA groups, hormone treatments, and life stages using general linear models. The root systems and rosettes of mutant lines in auxin related genes varied in response to auxin applications across life stages and varied between genotypes within life stages. In seedlings, exposure to auxin decreased size, but increased lateral root density, whereas at reproductive maturity, plants displayed greater aboveground mass and total root length. These differences may in part be due to a shift which delayed the reproductive stage when plants were treated with auxin. Root traits of auxin related mutants depended on the number of APA sites of mutant genes and the plant's developmental stage. Mutants with inserts in genes with many APA sites exhibited lower early seedling belowground biomass than those with few APA sites but only when exposed to exogenous auxin. As we observed different responses to exogenous auxin across the life cycle, we advocate for further studies of belowground traits and hormones at reproductive maturity. Studying phenotypic variation of genotypes across life stages and hormone environments will uncover additional shared patterns across traits, assisting efforts to potentially reach breeding targets and enhance our understanding of variation of genotypes in natural systems.

Genetic analysis and characterisation of Cmowf, a gene controlling the white petal colour phenotype in pumpkin (Cucurbita moschata D)

AbstractFlower colour, as an important morphological marker, plays an essential role in improving the identification efficiency of the purity seed in hybrid production. However, the molecular mechanism of white‐flower trait has not been reported in pumpkin (Cucurbita moschata D.). In this study, we obtained a white‐flower mutant (wf) through the ethyl methane sulfonate (EMS) mutagenesis of inbred line N87 (yellow flower). F2 populations were then constructed by crossing wf mutant and N87 plant to fine map the genes controlling white‐flower trait in pumpkin. Phenotypic identification revealed that carotenoid content significantly decreased in the petals of wf mutants compared with N87 plants. Genetic analysis indicated that the white flower mutant trait was controlled by a single recessive gene, Cmowf. Using bulked segregant analysis and KASP phenotyping, Cmowf was mapped to a 762 kb region on chromosome 14 containing three annotated genes. Among them, a nonsynonymous single‐nucleotide polymorphisms mutation was identified only in CmoCh14G005820 gene, which encoded a DUF1997 family protein. Compared with CmoDUF1997 amino acid sequences between the wf mutants and N87 plants, the critical amino acid mutations (early termination of amino acids) occurred in wf mutants, so CmoCh14G005820 was predicted as a potential candidate for controlling the white‐flower trait. RNA‐sequencing analysis revealed that the expression of CmoCh14G005820 and most genes involved in carotenoid biosynthesis was significantly downregulated in wf mutants, whereas the expression of several genes responsible for carotenoid degradation was upregulated in wf mutants. This finding suggested that carotenoid metabolism may participate in the formation of flower colour in pumpkin. Overall, our results provided a theoretical basis for understanding the genetic mechanisms underlying white‐flower formation in pumpkin.

Allelic variants of CYP2B6 gene expression and its implication on the pathogenesis of malaria among a cohort of outpatients in North-Central Nigeria

Abstract Background Human cytochrome P450 2B6 (CYP2B6) is fortified with the biotransformation of the antimalarial, artemisinin combination therapy (ACT). Owing to emerging reports of Plasmodium species resistance to ACT in other climes, CYP2B6*6 genotype significantly alters ACT metabolism. In North-Central Nigeria, the distribution of the CYP2B6*6 variant is poorly documented. This study investigated the distribution of CYP2B6 c.516G>T variants and its relationship with certain malaria pathogenesis among a cohort of clinical-malaria outpatients in Ilorin, Nigeria. Methods A total of 50 symptomatic P. falciparum malaria-positive samples were genotyped for CYP2B6 c.516G>T using restriction fragment length polymorphism and a specific haplotype population was established. The allele frequencies and genotype distributions were analyzed. Haplotypes were clustered using Ward’s method. Correlations determined include defective CYP2B6 versus parasitemia densities and thrombocytopenia, respectively. Results Forty-five samples show genotypic ratios and nine CYP2B6 genetic single nucleotide polymorphisms were identified. The following haplotypes (64C>T = *1/*2, 785A>G = *1/*4, and 1459C>T = *1/*5) occurred and *2, *3, and *18 alleles harbor 64C>T, 777C>A, −82T>C, and 499C>G. The codon 64CT, 516GT, and 785AG; −82TC and 777CA; and 499CG, 516GT, and 785AG were identified as *2/*6 heterozygotes. Samples with 516GT and 785GG genotypes occurred with *4/*6 heterozygotes. Mutant trait alleles recorded high parasitemia 72 h post-ACT regimen. Only individuals with CYP2B6*6 alleles had severe malaria and thrombocytopenia. Conclusion This report contributes to the growing knowledge of CYP2B6*6 genotype frequency and its relationship with malaria pathogenesis among a Nigerian population.

The speed of invasion in an advancing population

We derive rigorous estimates on the speed of invasion of an advantageous trait in a spatially advancing population in the context of a system of one-dimensional F-KPP equations. The model was introduced and studied heuristically and numerically in a paper by Venegas-Ortiz et al. (Genetics 196:497–507, 2014). In that paper, it was noted that the speed of invasion by the mutant trait is faster when the resident population is expanding in space compared to the speed when the resident population is already present everywhere. We use the Feynman–Kac representation to provide rigorous estimates that confirm these predictions.

A glossy mutant in onion (Allium cepa L.) shows decreased expression of wax biosynthesis genes.

Cuticular wax is a characteristic feature of land plants that provides protection against both biotic and abiotic stresses. In this study, a glossy mutant lacking an epicuticular wax layer was identified in the γ-irradiated M2 mutant population of the onion cultivar Bhima Super. The inheritance of the mutant's glossy phenotype was determined to be recessive and single locus. Scanning electron microscopy analysis showed poor accumulation of wax crystals in the glossy mutant, concentrated near the stomata. The plant height, number of leaves per plant, and stomatal parameters of the mutant were similar to the wild-type. RNA-seq was used to comprehend the expression variations of waxy cuticle-related genes in the glossy mutant and its wild-type waxy cultivars. Differential gene expression analysis of the RNA-seq data revealed that the genes involved in wax biosynthesis, such as AcCER1, AcCER26, AcMAH1, and AcWSD1, were downregulated by 2.72, 1.74, 2.59 and 2.12-fold, respectively, in the glossy mutant respectively. The expression patterns of these four unigenes were validated using semi-quantitative RT-PCR. The glossy mutant displayed a substantial 3.5-fold reduction in cuticular wax load compared to the wild-type due to the significant downregulation of these wax biosynthesis genes. These findings represent early advancements in understanding the molecular mechanisms of wax biosynthesis in onions. Furthermore, they provide a foundation for utilizing the glossy mutant trait in breeding programmes to enhance stress and pest resilience.

Genetic Variability and Diversity for Yield and Yield Attributing Traits in M3 and M4 Generations of Butter Bean (Phaseolus lunatus L.)

Background: Butter beans (Phaselous lunatus L) belong to the family Leguminaceae, is one of the oldest cool season food legume crops. A throughout knowledge of existing genetic variation among yield and its yield component traits is essential for developing high yielding varieties in butter bean. Realizing the importance of genetic diversity and variability in key economic characters, the present investigation had been planned to assess the genetic diversity and variability in for yield improvement in butter bean breeding programme. Methods: Investigation was carried at Horticultural Research Station, Tamil Nadu Agricultural University, Kodaikanal, Tamil Nadu during 2019-2021. A total of 2734 M2 mutant lines were evaluated as individual progenies in the previous study. Stringent selection was made based on yield, earliness and plant habit and a total of 35 mutant lines were identified and forwarded to M3 and a total of 12 mutant lines for M4 generations in present study. The data on elevan quantitative were analyzed using Mahalanobis D2 statistic. Result: The present study has assessed the genetic variation among studied traits of butter bean mutants for yield and its component traits. Thus, a total of five mutant lines namely BBMG-7-9-7, BBMG-9-10-6, BBMG-18-9-6, BBMG-25-13-3, BBMG-35-7-2 were identified to be forward to the M5 generation as promising mutant lines for developing high yielding varieties and to test its homogeneity and stability.

Qualitative mutant traits within the indigenous chicken population in selected ecological zones of Ghana

A study was carried out to find out the various mutant traits present in the indigenous chicken population and their influence on egg production in the three ecological zones of Ghana. Four hundred and five (405) households were purposively selected across the Guinea Savannah, Semi-deciduous Rain Forest and Coastal Savannah ecological zones. Structured questionnaire and on-site interviews were used to obtain information from the local chicken keepers. The individual birds were phenotypically observed for the presence of the following genes; frizzle, naked neck, silkiness, polydactyl, ptilopody, crest feathered and flightless. Data on flightless chickens were not available except their gene frequencies since the respondents do not keep them for economic purposes. The data collected were organised and analysed such that phenotypic groups were considered as treatments and ecological zones as blocks. The frequency of the genes responsible for mutant traits were obtained from a count of the proportion of recessive in the sample using the Hardy Weinberg rule. The calculated gene frequencies for the mutant traits observed within the local chicken population ranged from 0.01 to 0.05 which differed significantly (p<0.05) from the expected Mendelian values of 0.75. Average clutch size per year, number of eggs set and chicks hatched per natural incubation were not significantly different (p>0.05) among the three ecological zones. The percentage hatchability for Guinea savannah and Coastal savannah were relatively higher compared to Semi-deciduous rain forest. In terms of phenotypes, polydactyl birds were significantly better (p<0.05) in average eggs per clutch per bird, number of eggs set for natural incubation and number of chicks hatched. Despite the low frequencies of these mutant birds, they had a higher potential for egg laying compared to their recessive counterparts.

Design of high-monounsaturated fatty acid soybean seed oil using GmPDCTs knockout via a CRISPR-Cas9 system.

Design of high-monounsaturated fatty acid soybean seed oil using GmPDCTs knockout via a CRISPR-Cas9 system.

Fine Mapping of a Pleiotropic Locus (BnUD1) Responsible for the Up-Curling Leaves and Downward-Pointing Siliques in Brassica napus

Leaves and siliques are important organs associated with dry matter biosynthesis and vegetable oil accumulation in plants. We identified and characterized a novel locus controlling leaf and silique development using the Brassica napus mutant Bnud1, which has downward-pointing siliques and up-curling leaves. The inheritance analysis showed that the up-curling leaf and downward-pointing silique traits are controlled by one dominant locus (BnUD1) in populations derived from NJAU5773 and Zhongshuang 11. The BnUD1 locus was initially mapped to a 3.99 Mb interval on the A05 chromosome with a BC6F2 population by a bulked segregant analysis-sequencing approach. To more precisely map BnUD1, 103 InDel primer pairs uniformly covering the mapping interval and the BC5F3 and BC6F2 populations consisting of 1042 individuals were used to narrow the mapping interval to a 54.84 kb region. The mapping interval included 11 annotated genes. The bioinformatic analysis and gene sequencing data suggested that BnaA05G0157900ZS and BnaA05G0158100ZS may be responsible for the mutant traits. Protein sequence analyses showed that the mutations in the candidate gene BnaA05G0157900ZS altered the encoded PME in the trans-membrane region (G45A), the PMEI domain (G122S), and the pectinesterase domain (G394D). In addition, a 573 bp insertion was detected in the pectinesterase domain of the BnaA05G0157900ZS gene in the Bnud1 mutant. Other primary experiments indicated that the locus responsible for the downward-pointing siliques and up-curling leaves negatively affected the plant height and 1000-seed weight, but it significantly increased the seeds per silique and positively affected photosynthetic efficiency to some extent. Furthermore, plants carrying the BnUD1 locus were compact, implying they may be useful for increasing B. napus planting density. The findings of this study provide an important foundation for future research on the genetic mechanism regulating the dicotyledonous plant growth status, and the Bnud1 plants can be used directly in breeding.

Mutation of OsLPR3 Enhances Tolerance to Phosphate Starvation in Rice.

Low Phosphate Root (LPR) encodes a protein localized to the endoplasmic reticulum (ER) and cell wall. This gene plays a key role in responding to phosphate (Pi) deprivation, especially in remodeling the root system architecture (RSA). An identification and expression analysis of the OsLPR family in rice (Oryza sativa) has been previously reported, and OsLPR5, functioning in Pi uptake and translocation, is required for the normal growth and development of rice. However, the role of OsLPR3, one of the five members of this family in rice, in response to Pi deficiency and/or in the regulation of plant growth and development is unknown. Therefore, in this study, the roles of OsLPR3 in these processes were investigated, and some functions were found to differ between OsLPR3 and OsLPR5. OsLPR3 was found to be induced in the leaf blades, leaf sheaths, and roots under Pi deprivation. OsLPR3 overexpression strongly inhibited the growth and development of the rice but did not affect the Pi homeostasis of the plant. However, oslpr3 mutants improved RSA and Pi utilization, and they exhibited a higher tolerance to low Pi stress in rice. The agronomic traits of the oslpr3 mutants, such as 1000-grain weight and seed length, were stimulated under Pi-sufficient conditions, indicating that OsLPR3 plays roles different from those of OsLPR5 during plant growth and development, as well as in the maintenance of the Pi status of rice.

Correlation and Path Analysis Studies for Yield and Quality Traits of Rice Landraces and Mutants of Chhattisgarh, India

Background: The production of rice needs to grow as this is one of the major objective in plant improvement program to fulfill the requirement of the rapidly growing population.&#x0D; Objective and Methods: The field experiment was conducted to study character association among yield and its attributes among 58 rice genotypes at Indira Gandhi Krishi Vishwavidyalaya, College of Agriculture, Raipur (C.G.) to know the relationship among characters.&#x0D; Results: it is found out that Traits like panicle weight per plant, filled spikelets per panicle, harvest index, and biological yield per plant are having a high direct effect and significant correlation with grain yield per plant, and traits like milled grain length-width ratio, hulling %, and alkali spreading value are having a high direct effect and significant correlation with head rice recovery.&#x0D; Conclusions: Direct selection based on these traits for improvement of rice grain yield and grain quality can be effective.