[Growth stability of four drought resistant plant species in different regions]. / 四种抗旱植物在不同区域的生长稳定性.

There are abundant germplasm resources of drought resistant trees in China. It is difficult for foresters to evaluate and screen excellent germplasm that is suitable for various drought adverse circumstances. In this study, four tree species from different provenances, namely Amygdalus davi-diana, Prunus sibirica, Salix gordejevii, and Caryopteris mongolica, were used as test materials. Four soil regions, namely Dalad Banner, Siziwang Banner, Kouhezi town and Liujiazi town of Kulun Banner in the Central and Eastern Inner Mongolia Autonomous Region were selected as multi-point experiment sites to analyze the growth and physiological status of different tree species and provenances. The additive main effects and multiplicative interaction model was used to evaluate the regional adaptability and stability of the germplasm. The growth and physiological indices of four tree species differed between provenances and locations. Soil conditions (potassium content, nitrogen content, and pH) and climate conditions (annual average temperature, precipitation, and potential evaportranspiration) in different locations all influenced the growth of different provenance species. Concerning tree species, S. gordejevii and C. mongolica are more adapted to the sandy loam and chestnut soil of Dalad Banner and Siziwang Banner. A. davidiana and P. sibirica L. are more adapted to the loess and aeolian sandy soil of Kouhezi town and Liujiazi town. Concerning tree provenances, A. davidiana of Tuzuo, P. sibirica of Ningcheng and Yuanzhou, S. gordejevii of Lanqi, and C. mongolica of Jingbian displayed higher regional stability and better growth adaptability, indicating their suitability for afforestation in similar areas.

[Changes of non-structural carbohydrates in Caryopteris mongolica seedlings during the process of drought-induced mortality]. / 蒙古莸幼苗干旱致死过程中非结构性碳水化合物的变化.

The changes and distribution of non-structural carbohydrate (NSC, including soluble sugar and starch) content in different organs of one-year-old Caryopteris mongolica seedlings were investigated under suitable water condition (CK), slow-dying drought stress, and fast-dying drought stress. There was no significant difference in soluble sugar content of all organs between slow-dying drought stress and CK. With the extended duration of drought, the soluble sugar content in stem increased firstly and then decreased, while starch and NSC contents decreased. The soluble sugar content in coarse roots decreased, while starch and NSC contents increased. The soluble sugar content in leaves increased, while starch and NSC contents of leaves decreased. The NSC content of leaves, stems, coarse roots and fine roots were 6.2%, 7.8%, 8.3% and 7.4% at the death time (80 days), respectively. Under fast-dying drought stress, soluble sugar content in all organs was higher than that in CK, while starch and NSC contents were lower than that in CK. With the increasing time, soluble sugar content of roots decreased, while starch and NSC contents increased. The soluble sugar, starch and NSC contents in stems increased. The soluble sugar content of leaves increased, while starch and NSC contents decreased. The NSC content of leaves, stems, coarse roots and fine roots were 5.9%, 6.6%, 8.9% and 7.7% at lethal time (30 days), respectively. Under different drought stress, non-structural carbohydrates among different organs of C. mongolica seedlings showed different dynamics. Under slow-dying drought stress, NSC gave priority to allocate energy for maintaining physiological metabolism of organs. Under fast-dying drought stress, NSC mainly maintained plant metabolism in the form of soluble sugar, regulated osmotic potential, promoted water absorption, and coped with drastic drought stress.