TY - JOUR
T1 - Physiological dormancy and germination requirements of seeds of several North American Rhus species (Anacardiaceae)
AU - Li, Xiaojie
AU - Baskin, Jerry M.
AU - Baskin, Carol C.
PY - 1999/9
Y1 - 1999/9
N2 - Fourteen seedlots of five species of Rhus were surveyed for presence/absence of physiological dormancy and/or for germination requirements of nondormant seeds. Physiological dormancy was present in the four seedlots of R. aromatica studied, but not in either of the two seedlots of its close relative R. trilobata, which is in contrast to previous reports. Neither were seeds of R. glabra, R. typhina, nor R. virens physiologically dormant. Stratification at 5°C for 1 week or incubation in 500 or 1000 mg/l solutions of gibberellic acid broke physiological dormancy in > 90% of the R. aromatica seeds. Maturation desiccation acted as a switch from a developmental to a germinative mode in R. aromatica embryos, whereas it was not required for germination of R. glabra or R. virens (R. trilobata and R. typhina not tested). Seeds of all five species incubated on a moist substrate became fully imbibed in 2 d, at which time moisture content was approx. 70-80% of their initial weight. In general, germination of non-dormant seeds was rather insensitive to temperature and light. Seeds germinated equally well in light and in darkness over a daily (12 h/12 h) temperature range of 15/6-35/20°C. Over a 4 week period, the best germination percentages were obtained at 25/15 and 20/10°C, whereas 35/20°C appeared to be supraoptimal, though not always significantly so. If the incubation period was extended to 30 weeks, germination percentages were as high at 15/6°C as at 25/15 and 20/10°C.
AB - Fourteen seedlots of five species of Rhus were surveyed for presence/absence of physiological dormancy and/or for germination requirements of nondormant seeds. Physiological dormancy was present in the four seedlots of R. aromatica studied, but not in either of the two seedlots of its close relative R. trilobata, which is in contrast to previous reports. Neither were seeds of R. glabra, R. typhina, nor R. virens physiologically dormant. Stratification at 5°C for 1 week or incubation in 500 or 1000 mg/l solutions of gibberellic acid broke physiological dormancy in > 90% of the R. aromatica seeds. Maturation desiccation acted as a switch from a developmental to a germinative mode in R. aromatica embryos, whereas it was not required for germination of R. glabra or R. virens (R. trilobata and R. typhina not tested). Seeds of all five species incubated on a moist substrate became fully imbibed in 2 d, at which time moisture content was approx. 70-80% of their initial weight. In general, germination of non-dormant seeds was rather insensitive to temperature and light. Seeds germinated equally well in light and in darkness over a daily (12 h/12 h) temperature range of 15/6-35/20°C. Over a 4 week period, the best germination percentages were obtained at 25/15 and 20/10°C, whereas 35/20°C appeared to be supraoptimal, though not always significantly so. If the incubation period was extended to 30 weeks, germination percentages were as high at 15/6°C as at 25/15 and 20/10°C.
KW - Imbibition
KW - Light and seed germination
KW - Physiological seed dormancy
KW - Rhus spp.
KW - Temperature and seed germination
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U2 - 10.1017/s0960258599000240
DO - 10.1017/s0960258599000240
M3 - Article
AN - SCOPUS:0032713360
SN - 0960-2585
VL - 9
SP - 237
EP - 245
JO - Seed Science Research
JF - Seed Science Research
IS - 3
ER -