China is the distribution center of
Limei Yang, Ye Peng, Feng Yang, Donglin Zhang, and Wangxiang Zhang
China is the distribution center of
Le-Jing Lin, Li Lin, and Zhi-Yong Zhu
Li Xu, Fangyun Cheng, and Yuan Zhong
Paeonia ostii ‘Feng Dan’ is an economically important, multipurpose woody plant in terms of its medical, ornamental, and oil values; however, there is a noticeable contradiction between the increasing demands and the lack of excellent germplasm resources because of traditional breeding and propagation approaches. In vitro embryo culture is an attractive option for this issue. This study presents a protocol for in vitro immature embryo culture in P. ostii ‘Feng Dan’, which involves two steps: 1) immature seeds at 30 days after anthesis (DAA) (cellularization stage of endosperm, proembryo stage) or after being cultured in vitro for cotyledon embryo formation (upward micropyle with placenta was the best inoculation method with the highest ratio of seed with cotyledon embryo of 66.67%); and 2) seedling establishment was realized within 7 months via embryo (at 40 DAA or after) germination, shoot induction, rooting, and acclimatization. The multiplication potential was increased with embryo maturity. This protocol provides an available reference for embryo rescue and propagation of tree peony and will be beneficial to shortening the breeding cycle.
Herbaud P.F. Zohoungbogbo, Enoch G. Achigan-Dako, Judith Honfoga, Shih-Wen Lin, Tsung-Han Lin, Yen-Wei Wang, Yuan-Li Chan, Peter Hanson, and Derek W. Barchenger
Habanero (Capsicum chinense Jacq.) is widely grown and consumed in West and Central African countries, and viral diseases represent an important production challenge. Diagnosis of the viral species affecting habanero productivity in Benin is limited, and understanding this will enable more efficient host resistance breeding. During 2019 and 2020, we characterized the incidence and severity of the viral diseases infecting nine promising habanero breeding lines and one commercial hybrid check under open field conditions in Benin. The horticultural performance, including yield and yield component traits of the entries, was determined during the 2 years of the experiment. A randomized complete block design was used with three replications, each with 24 plants. Data were recorded on days to 50% flowering and 50% fruit maturity, yield and on the yield components of fruit weight (g), fruit length (cm), and fruit width (mm), as well as disease incidence and severity. In total, 35 leaf samples were collected for viral diagnosis among habanero breeding lines. We found that Pepper veinal mottle virus (PVMV; Potyvirus) was the overwhelmingly predominant virus in our trials, with an 80% incidence; however, we found frequent coinfection of PVMV with Cucumber mosaic virus (CMV, Cucumovirus), Polerovirus, and, to a lesser extent, Chili veinal mottle virus (ChiVMV; Potyvirus). The mean disease incidence across all entries was 60%. AVPP1932 and PBC 2010 had the lowest disease incidence (35% and 43%, respectively), whereas AVPP1929 had the highest (86%) disease incidence. The F1 hybrid check Afadja had the overall highest yield, with 30 t⋅ha−1, followed by AVPP1932, with 19 t⋅ha−1, both in 2019. There was a negative correlation between disease incidence and total yield (r = −0.44; P < 0.001), supporting previous studies indicating that viral diseases are major production constraints for habanero in West Africa. This study provides insight regarding the need to improve habanero for resistance to aphid-transmitted viruses and develop integrated pest management strategies to limit losses in Benin.
Kenneth Buck, Margaret Worthington, and Patrick J. Conner
Rooting hardwood cuttings from muscadine (Vitis rotundifolia Michx. syn. Muscadinia rotundifolia) vines has traditionally been considered an exceptionally difficult task. Many previous studies observed almost no root formation, leading to a general consensus that muscadines should either be propagated by softwood cuttings or vegetative layering. However, the University of Arkansas System Division of Agriculture Fruit Breeding Program has been using a hardwood rooting protocol for muscadines with moderate success for the past 10 years. The application of this protocol to meet the modest propagation needs of the breeding program has significantly shortened the time required to advance selections. The goal of this research was to more adequately describe the factors affecting the rooting ability of hardwood muscadine cuttings. This research investigated the effects of cultivar, bottom heat, cold storage, vineyard location, and cutting collection date on the outcome of muscadine hardwood cuttings. The study was conducted during the dormant seasons of 2019–20 and 2020–21, and an overall rooting percentage of 16% was observed. There were multiple higher-order interactions affecting rooting efficacy. Cuttings taken in November generally rooted at higher rates, although interactions with vineyard location and cultivar played a significant role in those results. The Ocilla, GA, location performed exceptionally well in November with rooting percentages greater than 40%. The effects of supplying bottom heat and/or a cold storage treatment on rooting success declined as the dormant season progressed. Other variables such as increased cutting length and diameter were associated with increased rooting success. A second statistical analysis using only data from November showed that when cuttings were not given a cold storage treatment that rooting percentages were greater than 27%. Ultimately, this research shows that institutions with modest muscadine propagation needs can successfully propagate plants from hardwood cuttings.
Maureen M. M. Fitch, Mary Joy Ancheta, Luyen C. Huynh, Xiaoling He, Marjorie A. Ortega, Hideko K. Fields, Carol M. Murakami, Josienellie R. Shaw, and Jeremiah-James Lopez
In Hawaii, the commercial papaya industry is based on cultivars that segregate as females or hermaphrodites. Multiple seedlings are planted and then thinned at flowering to single hermaphrodites at each site. The aim of this study was to increase propagation efficiency by improving our procedure for micropropagation of hermaphrodite plants only. Initially, shoots were multiplied in vented jars on M2 medium, a Murashige and Skoog formulation containing 0.25 μM 6-benzyladenine (BA) and 0.1 μM α-naphthalene acetic acid (NAA). At weekly intervals, micropropagated shoots were either incubated for 4 to 7 days in IBA2 medium containing 20 μM indole-3-butyric acid (IBA) or were dipped in autoclaved rooting powder containing 0.8% IBA (DIP); then, they were placed in M2 until root initials or small roots were visible. After root induction in both treatments, plants were transferred to an in vitro medium containing ½ MSO and 30 g⋅L−1 sucrose in vermiculite (VER). The IBA2 treatment produced 467 potted plants compared to 475 produced by the DIP treatment; however, the average number of days that each treatment required from root induction to potting of rooted plants was not significantly different (IBA2: 52.42 ± 5.65 days; DIP: 51.94 ± 3.61 days). Plants from both treatments were grown in either wet potting medium (500 mL water/300 g potting medium) or damp potting medium (120 mL water/300 g potting medium) to test the effect of moisture content on plant survival and growth after potting. Use of damp rather than wet potting medium resulted in significantly higher plant survival and growth. These results could facilitate more efficient commercial practice for papaya growers.
Seon-Ok Kim, Su Young Son, Min Ji Kim, Choong Hwan Lee, and Sin-Ae Park
Mycobacterium vaccae is a species of nonpathogenic bacterium that lives naturally in soil. This study compared the physiological effects at a metabolomic level with autonomic nervous system responses in adults during soil-mixing activities, based on the presence or absence of M. vaccae in the soil. Twenty-nine adult participants performed soil-mixing activities for 5 minutes using sterilized soil with culture media and M. vaccae, respectively. Blood samples were drawn twice from each participant after each activity. Electroencephalograms and electrocardiograms were measured during the activity. Serum metabolites underwent metabolite profiling by gas chromatography, followed by multivariate analyses. Soil-emitted volatile organic compounds were identified using the solid-phase microextraction and gas chromatography-mass spectroscopy, followed by multivariate analyses. The volatile compound analysis revealed that the metabolites related to esters and sulfur-containing compounds are greater in soil with M. vaccae. Serum metabolomics revealed that the treatment group (soil inoculated by M. vaccae) possesses relatively higher levels of inter-alia organic and amino acids compared with the control group (soil mixed with culture media). In the treatment group, the electroencephalogram and electrocardiogram revealed that alpha band activity of the occipital lobe increases, while heart rate decreases. This study concludes that M. vaccae soil contact can affect human metabolic and autonomic reactions.