Chinese cabbage ( Brassica rapa ) belongs to the Brassicaceae family and includes heading ( Brassica rapa ssp. pekinensis ) and nonheading ( Brassica rapa L. chinensis group) subspecies ( Ke, 2010 ). There are many excellent varieties of
Li Li, Ling Liu, Deshuang Zhang, Ping Wu, Fenglan Zhang and Xiulan Xu
W. Patrick Wechter, Mark W. Farnham, J. Powell Smith and Anthony P. Keinath
“ Brassica leafy greens” is a general term that includes several important vegetable crops, such as turnip greens ( Brassica rapa L.), mustard greens ( Brassica juncea L.), collards and kale ( Brassica oleracea L. Acephala Group). More than 28
De-Kun Dong, Jia-Shu Cao, Kai Shi and Le-Cheng Liu
, an F 2 population was produced from an intersubspecific hybrid between pakchoi [ Brassica rapa L. subsp. chinensis (L.) Hanelt] and turnip ( B. rapa L. subsp. rapifera Metzg); trait performance, QTL patterns, and two-locus epistasis of 11
Wendy A. Johnson, Raymond A. Cloyd, James R. Nechols, Kimberly A. Williams, Nathan O. Nelson, Dorith Rotenberg and Megan M. Kennelly
conventional fertilizer on various pac choi ( Brassica rapa subsp. chinensis cv. Mei Qing Choi) chemical composition and growth parameters; and 2) determine the corresponding effects on DBM development and survival. We chose this study system because a prior
Chandrappa Gangaiah, Amjad Ahmad, Hue V. Nguyen, Koon-Hui Wang and Theodore J.K. Radovich
of 71,659 per hectare with a spacing of 0.30 m between plants and 0.45 m between rows. The required amount of K per plant was divided by the % of K present in each species. For trials 1 and 2, we used pak choi ( B . rapa , Chinensis group) cv. Bonsai
Archana P. Pant, Theodore J.K. Radovich, Nguyen V. Hue and Susan C. Miyasaka
treatments. Three-week-old pak choi ( Brassica rapa, Chinensis) seedlings were transplanted in three rows with 21 plants/plot. Aerated vermicompost teas were prepared by extracting commercially produced chicken manure-based vermicompost in water at 1:10 and
Robert G. Fjellstrom and Paul H. Williams
Thirty-seven Brassica rapa L. and B. juncea L. lines from nine subspecies were tested for their reaction to two pathotypes of Fusarium yellows (Fusarium oxysporum Schlecht. f. sp. conglutinans (Wr.) Snyd. & Hans. race 1 and F.o. f. sp. raphani Kend. & Snyd. A subset of 16 lines from these same vegetable types were tested for their reaction to four strains of turnip mosaic virus (TuMV-C1, C2, C3, and C4). Resistance to both Fusarium pathotypes was widespread in these Brassica subspecies, whereas resistance to any strain of TuMV was uncommon. The broad availability of resistance to Fusarium yellows and scarcity of resistance to TuMV necessitate different approaches to obtain disease-resistant cultivars.
Timothy W. Coolong, William M. Randle, Heather D. Toler and Carl E. Sams
Rapid cycling Brassica rapa L. were grown for 7 days in the presence of 11 levels of zinc (Zn) in hydroponic solution culture and evaluated for changes in Zn and glucosinolate (GS) content. Zinc levels were 0.05, 1, 5, 10, 25, 50, 75, 100, 125, 150, and 200 mg·L-1 Zn. Plants grown in solutions with ≥50 mg·L-1 Zn displayed severe Zn toxicity symptoms, grew little, or died and were not subsequently evaluated for GS content. Shoot Zn concentrations increased linearly with increasing Zn treatment levels. Gluconapin, which accounted for nearly 90% of the aliphatic GSs present, was the only aliphatic GS influenced by Zn, and decreased linearly with increasing Zn levels. Accumulation of glucobrassicin and 4-methoxyglucosbrassicin, both indole GSs, responded with a linear increase and quadratically, respectively, to Zn fertility. An aromatic GS, gluconasturtiin, was also influenced by Zn levels in solution, and had a quadratic response to increasing Zn. This suggested that Zn fertility can influence changes in GS that may affect flavor (bitterness, etc.) or medicinal attributes associated with the GS and their breakdown products, as well as elevate the nutritional status of Zn in the leaves of Brassica.
Federico L. Iniguez Luy and James Nienhuis
Wisconsin Fast Plants (WFP) are small, rapid-cycling Brassica rapa populations that were developed by Paul Williams in the Dept. of Plant Pathology at the Univ. of Wisconsin, to facilitate classroom demonstration of biological principals. WFP exist as heterogenous populations, which have been selected for expression of different mutant phenotypes. Because of self-incompatibility mechanisms, it has been difficult to develop inbred lines of WFP via self-feritilization. Our objective was to inbreed a WFP population through full-sib mating. Genetic diversity was calculated for eight individuals from each of eight different WFF population, using 69 polymorphic RAPD (molecular marker) bands. The eight different WPF populatons were randomly mated (via chain crossing) for two generations. Six cycles of full-sib mating were initiated on 130 random families. After six cycles of full-sib mating, 79 families remain. The loss of families, during the process of inbreeding, may have been due to selection or drift. However, the expectation is that genetic variance will increase. The 79 inbred families express an array of different WFP phenotypes, e.g., anthocyanin pigmentation, yellow cotyledon, plant height, and seed color at different combinations in different inbred lines.
John O. Williams III, Nick Gawel and Jiang-Tian Ling
The lengthy generation times associated with woody ornamentals has led to the exploration of alternatives to traditional breeding methods for the development of new cultivars. This report summarizes the results of experiments designed to examine the feasibility of altering plant morphology by DNA assimilation following electroporation of intact seedlings. Brassica rapa (a nonwoody plant) was chosen as a model plant for initial experiments due to its rapid development and short generation time. Seedlings were subjected to either one or five 300-V pulses (99 ms) in the presence or absence of foreign DNA. Foreign DNA used was Ulmus parvarvifolia at a concentration of 200 μg·mL–1. Results indicate a lower survival rate of seedlings electoporated in the presence of DNA. Data were recorded after 21 days for plant height and leaf number. No significant differences were noted for plant height. However, significantly more leaves were produced on plants electroporated (five pulses) in the presence of foreign DNA. These results suggest the possible utilization of this technique for induction of variation in other plants.