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The current Cucumis taxonomic classification places C. hystrix Chakr. in subgen. Cucumis based on its morphological similarities to cucumber (C. sativus L., 2n = 14). However, the chromosome number of C. hystrix was identified as 2n = 24, the same number as in subgen. Melo. Cucumis hystrix is therefore considered the first wild Cucumis species of Asiatic origin possessing 12 basic chromosomes. Thus, any research regarding its biosystematics would challenge the basic chromosome number and geographic location theories that govern the current taxonomic system. The production of the amphidiploid species (Cucumis ×hytivus Chen and Kirkbride, 2n = 38) obtained from the cross between C. hystrix and C. sativus and subsequent chromosome doubling would provide an effective means of investigating the relationship between Cucumis species with two different basic chromosome numbers. Thus, RAPD markers were used to study the taxonomic placement of C. hystrix and its interspecific hybrid with cucumber. Of the 220 arbitrary primers screened, 31 were used for analysis where 402 (96.3%) fragments were polymorphic among the germplasm examined. A UPGMA-based cluster analysis partitioned 31 accessions into two main groups [C. sativus (CS) and C. melo (CM)]. Under the similarity coefficient threshold of 0.23, these two groups can be further divided into five clusters with C. hystrix, C. ×hytivus, and C. sativus as separate clusters in the CS group. A modified taxonomic system is proposed based on these results and findings of a previous chloroplast DNA analysis with the genus Cucumis containing subgen. Cucumis with three species and subgen. Melo with six series.
Variegated temple bamboo (Sinobambusa tootsik f. luteoloalbostriata) is one of the native variegated bamboo species has some whole green (WG) and whole white (WW) leaves in addition to striped green and white ones. The life span of WW leaves is short, but the life span of striped leaves (SLs) is unaffected by the area of white mesophyll, and the SL phenotype is well maintained. To explore the mechanism of phenotypic stability of SL, we took five leaf phenotypes as study materials: WG, WW, SL, the green part of SL (SG), and the white part of SL (SW). Through the measurement of photosynthetic pigments, leaf nutrient elements, chloroplast synthesis–related hormones and their precursors in the leaves, and antioxidant system parameters, we examined the antioxidant adaptation mechanism of the white mesophyll cells of S. tootsik f. luteoloalbostriata. The results indicated that abscisic acid (ABA) levels were substantially higher in WW leaves than in SW leaves, and salicylic acid (SA) levels were significantly higher in SW leaves compared with WW leaves. Levels of 12-oxo-phytodienoic acid (OPDA), and SA were substantially higher in WW and SW than in the leaves of the other three phenotypes. Glutathione (GSH) levels were substantially higher in SW than in SG and reactive oxygen species (ROS) levels were significantly lower. Overall, the white mesophyll cells of S. tootsik f. luteoloalbostriata had strong antioxidant properties. SA and OPDA jointly act on the antioxidant pathway to reduce the content of ROS in leaves, thus ensuring the stability of SL.
Tea (Camellia sinensis L.) is an important cash crop. In the context of climate change, analyzing the current distribution of tea trees and climate change environmental variables to predict the potential distribution area of tea trees in the future can help decision-makers make appropriate planting decisions and promote sustainable management. In this study, an optimized MaxEnt model was used to predict the limiting factors of tea tree growth and distribution under current and future climate change scenarios. The climate soil mixing model [area under the curve (AUC) = 0.934] performed excellently. The results showed that precipitation, temperature, slope, and soil factors all affected the distribution of suitable habitats for tea trees. Compared with the current distribution area of tea trees, under three shared socioeconomic pathways (SSP126, SSP245, and SSP585), the area of highly suitable habitats for tea trees will expand, especially in 2061–2080 and 2081–2100 years, and the suitable area will extend overall to the north of China, indicating that future climate change may create more new suitable habitats for tea production, especially in Shandong, Shaanxi, Guizhou, and Yunnan provinces. This study will provide important scientific insights for tea production decision-making, tea garden location selection, and future adaptation methods, and will help in the cultivation and transplantation of tea trees in the future.
Advancements in electronic devices have led to increases in mental stress in modern adults, and removing this stress is crucial for mental health. The purpose of this study is to examine the psychophysiological benefits of contact with indoor plants. The effects of transplanting plants (horticultural activity) and work on a mobile phone (control activity) were assessed by blood pressure measurement, electroencephalography (EEG), the semantic differential method (SDM), and the State-Trait Anxiety Inventory (STAI). The SDM data showed that the subjects felt more relaxed, comfortable and natural, and experienced lower anxiety after the transplantation of plants than the control group. Participant’s total alpha and beta wave mean values increased over time during the transplantation task but decreased at the end of the control task. The mean meditation score was significantly higher after transplanting plants. Our study results indicate that contact with plants may minimize mental stress.
Cytosine methylation plays important roles in regulating gene expression and modulating agronomic traits. In this study, the fluorescence-labeled methylation-sensitive amplified polymorphism (F-MSAP) technique was used to study variation in cytosine methylation among seven pecan (Carya illinoinensis) cultivars at four developmental stages. In addition, phenotypic variations in the leaves of these seven cultivars were investigated. Using eight primer sets, 22,796 bands and 950 sites were detected in the pecan cultivars at four stages. Variation in cytosine methylation was observed among the pecan cultivars, with total methylation levels ranging from 51.18% to 56.58% and polymorphism rates of 82.29%, 81.73%, 78.64%, and 79.09% being recorded at the four stages. Sufficiently accompanying the polymorphism data, significant differences in phenotypic traits were also observed among the pecan cultivars, suggesting that cytosine methylation may be an important factor underlying phenotypic variation. Hypermethylation was the dominant type of methylation among the four types observed, and full methylation occurred at higher levels than did hemimethylation in the pecan genomes. Cluster analysis and principal coordinate analysis (PCoA) identified Dice coefficients ranging from 0.698 to 0.778, with an average coefficient of 0.735, and the variance contribution rates of the previous three principal coordinates were 19.6%, 19.0%, and 18.2%, respectively. Among the seven pecan cultivars, four groups were clearly classified based on a Dice coefficient of 0.75 and the previous three principal coordinates. Tracing dynamic changes in methylation status across stages revealed that methylation patterns changed at a larger proportion of CCGG sites from the 30% of final fruit-size (30%-FFS) stage to the 70%-FFS stage, with general decreases in the total methylation level, the rate of polymorphism, and specific sites being observed in each cultivar. These results demonstrated that the F-MSAP technique is a powerful tool for quantitatively detecting cytosine methylation in pecan genomes and provide a new perspective for studying many important life processes in pecan.