Search

Lily pollen causes many problems affecting humans’ quality of life and health, such as clothing contamination and skin or nasal allergies. The manual removal of anthers is time-consuming and labour-intensive, and thus, not conducive to commercial production. It is of great importance to produce pollen-free lily varieties with beautiful shapes. In this study, we studied the morphological characteristics of flower organs and polyploids of six pollen-free filial generations of four lily species and their micropropagations. Lily ‘5-21’ is male sterile and produces uncrackable anthers with inactive pollens under natural conditions. Lily ‘3-12’ is unable to produce anthers, because the petals become stamens, thereby leading to infertility. Lilies ‘3-1’, ‘5-4’, ‘5-35’ and ‘0-0.2’ are unable to produce anthers, because they lack floral organs. Polyploids of six hybrid lilies were identified by flow cytometry and chromosome counting, and the results showed that lily ‘5-4’ was triploid and the rest were diploid. Morphological observation indicated that flowering periods were from early July to early August and lasted for about 11 days. Six male sterile lilies had low seed setting rates when they were used as female parents. Most of the seeds were flaky with developed embryos. Therefore, asexual reproduction is optimal for these six male sterile lilies. The male sterility of six lilies was associated with their parents’ pollen activity. Scales of ‘5-4’ and ‘5-35’ were used as explants for in vitro micropropagation. The findings of the present study lay a foundation for breeding of pollen-free lilies.

Oolitic hematite abounds in the Guizhou Province of China but is hard to use with the traditional process. The reduction of Guizhou oolitic hematite by H2 was studied. Ore microscopy, phase change, and the metallization rate of oolitic hematite under different reduction conditions were characterized by optical microscopy, X-ray diffraction, and chemical analysis, respectively. The metallization ratio of the reduced sample increased with the increase of reduction time. The metallization ratio reached 80.75% when the temperature was 1000°C and the reduction time was 120 min. The new phases of FeAl2O4 and Fe2SiO4 can be generated during the reduction process, which hindered the reduction of the oolitic hematite.

With the development of the vehicle industry, controlling stability has become more and more important. Techniques of evaluating vehicle stability are in high demand. Integration of Global Positioning System (GPS) and Inertial Navigation System (INS) is a very practical method to get high-precision measurement data. Usually, the Kalman filter is used to fuse the data from GPS and INS. In this paper, a robust method is used to measure vehicle sideslip angle and yaw rate, which are two important parameters for vehicle stability. First, a four-wheel vehicle dynamic model is introduced, based on sideslip angle and yaw rate. Second, a double level Kalman filter is established to fuse the data from Global Positioning System and Inertial Navigation System. Then, this method is simulated on a sample vehicle, using Carsim software to test the sideslip angle and yaw rate. Finally, a real experiment is made to verify the advantage of this approach. The experimental results showed the merits of this method of measurement and estimation, and the approach can meet the design requirements of the vehicle stability controller.

To seek the optimal combination of water–air for drip irrigation processing tomatoes in Northern Xinjiang, China, field experiments consisted of four irrigation levels, and two types of gas-filling methods were proposed. Throughout the whole growth period, the water consumption by physical aeration and chemical aeration increased by 13.65% and 9.27%, respectively compared with the nonaerated treatment. Under the conditions of physical aeration, the processing tomato fruit yield and irrigation water use efficiency (IWUE) increased by 8.14% and 4.74%; while by chemical aeration, they increased by 7.91% and 4.61%, respectively. Physical aeration had the most prominent role in increasing the contents of organic acid, soluble solids, soluble sugar, lycopene, and VC in processing tomatoes. The presented indicators show that the effect of physical aeration was better than that of chemical aeration. Physical aeration in combination with different irrigation levels, the 4,950 m3·hm−2 irrigation level gave the highest yield of processing tomato, whereas the highest IWUE was obtained in the 4,500 m3·hm−2 irrigation treatment, and the quality parameters of processing tomatoes at the 4,500 m3·hm−2 irrigation level performed better than those at the 4,950 m3·hm−2 irrigation level. To take into account the requirements of processing tomatoes for maximum IWUE and fruit yield and quality, the entropy weight method was used to determine that the irrigation water volume of 4,500 m3·hm−2 under the conditions of physical aeration can be used as a suitable water and air combination pattern for processing tomatoes in drip irrigation in Northern Xinjiang. [ABSTRACT FROM AUTHOR]

Nanoscale graphene has demonstrated effectiveness in self-sensing cement composites and energy harvesting in buildings. However, the widespread application of graphene reinforced cement composites (GRCCs) in energy conversion is hindered by their low thermoelectric conversion efficiency. To address this limitation, multiphase cement composites with high Seebeck coefficient and low thermal conductivity are designed by using Cu2Se and ZnO. The increase in carrier mobility and enhanced phonon scattering lead to an order of magnitude improvement in the figure of merit (ZT) compared to GRCCs without incorporating Cu2Se/ZnO. A hybrid micromechanical model (HMM) based on effective medium theory and the Mori–Tanaka method is developed for predicting the electrical and thermal conductivity of the multiphase cement composites, which can be used to evaluate the thermoelectric performances of the composites. The combined experiments and modeling aim to provide guidelines for developing high-performance GRCCs with improved thermoelectric properties, potentially expanding their application in energy conversion technologies. [ABSTRACT FROM AUTHOR]

Light is crucial for flower bud development in plants, serving as both signal and energy source. However, the mechanisms by which daylength and light intensity regulate flowering in modern roses remain unclear. In Rosa hybrida 'Carola', insufficient light delays flowering and reduces the sugar content in terminal buds. RNA sequencing identified the Trehalose‐6‐phosphate phosphatase F (RhTPPF) gene as a key responder to insufficient light, modulating Tre6P metabolism. Overexpression of RhTPPF in rose calli enhanced sugar accumulation and suppressed the synthesis of RhCO/FT. In tobacco, overexpression of RhTPPF delayed the transition from vegetative growth to flowering, while silencing RhTPPF in roses accelerated flowering. Silencing RhTPPF in roses elevated trehalose‐6‐phosphate (Tre6P) levels and decreased trehalose. Transcriptome data showed that the expression level of RhTPPF was highly correlated with the circadian rhythm gene LATE ELONGATED HYPOCOTYL (RhLHY). Yeast one‐hybrid assays, dual luciferase assays and EMSA revealed that RhLHY directly binds to the RhTPPF promoters. Overexpression of RhLHY suppressed flowering, while silencing RhLHY promoted flowering. Furthermore, altering the expression of RhLHY influenced Tre6P synthesis and the expression of sucrose‐related transport genes. These findings suggest a RhLHY‐RhTPPF‐Tre6P regulatory module that maintains sugar balance and inhibits flower formation under reduced light conditions by modulating sugar distribution. Summary statement: The duration and intensity of light are critical in governing the flowering phase of roses. They play a significant role in the regulation of LATE ELONGATED HYPOCOTYL (RhLHY)‐Trehalose‐6‐phosphate phosphatase F (RhTPPF)‐Trehalose‐6‐phosphate (Tre6P) module, impacting sugar distribution and establishing a regulatory framework. This framework is essential for maintaining sugar equilibrium and inhibiting flower blooming in conditions of short daylight duration and low light intensity. [ABSTRACT FROM AUTHOR]

The parallel mechanism exhibits high stiffness and excellent dynamic response, making it ideal for high-precision applications. In our early work, a novel 6-DOF redundant parallel posture mechanism with four limbs for solar wing docking has been proposed; each limb consists of three links and four joints. This paper primarily focuses on optimization design of the mechanism. The calculation of workspace volume reveals that factors influencing the range of posture adjustment include dynamic platform parameters, static platform parameters, the drive trajectory of each kinematic pair, and the angles between each kinematic pair. A sensitivity analysis was conducted to examine the impact of each parameter on the range of posture adjustment. To reduce computational complexity and improve analysis efficiency, a combined approach of single-factor analysis and response surface methodology (RSM) is used in the paper. Single-factor analysis is utilized to evaluate the effect of each parameter on the posture adjustment range. Based on these results, RSM is used to establish a regression model for parameters; thereby, the optimal parameter combination for the mechanism is determined. The regression coefficient R2 = 0.9374 attests to the validity of the proposed model. Finally, a comparison of the posture adjustment range before and after optimization is presented, providing a foundation for the practical application of the redundant parallel mechanism. This paper introduces a novel structural design concept aimed at resolving the conflict between heavy loads and compact sizes in redundant parallel mechanisms while providing valuable insights for miniaturized design. [ABSTRACT FROM AUTHOR]

Propagation of cuttings is the primary method of rose multiplication. Aux/IAA, early response genes to auxin, play an important role in regulating the process of adventitious root formation in plants. However, systematic research on the identification of RhAux/IAA genes and their role in adventitious root formation in roses is lacking. In this study, 34 RhAux/IAA genes were identified by screening the rose genome, distributed on seven chromosomes, and classified into three clades based on the evolutionary tree. An analysis of the cis-acting elements in the promoters of RhAux/IAA genes revealed the presence of numerous elements related to plant hormones, the light signal response, the growth and development of plants, and abiotic stress. RNA-seq analysis identified a key RhIAA25 gene that may play an important role in the generation of adventitious roots in roses. Subcellular localization, yeast self-activation, and tissue-specific expression experiments indicated that RhIAA25 encoded a nuclear protein, had no yeast self-activated activity, and was highly expressed in the stem. The overexpression of RhIAA25 promoted the elongation of the primary root in Arabidopsis but inhibited adventitious root formation. This study systematically identified and analyzed the RhAux/IAA gene family and identified a key gene, RhIAA25, that regulates adventitious root generation in roses. This study offers a valuable genetic resource for investigating the regulatory mechanism of adventitious root formation in roses. [ABSTRACT FROM AUTHOR]

Roses, a popular ornamental crop, often face various abiotic stresses during growth and development, such as cold, drought, and salinity. Rosa multiflora is a commonly used rootstock and exhibits strong resistance to both biotic and abiotic stresses, making it an ideal material for studying mechanisms for resistance. Among the largest plant families, MYB transcription factors play a crucial role in plant abiotic stresses. Our previous research has indicated that RmMYB44 could be involved in the low-temperature response of R. multiflora. This study further investigated RmMYB44, revealing that its expression levels were upregulated in response to chilling, drought, and salt stress. The results suggested its potential role as a key transcription factor in plant resistance to abiotic stresses. Additionally, RmMYB44 encoded a nuclear-localized protein without the self-activating function. The overexpression of RmMYB44 in tobacco plants enhanced the resistance to cold, drought, and salt stresses, as evidenced by the improved growth compared to wild-type (WT) plants under conditions of 4 °C, 30% water-holding capacity, and 200 mM of NaCl, respectively. Moreover, in overexpression tobacco plants, the levels of hydrogen peroxide and malondialdehyde (MDA) were significantly reduced; and the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT); as well as the proline content and the expression levels of NtPOD, NtCAT, and NtCBF; were significantly elevated under abiotic stresses. We assumed that the resistance to abiotic stress in plants conferred by RmMYB44 was associated with the regulation of cell membrane integrity. This study aimed to elucidate the role of the RmMYB44 gene in the resistance mechanism of R. multiflora against abiotic stress, thereby providing a candidate gene for the molecular breeding of abiotic stress resistance in roses and related species. [ABSTRACT FROM AUTHOR]