-elongated ex vitro explants as the source under dark–light cycles for plant regeneration through internode tissue cultures. The results of this study provide a new approach to micropropagation of P. callosum for commercial propagation. Materials and Methods
Nguyen Phuc Huy, Vu Quoc Luan, Le Kim Cuong, Nguyen Ba Nam, Hoang Thanh Tung, Vu Thi Hien, Dung Tien Le, Kee Yoeup Paek, and Duong Tan Nhut
Abbas M. Shirazi, Leslie H. Fuchigami, and Tony H.H. Chen
Red-osier dogwood sterns, Cornus sericea L., at ten different growth stages were subjected to a series of temperatures ranging from 25C to 60C by immersing them in a water bath for one hour. After heat treatments, the viability of internode tissues were determined by electrical conductivity and ethylene production. Heat tolerance was expressed as LT50, the temperature at which 50% of the tissues were injured. The results suggest that the LT50 of dormant plants remained relatively constant, approximately 53C. During dormancy, heat stress did not stimulate ethylene production from internode tissues. In contrast, tissues from non-dormant plants exposed to heat stress produced increasing levels of ethylene reaching a peak at 40C followed by a steady decrease at higher temperatures. Application of 1-aminocyclopropane-1-carboxylic acid (ACC) to stem segments from dormant plants, following heat treatment, enhanced production of ethylene.
Tao Wu and Jiashu Cao
Comparisons of total peroxidase activity and peroxidase isozymes as well as protein profiles among segregating, near-isogenic bush and vine phenotypes of pumpkin (Cucurbita moschata Duchesne) were investigated. Peroxidase activities of internode and leaf tissues of the bush plants were higher than those of respective vine tissues. Roots of bush plants, however, had a lower peroxidase activity than vine plants. In both bush and vine plants, peroxidase activities were lower in leaf tissues than in root and internode tissues. Electrophoretic comparisons revealed qualitative differences in peroxidase patterns in internodes between bush and vine plants. Moreover, qualitative differences between internode and root profiles were found between bush and vine plants in C. moschata. In conclusion, the results of this report revealed that a single gene conferring the bush phenotype in C. moschata might affect the relative expression of peroxidase activity, peroxidase isozymes, and protein profiles in leaf, internode, and root tissues.
Andrea Swanberg and Wenhao Dai
capabilities were caused by many factors, especially genotype and explant. This research showed that among leaf and internode tissues in this research and cotyledon and hypocotyl explants (in another experiment, data not shown), only internodal tissues
Alexander G. Litvin, Marc W. van Iersel, and Anish Malladi
) ( Berlyn and Miksche, 1976 ). Internode tissue was sliced longitudinally (40–50 μm thick) using a vibratome (Micro-Cut H1200; Bio-Rad, Hercules, CA) and stained with toluidine blue. Immediately after preparation, sections were viewed under a digital