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ARS Home » Pacific West Area » Logan, Utah » Forage and Range Research » Research » Publications at this Location » Publication #325324
Title: Germination response of Apocynum venetum seeds to temperature and water potential

Author
item RONG, YUPING - China Agricultural University
item LI, HONGXIANG - China Agricultural University
item Johnson, Douglas

Submitted to: Journal of Applied Botany
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/22/2016
Publication Date: 1/24/2016
Citation: Rong, Y., Li, H., Johnson, D.A. 2016. Germination response of Apocynum venetum seeds to temperature and water potential. Journal of Applied Botany. 88:202-208.

Interpretive Summary: Luobuma (Apocynum venetum) is a shrub that is native to Eurasia. It is economically important for sand fixation, forage production, honey production, medicine, fiber and fuel. Rapid and uniform seed germination is critical for successful crop establishment and vegetation restoration. The purpose of this study was to determine the germination responses of luobuma seeds to temperature and water availability. Luobuma seeds germinated the best in a relatively narrow range of temperatures and water availability. These narrow windows of germination and establishment may limit the use of luobuma in arid and semi-arid environments. Plant breeding and selection in A. venetum may be useful in modifying these responses.

Technical Abstract: Apocynum venetum (commonly known as luobuma or rafuma) is a shrub that is native to Eurasia. It is economically important for sand fixation, forage production, honey production, medicine, fiber and fuel. Rapid and uniform seed germination is critical for successful crop establishment and vegetation restoration. The purpose of this study was to determine the germination responses of A. venetum seeds to temperature and water availability using hydrotime, thermal time and hydrothermal model analysis. Seed germination was relatively high for A. venetum from 25 to 30°C. The base (Tb), optimum (To) and ceiling temperatures (Tc(50)) of A. venetum seed germination were 16.6, 27.0 and 45.9°C, respectively. Values of base water potential ('b(g)) shifted to zero with increasing temperature, which was reflected in the greater effect of low ' on germination for temperatures above 30°C. Hydrotime analysis suggested that Tb may not be independent of ', and 'b(g) may change as a function of temperature at temperatures below 30°C. The interaction effects of ' and temperature reduced the ability of the hydrothermal time model to predict germination performance across a wide range of temperature and ' conditions. The narrow thermal range for seed germination and non-uniform germination in response to ' and temperature variation are important limitations to seed germination in A. venetum. These limitations may sufficiently delay or even prevent germination in arid and semi-arid environments, which may limit its usefulness in these water-limited environments. Plant breeding and selection in A. venetum may be useful in modifying these responses.