The effects of salinity （50 mmol/L NaCI） and Cd （1 μmol/L CdCl2） as sole and combined on growth and photosynthetic parameters were studied using two soybean genotypes, Huachun 18 and NGB. The concentrations of C...The effects of salinity （50 mmol/L NaCI） and Cd （1 μmol/L CdCl2） as sole and combined on growth and photosynthetic parameters were studied using two soybean genotypes, Huachun 18 and NGB. The concentrations of Cd^2＋, Zn^2＋, Ca^2＋, Mg^2＋, K^＋ and Na^＋were also determined in seeds and pods. Huachun 18 suffered a more serious decrease than NGB in net photosynthetic rate （P,） in the treatments of salinity stress alone and combined stress （NaCl＋Cd）, showing that it is relatively sensitive to salinity. The decrease in P, caused by salt stress in Huachun 18 was mainly due to the reduced total chlorophyll content and photosynthetic efficiency （the ratio of variable fluorescence to maximal fluorescence, Fv/Fm）, whereas the decease in NGB was mainly related to reduced stomatal conductance （Gs）, The combined stress of both Na and Cd did not induce further decrease in photosynthesis and fluorescence in the two genotypes relative to salt or Cd stress alone. Greater change in the pod concentrations of Zn^2＋, Ca^2＋, Mg^2＋, K^＋ and Na^＋was detected under salt stress for Huachun 18 than for NGB. The results suggested that the interactive effect of NaCl-Cd on growth and nutrient uptake differs between the two soybean genotypes.展开更多
The aim of this experimental work is to select wheat progenies tolerant high levels of salinity. Studies were conducted to determine the realized response in salt tolerance of some selected progeny （F3） through one ...The aim of this experimental work is to select wheat progenies tolerant high levels of salinity. Studies were conducted to determine the realized response in salt tolerance of some selected progeny （F3） through one cycle of screening and selection and the extent of variability for salt tolerance among selected progeny （F3） of wheat. All the selected progeny （F3） derived from （F2） populations after exposure are to high salinity level, were tested for salt tolerance during all growth stages in sand cultures salinized with 0, 100, 175 mM NaCI as compared with the unselected progeny （F2）. Results showed that the selected progeny （F3） were in all cases except one, superior in yield at maturity and in most cases significantly so, both at 100 and 175 mM NaCl, to the yield of the unselected progeny （F2） controls. In this study, some selected progeny exhibited more than twice the seed yield compared with that obtained from unselected progeny at 175 mM NaCl, and their seed yield was also significantly higher than that at 0 mM NaCl. Results also indicated that the highest value percentage of realized response in salt tolerance was in （F3AS1） and （F3AS2） at 175 mM NaCI. It is important to bear in mind that the significant improvement in selected progeny was achieved just in a single cycle of selection. There is then a strong possibility that further increases in tolerance may be obtained through further cycles of selection till reaching F6 or F7 where would show genetics stability.展开更多
基金Project (No. Z304104) supported by Natural Science Foundation of Zhejiang Province, China
文摘The effects of salinity （50 mmol/L NaCI） and Cd （1 μmol/L CdCl2） as sole and combined on growth and photosynthetic parameters were studied using two soybean genotypes, Huachun 18 and NGB. The concentrations of Cd^2＋, Zn^2＋, Ca^2＋, Mg^2＋, K^＋ and Na^＋were also determined in seeds and pods. Huachun 18 suffered a more serious decrease than NGB in net photosynthetic rate （P,） in the treatments of salinity stress alone and combined stress （NaCl＋Cd）, showing that it is relatively sensitive to salinity. The decrease in P, caused by salt stress in Huachun 18 was mainly due to the reduced total chlorophyll content and photosynthetic efficiency （the ratio of variable fluorescence to maximal fluorescence, Fv/Fm）, whereas the decease in NGB was mainly related to reduced stomatal conductance （Gs）, The combined stress of both Na and Cd did not induce further decrease in photosynthesis and fluorescence in the two genotypes relative to salt or Cd stress alone. Greater change in the pod concentrations of Zn^2＋, Ca^2＋, Mg^2＋, K^＋ and Na^＋was detected under salt stress for Huachun 18 than for NGB. The results suggested that the interactive effect of NaCl-Cd on growth and nutrient uptake differs between the two soybean genotypes.
文摘The aim of this experimental work is to select wheat progenies tolerant high levels of salinity. Studies were conducted to determine the realized response in salt tolerance of some selected progeny （F3） through one cycle of screening and selection and the extent of variability for salt tolerance among selected progeny （F3） of wheat. All the selected progeny （F3） derived from （F2） populations after exposure are to high salinity level, were tested for salt tolerance during all growth stages in sand cultures salinized with 0, 100, 175 mM NaCI as compared with the unselected progeny （F2）. Results showed that the selected progeny （F3） were in all cases except one, superior in yield at maturity and in most cases significantly so, both at 100 and 175 mM NaCl, to the yield of the unselected progeny （F2） controls. In this study, some selected progeny exhibited more than twice the seed yield compared with that obtained from unselected progeny at 175 mM NaCl, and their seed yield was also significantly higher than that at 0 mM NaCl. Results also indicated that the highest value percentage of realized response in salt tolerance was in （F3AS1） and （F3AS2） at 175 mM NaCI. It is important to bear in mind that the significant improvement in selected progeny was achieved just in a single cycle of selection. There is then a strong possibility that further increases in tolerance may be obtained through further cycles of selection till reaching F6 or F7 where would show genetics stability.
