The effects of various salinities and desalination on seed germination of six annual glycophytes （Artemisia sieversiana, A. scoparia, Chloris virgata, Eragrostis pilosa, Chenopodium acuminatum and Chenopodium glaucum...The effects of various salinities and desalination on seed germination of six annual glycophytes （Artemisia sieversiana, A. scoparia, Chloris virgata, Eragrostis pilosa, Chenopodium acuminatum and Chenopodium glaucum） were studied in Horqin Sandy Land, Inner Mongolia, China. NaCl solutions of five concentrations （0 mM, as the control, and 50, 100, 200 and 300 mM） were used for saline stress and desalination treatments. Increasing salinity significantly reduced germination percentages of A. sieversiana, A. scoparia, Ch.virgata and Ch. acuminatum, but had no effect on the germination percentages of E. pilosa. Lower salinity levels （50 mM） significantly increased germination percentage of Ch. glaucum. High salinity might be a precondition for germi- nation after desalination for five of the six species, excepting E. pilosa at NaCl concentration of 300 mM in comparison with non-primed seeds. Higher salinity （200 mM） led to some specific ion toxicity and reduced seed viability of A. sieversiana. No specific ion toxicity but an osmotic effect limited the germination of other five species was observed The final germination percentages （salinity stress and desalination） of the six species showed three variations in comparison with the controls, namely, indiscrimination, stimulation, and reduction. Germination responses to salinity and desalination suggested that the six species were separated into three categories. Three species （A. sieversiana, Ch. virgata and Ch. acuminatum） showed similar germination responses to salinity with those of halophyte, but also showed a lower tolerance limit than most halophytes, although this was not always the case. A. scoparia and Ch. glaucum exhibited some ‘salt stimulation’ in seed germination percentages after desalination, whereas E. pilosa did not show any obvious responseto salinity. Therefore, salinity usually induces dormancy of seeds with strong germination capacity in fresh water, but has few, or even positive, effects on seeds with strong innate dormancy.展开更多
评价20%精草铵膦铵盐可溶液剂对非耕地杂草的防除效果。于杂草生长盛期采用茎叶喷雾法进行田间小区试验。试验药剂20%精草铵膦铵盐可溶液剂剂量为300~600 g a.i./hm^(2)时,对非耕地禾本科杂草和阔叶杂草均有较好的防效,药后20 d,总草株...评价20%精草铵膦铵盐可溶液剂对非耕地杂草的防除效果。于杂草生长盛期采用茎叶喷雾法进行田间小区试验。试验药剂20%精草铵膦铵盐可溶液剂剂量为300~600 g a.i./hm^(2)时,对非耕地禾本科杂草和阔叶杂草均有较好的防效,药后20 d,总草株防效和鲜重防效分别为93.32%~97.69%、97.69%~99.53%;对照药剂20%精草铵膦铵盐可溶液剂在450 g a.i./hm^(2)剂量时的总草株防效和鲜重防效分别为95.14%、98.52%。20%精草铵膦铵盐可溶液剂可以有效防除非耕地杂草,推荐剂量300~600 g a.i./hm^(2)。展开更多
基金supported by National Nature Science Foundation of China(No.40701097,41071187)
文摘The effects of various salinities and desalination on seed germination of six annual glycophytes （Artemisia sieversiana, A. scoparia, Chloris virgata, Eragrostis pilosa, Chenopodium acuminatum and Chenopodium glaucum） were studied in Horqin Sandy Land, Inner Mongolia, China. NaCl solutions of five concentrations （0 mM, as the control, and 50, 100, 200 and 300 mM） were used for saline stress and desalination treatments. Increasing salinity significantly reduced germination percentages of A. sieversiana, A. scoparia, Ch.virgata and Ch. acuminatum, but had no effect on the germination percentages of E. pilosa. Lower salinity levels （50 mM） significantly increased germination percentage of Ch. glaucum. High salinity might be a precondition for germi- nation after desalination for five of the six species, excepting E. pilosa at NaCl concentration of 300 mM in comparison with non-primed seeds. Higher salinity （200 mM） led to some specific ion toxicity and reduced seed viability of A. sieversiana. No specific ion toxicity but an osmotic effect limited the germination of other five species was observed The final germination percentages （salinity stress and desalination） of the six species showed three variations in comparison with the controls, namely, indiscrimination, stimulation, and reduction. Germination responses to salinity and desalination suggested that the six species were separated into three categories. Three species （A. sieversiana, Ch. virgata and Ch. acuminatum） showed similar germination responses to salinity with those of halophyte, but also showed a lower tolerance limit than most halophytes, although this was not always the case. A. scoparia and Ch. glaucum exhibited some ‘salt stimulation’ in seed germination percentages after desalination, whereas E. pilosa did not show any obvious responseto salinity. Therefore, salinity usually induces dormancy of seeds with strong germination capacity in fresh water, but has few, or even positive, effects on seeds with strong innate dormancy.
文摘评价20%精草铵膦铵盐可溶液剂对非耕地杂草的防除效果。于杂草生长盛期采用茎叶喷雾法进行田间小区试验。试验药剂20%精草铵膦铵盐可溶液剂剂量为300~600 g a.i./hm^(2)时,对非耕地禾本科杂草和阔叶杂草均有较好的防效,药后20 d,总草株防效和鲜重防效分别为93.32%~97.69%、97.69%~99.53%;对照药剂20%精草铵膦铵盐可溶液剂在450 g a.i./hm^(2)剂量时的总草株防效和鲜重防效分别为95.14%、98.52%。20%精草铵膦铵盐可溶液剂可以有效防除非耕地杂草,推荐剂量300~600 g a.i./hm^(2)。
