Waterlogging is a major stress that impacts the chrysanthemum industry. Large-scale germplasm screening for identifying waterlogging-tolerant resources in a quick and accurate manner is essential for developing new cultivars with improved waterlogging tolerance. To overcome this phenotyping bottleneck, consumer-grade digital cameras have been used to acquire the red-green-blue (RGB) images of 180 chrysanthemum cultivars and their wild relatives under waterlogging stress and well-watered conditions. A total of 103 image-based digital traits (i-traits), including 10 morphological i-traits and 93 texture i-traits, were extracted and systematically analyzed. Most of these i-traits presented high coefficients of variation (CVs) and broad-sense heritability (H2), with an average CV of 34.04 % and an average H2 of 0.93. We identified several novel texture i-traits associated with the hue (H) component, which strongly correlated with the traditional waterlogging tolerance index, the membership function value of waterlogging (MFVW) (R = 0.63–0.77). We further employed the random forest (RF) and gradient boosting tree (GBT) machine learning algorithms to predict aboveground biomass and MFVW on the basis of different i-trait datasets. The RF model achieved superior predictive performance, with a coefficient of determination (R2) of up to 0.88 for shoot weight and 0.86 for MFVW. Moreover, a subset of the top 13 most important i-traits could accurately predict MFVW (R2 > 0.80) via the cross-validation method. A total of 10 highly tolerant resources were selected by traditional and RGB-based evaluation, and 50 % belonged to Artemisia. Our findings confirmed that RGB-based technology provides a promising novel approach for quantifying waterlogging response that contributes to future breeding programs and genetic dissection for waterlogging tolerance.
- Article type
- Year
- Co-author
Open Access
Research Article
Issue
The purpose was to establish an evaluation system to screen out elite hybrid lines of large-flowered tea chrysanthemum, so as to provide a theory reference and material base for the breeding of new varieties.
A total of 20 factors representative of agronomic traits, sensory quality, and active ingredient were investigated for 46 F1 offsprings derived from maternal large-flowered tea chrysanthemum Jinsi Huangju and for five parental cultivars, including dry flower weight, ray floret number, florescence, plant height, crown diameter, number of flowers per plant, yield of dry flower, drought resistance, disease resistance, dry flower diameter, dry flower type, dry flower color, aroma, liquor flower type, liquor flower color, taste, total flavones, chlorogenic acid, luteolin glycosides, and iso-chlorogenic acid A. The analytic hierarchy process and K-Means cluster analysis were used to establish a comprehensive evaluation system for assessing the hybrid offsprings.
Through the observation and analysis of the characters of F1 offsprings of large-flowered tea chrysanthemum, the results showed that the flowering period of most F1 offsprings was relatively late. Compared with ‘Jinsi Huangju’, the drought resistance of F1 offsprings was improved to a certain extent, but the disease resistance was average. The inflorescence-related ornamental traits of the most F1 offspring were generally improved, but the flower diameter was not significantly increased, and the performances of growth, yield and taste traits were not improved as expected. The weight of the 20 factors was determined by analytic hierarchy process, and the result showed that dry flower diameter shared the largest weight value of 0.148, followed by liquor flower type, liquor flower color, and taste with a weight value of 0.084, florescence and yield of dry flower with a weight value of 0.080. The K-Means cluster analysis divided the investigated materials into 3 grades, i.e., 6 superior, 29 good, and 16 poor accessions, accounted for 11.76%, 56.86%, and 31.37%, respectively. Among them, compared with Jinsi Huangju, the superior F1 offsprings showed heavier fresh flower weight, wider and thicker petals, and more petals, more pure and bright color, higher active ingredients, which could be further conducted regional test.
The evaluation system of large-flowered tea chrysanthemum was established by the analytic hierarchy process and K-Means cluster analysis, and 5 elite hybrid lines with good agronomic traits, strong resistance, high quality were screened out for future breeding use.
Open Access
Research paper
Issue
Basic helix–loop–helix (bHLH) transcription factor gene family in plants controls various growth and development aspects; however, the actual roles of these genes in flowering plants are not well known. In this study, a novel bHLH protein CmbHLH110 was found to interact with CmERF110 by in vitro and in vivo experiments, a chrysanthemum ERF110 homolog that acts as a positive flowering regulator. In addition, CmbHLH110 was also found to regulate the flowering of chrysanthemums, overexpression of CmbHLH110 causes chrysanthemums to flower earlier, and suppressed CmbHLH110 leads to delayed flowering. Furthermore, the loss-of-function Arabidopsis mutant of its homologue PERICYCLE FACTOR TYPE-A 5 (PFA5) had a noticeable late flowering phenotype, and CmbHLH110 completely complemented the late flowering phenotype of the pfa5 mutant, whereas heterologous overexpression of CmbHLH110 in Arabidopsis Col-0 caused early flowering. Transcriptome sequencing revealed significant differential expression of flowering-related and circadian clock-related genes in transgenic chrysanthemum. Therefore, we concluded that CmbHLH110, as a novel flowering regulator, could interact with CmERF110 to regulate flowering in chrysanthemum.
京公网安备11010802044758号