The main objective of the present study was to identify chromosome number variation in the progenies from triploid × diploid/tetraploid (3x × 2x/4x) crosses in Lilium to analyze the survival of aneuploid embryos from 3x × 2x/4x crosses and the potential significance of triploid for lily breeding. Two male-sterile autotriploid Asiatic lily cultivars were crossed with four diploid and/or two autotetraploid Asiatic cultivars. The results showed that the fruits of all triploid × diploid/tetraploid (3x × 2x/4x) crosses fully developed, and seedlings were obtained from the 3x × 2x/4x crosses, indicating that male-sterile autotriploid lilies can be used as female parents. Chromosome preparation showed that the progenies of the 3x × 2x/4x are predominantly aneuploid. Based on megasporogenesis, we deduce that the endosperm of 3x × 2x is 7x and that of 3x × 4x is 8x in Lilium and conclude that the aneuploid embryo survival of 3x × 2x/4x in Lilium is the result of the euploid endosperm. Lily is usually propagated by scaling or tissue culture; therefore, aneuploids obtained from triploid × diploid/tetraploid lilies would be a good source for cultivar breeding.
Shujun Zhou, Guixue Zhou and Kehu Li
Zhou Li, Yan Peng and Bingru Huang
Gama-aminobutyric acid (GABA) is a nonprotein amino acid in plant cells, which responds to changes in environmental factors. The objectives of this study were to evaluate the effects of foliar spray of GABA on drought and heat tolerance in creeping bentgrass (Agrostis stolonifera), and to investigate physiological factors altered by GABA application that contribute to improved drought tolerance and heat tolerance. GABA-treated plants (cv. Penncross) or non-GABA-treated control plants were then subjected to the following three treatments in growth chambers: 1) nonstress control [plants irrigated every 2 days to maintain soil water content at the pot capacity and maintained at 21/19 °C (day/night) for 35 days], 2) heat stress [plants exposed to 35/30 °C (day/night) and well-watered conditions for 35 days], and 3) drought stress [plants unirrigated for 9 days and maintained at 21/19 °C (day/night), and then rewatered for 2 days]. As compared with untreated plants, GABA-treated plants showed 22% to 39% and 8% to 21% significantly lower leaf electrolyte leakage (EL) and 35% to 143% and 21% to 24% significantly higher turf quality (TQ), 8% to 17% and 17% to 24% relative water content (RWC), 22% to 39% and 25% to 27% chlorophyll content, 7% to 11% and 6% to 17% photochemical efficiency, and an 84% to 683% and 57% to 76% osmotic adjustment (OA) exposed to heat or drought stress across days of treatment, respectively. GABA-treated plants accumulated 7% to 10% more water-soluble carbohydrates (WSC) and 11% to 43% more free proline than nontreated plants under heat stress, and 12% to 30% higher accumulation of WSC under drought stress. After 2 days of rewatering, a significantly better recovery also was observed in GABA-treated plants than that in nontreated plants previously exposed to drought stress. The results suggest that foliar application of GABA significantly improved heat and drought tolerance of creeping bentgrass, which was associated with maintenance of cell membrane stability, delaying in leaf senescence, and enhancing OA. The effectiveness of exogenous GABA application was more pronounced under heat stress than under drought stress.
Xiao-Xian Li and Zhe-Kun Zhou
Northwestern Yunnan is situated in the southern part of the Hengduan Mountains, which is a complex and varied natural environment. Consequently, this region supports a great diversity of endemic plants. Using field investigation in combination with analysis of relevant literature and available data, this paper presents a regional ethnobotanical study of this area. Results indicated that northwestern Yunnan has an abundance of wild ornamental plants: this study identified 262 endemic species (belonging to 64 genera and 28 families) with potential ornamental value. The distinguishing features of these wild plants, their characteristics and habitats are analyzed; the ornamental potential of most plants stems from their wildflowers, but some species also have ornamental fruits and foliage. Among the endemic genera, Pedicularis and Rhododendron have particularly high numbers of ornamental wild species, while Aconitum, Gentiana, Corydalis, Silene, Delphinium, Cremanthodium, and Saussurea also contain significant numbers of wild ornamental species. It is suggested that cultivation of these species may be beneficial, both commercially and to help conserve endangered endemic plant species.
Zhou Li, Yan Peng and Bingru Huang
Small molecules, including H2O2 and Ca, mediate stress signaling and drought tolerance in plants. The objective of this study was to determine whether improvement in drought tolerance by H2O2 and Ca were associated with the regulation of transcription factors and stress-protective genes in perennial grass species. Plants of creeping bentgrass (Agrostis stolonifera) were sprayed with water (control), H2O2 (9 mm), or CaCl2 (10 mm) and exposed to drought stress for 20 days in controlled-environment growth chambers. Foliar application of H2O2 or Ca led to significant improvement in drought tolerance of creeping bentgrass, as demonstrated by greater turf quality, leaf relative water content, chlorophyll content, photochemical efficiency, and cell membrane stability, as compared with the untreated control. The application of H2O2 and Ca resulted in significant up-regulation of genes in Ca signaling transduction pathways [Ca-dependent kinase 26 (CDPK26), mitogen-activated protein kinase 1 (MAPK1), and 14-3-3] and transcript factors (WRKY75 and MYB13). For genes encoding antioxidant enzymes, H2O2 mainly enhanced superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), and dehydroascorbate reductase (DHAR) expression, while Ca primarily improved transcript levels of SOD, monodehydroascorbate reductase (MDHAR), and GR. In addition, heat shock protein 70 (HSP70), metallothionein 1 (MT1), and glutamine synthetase 2 (GS2) were also markedly up-regulated by H2O2 and Ca under drought stress. However, the transcript level of lipoxygenase 3 (LOX3) was significantly down-regulated by H2O2 and Ca under well-watered and drought conditions. These results imply that H2O2 and Ca commonly or differentially regulate genes expression in association with drought tolerance through activating Ca signaling pathway and regulating transcription factors and stress-protective genes expression, leading to the alleviation of lipid peroxidation, maintenance of correct protein folding and translocation, and enhancement of nitrogen metabolism under a prolonged period of drought stress in creeping bentgrass.
Jia Li, Liyun Liu, Huanqi Zhou and Meng Li
Areca (Areca catechu L.) is a tropical plant with great economic importance. In China, the fruit of areca (betel nut) is produced mainly in Hainan Province. However, the yield of betel nuts was impacted seriously by frequent water deficits in Hainan Province. Drought causes deleterious effects on the growth and development of areca plants, especially on young seedlings, which hampered the extensive planting of areca. In this study, a reagent of a superabsorbent polymer (SAP) was applied into the culture soil and we analyzed its function against drought stress when seedlings were grown under different irrigation levels. We observed that SAP application caused a significant increase in plant weight under severe drought, as well as in the maximum photochemical efficiency of PSII (Fv/Fm) and actual photochemical efficiency of PSII [Y(II)] index of chlorophyll (chl), indicating the photosynthetic efficiency of seedlings under severe drought (D) was enhanced by SAP. The antioxidant enzyme activity of areca seedlings under D was indicated to be enhanced by the increasing activity of superoxide dismutase (SOD) and peroxidase (POD), but not catalase (CAT). In addition, SAP even has slight negative effects on the growth of seedlings under adequate water. Our results provide a theoretical basis to improve the viability of areca seedlings under severe drought using SAP, which is urgently needed for the market.
Xiaomeng Li, Rangjin Xie, Zhenhua Lu and Zhiqin Zhou
Citrus species are among the most important fruit trees in the world and have a long cultivation history. However, until now, the exact genetic origins of cultivated Citrus such as sweet orange (Citrus sinensis), lemon (C. limon), and grapefruit (C. paradisi) have remained unidentified. In the present study, amplified fragment length polymorphism (AFLP) fingerprints, nuclear internal transcribed spacer (ITS), and three plastid DNA regions (psbH – petB, trnL – trnF, and trnS - trnG) of 30 accessions of the cultivated citrus and their putative wild ancestors were analyzed in an attempt to identify their paternal and maternal origins. Molecular phylogenetic trees were constructed based on the AFLP data, and chloroplast DNA and ITS sequences using the genus Poncirus as the outgroup. Our results indicated that bergamot (C. aurantifolia) and lemon were derived from citron (C. medica) and sour orange (C. aurantium), and grapefruit was a hybrid that originated from a cross between pummelo (C. grandis) and sweet orange. Rough lemon (C. limon) was probable as a parent of rangpur lime (C. limonia) and guangxi local lemon (C. limonia). Our data also demonstrated that sweet orange and sour orange were hybrids of mandarin (C. reticulata) and pummelo, while rough lemon was a cross between citron and mandarin. For mexican lime (C. aurantifolia), our molecular data confirmed a species of Papeda to be the female parent and C. medica as the male. These findings provide new information for future study on the taxonomy, evolution, and genetic breeding of Citrus.
Jing Zhou, PingPing Li, JiZhang Wang and Weiguo Fu
Light and temperature are two crucial factors affecting plant growth. Light intensities vary considerably with season and weather conditions. Reasonable light regulation at different temperatures is a key issue in environmental regulation. In this study, we determined the effects of light intensity and temperature on crop growth and development. Furthermore, we determined an optimal light value and a suitable light range at different temperatures for producing the lettuce Lactuca sativa L. Artificial climate chamber experiments were conducted at five light intensities (100, 200, 350, 500, and 600 μmol·m−2·s−1), as well as at low (15 °C/10 °C), medium (23 °C/18 °C), and high (30 °C/25 °C) temperatures. In these experiments, we investigated the photosynthetic rate; chlorophyll fluorescence parameters; total N, P, and K uptake; and growth of lettuce plants. The results indicated that at a low temperature, the values of effective quantum yield of photosystem II photochemistry (ΦPSII), net photosynthetic rate (P n), stomatal conductance (g S), and transpiration rate (T r) —as well as those of N, K, and P uptake—were the highest at 350 μmol·m−2·s−1, followed by 500 μmol·m−2·s−1, which resulted in higher values for leaf number (LN), leaf area (LA), dry weight (DW), and fresh weight (FW). At the medium temperature, the values of ΦPSII, P n, g S, and T r, as well as those of N, K, and P uptake were higher at 350, 500, and 600 μmol·m−2·s−1 than at other light intensities, resulting in high values for LN, LA, DW, and FW of lettuce plants. The LN, LA, and FW of lettuce plants were the highest at 500 μmol·m−2·s−1, whereas DW was the highest at 600 μmol·m−2·s−1. At a high temperature, lettuce plants exhibited the highest values of F v/F m, ΦPSII, P n, g S , and T r, as well as those of N, K, and P uptake for the 500 μmol·m−2·s−1 treatment; whereas LN, LA, FW, and DW were the highest at 600 μmol·m−2·s−1. In addition, the values of F v/F m indicated that lettuce plants were under stress under the following combinations: 600 μmol·m−2·s−1 at the low temperature, 100 μmol·m−2·s−1 at the medium temperature, and 100–350 μmol·m−2·s−1 at the high temperature. Based on these results, an optimal regulation strategy for light intensity at different temperature environments was proposed for lettuce cultivars similar to L. sativa L. in some regions, such as the subtropical regions of China. Specifically, for low temperatures, light intensities of 350 to 500 μmol·m−2·s−1are recommended for production, and an intensity of 350 μmol·m−2·s−1 provides optimal supplementary light during early spring and winter in greenhouses. For medium temperatures, light intensities of 350 to 600 μmol·m−2·s−1 are recommended, and 500 μmol·m−2·s−1 is the optimal value during the middle of spring and autumn. For high temperatures, light intensities of 500 to 600 μmol·m−2·s−1are recommended, and 600 μmol·m−2·s−1 is the optimal value of light intensity during late spring and early autumn.
Qianqian Shi, Long Li, Lin Zhou and Yan Wang
Paeonia delavayi is a species endemic to Southwest China and an important genetic resource for flower color breeding of tree peonies. The mechanisms underlying the flower coloration of this plant have not been fully elucidated. In this article, the petals of yellow-colored individual (Pl) and purple–red-colored individual (Pd) of P. delavayi were studied. And anatomical observations revealed that a large amount of yellow protoplasts and a small amount of colorless protoplasts were located in the yellow-colored Pl petals, whereas a mixture of purple, red, and pink protoplasts were observed in the purple–red-colored Pd petals. The Pl cells were subrotund and flat, whereas the Pd cells were irregularly polygon-shaped and bulging. Chemical analyses were performed, and the results indicated that significant differences occurred between the cell sap pH of the Pl and Pd flowers and large differences occurred in the contents of Fe and Al between Pl and Pd. Cyanidin- and peonidin-based anthocyanins with flavones and flavonols as copigments determined the Pd flower color, whereas chalcone 2 ′G with apigenin 7-O-neohesperidoside and chrysoeriol 7-O-glucoside as copigments determined the yellow color of Pl. Correspondingly, the genes dihydroflavonol 4-reductase (DFR) and anthocyanidin synthase (ANS) were significantly highly expressed in Pd, whereas chalcone isomerase (CHI), flavanone 3-hydroxylase (F3H), flavone synthase (FNS), flavonol synthase (FLS), flavonoid 7-O-glycosyltransferase (7GT), and 2′4′6′4-tetrahydroxychalcone 2′-glucosyltransferase (THC) had high transcript levels in Pl relative to Pd. The results indicate that the color variation of P. delavayi petals may be related to a delicately controlled balance of the aforementioned factors.
Hui He, Yanwei Yu, Jiamin Li, Luyun Hu and Fan Zhou
We quantitatively assessed the effects of a six-session edible horticultural therapy (EHT) program on long-term-hospitalized (LTH) female patients with schizophrenia. A total of 60 patients were enrolled in the project and randomly divided into an experimental group (30 patients, received EHT) and a control group (30 patients, did not receive EHT). The two groups were evaluated before and after EHT using the Brief Psychiatric Rating Scale (BPRS), the Chinese version Scale of Social Functioning for Psychotic Inpatients (SSFPI), and the Life Satisfaction Index A (LSIA). The clinical symptoms of patients with schizophrenia improved significantly and they recovered social function, but there was no significant change in life satisfaction. In the control group, clinical symptoms recovered but there was no improvement in social function and life satisfaction significantly decreased. In addition, patients in the EHT group expressed satisfaction with the program. In conclusion, EHT can improve the clinical symptoms of schizophrenia and promote recovery of social function; however, its impact on life satisfaction remains unclear.
Wei Zhou, Hong Wang, De-Zhu Li, Jun-Bo Yang and Wei Zhou
Luculia pinceana Hook. (Rubiaceae) is a typical distylous species with dimorphic and long-styled monomorphic populations. Within this study, we developed 13 microsatellite markers from L. pinceana using a modified biotin–streptavidin capture method. Polymorphism of each locus was assessed in 30 individuals from four dimorphic populations and one monomorphic population. The average allele number of these microsatellites was 4.153 per locus ranging from three to seven. The observed and expected heterozygosities were from 0.040 to 0.840 and from 0.571 to 0.769, respectively. Additionally, all 13 identified microsatellite markers were successfully amplified in its related species, L. yunnanensis, 10 of which showed polymorphism. These microsatellite markers could provide a useful tool for further study of the breeding system and the population genetic structure in this species and within other Luculia species.