GUL, BILQUEES* AND DARRELL J. WEBER. Department of Botany and Range Science, Brigham Young University, Provo, Utah 84602-5181. - Alleviation of seed dormancy in Allenrolfea occidentalis.
Allenrolfea occidentalis (Wats.) Kuntze, a perennial halophytic
shrub in the family Chenopodiaceae, is widely distributed in the
temperate deserts of Western North America. Plants produce seeds under
high salinity conditions and seeds readily germinated at low or no
salinity and increase in salinity inhibited or delayed germination and
no seed germinated at 800 mM NaCl. Experiments were conducted to
determine the influence of compatible osmotica (Betaine and Proline)
and growth regulators (Gibberellic acid and Kinetin) in alleviating
salinity stress on the seed germination of A. occidentalis. All
dormancy relieving compounds significantly (P < 0.0001) promoted
germination at all salinity treatments. The compatible osmotica and
growth regulators stimulated the seed germination under salt stress
but also overcame the delaying effect of the salt on the seed
germination. Low concentrations of betaine (0.1 mM) and proline (0.1
mM) completely alleviated the salinity-induced dormancy of the seeds
at all salinity treatments. Plant growth regulators, GA3 (0.3 mM) and
Kinetin (0.05 mM) at their low concentrations significantly (P <
0.0001) improved the germination under salinity treatment. The effect
of Kinetin was more pronounced than GA3.
Key words: Allenrolfea occidentalis, compatible osmotica, germination, growth regulators, halophyte, salinity