In this study, molecular-genetic analyses were carried out to identify resistance to yellow rust (
Winged bean (
Carbohydrates and genetic factors influence cell division in citrus fruits from ovule cultures. Here, we investigated the effects of various carbohydrate sources (sorbitol, maltose, galactose, and lactose) on cell proliferation, somatic embryogenesis, and plant regeneration in three
Black sapote (
The genetic control of rice resistance has been extensively studied, but how the resistance mechanism is genetically controlled has received less attention. This study revealed that the rice resistance mechanism toward brown planthopper was genetically controlled by several genes with several mendelian patterns. The tolerance mechanism is controlled by three complementary genes; this is confirmed by QTL analysis, whereas the Antibiosis is controlled by three separate loci on chromosomes 2, 8, and 11. The antixenosis was controlled by polygenic, but detected locus only on chromosome 3, with minor effects.
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Bread wheat
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Plant breeding relies on genetic variation to produce new and improved cultivars. One way to obtain novel traits is by inducing mutations. The present study aimed to create a Fusarium crown rot (FCR) and Fusarium head blight (FHB)-resistant mutagenized wheat population using ethyl methane sulphonate (EMS) and identify mutant resistance to FCR and FHB, which could provide a starting point for resistance breeding. The optimal mutagenesis conditions were determined based on the germination percentage. This study used six Chinese wheat cultivars, namely Jimai22, Hengguan35, Shixin828, Gaoyou2018, Keiwei20, and Keiwei18, to create a mutant population by treating them with EMS. For Shixin828, the optimal condition was 0.8% EMS with a 50-55% germination rate. For Hengguan35 and Jimai22, it was 0.6% EMS. For Gaoyou2018 and Kewei20, it was 0.8% and 0.4-0.6%, respectively. The FCR disease index of the mutant lines (M1) ranged from 10.00 to 77.67. For M2, the number of individual mutant plants demonstrating resistance to FCR varied from 76 to 102. In M3, 570 healthy plants were obtained using various EMS concentrations. The mutant line Kewei18 demonstrated the most resistance to FCR, FHB, and Deoxynivalenol (DON) infection. Kewei20 mutants had a higher FHB susceptibility than other mutants. Overall, mutants from the Kewei18 genetic background displayed better disease resistance to both diseases and DON contamination than natural plants. Mutants with or moderate resistance to FCR and FHB could be used in breeding and genetic studies to identify FHB and FCR-resistant Quantitative Trait Locus (QTL) in wheat.
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The genus
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Hybridization studies and reciprocal crosses were carried out on
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Drought tolerance is derived from complex quantitative traits that are associated with different shoot and root morphological characters. This study assessed the genetic and phenotypic variation of 12 maize inbred lines and performed association analysis of 11 drought-related traits using 360 simple sequence repeats (SSRs), detecting 1,604 alleles, with an average of 4.4 alleles per locus. The average values of gene diversity (GD) and polymorphism information content (PIC) were 0.648 and 0.598, respectively. In principal component analysis (PCA), shoot fresh weight (SFW), shoot dry weight (SDW), stem weight (SW), leaf weight (LW), root fresh weight (RFW), root dry weight (RDW), and leaf area (LA) traits contributed greatly to the PCA. Association analysis was performed using a general linear model with a Q-matrix (Q GLM) and a mixed linear model with Q and K-matrices (Q + K MLM). Twelve SSR markers for drought tolerance trait were detected by Q GLM, and all maize inbred lines were clearly divided into two groups in accordance with their drought tolerance. Duplicated significant marker-trait associations (SMTAs) between Q GLM and Q + K MLM identified eight marker-trait associations involving four SSR markers that were associated with the traits of SW, SFW, RFW, and RDW with a significant level of
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The coffee value chain is a source of livelihood for millions of people across the world and yet the resilience of coffee is limited by the relatively narrow genetic base among commercial coffee cultivars. A study was conducted to determine genetic variation, heritability estimates and relationships among coffee genotypes in Zimbabwe. Quantitative morphological characteristics of twelve genotypes were recorded under field conditions. There were significant variations in coffee yield, plant height, stem girth, number of primary branches, number of bearing branches, internode length and leaf characteristics, with no significant variations in seed characteristics and number of nodes. Broad sense heritability estimates for the quantitative traits ranged from 0.03% to 91.4%, being highest for plant height, coffee yield, stem girth, leaf length and leaf area. The implications are that coffee yield and plant height are independent of significant environmental influences while seed, branching traits and leaf traits are influenced by the environment in their expression. Yield was significantly correlated to branches per plant, plant height, seed traits and stem girth. Clustering of genotypes was influenced by plant height, yield and stem girth. Overall, few traits were important in distinguishing coffee genotypes, implying narrow diversity. Hybridization, further introductions from other producer countries, coffee gene banks and/or introductions from the wild, and concerted germplasm conservation efforts are recommended.
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The number of four-seeded pods is a plant trait that is of great interest in terms of increasing soybean production. The
objective
of this study was to understand the agronomic characteristics of four-seeded pods of FS1159, which contain a significantly higher ratio of four-seeded pods than do other genotypes. FS1159 showed a significantly lower ratio of one- and two-seeded pods and a significantly higher ratio of three- (39.6%) and four- (11.3%) seeded pods than did the four check soybeans. The average values of the traits of FS1159 in this study were: plant height, 58.1 cm; the number of nodes, 15.7; the number of branches, 6.5; and 100-seed weight, 20.3 g. These results indicate that FS1159 can be used as a new genetic resource to explore the traits of four-seeded-pod and improve the soybean yield.
Cultivation of the medicinal herb
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Squash (
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This study estimated the genetic variability and gene action of several traits in the F4 and F5 rice populations to determine a trait for selection program. The trait of date to flowering and date to harvesting had narrow genetic variability, whereas trait productive tillers, number of fertile grain, and total grains had moderate to wide genetic variability. Genetic variability in trait number of fertile grain and total grains showed decreased in F5 generation compare to the F4 generation, whereas trait productive tillers, date to flowering, and date to harvesting showed an increase. Additive gene action with duplicate and complementary epistasis was found in all traits, except for trait productive tillers only showed additive gene action with duplicate epistasis. Kurtosis less than 3 was found in all traits which indicate many genes control the traits. The number of fertile grain trait showed wide genetic variability which decreased in F5 generation compare to the F4 generation, and there is an additive gene action with duplicate epistasis. It indicates selection will be effective with the trait of number of fertile grain.
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First initiation of breeding started thousands of years ago when human practiced selection based in visually appealing traits. Further, domestication of wild plants eased adaptation of plant breeding. With increase in population the demand for food also increased which resulted in development of various breeding methodologies. Conventional breeding is a selective breeding methodology where crops are selected based on superior performances. Pure-line selections, mass selection, back cross breeding, recurrent selection, hybridization were most famous traditional breeding methods. It is a longer breeding method and is over-dependent on phenotype of plants. However, phenotypes of a plant are affected by various externalities. So, selection based on phenotypic expression is not accurate. As a result, breeder started integrating various branches of biology in plant breeding and developed modern breeding practices. After Mendelian theory and identification of DNA and RNA, plant breeding diverted to molecular era. People started breeding based on less environmentally susceptible parameters like genotypes, visual and genetic markers, image analysis and loci mapping. Some of the most common modern breeding practices include genomic selection, markers assisted breeding, high throughput phenotyping and CRISPR-Cas9. Despite these, plant breeding has fired up the problems of gene erosion due to loss of local landraces and wild-type plants.
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Six durum and twelve bread wheat genotypes were evaluated under favorable and drought-stressed field conditions, and screened with thirty simple sequence repeats (SSR) markers. The traits studied were stomata frequency (STF), relative water content (RWC), flag leaf area (FLA), flag leaf weight (FLW), flag leaf dry matter content (FLD), chlorophyll a content (Chl.a), chlorophyll b content (Chl.b), grain yield/plant (GYP) and 1000-kerenl weight (TKW). Highly significant differences were observed among wheat genotypes for all the traits, indicating considerable genetic variation. Moderate to high broad-sense heritability estimates were observed for the studied traits. Under drought stress, GYP was positively correlated with RWC, FLA, FLW and TKW, whereas negatively correlated with STF. G3 (Svevo) and G6 (WK-12-1) were the most drought-tolerant durum wheat, whereas G11 (L.S-15) and G16 (SIDS-1) were the most drought-tolerant bread wheat genotypes. SSR markers analysis indicated considerable genetic variation between and within durum and bread wheat genotypes. The percentage of polymorphism ranged from 14.3% (Xgwm174-5D) to 100% (Xgwm294-2A and Xgwm573-7B), with an average of 61.4%. The polymorphism information content (PIC) ranged from 0.20 (Xwmc596-7A) to 0.48 (Xgwm294-2A), with an average of 0.33.The highest polymorphism (77.1%) was observed in the B genome followed by A (57.8%) and D (50.0%) genomes. Cluster analysis based on phenotypic data distinguished the most drought-tolerant genotypes (G6 and G11) from the remaining genotypes. Cluster analysis based on SSR markers distinguished durum from bread wheat genotypes. The study indicated that phenotypic data and SSR markers were effective in assessing the genetic diversity in the studied genotypes.
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Faba bean is amongst the most important food legumes in the world. Ninety landraces and six released faba bean accessions were evaluated for variability parameters, correlation, and path coefficients for nineteen traits at two locations over two years. There were significant differences (
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Water deficit is a critical factor obstructing the growth and survival of plant. Therefore, researchers have been trying to develop drought-resistant varieties. To find indicators of drought stress-tolerance of cypress (
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One of approaches to maintain the yield stability of the lowland tropical wheat is the use of secondary traits in the selection process. The identification of these characters requires a statistical approach in the form of genetic parameter analysis and multivariate analysis. The
objective
of this study was to determine the secondary traits of adaptive wheat mutants in the lowlands through the use of genetic parameters and multivariate analysis on the parameters. The study consisted of three field trials conducted in three different regencies, namely Jeneponto (135 m above sea level (asl)), Maros (100 m asl) and Bantaeng (125 m asl). The study used a nested design, where replications were nested in the environments. The genotype factors consisted of 20 genotypes repeated three times. 11 characters were observed including vegetative and reproductive characters. The analysis used consisted of repeatability, correlation, cluster analysis, principal component analysis, factor analysis, and cross print analysis. The overall results of the analysis indicate that the number of productive tillers is the main secondary trait for the selection of adaptive wheat in the lowlands. The character can be recommended for selection criteria in testing wheat lines in the lowlands to make an effective selection.
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Knowledge of genetic resources is essential for breeders to create new crop varieties with improved characteristics. In this respect, mutant populations may conveniently provide a powerful tool for identifying new functional genes. Therefore, we used the Micro-Tom tomato variety, which has a reduced size and a relatively short life-cycle compared to other commercial tomato cultivars, to construct a mutant population using gamma-ray radiation as a mutagen. To determine the optimal mutagenic intensity of gamma rays for tomato, dry seeds of Micro-Tom were irradiated with gamma-ray intensities from 0 to 1000 gray (Gy) with increments of 100 Gy. The germination rate of mutagenized seeds (M1 seeds) on MS media was not affected by the tested gamma-ray intensity range. However, seedling growth was severely reduced with increasing irradiation. Seedling growth rate at eight days after germination showed that the median gamma-ray doses for hypocotyl and root elongation were 600 and 300-400 Gy, respectively. The survival test for 300, 400, and 500 Gy-treated M1 seeds showed that survival rates significantly decreased with increasing irradiation. The survival rate of 400 Gy-radiated seeds was 48%, while that of 500 Gy-radiated seeds was only 25%, compared with the control treatment. Therefore, we concluded that gamma-ray irradiation at 300-400 Gy is best for tomato mutagenesis. To find new mutants, M2 seeds produced by M1 plants were grown. We found several mutants, including plants with varying cotyledon number, variegated or red leaves, and green hypocotyls.
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Mutation is an effective strategy not only for creating novel variation into crop genome but also for direct releasing adapted and high-yielding genotypes. The current work explores inducing genetic variability in bread wheat using physical and chemical mutagens. Three wheat cultivars were treated by three mutagens; gamma irradiation (five doses; 250, 300, 350, 400 and 450 Gray); laser ray (three treatments; 1, 1.5, and 2 hour exposure) and EMS (three concentrations; 0.2, 0.3 and 0.4%). Besides, a combination of physical (laser) and chemical (EMS) mutagens using middle range of each treatment (1.5 hour laser and 0.3% EMS) was attempted to be applied. The treated seeds were sown in the first season and 4050 M1 plants were harvested. The harvested seeds were sown in the second season, and 78750 M2 plants were obtained. The selection was performed in second season (M2) based on morpho-physiological and yield traits; flag leaf area, flag leaf chlorophyll content, plant height, spike length, grain yield per plant and its components. Based on evaluated traits fourteen mutants were selected to be evaluated in the third generation (M3). The results indicated that the used mutagens had direct impact and significantly improved agronomic traits in derivative mutants compared to their parent cultivars. Moreover, the maximum increment in yield related traits were obtained by 0.4% EMS, 1 and 2 hour-laser, 350-Gy, 1.5 hour × 0.3% EMS and 250-Gy. The obtained results highlighted the importance of these doses of applied mutagens to induce useful genetic variability in bread wheat for improving grain yield and contributing traits.
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Bitter gourd is an important vegetable of the family Cucurbitaceae, cultivated mainly in humid and subtropical Asia. Bitter gourd is a vegetable with immense health benefits due to the presence of medicinal compounds such as charantin, vicine, and polypeptide-p, which play essential roles in lessening blood glucose levels. Moreover, bitter gourd fruits are particularly rich in vitamin C, minerals, and carotenes. Here, an effort has been made to critically evaluate the extent of achievements during the enhancement and enactment of bitter gourd breeding programs with the use of latest technologies. Broadening the genetic base of cultivated bitter gourd varieties as a result of enrichment of existing resources by using wild species in breeding programs. Practical seed production technological know-how along with the use of the MS system (male sterility)/chemical-induced sterility procedure is nonetheless vital to cope with market demands. Superior yielding bitter gourd hybrids combining early maturity and resistance to biotic and abiotic stresses are regularly needed to cope with the challenge of bitter gourd production.
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The integration of advanced technologies into breeding programs in the 21st century can result in a powerful step change in crop productivity when aligned with components of genetic gain. Genetic gain depends upon four factors: accuracy, selection intensity, genetic variation, and time. It is a useful starting point, as it articulates the parameters breeders operate as part of the crop improvement process. This review article has compiled advanced breeding technologies such as phenomics, genotyping and se-quencing platforms, genome editing, and double haploid, which can be applied to each component of the genetic gain equation. In addition, it has explained the strategies, opportunities, and limitations in order to support breeders in making wise decisions in regard to the technologies and therefore increase efficiency with the breeding programs.
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Fonio, known to be the smallest and oldest form of millet grown in sub-Saharan Africa, has remained relatively poor of research despite its nutritional, sociocultural, agroecological, therapeutic and economic potentials. Based on systematic literature review, this critical study showed that fonio genetic breeding progress is at a low level. Genetic resources are threatened by erosion, particularly extra-early cultivars of
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Spotted leaf mutants which produce necrotic lesions spontaneously are important sources to study programmed cell death in plant defense responses. A novel white-spotted leaf (
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Field evaluation of 33 Bambara groundnut lines were carried out to estimate genetic variability, heritability and genetic advance. One-way analysis of variance (ANOVA) result showed significant differences for 14 of the 17 agronomic traits studied. The results on the variance components revealed that phenotypic variance had values (vigour index 2.30, pod length 10.09, seed length 1.64) that were slightly higher than the respective genotypic variance (vigour index 1.68, pod length 9.88, seed length 0.26). Similarly, the values (number of branches 41.91, number of nodes 68.72, internode length 59.02) of phenotypic coefficient of variation (PCV) were slightly higher than the corresponding genotypic coefficient of variation (GCV) (number of branches 40.11, number of nodes 66.98, internode length 57.31), suggesting a substantial genetic variability that can serve as a base for Bambara groundnut improvement. High estimates of heritability were observed for most characters like number of branches (95.70%), number of nodes (97.46%), internode length (97.10%), pod length (97.91%), and seed length (93.79%). Likewise, genetic advance values for most traits were high, pod length (201), number of nodes (200), internode length (200), number of branches (197) and seed yield (195), implying that improvement of seed yield in Bambara groundnut can be achieved through direct selection.
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In salinity affected areas, variation in salinity level is the major cause of yield fluctuations in rice during the dry season (
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Since traditional taxonomic studies possess intrinsic limitations with plant species identification, combinations of DNA barcodes have been considered a powerful tool to discover undetected genetic variation within species across large geographic areas, providing more precise estimates of biodiversity. However, the lack of efficient and universal markers is often considered a peculiar challenge in molecular taxonomic studies across plant taxa. Similarly, many loci have been proposed for DNA barcodes; still standardizing regions as a DNA barcode is vital for making them efficiently discriminate plant species. In this study, we tested the phylogenetic utility of nuclear (nrDNA) region (ITS2) with chloroplast (cpDNA) regions (
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High-throughput molecular markers with high genotyping accuracy will be helpful for genetic analysis, mapping of interesting genes, and rice breeding program. To develop high-throughput and cost-effective molecular markers for Korean
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