Evaluation On The Drought And Heat-Tolerance Of Populations Of Eupatorium Adenophorum Spreng. And Study On It's Physiological And Biochemical Characteristics

Crofton weed (Eupatorium adenophorum Spreng.) was one of the most noxious invasive weeds in the world. Since it was firstly introduced to China in the 1940s, it had spread rapidly throughout the southwestern China including Yunnan, Guizhou, Guangxi, Sichuan and even to Hubei Provinces. Its invasion had caused serious economic consequences for agriculture, forestry and husbandry and had become one of the worst weeds in these regions. It inhibited indigenous plant growth and thus replaced desirable native species, which may be related to its strong ecological adaptation. However, the study on crofton weed was mainly focused on its biological characteristics, harmness and controlling. Few works have been done on its ecological adaptation. Osmotic potentials (PEG6000), chamber test and asubordinate function value test were used to evaluate their drought-resistence or heat-tolerance among different populations of the Eupatorium adenophorum Spreng in order to select and identify different resistance populations in this paper. Then on the basis of these study, different heat-tolerance populations were employed to study their response to high temperature stress.Relative germination percentage, promptness index, vigor index of crofton weed from 14 populations were tested under different osmotic potentials (PEG6000) to evaluate their drought resistance using the fussy subordinative function. The results showed that there were differences in drought-resistance among the populations tested. Luoping of Yunnan Province, Panzhihua of Sichuan Province and Yuanjiang of Yunnan Province had the relative higher drought resistance while Simao of Yunnan Province had lower resistance. The total of average subordinative value of the former three populations with resistance to drought stress were 0.766, 0.689, 0.658, while the later susceptible to drought stress was...