Seed germination (in laboratory and field conditions) and vegetative reproduction (by cuttings) of a promising decorative species—Lonicera tatarica L. (Caprifoliaceae Juss.) was studied for the first time in the cond...Seed germination (in laboratory and field conditions) and vegetative reproduction (by cuttings) of a promising decorative species—Lonicera tatarica L. (Caprifoliaceae Juss.) was studied for the first time in the conditions of introduction of the Tashkent Botanical Garden of Uzbekistan. Thus, the optimal temperature for germination of L. tatarica seeds in laboratory conditions is +20°C + 22°C, at which germination was 73%. The germination rate of seeds sown in autumn in the field was 62%, and the germination rate of seeds sown in spring was 71%. It was noted that in greenhouse conditions at an air temperature of 20°C - 22°C and a relative humidity of 49% - 53%, the rootability of cuttings was 75%. It was revealed that the studied species adapted well to the conditions of introduction. Taking into account the effectiveness of vegetative reproduction of L. tatarica, it can be recommended for improving the aesthetic condition and landscaping of cities, landscaping and landscape design.展开更多
This paper focused on the water relations of two halophytes differing in photosynthetic pathway, phe- notype, and life cycle： Karelinia caspica （Pall.） Less. （C3, deep-rooted perennial Asteraceae grass） and Atrip...This paper focused on the water relations of two halophytes differing in photosynthetic pathway, phe- notype, and life cycle： Karelinia caspica （Pall.） Less. （C3, deep-rooted perennial Asteraceae grass） and Atriplex tatarica L. （C4, shallow-rooted annual Chenopodiaceae grass）. Gas exchange, leaf water potential, and growth characteristics were investigated in two growing seasons in an arid area of Xinjiang to explore the physiological adaptability of the two halophytes. Both K. caspica and A. tatarica showed midday depression of transpiration, in- dicating that they were strong xerophytes and weak midday depression types. The roots of A. tatarica were con- centrated mainly in the 0-60 cm soil layer, and the leaf water potential （~L） increased sharply in the 0-20 cm layer due to high soil water content, suggesting that the upper soil was the main water source. On the other hand, K. caspica had a rooting depth of about 1.5 m and a larger root/shoot ratio, which confirmed that this species uptakes water mainly from deeper soil layer. Although A. tatarica had lower transpiration water consumption, higher water use efficiency （WUE）, and less water demand at the same leaf water potential, it showed larger water stress impact than K. caspica, indicating that the growth of A. tatarica was restricted more than that of K. caspica when there was no rainfall recharge. As a shallow-rooted C4 species, A. tatarica displayed lower stomatal conductance, which could to some extent reduce transpiration water loss and maintain leaf water potential steadily. In contrast, the deep-rooted C3 species K. caspica had a larger root/shoot ratio that was in favor of exploiting groundwater. We concluded that C3 species （K. caspica） tapes water and C4 species （A. tatarica） reduces water loss to survive in the arid and saline conditions. The results provided a case for the phenotype theory of Schwinning and Ehleringer on halophytic plants.展开更多
To estimate the genetic diversity of the only captive Saiga antelope(Saiga tatarica) population in China,40 umbilical cord samples were collected and mitochondrial(control region) and nuclear(microsatellite) variabili...To estimate the genetic diversity of the only captive Saiga antelope(Saiga tatarica) population in China,40 umbilical cord samples were collected and mitochondrial(control region) and nuclear(microsatellite) variabilities were assessed.Both of the markers revealed low genetic variability(or high genetic homogeneity) within the population.The microsatellites yielded monitoring ranges of 2-6 alleles.The observed heterozygosities ranged from 0.28 to 0.83,and the expected heterozygosities were between 0.27 and 0.71.The Shannon information index(Shannon I) and Polymorphic Information Content(PIC) presented overall means of 0.87 and 0.43,respectively.The gene diversity was 0.49.We found only two haplotypes in the population,and the haplotype and nucleotide diversities were 39.1% and 1.13%,respectively.Founder events,bottlenecks and inbreeding have contributed to the low genetic variation observed in this population.Our findings revealed the extent of genetic diversity maintained in the present population and the urgency of implementing a protection plan,introducing animals from other populations to enhance saiga's genetic variation.展开更多
文摘Seed germination (in laboratory and field conditions) and vegetative reproduction (by cuttings) of a promising decorative species—Lonicera tatarica L. (Caprifoliaceae Juss.) was studied for the first time in the conditions of introduction of the Tashkent Botanical Garden of Uzbekistan. Thus, the optimal temperature for germination of L. tatarica seeds in laboratory conditions is +20°C + 22°C, at which germination was 73%. The germination rate of seeds sown in autumn in the field was 62%, and the germination rate of seeds sown in spring was 71%. It was noted that in greenhouse conditions at an air temperature of 20°C - 22°C and a relative humidity of 49% - 53%, the rootability of cuttings was 75%. It was revealed that the studied species adapted well to the conditions of introduction. Taking into account the effectiveness of vegetative reproduction of L. tatarica, it can be recommended for improving the aesthetic condition and landscaping of cities, landscaping and landscape design.
基金supported by the National Basic Research Program of China(2009CB825101)the Specialized Research Fund for the Doctoral Program of Higher Education of China(20110008110035)
文摘This paper focused on the water relations of two halophytes differing in photosynthetic pathway, phe- notype, and life cycle： Karelinia caspica （Pall.） Less. （C3, deep-rooted perennial Asteraceae grass） and Atriplex tatarica L. （C4, shallow-rooted annual Chenopodiaceae grass）. Gas exchange, leaf water potential, and growth characteristics were investigated in two growing seasons in an arid area of Xinjiang to explore the physiological adaptability of the two halophytes. Both K. caspica and A. tatarica showed midday depression of transpiration, in- dicating that they were strong xerophytes and weak midday depression types. The roots of A. tatarica were con- centrated mainly in the 0-60 cm soil layer, and the leaf water potential （~L） increased sharply in the 0-20 cm layer due to high soil water content, suggesting that the upper soil was the main water source. On the other hand, K. caspica had a rooting depth of about 1.5 m and a larger root/shoot ratio, which confirmed that this species uptakes water mainly from deeper soil layer. Although A. tatarica had lower transpiration water consumption, higher water use efficiency （WUE）, and less water demand at the same leaf water potential, it showed larger water stress impact than K. caspica, indicating that the growth of A. tatarica was restricted more than that of K. caspica when there was no rainfall recharge. As a shallow-rooted C4 species, A. tatarica displayed lower stomatal conductance, which could to some extent reduce transpiration water loss and maintain leaf water potential steadily. In contrast, the deep-rooted C3 species K. caspica had a larger root/shoot ratio that was in favor of exploiting groundwater. We concluded that C3 species （K. caspica） tapes water and C4 species （A. tatarica） reduces water loss to survive in the arid and saline conditions. The results provided a case for the phenotype theory of Schwinning and Ehleringer on halophytic plants.
基金supported by a special grant from the State Forestry Administration of China (201004054)
文摘To estimate the genetic diversity of the only captive Saiga antelope(Saiga tatarica) population in China,40 umbilical cord samples were collected and mitochondrial(control region) and nuclear(microsatellite) variabilities were assessed.Both of the markers revealed low genetic variability(or high genetic homogeneity) within the population.The microsatellites yielded monitoring ranges of 2-6 alleles.The observed heterozygosities ranged from 0.28 to 0.83,and the expected heterozygosities were between 0.27 and 0.71.The Shannon information index(Shannon I) and Polymorphic Information Content(PIC) presented overall means of 0.87 and 0.43,respectively.The gene diversity was 0.49.We found only two haplotypes in the population,and the haplotype and nucleotide diversities were 39.1% and 1.13%,respectively.Founder events,bottlenecks and inbreeding have contributed to the low genetic variation observed in this population.Our findings revealed the extent of genetic diversity maintained in the present population and the urgency of implementing a protection plan,introducing animals from other populations to enhance saiga's genetic variation.
