Modifying Controlled Deterioration for Evaluating Field Weathering Resistance of Soybean

ABSTRACT To develop practical methods for testing field weathering resistance of soybean varieties, pods and seeds from CM60 (susceptible) and GC10981 (resistant) were tested by seven treatments. Among the treatments, modified incubator weathering (yellow pods were incubated at 30°C under 90-100% relative humidity for 7 days) and the controlled deterioration (dry seeds were soaked in distilled water for 60 minutes and then incubated at 41°C under 90-100% relative humidity for 3 days) showed widerange differences in seed germination and viability between CM60 and GC10981. These two treatments were then tested on 11 soybean varieties comparing with a field weathering treatment. The germination of seeds treated by controlled deterioration was highly correlated to the germination of seeds subjected to field weathering treatment (r=0.964**, n=11). The viability of seeds submitted to both incubator weathering and controlled deterioration were also correlated to the viability of seeds exposed to field weathering (r=0.697* and 0.716*, n=11). The modified incubator weathering and controlled deterioration methods were further used to evaluate the field weathering resistance of 139 F 2 progenies derived from the cross CM60/GC10981. There was a significant correlation between the incubator weathering and the controlled deterioration by considering the germination and viability of seeds (germination r=0.331**, viability r=0.425**, n=139). Both the modified incubator weathering and controlled deterioration were efficient for evaluating the field weathering resistance of soybean varieties. Particularly, controlled deterioration method was found to be a useful way for evaluating the field weathering resistance of soybean seeds

Effect of drought stress on flowering characteristics in rice (Oryza sativa L.): A study using genotypes contrasting in drought tolerance and flower opening time

Rice is most susceptible to heat and drought stress at flowering stage, but flowering characteristics under drought stress are not well characterized. This study investigated flowering characteristics of rice genotypes contrasting in their flower opening time (FOT) and level of drought tolerance. Near-isogenic lines for the early-morning flowering trait (IR64+ qEMF3) and for drought tolerance (IR87707-445-B-B-B), and their recurrent parent cultivar (IR64) were used. IR64+ qEMF3 had stable earlier FOT than IR64 and IR87707-445-B-B-B under drought stress conditions. Drought stress occasionally affects FOT depending on genotype. The number of open spikelets was higher in IR87707-445-B-B-B than in IR64 and IR64+ qEMF3, and the difference among genotypes increased as the rice plants were subjected to more severe stress levels. Panicle temperature increased under drought stress conditions and was similar among genotypes when it was measured at the same time of day, demonstrating that earlier FOT in IR64+ qEMF3 must be beneficial to avoid heat stress at flowering under drought stress conditions. However, IR64+ qEMF3 did not exhibit drought avoidance, as evidenced by the root mass at depth. To assess the potential for the EMF trait to complement ongoing drought breeding efforts, heat tolerance among 13 advanced drought breeding lines and released cultivars was tested. Wide variation in heat tolerance at flowering was observed and, notably, none of the 13 lines possessed the EMF trait. This study therefore proposes that a breeding strategy that transfers the EMF trait into drought tolerant lines could enhance the resilience of rice spikelets to the combined stresses of heat and drought at flowering

Heat Stress Tolerance in Rice (Oryza sativa L.): Identification of Quantitative Trait Loci and Candidate Genes for Seedling Growth Under Heat Stress

Productivity of rice, world's most important cereal is threatened by high temperature stress, intensified by climate change. Development of heat stress-tolerant varieties is one of the best strategies to maintain its productivity. However, heat stress tolerance is a multigenic trait and the candidate genes are poorly known. Therefore, we aimed to identify quantitative trait loci (QTL) for vegetative stage tolerance to heat stress in rice and the corresponding candidate genes. We used genotyping-by-sequencing to generate single nucleotide polymorphic (SNP) markers and genotype 150 F8 recombinant inbred lines (RILs) obtained by crossing heat tolerant “N22” and heat susceptible “IR64” varieties. A linkage map was constructed using 4,074 high quality SNP markers that corresponded to 1,638 recombinationally unique events in this mapping population. Six QTL for root length and two for shoot length under control conditions with 2.1–12% effect were identified. One QTL rlht5.1 was identified for “root length under heat stress,” with 20.4% effect. Four QTL were identified for “root length under heat stress as percent of control” that explained the total phenotypic variation from 5.2 to 8.6%. Three QTL with 5.3–10.2% effect were identified for “shoot length under heat stress,” and seven QTL with 6.6–19% effect were identified for “shoot length under heat stress expressed as percentage of control.” Among the QTL identified six were overlapping between those identified using shoot traits and root traits: two were overlapping between QTL identified for “shoot length under heat stress” and “root length expressed as percentage of control” and two QTL for “shoot length as percentage of control” were overlapping a QTL each for “root length as percentage of control” and “shoot length under heat stress.” Genes coding 1,037 potential transcripts were identified based on their location in 10 QTL regions for vegetative stage heat stress tolerance. Among these, 213 transcript annotations were reported to be connected to stress tolerance in previous research in the literature. These putative candidate genes included transcription factors, chaperone proteins (e.g., alpha-crystallin family heat shock protein 20 and DNAJ homolog heat shock protein), proteases, protein kinases, phospholipases, and proteins related to disease resistance and defense and several novel proteins currently annotated as expressed and hypothetical proteins

Identifying and confirming quantitative trait loci associated with heat tolerance at flowering stage in different rice populations

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited.Background Climate change is affecting rice production in many countries. Developing new rice varieties with heat tolerance is an essential way to sustain rice production in future global warming. We have previously reported four quantitative trait loci (QTLs) responsible for rice spikelet fertility under high temperature at flowering stage from an IR64/N22 population. To further explore additional QTL from other varieties, two bi-parental F2 populations and one three-way F2 population derived from heat tolerant variety Giza178 were used for indentifying and confirming QTLs for heat tolerance at flowering stage. Results Four QTLs (qHTSF1.2, qHTSF2.1, qHTSF3.1 and qHTSF4.1) were identified in the IR64/Giza178 population, and two other QTLs (qHTSF6.1 and qHTSF11.2) were identified in the Milyang23/Giza178 population. To confirm the identified QTLs, another three-way-cross population derived from IR64//Milyang23/Giza178 was genotyped using 6K SNP chips. Five QTLs were identified in the three-way-cross population, and three of those QTLs (qHTSF1.2, qHTSF4.1 and qHTSF6.1) were overlapped with the QTLs identified in the bi-parental populations. The tolerance alleles of these QTLs were from the tolerant parent Giza178 except for qHTSF3.1. The QTL on chromosome 4 (qHTSF4.1) is the same QTL previously identified in the IR64/N22 population. Conclusion The results from different populations suggest that heat tolerance in rice at flowering stage is controlled by several QTLs with small effects and stronger heat tolerance could be attained through pyramiding validated heat tolerance QTLs. QTL qHTSF4.1 was consistently detected across different genetic backgrounds and could be an important source for enhancing heat tolerance in rice at flowering stage. Polymorphic SNP markers in these QTL regions can be used for future fine mapping and developing SNP chips for marker-assisted breeding

Cancer Classification with a Cost-Sensitive Naive Bayes Stacking Ensemble

Ensemble learning combines multiple learners to perform combinatorial learning, which has advantages of good flexibility and higher generalization performance. To achieve higher quality cancer classification, in this study, the fast correlation-based feature selection (FCBF) method was used to preprocess the data to eliminate irrelevant and redundant features. Then, the classification was carried out in the stacking ensemble learner. A library for support vector machine (LIBSVM), K-nearest neighbor (KNN), decision tree C4.5 (C4.5), and random forest (RF) were used as the primary learners of the stacking ensemble. Given the imbalanced characteristics of cancer gene expression data, the embedding cost-sensitive naive Bayes was used as the metalearner of the stacking ensemble, which was represented as CSNB stacking. The proposed CSNB stacking method was applied to nine cancer datasets to further verify the classification performance of the model. Compared with other classification methods, such as single classifier algorithms and ensemble algorithms, the experimental results showed the effectiveness and robustness of the proposed method in processing different types of cancer data. This method may therefore help guide cancer diagnosis and research

Cancer Classification Based on Support Vector Machine Optimized by Particle Swarm Optimization and Artificial Bee Colony

Intelligent optimization algorithms have advantages in dealing with complex nonlinear problems accompanied by good flexibility and adaptability. In this paper, the FCBF (Fast Correlation-Based Feature selection) method is used to filter irrelevant and redundant features in order to improve the quality of cancer classification. Then, we perform classification based on SVM (Support Vector Machine) optimized by PSO (Particle Swarm Optimization) combined with ABC (Artificial Bee Colony) approaches, which is represented as PA-SVM. The proposed PA-SVM method is applied to nine cancer datasets, including five datasets of outcome prediction and a protein dataset of ovarian cancer. By comparison with other classification methods, the results demonstrate the effectiveness and the robustness of the proposed PA-SVM method in handling various types of data for cancer classification

Breeding efforts to mitigate damage by heat stress to spikelet sterility and grain quality

Global warming is predicted to aggravate the risk of unstable crop production. It is of great concern that damage to rice spikelet sterility and grain quality will increase, resulting in yield and economic losses. To secure the global food supply and farmers’ income, the development of rice cultivars with heat resilience is a pressing concern. Regarding spikelet sterility, rice cultivars with heat tolerance at different growth stages have been identified in recent years. The early-morning flowering (EMF) trait is effective in heat escape because it shifts the time of day of flowering to earlier in the morning when it is cooler. Although varietal differences are very small, there are some genetic resources for EMF in wild rice accessions. Regarding heat-induced grain chalkiness, heat-tolerant japonica cultivars for mitigating white-back type of chalky grains (WBCG) were found. Quantitative trait loci for heat tolerance at flowering, EMF, and for WBCG in grain quality have been mapped on the rice chromosomes. Further genetic efforts have been successfully connected to the development of near-isogenic lines for each trait with tagged molecular markers. These breeding materials are quite unique and useful in facilitating marker-assisted breeding toward the development of heat-resilient rice in terms of spikelet sterility and grain quality

Calycosin and Genistein Induce Apoptosis by Inactivation of HOTAIR/p-Akt Signaling Pathway in Human Breast Cancer MCF-7 Cells

Background: Calycosin and genistein are the two main components of isoflavones. Previously, we reported that these compounds display antitumor activities in the breast cancer cell lines MCF-7 and T47D. In the present study, we investigated the mechanism of action of calycosin and genistein, and their respective efficacies as potential therapies for the treatment of breast carcinoma in the clinic. Methods: MCF-7 cells were treated with calycosin or genistein. Cell proliferation and apoptosis were measured using CCK8 assay and Hoechst 33258. The expression level of phosphorylated Akt protein was determined by western blotting. Expression level of HOTAIR was quantified by real-time PCR. Results: Both calycosin and genistein inhibited proliferation and induced apoptosis in MCF-7 breast cancer cells, especially after treatment with calycosin. Treatment of MCF-7 cells with calycosin or genistein resulted in decreased phosphorylation of Akt, and decreased expression of its downstream target, HOTAIR. Conclusion: Calycosin is more effective in inhibiting breast cancer growth in comparison with genistein, through its regulation of Akt signaling pathways and HOTAIR expression

Three-dimensional CFD modeling of transport phenomena in anode-supported planar SOFCs

In this study, a three-dimensional computational fluid dynamics model has been developed for an anode-supported planar SOFC. The conservation equations of mass, momentum, species/charges and thermal energy are solved by finite volume method for a complete unit cell consisting of 13 parallel channels in both anode and cathode. The simulation results of the developed model are well in agreement with the experimental data obtained at same conditions. In this study, the co-flow arrangement with hydrogen utilization of 60 % and operating voltage of 0.7 V is used as the base case, and compared with the counter-flow arrangement. The predicted results reveals that the maximum temperature obtained in the counter-flow arrangement is about 10 A degrees C lower than that of co-flow, but the counter-flow arrangement has a higher temperature gradient between the respective anodes and cathodes in a cross-section normal to the main flow direction, especially in the air inlet region of the cell (x = 0.04 m),which is very harmful to the lifetime of materials. The current density is very unevenly distributed along and normal to the flow direction for both the co- and counter-flow arrangements, and the maximum values occur at junctions of the electrodes, channels and ribs, which causes higher over-potentials and ohmic heating