Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Accueil du site → Doctorat → Chine → 2010 → Studies on Drought Resistant Indexs and Evaluated Drought Resistant Capability of Desert Plant Reaumuria Soongorica, Nitraria Tangutorum and Calligomum Mongolicum

Gansu Agricultural University (2010)

Studies on Drought Resistant Indexs and Evaluated Drought Resistant Capability of Desert Plant Reaumuria Soongorica, Nitraria Tangutorum and Calligomum Mongolicum

种培芳;Zhong Pei Fang

Titre : Studies on Drought Resistant Indexs and Evaluated Drought Resistant Capability of Desert Plant Reaumuria Soongorica, Nitraria Tangutorum and Calligomum Mongolicum

Auteur : 种培芳;Zhong Pei Fang

Grade : Doctoral Dissertation 2010

Université : Gansu Agricultural University

Résumé partiel
Reaumuria soongorica, Nitraria tangutorum and Calligomum mongolicum are the best plants to prevent wind and sand , to conservate soil and water at the arid and semi-arid areas because they are drought-resistant,salt-resistant and high temperature-resistant. They are wide-ranging distributed over desert especially over semi-arid area of NorthWest, and they have the drought-resistant ablities. So it is very important to study the drought-resistance of these plants. This paper presented the studies on the change of photosynthetic characteristic, chlorophyll fluorescence characteristic, water physiology, metabolic products, activities of enzyme and chlorophyll in Reaumuria soongorica, Nitraria tangutorum and Calligomum mongolicum from four area (LZJ, WWM, ZYL and JQJ) under natural environment. This studies were analyzed and discussed to elucidate further the mechanisms of drought-resistance in the three plants,and comprehensive evaluated their drought-resistance.The main results were summarized as follows:1. Diurnal changes of net photosynthetic rate and transpiration rate in leaves of Reaumuria soongorica, Nitraria tangutorum and Calligomum mongolicum could be classified tow types :(1) bimodal curve, including Reaumuria soongorica,(2)single curve, including Nitraria tangutorum and Calligomum mongolicum ; Their phtosynthetic typy could be classified tow typies : (1)low net photosynthetic rate(Pn) and transpiration rate(Tr) , including Reaumuria soongorica,(2)high Pn and Tr, including Nitraria tangutorum,(3) low Pn and high Tr, including Calligomum mongolicum. Among the environmental factors, photosynthetically active radiation (PAR) had a leading effect on both Pn and Tr ,the high light intensity of noon caused photoinhibition on Nitraria tangutorum and Calligomum mongolicum,but did not produce on Reaumuria soongorica. The scope of the most suitable photosynthetic temperature of the three plants are 25 30℃(Reaumuria soongorica),28 32℃(Nitraria tangutorum)and 35 37℃(Calligomum mongolicum) respectively. Water condition was the main factor that caused the different Pn and Tr of different area, and relative humidity (RH)mainly effected on Tr. Among internal factors, stomatal conductance (Gs) was the major determinant of midday depression in Pn of Reaumuria soongorica and Pn before 10:00 of Calligomum mongolicum, and the water stress would increase the Gs ability of the tow plants. The Gs adjustment ability of Nitraria tangutorum was effected by many factors, but the ability effected on Pn more than on Tr. The results showed that under the water stress condition, Reaumuria soongorica increased water use efficiency(WUE) through adjusting its Gs and osmoregulation matters ; WUE of Nitraria tangutorum changed with the enviromrntal condition,while WUE of Calligomum mongolicum was all over higher than other plants because its different photosynthetic way and transpiraion property.2. A decline in maximal photochemical efficiency of PSII (Fv/Fm) and actual photochemistry efficiency(ΦPSⅡ) but not photoinhibition of Reaumuria soongorica was caused by high light intensity. The decline of photochemical efficiency of PSII which was one of non-stomatal factors on midday depression in Pn of Reaumuria soongorica was caused by drought stress.High light intensity produced photoinhibition of Nitraria tangutorum and Calligomum mongolicum,and the decline of soil water aggravated this phenomenon.The photoinhibition of Calligomum mongolicum was not serious because it lagged behind that of Nitraria tangutorum. The major photoprotective mechanism which helped Reaumuria soongorica to adap the adverse circumstances was the xanthophyll cycle_dependent thermal energy dissipation but not the photoinhibition under extreme soil drought coupling with high temperature, strong solar radiation and low air humidity,while Nitraria tangutorum and Calligomum mongolicum were dependent on tow photoprotective mechanisms.

Mots clés : Deser plant; diurnal variations in photosynthesis; metabolic products; activities of enzyme; drought resistant indexes; comprehensive evaluation;

Présentation (CNKI)

Page publiée le 3 avril 2014, mise à jour le 3 mai 2018