Germination characteristics of plump and shriveled seeds of Tamarix ramosissima matured in different seasons

Tamarix ramosissima has bi-seasonal flowering and fruiting. Although the basic germination characteristics of T. ramosissima seeds have been evaluated, there is a lack of information about the effects of seed plumpness on germination. Effects of seed plumpness and season of maturity and light conditions on germination were tested. Plump seeds matured in spring or summer had similar size and pappus length. The size of plump seeds was significantly larger than that of shriveled seeds. Both types of seeds matured in summer germinated better than seeds matured in spring. Germination percentage of plump seeds was significant higher than that of shriveled seeds, especially for seeds matured in spring. Darkness significantly decreased the germination of seeds matured in summer. This study provides comprehensive information about the seed germination requirements of T. ramosissima and the results can be used in restoration of desert lands.

ON THE SEED RENEWAL OF TAMARIX RAMOSISSIMA LEDEB. IN THE COLLECTION ALPINARIUM OF PETER THE GREAT BOTANIC GARDEN

Information about Tamarix ramosissima Ledeb. has been growing in the Peter the Great Botanical Garden of the Komarov Botanical Institute of the Russian Academy of Sciences in St. Petersburg since 1939. It reached 6.2 m in height at the age of 82. It is considered the most winter-hardy, characterized by long flowering and high decorative effect. The first flowering was noted in 1942, for a long time the plants only bloomed without tying the fruit. After the hot summer of 2010, fruits were first formed and self-seeding appeared in 2011-2012. This is a unique fact for such northern latitudes. The species can be recommended for landscaping and promote its culture further north. In the context of climate change and its warming at the beginning of the XXI century, constant monitoring and continuous phenological observations of Tamarix ramosissima are important.

Tamarix ramosissima (saltcedar).

A datasheet on Tamarix ramosissima covering, as an economically important tree, its taxonomy, importance, silviculture, distribution, biology and ecology, uses, products and pests.

Contrasting Water Use Strategies of Tamarix ramosissima in Different Habitats in the Northwest of Loess Plateau, China

As a species for ecological restoration in northern China, Tamarix ramosissima plays an important role in river protection, flood control, regional climate regulation, and landscape construction with vegetation. Two sampling sites were selected in the hillside and floodplain habitats along the Lanzhou City, and the xylems of T. ramosissima and potential water sources were collected, respectively. The Bayesian mixture model (MixSIAR) and soil water excess (SW-excess) were applied to analyze the relationship on different water pools and the utilization ratios of T. ramosissima to potential water sources in two habitats. The results showed that the slope and intercept of local meteoric water line (LMWL) in two habitats were smaller compared with the global meteoric water line (GMWL), which indicated the existence of drier climate and strong evaporation in the study area, especially in the hillside habitat. Except for the three months in hillside, the SW-excess of T. ramosissima were negative, which indicated that xylems of T. ramosissima are more depleted in δ2H than the soil water line. In growing seasons, the main water source in hillside habitat was deep soil water (80~150 cm) and the utilization ratio was 63 ± 17% for T. ramosissima, while the main water source in floodplain habitat was shallow soil water (0~30 cm), with a utilization ratio of 42.6 ± 19.2%, and the water sources were different in diverse months. T. ramosissima has a certain adaptation mechanism and water-use strategies in two habitats, and also an altered water uptake pattern in acquiring the more stable water. This study will provide a theoretical basis for plant water management in ecological environment protection in the Loess Plateau.

The Complete Chloroplast Genome of Tamarix Ramosissima and Comparative Analysis of Tamaricaceae Species

Background: Tamarix ramosissima is a deciduous shrub resided in arid and semi-arid regions. Although of ecological and medicinal values, some Tamarix species are considered invasive as they have dominated the riparian zones of dryland in some parts of the world. Chloroplast (cp) DNA is highly conserved in structure and gene arrangement, making cp genomic data valuable resources for species delimitation and phylogenetics. The cp genome of T. ramosissima was de novo assembled with the aim of providing reference and data resource for further cp-derived marker development and species delimitation of Tamarix.Results: Here, the complete chloroplast (CP) genome of T. ramosissima was sequenced and analyzed, showing a size of 156150 bp and a GC content of 36.5%. The plastome displayed a typical quadripartite structure, consisting of a pair of inverted repeat (IR) regions of 26554 bp, separated by a large single copy (LSC) region of 84795 bp, and a small single copy (SSC) region of 18247 bp. The cp genome encoded 130 genes, including 85 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. A total of 32 repeat sequences and 64 simple sequence repeats (SSR) were identified in the plastome, and an obvious A/T bias was observed in the majority of the SSRs detected. By comparing the T. ramosissima cp genome with those of four other Tamaricaceae species, a number of divergence hotspots were identified among these plastomes. Together with the SSRs and long repeats identified, these divergence hotspots could be developed as potential molecular markers facilitating species discrimination and evolutionary studies. Using plastome sequences, we re-investigated the phylogenetic relationship among 19 species, and T. ramosissima was found to be a sister of Tamarix chinensis.Conclusions: Taken together, our study provides valuable genomic resources to deepen the understanding of the plant photosynthetic mechanism and phylogenomics.