The aims of this study were to explore the interspecific differences of Populus euphratica Oliv.and Populus pruinosa Schrenk populations and the intraspecific differences of males and females within the same species in flowering phenological traits,and the effects of temperatures on flowering phenological traits in different growth years(2001–2003 and 2013–2015).The results showed that P.euphratica population flowered earlier than P.pruinosa population.Moreover,flowering phenological period of population,number of days of flowering phenological period per population,number of days of flowering phenological period per plant and average number of days of flowering period per plant of P.euphratica population were less than those of P.pruinosa population.The differences between male and female within the same species indicated that the flowering periods of males P.euphratica and P.pruinosa populations were earlier than those of female plants.For both species,flowering phenological traits were significantly and negatively correlated with the average temperatures in previous ten days,previous one month and previous three months of flowering.Both species are sensitive to temperature changes and adjust to the changes by advancing the start of flowering and prolonging the duration of flowering.
LI ZhijunZHANG XiaoZHENG YaqiongQIU AijunZHANG Ling
The influence of NaCl and Na 2SO 4 on the germination rate and cotyledon outspread rate of Populus euphratica and P. pruinosa seeds from different seed sources was studied in this paper. The results showed that the seed relative germination rate and cotyledon outspread rate were negatively correlated with salt concentration significantly. The order of salt tolerance of P. euphratica seeds and P. pruinosa seeds from different seed sources was given respectively.In the same concentration,to the germination and cotyledon outspread rate of P. euphratica from different seed sources,NaCl was more influential than Na 2SO 4.In 0～0 4% concentration,to the relative seed germination rate and cotyledon outspread rate of P. pruinosa from different seed sources,NaCl was less influential than Na 2SO 4,and in 0 4%～1 5%, NaCl was more influential than Na 2SO 4 Compared with P. pruinosa, the salt tolerance of P. euphratica in seed germination period was better.
