Seeds of many woody plant species have one of several types of dormancy. They do not germinate unless ,specific environmental signals are in place or events occur. This study was conducted to evaluate the effects of s...Seeds of many woody plant species have one of several types of dormancy. They do not germinate unless ,specific environmental signals are in place or events occur. This study was conducted to evaluate the effects of scarification treatments on seed dormancy and germination of Acacia nilotica （L.） Willd. ex Del., Prosopis juliflora （Sw.） DC. ：and Dodonaea viscosa （L.） Jacq. The following treatments were applied： T1, untreated seed （control）; T2, sulphuric acid （97%） for 45 min; T3, boiling water for 5 min. The seeds were cultured on a Murashige and Skoog （MS） medium after sterilization. The responses of seeds to treatments were compared with each other and with the control treatment. Germination was observed daily for a 30-day period. Results indicated positive responses to treatments, while impermeable Seed coats may be responsible for low germination rates in intact seeds as seen experimentally in the untreated control. The highest germination was obtained for P. juliflora and D. viscosa acid-scarified seeds （80.8%-90.8%） and for scarified seeds of A. nilotica （50.2%） boiled in water. The germination indices, i.e., final germination percentage （FG）, mean daily germination （MDG） and germination rate （GR）, were significantly affected by treatments and species （p 〈 0.01）.展开更多
Soil salinity is becoming an increasingly serious constraint to plant growth in many parts of the world; this is particularly common in semi-arid and arid zones. This study was conducted to evaluate the effect of diff...Soil salinity is becoming an increasingly serious constraint to plant growth in many parts of the world; this is particularly common in semi-arid and arid zones. This study was conducted to evaluate the effect of different concentrations of salt on seed germination and seedling growth of Acacia albida and A. salicina. Collected seeds were treated with H2SO4 98% for 35 min then left to germinate in a controlled growth chamber. Seeds were grown at salinity levels of 0.1, 0.2 and 0.3 mol.L1 of NaH2PO4.H20. Germination parameters and seedling growth indices were measured after 35 days. The mean of total length ofA. salicina in all salinity concentrations was more than that of ：4. albida. The fresh weight of stem and root of ：4, albida was more than that of ：4. salicina. Growth of control seedlings was higher than for other treatments and the fresh weight of stems of two species at salt concentrations of 0.2 and 0,3 mol.Ll decreased with increasing concentration of salt. Most Control seeds germinated at salinity of 0.1 mol.Ll and germination index, final germination and seeds stamina was greater at low levels of salinity.展开更多
Juniperus species （juniper） are resistant to drought and have medicinal properties. In order to investigatethe condition of juniper reproduction and prevent a decline in its area, largely caused by problems in natur...Juniperus species （juniper） are resistant to drought and have medicinal properties. In order to investigatethe condition of juniper reproduction and prevent a decline in its area, largely caused by problems in natural regeneration, the asexual reproduction of juniper has received special attention besides its sexual propagation. Among the six species of juniper in Iran, the most abundant are Juniperus polycarpos and J. excelsa. Juniperus polycarpos is ambi-sexual and J. excelsa unisexual. We show that collecting seeds in September provided for better germination than in November. In sexual propagation 82.0% and in asexual （graft） 47.6% success were achieved. Compared to a mixture of water, lime and hormones, a natural treatment of only water had better results. Diurnal change of temperature increased germination of juniper seeds over a constant temperature. Aphyllous stem cuttings from mature and old trees are less successful in rooting than leafy cuttings of juniper saplings. A treatment with Aaterra significantly reduced the percentage of rooted cuttings and total root length. Aliette, Fongarid, Octave, Benomyl, Delsene M and Maneb fungicides significantly increased the percentage of rooted cuttings but did not affect total root length. Autumn explants formed more calli than spring explants. Successful multiplication was achieved by treating buds with a mixture of 0.7% polyvinyl pyrrolidone （PVP） and 2% sucrose and cultured in a basal MS or WRC medium, with a maximum number of new buds. In consideration of extracted material of juniper species in remedy of infectious, fungus, contagious diseases as well as for drought resistance and longevity of this species in severe arid environmental conditions and various industrial applications, reproduction and seed production by micro propagation and biotechnology are necessary.展开更多
文摘Seeds of many woody plant species have one of several types of dormancy. They do not germinate unless ,specific environmental signals are in place or events occur. This study was conducted to evaluate the effects of scarification treatments on seed dormancy and germination of Acacia nilotica （L.） Willd. ex Del., Prosopis juliflora （Sw.） DC. ：and Dodonaea viscosa （L.） Jacq. The following treatments were applied： T1, untreated seed （control）; T2, sulphuric acid （97%） for 45 min; T3, boiling water for 5 min. The seeds were cultured on a Murashige and Skoog （MS） medium after sterilization. The responses of seeds to treatments were compared with each other and with the control treatment. Germination was observed daily for a 30-day period. Results indicated positive responses to treatments, while impermeable Seed coats may be responsible for low germination rates in intact seeds as seen experimentally in the untreated control. The highest germination was obtained for P. juliflora and D. viscosa acid-scarified seeds （80.8%-90.8%） and for scarified seeds of A. nilotica （50.2%） boiled in water. The germination indices, i.e., final germination percentage （FG）, mean daily germination （MDG） and germination rate （GR）, were significantly affected by treatments and species （p 〈 0.01）.
基金supported by Sari Agricultural Sciences and Natural Resources University
文摘Soil salinity is becoming an increasingly serious constraint to plant growth in many parts of the world; this is particularly common in semi-arid and arid zones. This study was conducted to evaluate the effect of different concentrations of salt on seed germination and seedling growth of Acacia albida and A. salicina. Collected seeds were treated with H2SO4 98% for 35 min then left to germinate in a controlled growth chamber. Seeds were grown at salinity levels of 0.1, 0.2 and 0.3 mol.L1 of NaH2PO4.H20. Germination parameters and seedling growth indices were measured after 35 days. The mean of total length ofA. salicina in all salinity concentrations was more than that of ：4. albida. The fresh weight of stem and root of ：4, albida was more than that of ：4. salicina. Growth of control seedlings was higher than for other treatments and the fresh weight of stems of two species at salt concentrations of 0.2 and 0,3 mol.Ll decreased with increasing concentration of salt. Most Control seeds germinated at salinity of 0.1 mol.Ll and germination index, final germination and seeds stamina was greater at low levels of salinity.
文摘Juniperus species （juniper） are resistant to drought and have medicinal properties. In order to investigatethe condition of juniper reproduction and prevent a decline in its area, largely caused by problems in natural regeneration, the asexual reproduction of juniper has received special attention besides its sexual propagation. Among the six species of juniper in Iran, the most abundant are Juniperus polycarpos and J. excelsa. Juniperus polycarpos is ambi-sexual and J. excelsa unisexual. We show that collecting seeds in September provided for better germination than in November. In sexual propagation 82.0% and in asexual （graft） 47.6% success were achieved. Compared to a mixture of water, lime and hormones, a natural treatment of only water had better results. Diurnal change of temperature increased germination of juniper seeds over a constant temperature. Aphyllous stem cuttings from mature and old trees are less successful in rooting than leafy cuttings of juniper saplings. A treatment with Aaterra significantly reduced the percentage of rooted cuttings and total root length. Aliette, Fongarid, Octave, Benomyl, Delsene M and Maneb fungicides significantly increased the percentage of rooted cuttings but did not affect total root length. Autumn explants formed more calli than spring explants. Successful multiplication was achieved by treating buds with a mixture of 0.7% polyvinyl pyrrolidone （PVP） and 2% sucrose and cultured in a basal MS or WRC medium, with a maximum number of new buds. In consideration of extracted material of juniper species in remedy of infectious, fungus, contagious diseases as well as for drought resistance and longevity of this species in severe arid environmental conditions and various industrial applications, reproduction and seed production by micro propagation and biotechnology are necessary.
