PCA showed that seed yield and harvest index were the traits that contributed most of the variation. Genetic comparison of ten soybean genotypes with eight microsatellite markers revealed the close genetic relationship between Williams, LS6161 R and Magoye. However, various production constraints limited the potential growth and development of the soybean industry in Africa (Tefera, 2011).
The results of the study may help determine the optimal application rates of silicon and T.
CHAPTER ONE
SOYBEAN
- Economic importance of soybean
- Taxonomy
- Morphology
- Nodulation .1 Nitrogen
- Nitrogen fixation by bacteria
- Formation of root nodules
- Successful nodulation practices
- Production of soybean .1 Land preparation
- Planting
- Seeding rate
- Fertilization
- Irrigation
- Harvesting
- Diseases on soybean
- Ecology of soybean
- Factors that influence successful soybean production General factors that affect soybean production are as follows
- Selection in soybean
- Soybean genetic diversity
The first leaves are simple and grow opposite each other on the stem, while the leaves that form subsequently are trilobed, that is, the leaf consists of three leaflets, and alternates up the stem (Figure 1.1) (Kumudini, 2010). Three layers can be seen in the seed coat, i.e. epidermis, hypodermis and the inner parenchyma layer (Figure 1.4). Nodules formed on the roots of the soybean plant are caused by the interaction of a specific nitrogen-fixing bacterium (Bradyrhizobium japonicum), which may be present in the soil or inoculated on the seed.
The most important weeds in soybean include Abutilon theophrasti L. wild rhubarb), and Cynodon dactylon (L.) Pers (bedweed). The space between the planted rows should be covered with residues in order to discourage the growth of weeds.
MOLECULAR MARKERS
- DNA based molecular markers and their applications in plant breeding
- Simple sequence repeats (SSR) DNA markers
However, this has resulted in a bottleneck effect of genetic diversity in soybeans (Hyten et al., 2006). The decrease in genetic diversity can lead to increased susceptibility to pests and pathogens and a decrease in adaptability (Wang et al., 2010). The Simple Sequence Repeats (SSRs) DNA markers or microsatellites are tandem repeats of 1–6 nucleotides of DNA used to identify the presence or absence of alleles (Zane et al., 2002).
SSR markers were used in several studies, for example Yoon et al. 2009) genotyped 2,758 accessions of soybean landraces in Korea using 6 SSR primers.
BIO-FERTILIZERS
- Morphology
- Trichoderma as a biological control agent and growth promoter
- Silicon
- How essential is silicon to plants?
- Effect of silicon on plant growth
- Uptake and accumulation of silicon in plants
- Possible Genes that control silicon uptake in plants
- Possible mechanisms by which silicon controls plant diseases
- Effect of silicon on biotic stress resistance
- Effect of silicon on abiotic stress resistance
- Effect of silicon on chemical stress
Silicon is an element commonly available in soil and is an essential nutrient important for plant growth in trace amounts. However, the Si content of the Si-deprived plants showed that 4.2 ppm Si was found in the plants and 2.8 ppm in the roots, suggesting that these amounts of Si are sufficient for plant growth (Epstein, 1994 ). The use of Si as a growth promoter made it an essential component in the commercial production of rice and sugarcane (Jones and Handreck, 1967).
Monocots are usually able to take up and store more Si in the shoots than dicots (Ma and Takahashi, 2002). A second transporter then takes the Si to the xylem and Si then accumulates in the xylem leading to xylem loading. An increased concentration of the two transporters results in more silicic acid being transported and accumulated in the plant.
By increasing the level of Si in the plant, disease symptoms on the plant are reduced. In the first mechanism, Si forms a physical barrier that cannot be penetrated by fungi or insects, and in the second, Si acts as a modulator of host resistance to the pathogen. However, Si can affect the absorption of manganese and iron in the soil.
Soil treated with Si showed a decrease in the amount of absorbed manganese and iron. Phosphorus shows a high affinity for manganese and iron, and if it is absent, there will be more phosphorus available internally in the plant.
CONCLUSION
LITERATURE CITED
Effect of environmental and genetic factors on the stability of pea (Pisum sativum L.) isozyme and DNA markers. Genetic diversity in domesticated soybean (Glycine max) and its wild progenitor (Glycine soja) for simple sequence repeat and single nucleotide polymorphism loci. The beneficial effect of biofertilizers and antioxidants on olive trees under calcareous soil conditions.
Growth enhancement by silicon in cucumber plants (Cucumis sativus) depends on an imbalance in the supply of phosphorus and zinc. Soybean - Genetics and new techniques for yield enhancement: Genetic diversity and allele mining in soybean germplasm.
RESPONSE OF SELECTED SOYBEAN GENOTYPES TO DIFFERENT SILICON CONCENTRATIONS
- INTRODUCTION
- MATERIALS AND METHOD
- Study site, plant materials and treatments
- Preparation of silicon concentrations
- Experimental design and planting
- Application of silicon and fertilizers
- RESULTS
- DISCUSSION
- CONCLUSION
- LITERATURE CITED
The details of the soil samples shown in Table 2.2 were used as a guide for fertilizer application. The genotype that produced the lowest root dry mass was Barc-14 at 200 ppm Si (0.19 g/plant) (Table 2.4), while several other genotypes produced low root dry masses that showed no. While Williams at 200 ppm Si had a good level of seed yield (0.98 g/pot) (Table 2.4), with several other genotypes producing high seed yield not significantly different from this genotype.
The genotype with the lowest harvest index (0.05) (Table 2.4) was Barc-14 at 250 ppm Si, with several other genotypes producing harvest indices with no significant differences relative to this genotype. The highest value was shown by Williams (0.58) (Table 2.4) at 200 ppm Si, with several other genotypes giving harvest indices with no significant differences compared to this genotype. Genotypes Barc-17, L76-1988 and Williams at 0 ppm Si also flowered relatively early at 43 days (Table 2.8) and were significantly different from genotype L82-1449-ll at each silicon level.
Although genotype LS 6161 R at 0 ppm Si produced the lowest 100 seed weight value (4.96 g) (Table 2.8), several other genotypes produced low seed weights that showed no significant difference with this genotype. Barc-17 at 0 ppm Si, Magoye at 200 ppm Si and Clark at 250 ppm Si produced the lowest root dry masses (0.17g/plant) (Table 2.8), although several other genotypes produced low root dry masses that were not significantly different from these genotypes. Although Barc-4 at 0 ppm Si produced the lowest seed yield, several other genotypes produced low seed yield that was not significantly different from this genotype and genotype Williams at 200 ppm Si produced a high seed yield (1.98 g/pot) ( Table 2.8). which is not significantly different from Barc-2 at 200 ppm Si.
The harvest index showed a significant positive correlation with plant height, number of pods per plant, number of seeds per hundred seed pod weight and seedling yield (Table 2.9) except for dry root mass and shoot mass. dry shoots showing a non-significant weakness negative correlation. PC1 with 39% of the total variance explained was well correlated with plant height, number of pods per plant, number of seeds per pod, 100-seed weight, seed yield and harvest index (Table 2.10). In experiments 1 and 1 days to maturity showed a significant difference between genotypes for each level of silicon used (Tables 2.3 and 2.7).
The genotypes with the highest harvest index value in experiment 1 was Williams at 200 ppm Si (0.58) (Table 2.3) which was higher than the highest harvest index for experiment two which was for Williams at 200 ppm (0.45 ) (Table 2.8).
RESPONSE OF SELECTED SOYBEAN GENOTYPES TO SILICON AND Trichoderma harzianum (ECO-T ® ) APPLICATIONS
- INTRODUCTION
- MATERIALS AND METHOD
- Field study, plant materials and treatments
- Preparation of silicon concentration
- Seed treatment with Trichoderma harzianum (Eco-T ® )
- Experimental design, planting and application of fertilizer
- Application of silicon
- Data collection and analysis
- RESULTS
- DISCUSSION
- CONCLUSION
- LITERATURE CITED
The number of pods produced per plant and the number of seeds per pod were recorded at maturity. Seed yield showed significant positive correlation with other traits including plant height, number of pods per plant, number of seeds per pod, hundred seed weight and harvest index (Table 3.4). Strong and significant correlations were observed between harvest index and plant height, number of pods produced per plant, number of seeds produced per pod, hundred seed weight and seed yield.
Weak associations were noted for the total number of nodes per plant and the number of active nodes produced (Table 3.4). Therefore, the above associations indicate a high seed yield, and harvest index values are associated with increased plant height, number of pods per plant, number of seeds per plant and hundred seed weight. PC1 alone contributed 46% of the variation, which was well correlated with plant height, number of pods per plant, number of seeds per pods, 100 seed weight, seed yield and harvest index.
PC2 explained 21% of the variation and correlated with the total number of nodules per plant and the number of active nodules (Table 3.5). Plant height, number of pods produced per plant, number of seeds produced per pod, 100 seed weight, seed yield and harvest are therefore important in the selection of soybean genotypes when tested with the application of silicon and T. In the study, high seed yields are important. and harvest index values were positively associated with high plant height, number of pods per plant, number of seeds per pod, and weight of one hundred seeds (Table 3.4).
The result of the principal component analysis (PCA) revealed that the components that contributed most of the variation were plant height, number of pods produced per plant, number of seeds produced per pod, hundred seed weight, seed yield and harvest index (Table 3.5). The results of the principal component analysis showed that selection of soybean genotypes should be based on plant height, number of pods produced per plant, number of seeds produced per plant, hundred seed weight, seed yield and harvest index.
GENETIC DIVERSITY ANALYSIS OF SELECTED SOYBEAN GENOTYPES USING SSR MARKERS
- INTRODUCTION
- MATERIAL AND METHODS
- Plant materials
- DNA Extraction
- DNA Quantification
- SSR primers
- Polymerase chain reaction
- Reagents and chemicals used in DNA extraction, quantification and PCR The following reagents and chemicals were used for DNA extraction, quantification and
- Data analysis
- RESULTS
- DISCUSSION
- CONCLUSION
- REFERENCES
- IMPLICATIONS
- RECOMMENDATIONS
The result in Table 4.3 shows the fragment size of the expressed alleles for each SSR marker per soybean genotype. SOYPRP1 revealed 4 different allele fragment sizes, with the most common size of 210 common to most genotypes (Table 4.3). The fragment sizes summarized in Table 4.3 and the matrix of Euclidean genetic distances in Table 4.4 were used to construct the UPGMA dendrogram (Figure 4.2). The dendrogram revealed two distinct groups, i.e.
In order to develop successful breeding programs to assist in the diversification of soybean genotypes, the pedigree of the genotypes must be determined. Research conducted by Diwan and Cregan (1997) on soybean revealed that approximately 95% of the alleles in the local soybean were explained by 35 soybean genotypes distinguished by 20 SSR markers. The pedigree of the genotypes in Table 2.1 indicates a common parent (Clark 63(8)) between Barc-2 and Barc-4.
Therefore, the similar and positive response of the genotypes to the combined treatment with Si and Eco-T® can be attributed to the close genetic relationship. Thus, the use of SSR markers is effective and agrees with phenotypic analysis, which can be used in diversity analysis and establish the genetic relationship between soybean genotypes. The results obtained in Chapter 2 show that for the observed agronomic traits, total Si applied at 200 ppm showed a positive response on most traits such as plant height, number of pods produced per plant, hundred seed weight, seed yield and.
The genotypes that received Si and Eco-T® in combination showed an overall positive response with the exception of the total number of nodules produced and number of active nodules. The results obtained in Chapter 4 show the linkage between genotypes Williams, LS 6161 R, Magoye and Barc-2 which showed a superior performance in general of the agronomic traits observed in Chapters 2 and 3.
