Direct Classification and Selection of Superior Alleles for Crop Improvement

Crop Science ◽  
1997 ◽  
Vol 37 (3) ◽  
pp. 691-697 ◽  
Author(s):  
Mark E. Sorrells ◽  
William A. Wilson
Genes ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1407
Author(s):  
Larisa N. Efremova ◽  
Svetlana R. Strelnikova ◽  
Guzel R. Gazizova ◽  
Elena A. Minkina ◽  
Roman A. Komakhin

Synthetic promoters are vital for genetic engineering-based strategies for crop improvement, but effective methodologies for their creation and systematic testing are lacking. We report here on the comparative analysis of the promoters pro-SmAMP1 and pro-SmAMP2 from Stellaria media ANTIMICROBIAL PEPTIDE1 (AMP1) and ANTIMICROBIAL PEPTIDE2 (AMP2). These promoters are more effective than the well-known Cauliflower mosaic virus 35S promoter. Although these promoters share about 94% identity, the pro-SmAMP1 promoter demonstrated stronger transient expression of a reporter gene in Agrobacterium infiltration of Nicotiana benthamiana leaves, while the pro-SmAMP2 promoter was more effective for the selection of transgenic tobacco (Nicotiana tabacum) cells when driving a selectable marker. Using the cap analysis of gene expression method, we detected no differences in the structure of the transcription start sites for either promoter in transgenic plants. For both promoters, we used fine-scale deletion analysis to identify 160 bp-long sequences that retain the unique properties of each promoter. With the use of chimeric promoters and directed mutagenesis, we demonstrated that the superiority of the pro-SmAMP1 promoter for Agrobacterium-mediated infiltration is caused by the proline-inducible ACTCAT cis-element strictly positioned relative to the TATA box in the core promoter. Surprisingly, the ACTCAT cis-element not only activated but also suppressed the efficiency of the pro-SmAMP1 promoter under proline stress. The absence of the ACTCAT cis-element and CAANNNNATC motif (negative regulator) in the pro-SmAMP2 promoter provided a more constitutive gene expression profile and better selection of transgenic cells on selective medium. We created a new synthetic promoter that enjoys high effectiveness both in transient expression and in selection of transgenic cells. Intact promoters with differing properties and high degrees of sequence identity may thus be used as a basis for the creation of new synthetic promoters for precise and coordinated gene expression.


Author(s):  
K. Shruthi ◽  
R. Siddaraju ◽  
K. Naveena ◽  
T.M. Ramanappa ◽  
C. Gireesh ◽  
...  

Background: Identification of suitable factors that influence significantly to the response is crucial for the traits based breeding program to make a better decision about improvement in productivity. Multiple linear regression (MLR) is the benchmark method commonly using to identify suitable factors for crop improvement. It doesn’t work always due to stringent assumption (Multicollinearity, Linearity) behind the MLR model. Here we tried to develop an efficient model for the selection of major traits that contribute to seed yield in soybean by comparing different models.Methods: Field experiment was conducted using 98 soybean core population through augmented design.18 morphometric traits obtain from soybean core population were considered under the study as regressors.Multiple linear regression (MLR), Principle component Regression (PCR), Regression tree and Random Forest models were compared to select traits based on prediction accuracy.Result: All the models identified the number of pods per plant (NPP) has the most influencing variable to the soybean yield. However random forest has a much higher prediction power (RMSE=4.59, MAPE=0.18) compared to other models under study. The results of random forest revealed that the number of pods per plant, number of branches per plant and other associated characters like plant height at harvest as highly influencing traits for seed yield in soybean.Finally, tried to identify genotypesthat possess superiority about most influencing morphological characters on seed yield using cluster analysis.


2016 ◽  
Vol 67 (6) ◽  
pp. 605 ◽  
Author(s):  
Vasileios Greveniotis ◽  
Vasilia A. Fasoula

Innovative approaches and new efficiencies in plant breeding are required to accelerate the progress of genetic improvement through selection. One such approach is the application of prognostic breeding, which is an integrated crop-improvement methodology that enables selection of plants for high crop yield potential by evaluating its two components: plant yield potential and stability of performance. Plant yield and stability are assessed concurrently in each generation by utilising the plant prognostic equation. The genetic material used for this study was 2350 F2 plants (C0) of the commercial maize hybrid Costanza. The study presents the results of the application of prognostic breeding for 6 years in two contrasting environments (A and B), starting from C0 and ending in C5. It utilises ultra-high selection pressures (1.5% to 0.5%) to isolate superior lines with crop yield comparable to Costanza, and estimates the annual genetic gain accomplished through application of this selection strategy. Application of prognostic breeding led to the isolation of superior lines whose productivity was comparable to Costanza. The productivity gap between Costanza and the best selection was reduced from 87% (C0) to 0.5% (C5) in trial 1 (environment A), from 87% (C0) to 2% (C5) in trial 2 (environment B) and from 70% (C0) to 1% (C3) in trial 3 (environment B). Genetic gain was much higher (up to 50%) in the early cycles C0–C2 of prognostic breeding and smaller in cycles C3–C5. The best lines selected were evaluated in randomised complete block trials across both environments and 2 years. Across years, the top two lines in environments A and B averaged 87% and 91% of the Costanza yield, respectively, and they had higher prolificacy (greater number of ears per plant) than Costanza. Across all cycles, the average annual genetic gain ranged from 23% to 36% in the different trials, providing evidence that selection efficiency can be significantly maximised by using this breeding strategy.


Author(s):  
Tinee Adlak ◽  
Sushma Tiwari ◽  
M. K. Tripathi ◽  
Neha Gupta ◽  
Vinod Kumar Sahu ◽  
...  

Plant breeding is mainly concerned with genetic improvement of crops through hybridization, screening and selection of advance lines. The conventional methods give advance varieties with desirable traits but take consume more time (6 to 12 years) to achieve. Biotechnology tools makes breeding methods more advance by reducing the time to get improved varieties. Other than conventional methods varietal advancement can be achieved by applying plant tissue culture, transgenic approaches and molecular breeding methods. Crop improvement by using biotechnology approaches is mostly concerned with protoplast fusion to get somatic hybrids, gene transfer to get genetically modified organisms and use of DNA markers to select trait of interests. Variety with improved biotic and abiotic stress resistance can be developed in less time and more accuracy using recent biotechnological approaches. Several advance tools are being utilized for that purpose including, nanotechnology, bioinformatics tools offers new era of genomics assisted molecular breeding. Next Generation Sequencing and high throughput genotyping approaches are increasing efficiency and output of biotechnological tools in agriculture. Current review focused on overview of biotechnological tools being applied for crop improvement.


2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Sikander Singh Cheema ◽  
Amardeep Singh ◽  
Hassène Gritli

For the economic growth of the crop, the optimal utilization of soil is found to be an open area of research. An efficient utilization includes various advantages such as watershed insurance, expanded biodiversity, and reduction of provincial destitution. Generally, soils present synthetic confinements for crop improvement. Therefore, in this paper, a novel diversified crop model is proposed to predict the suitable soil for good production of the crop. The proposed model utilizes a quantum value-based gravitational search algorithm (GSA) to optimize the best solution. Various features of soil are required to be investigated before crop selection. These features are refined further by applying quantum optimization. The crop selection based upon the soil requirement does not require any additional fertilizers which will reduce the production cost. Thus, the proposed model can select the optimal crop according to the soil components using the gravitational search algorithm. Therefore, the gravitational search algorithm is applied to the quantum values obtained from the crop and soil dataset. Extensive experiments show that the proposed model achieves an optimal selection of crops.


2020 ◽  
Vol 4 (4) ◽  
pp. 314-326
Author(s):  
Elizabeth French ◽  
Tri Tran ◽  
Anjali S. Iyer-Pascuzzi

Using microbial inoculants to enhance plant health is promising for crop improvement. However, for success, knowledge of how different cultivars within a crop species select and respond to the root microbiome is critical. The aims of this study were to (i) determine the contribution of tomato genotype to the tomato root bacterial microbiome and (ii) investigate whether closely related tomato genotypes differ in their selection of and response to root endophytes. We used 16S ribosomal RNA amplicon sequencing to examine the root bacterial communities of six Solanum lycopersicum (domesticated tomato) and two S. pimpinellifolium (wild tomato) accessions. We found that, across accessions, both the root endosphere and rhizosphere were affected by genotype. Genotype accounted for 10% of the variation in root microbiota. Two bacterial families, Bacillaceae and Rhizobiaceae, were significantly enriched in the root endosphere in at least six of the eight tomato genotypes. To investigate whether closely related tomato genotypes differed in selection of these endosphere-enriched taxa, we profiled the root endosphere of 20 recombinant inbred lines (RILs) derived from two of the genotypes. The abundance of Bacillaceae and Rhizobiaceae isolates varied quantitatively in the root endosphere of the RILs. Inoculation of 16 RILs with a Bacillaceae isolate identified from the root endosphere of field-grown tomato showed that RIL responses, in terms of shoot and root growth, varied from less than 5% growth enhancement to more than 40%. Our data show that tomato genotypes have distinct but overlapping root bacterial microbiomes and respond differently to specific bacterial endophytes.


1995 ◽  
Vol 31 (1) ◽  
pp. 89-108 ◽  
Author(s):  
R. J. Lawn ◽  
R. J. Summerfield ◽  
R. H. Ellis ◽  
A. Qi ◽  
E. H. Roberts ◽  
...  

SummaryVariation in time from sowing to flowering (f) was examined for 44 cultivars of soyabean, mungbean, black gram, ricebean, cowpea, chickpea, lentil and barley, when grown in up to 21 diverse environments obtained by making one or more sowings at each of six locations spanning tropical, sub-tropical and temperate climates in Australia. The utility of simple linear models, relating rate of development (l/f) towards flowering to mean photoperiod and temperature prevailing between sowing and flowering, was evaluated. The models were highly efficient, explaining most (86.7%) of the variation observed across species, cultivars and environments. They were particularly efficient in describing responses where cultivars were relatively well-adapted, in agronomic terms, and least efficient where cultivars were exposed to unfavourable temperature and, to a lesser extent, photoperiod. Opportunities for exploiting the models in applied crop improvement include their use in interpretation of G × E interaction, genotypic characterization and selection of parental genotypes, selection of test environments, designing screening procedures, and more efficiently matching genotypes to target environments. The main strengths of these linear, additive rate models in crop improvement are their wide applicability across species and genotypes, their relative simplicity, and the requirement for few genotype-specific response parameters. Their main weakness is their lack of precision in describing responses when plants are exposed to unfavourable photothermal extremes, albeit in circumstances that are sometimes unrealistic for cropping those particular genotypes.Predicciones del tiempo que ha de transcurrir hanta la floración. VI.


2016 ◽  
Vol 8 (1) ◽  
pp. 38 ◽  
Author(s):  
Endang G. Lestari

<p>Mutation-based<br />plant improvement, which changes one or a few specific<br />traits of a cultivar, can contribute to crop improvement.<br />Tissue culture increases the efficiency of mutagenic<br />treatment to induce variations. In vitro culture in<br />combination with induced mutation can speed up the<br />breeding program by generating variability, followed by<br />selection and multiplication of the desired genotypes. In<br />many vegetative propagated crops, mutation induction in<br />combination with in vitro culture techniques can be the<br />most effective method for plant improvement. In seed<br />propagated species, the application of mutation coupled<br />with doubled haploid systems seems to be highly promising<br />in crop improvement. This approach speeds up the breeding<br />program through generation of variability followed by<br />selection of homozygousity and rapid multiplication of<br />desired genotypes.</p>


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