Search Results

You are looking at 41 - 50 of 55 items for

  • Author or Editor: Donglin Zhang x
Clear All Modify Search

Lagerstroemia is a genus with a wide geographical range extending from Southeast Asia to Australia, and it plays a significant role in many aspects of urban life, including supporting ecosystems, beautifying cities, and affecting human health. To gain insights into the current state of Lagerstroemia research, a bibliometric analysis was conducted using 138 publications from the Web of Science core database between 2002 and 2022. The analysis involved co-occurrence analyses of authors’ affiliated institutions, a keyword co-occurrence analysis, and a timeline view of keywords. The results of the analysis revealed three stages of Lagerstroemia research: the initial stage (2002–04); the rapid growth stage (2005–13); and the in-depth stage (2014–present). Furthermore, 335 keywords from 10 clusters were identified, which indicated that genetic diversity, breeding, and landscape utilization were the three main research areas of Lagerstroemia. Collaboration among authors mainly occurred within major natural and cultivated regions, such as China and the United States. Based on the bibliometric evaluation, future research of Lagerstroemia should focus on areas such as whole-genome sequencing, male sterility problems, resistance, ornamental characteristics, and landscape utilization guidelines. The findings of this study provide an important reference for further studies and can guide the development, innovation, and application of Lagerstroemia.

Open Access

Platycodon grandiflorus (Jacq.) A. DC. `Sentimental Blue' can be used as a pot plant and garden perennial. Plants can be grown year-round in a greenhouse as cutting flowers if supplemental heat is provided in the winter. Sowing time did not affect plant growth and flowering. Seeds took 10 to 20 days to germinate at 20–25 °C day/15–20 °C night temperatures. As the day/night temperature decreased, time to germination increased and germination rate decreased. Temperature also influenced shoot proliferation and number of basal branches increased as temperature decreased. Plants reached reproductive growth about 20 days after transplanting and took another 20 days to reach full bloom. Open flowers lasted 3–7 days. Cold treatment was not necessary for flowering, but plants were forced into dormancy when provided with 5 °C for 4 or more weeks. Plants began to emerge 2 to 3 months later and two growth forms, “rosette” and “dwarf”, occurred in the second growth cycle. The dwarf form produced one or two stems with six to eight clustered flowers per stem while the rosette form produced an average of 10 stems with one or two flower per stem. For the “rosette” form, each stem could be divided as a new plant.

Free access

Arabis sturii Mottet (Brassicaceae) has potential as a new crop for American nurseries and may be used as a perennial pot plant. Cold treatment was required for flowering of Arabis sturii and a 6-week cold treatment resulted in the greatest number of racemes and flowers per plant. Increasing or decreasing length of cold treatment resulted in less flowers per plant. Plant height increased as duration of cold treatment increased. Photoperiod had a significant effect on flowering and growth only after plants received 3 weeks or more cold treatment. All plants given a 16-h photoperiod flowered, while only 50% and 80% flowered under an 8- or 12-h photoperiod, respectively. A 16-h photoperiod shortened the time to production of flower buds and anthesis and the greatest difference occurred after the 9-week cold treatment. At the 6-week cold treatment, number of flowers per plant different significantly between long (145 flowers) and short day (59). The effect of photoperiod on number of flowers per plant became less as cold treatment increased or decreased. Although photoperiod did not induce flower initiation, it had a tremendous effect on flower development. Many more flowers were produced and plants were taller as photoperiod increased. No significant difference was found in plant dry weight.

Free access

Lysimachia congestiflora Wils. (Primulaceae) is a new crop for American nurseries and may be used as an annual in the north and a half-hardy perennial in the south. The purpose of this study was to investigate the influence of photoperiod, temperature, and irradiance on its flowering and growth. Three experiments were conducted with photoperiod of 8, 12, 16 hrs day-1, temperature of 10, 18, 26C, and irradiance of 100, 200, 300 μmol m-2s-1, respectively. Plant.9 given long day photoperiod (16 hours) flowered 21 and 34 days earlier, respectively, than plants at 12 sad 8 hour photoperiods. Plants under long day treatment produced more flowers than those at 8 and 12 hours. Plant dry weight did not differ between treatments, but plants grown in the long day treatment produced fewer but larger leaves. Total plant growth increased as temperature increased, but lower temperature (10C) decreased flower initiation and prevented flower development, while high temperature (26C) reduced the longevity of the open flowers. Flowering was accelerated and dry weight increased as plants were subjected to high irradiance levels. The results suggest that Lysimachia congestiflora is a quantitative long day plant. It should be grown under a photoperiod of at least 12 hours at a temperature of approximately 20C. Low light areas should be avoided and supplemental lighting to provide the long days may improve the plant quality.

Free access

Chimonanthus praecox (wintersweet) is endemic to China. It has been cultivated there for more than 1000 years as a garden, potted, and cut-flower plant. Many cultivars have been developed during its long history of cultivation, and recently many germplasms were collected in Wuhan and Nanjing, China. The identification and genetic relationship of these resources were studied based mainly on morphological traits. In the current study, intersimple sequence repeat markers (ISSR) and random amplified polymorphic DNA markers (RAPD) were used for the first time to investigate 72 wintersweet clones from the two regions. Eleven ISSR primers amplified 115 bands, 90 (78.26%) of which were polymorphic. Nineteen RAPD primers amplified 165 bands, 105 (63.63%) of which were polymorphic. Either ISSR or RAPD markers were sufficient to distinguish all the clones surveyed. A Dendrogram based on Jaccard's similarity coefficients indicated that the distribution pattern of the 72 clones was coherent with their geographical origins. Most of the genetic variation (85.68% with ISSR data; 86.75% with RAPD data) occurred among clones within each region. However, the difference between Wuhan and Nanjing groups is statistically significant (ΦST = 0.143, P < 0.001, with ISSR data; ΦST = 0.132, P < 0.001, with RAPD data). Morphological variation and classification of wintersweet cultivars were also discussed compared with the genetic relationship based on ISSR and RAPD markers. This is the first report of the partitioning of genetic variability within and between different cultivated wintersweet regions, and it provides useful baseline data for optimizing sampling strategies in breeding. These results are important for future genetic improvement, identification, and conservation of Chimonanthus praecox germplasm.

Free access