Mountain Scholar

Mountain Scholar is an open access repository service that collects, preserves, and provides access to digitized library collections and other scholarly and creative works from Colorado State University and the University Press of Colorado. It also serves as a dark archive for the Open Textbook Library.

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Colorado State University, Fort Collins 29131
Explore the Colorado State University community’s scholarly output as well as items from the University at large and the CSU Libraries.
Open Textbook Library Archive 1866
A limited number of titles are available here. To see all OTL titles, please visit the Open Textbook Library at https://open.umn.edu/opentextbooks. Only Open Textbook Library staff have access to all OTL Archive titles held in Mountain Scholar.
University Press of Colorado 1106
Access is limited to University Press of Colorado members. Non-members: to purchase books, please visit https://upcolorado.com/.

Recent Submissions

Access status: Open Access ,
Colorado Wood Utilization and Marketing Program: technical bulletin
(2006) Colorado Wood Utilization and marketing Program, author; Colorado State Forest Service, publisher
Access status: Open Access ,
Forest products business planning guide: business plan strategies for start-up and existing business owners
(2013) Gardner, Dawn, author; Johnson, Randy, author; Colorado State Forest Service, publisher
Access status: Open Access ,
Colorado forest carbon inventory: forest ecosystem and harvested wood product carbon accounting framework through 2019
(2024-12-11) Vorster, Anthony G., author; Choi, Christopher Tsz Hin, author; Prentice, Ashley M. author; Young, Nicholas, author; Kuegler, Olaf, author; Gaetani, Maria author; Fordham, Amanda West, author; Bucholz, Ethan, author; Colorado State Forest Service, publisher
Access status: Open Access ,
2024 Incentives for Local Government Grant Program report
(2024-12-23) Colorado State Forest Service, author
Access status: Open Access ,
Sensory physiology of dodder (Cuscuta spp) seedlings prior to host attachment
(1992) Haidar, Mustapha A., author; Orr, Gregory L., advisor; Westra, Philip, advisor
Dodder is an obligate stem parasite. Characteristic of seedlings of holoparasitic higher plants, early detection of potential hosts by young seedlings is essential for survival. An array of sequential environmental cues mediate dodder development and modify its growth from a non-parasitic higher plant to a parasitic growth mode. Exposure of the apical hook of etiolated seedling to red light stimulates hook opening. Only de-etiolated higher plant seedlings have the potential to transform to the parasitic mode of growth. In white light dodder begins nutating 'in search' of a host. Neighboring plants (i.e., potential hosts) are detected by dodder initially by changes in light quality. Within the sphere of influence of a neighboring plant, an environment enriched in B and FR light potentiates a change in the state of the thread-like organ of dodder to that of its parasitic growth mode. When a dodder seedling contacts a potential host, its growth slows. Potentiation for change in growth has now become actuated. The seedling forms tight coils around the host stem. At this stage, dodder seedlings become susceptible to mechanical stimulation (thigmomorphogenesis). Soon prehaustoria develop (an early stage infection structure) on the concave side of coils. Auxin/cytokinin ratios and other chemicals· influence development of these structures. Ethylene has no effect at this stage. De-etiolation of dodder seedlings (hook opening) is controlled by phytochrome. Phytochrome maintains dodder as a non-parasitic higher plant seedling. Parasitic growth of dodder (twining and prehaustoria development) is controlled by two photoreceptors: phytochrome and a specific UV-A/B light photoreceptor (cryptochrome). The involvement of phytochrome was demonstrated by light pulses and R/FR reversibility experiments. Based on chemical and light studies, our results indicate that phytochrome (type I and II) alone cannot mediate parasitic growth of dodder under B light. Blue light acts via a specific UV-A/B photoreceptor, possibly flavin. However, the state of phytochrome is the principal limiting factor that affects B light action. The FR-absorbing form of type II phytochrome (Pfr II) opposes the action of cryptochrome; Pfr II opposes the action of an excited state of cryptochrome on coiling and prehaustoria formation. The data indicate that cryptochrome action is dependent on the state of phytochrome (ϕ). A model of interaction between phytochrome and cryptochrome have been proposed. Both photoreceptors are competing for the same intermediate, X; or same intermediate state, X' in mediating dodder parasitic growth.