Search Results (4)

In a hypothetical climate change scenario, zoysiagrass species could be a good choice for turfgrass areas due to their adaptation to heat conditions and the great variability in species and cultivars. Knowledge of the root system’s characteristics is paramount for predicting cultivar adaptation to different heat–drought scenarios and therefore for designing proper turfgrass management programs, especially irrigation. A field experiment was conducted in the Mediterranean environment of Valencia (Spain) to study the root weight density (RWD), root length density (RLD), and average root diameter (RDI) at three different soil depths (0–5, 5–15, and 15–30 cm) of five new zoysiagrass genotypes (Zoysia matrella (L.) Merr., Zoysia japonica Steud., and their hybrid), relating these parameters to the performance of these experimental lines during their establishment. All the tested experimental lines had a higher RWD and RLD in the upper soil layer (0–5 cm), while the RDI was higher in the lowest layer of the sampled soil profile (0.269 mm compared with 0.249 mm and 0.241 mm in the upper layers). All the tested genotypes showed the same RWD and RLD, while the Zoysia matrella experimental line A showed a higher RDI value (0.2683 mm) than those for the Z. japonica (0.2369 mm) and the hybrid (0.2394 mm) genotypes. This last finding could have influenced its more rapid establishment, although it was not linked to its NDVI values during autumn. In conclusion, different morphological root characteristics were detected among new zoysiagrass genotypes and soil depths, which could have affected their canopy performance, and they are expected to affect irrigation management in a possible future drought scenario. Full article

Zoysia japonica (Zoysia japonica Steud.) is a kind of warm-season turfgrass with many excellent characteristics. However, the shorter green period and longer dormancy caused by cold stress in late autumn and winter are the most limiting factors affecting its application. A previous transcriptome analysis revealed that ethephon regulated genes in chlorophyll metabolism in Zoysia japonica under cold stress. Further experimental data are necessary to understand the effect and underlying mechanism of ethephon in regulating the cold tolerance of Zoysia japonica. The aim of this study was to evaluate the effects of ethephon by measuring the enzyme activity, intermediates content, and gene expression related to ethylene biosynthesis, signaling, and chlorophyll metabolism. In addition, the ethylene production rate, chlorophyll content, and chlorophyll a/b ratio were analyzed. The results showed that ethephon application in a proper concentration inhibited endogenous ethylene biosynthesis, but eventually promoted the ethylene production rate due to its ethylene-releasing nature. Ethephon could promote chlorophyll content and improve plant growth in Zoysia japonica under cold-stressed conditions. In conclusion, ethephon plays a positive role in releasing ethylene and maintaining the chlorophyll content in Zoysia japonica both under non-stressed and cold-stressed conditions. Full article

Nitrogen (N) is one of the promising nutrients for lawn growth and is required for the lawn’s proper growth and development, but it also increases mowing frequency. Glyphosate herbicide application in sub-doses, as a growth regulator, can reduce the maintenance costs without any adverse reduction in the density and nutritional status of grasses. The objective of this study was to evaluate the influences of nitrogen and glyphosate doses on the growth, aesthetic quality and nutritional status of emerald grass (Zoysia japonica Steud.). The experiment was conducted at the Research and Extension Education Farm of São Paulo State University (UNESP), Ilha Solteira, SP, Brazil, in an Ultisol. The experiment was designed as a randomized block with 12 treatments arranged in a 3 × 4 factorial scheme with 4 replications, comprised of a control (without N), 15 and 30 g N m⁻² of urea, applied in five splits annually, and glyphosate doses (0, 200, 400 and 600 g ha⁻¹ of the active ingredient, a.i.). The split N fertilization at the rate of 15 g m⁻² and glyphosate at the dose of 400 g ha⁻¹ maintained nutritional status of emerald grass. Nitrogen at the rate 15 g N m⁻² (in five splits per year) was observed to produce lower growth traits, an adequate aesthetic quality and longer stability of the nutrients in emerald grasses through lower exportation, with removal of “clipping” after mowing. In addition, glyphosate, at the dose of 400 g a.i. ha⁻¹, was efficient in reducing the leaf area, plant height, shoot dry matter and total dry matter by 18.3, 14.7, 6.8 and 8.1%, respectively, as compared to the control. However, this dose did not impair the coloration and resulted in a lower exportation of nutrients by reducing the need to replenish by fertilization. Therefore, fertilization with 15 g N m⁻², associated with application of 400 g a.i. ha⁻¹ of glyphosate, is recommended for emerald grass in the tropical savannah of Brazil. Full article

The genus Zoysia Willd. (Chloridoideae) is widely distributed from the temperate regions of Northeast Asia—including China, Japan, and Korea—to the tropical regions of Southeast Asia. Among these, four species—Zoysia japonica Steud., Zoysia sinica Hance, Zoysia tenuifolia Thiele, and Zoysia macrostachya Franch. & Sav.—are naturally distributed in the Korean Peninsula. In this study, we report the complete plastome sequences of these Korean Zoysia species (NCBI acc. nos. MF953592, MF967579~MF967581). The length of Zoysia plastomes ranges from 135,854 to 135,904 bp, and the plastomes have a typical quadripartite structure, which consists of a pair of inverted repeat regions (20,962~20,966 bp) separated by a large (81,348~81,392 bp) and a small (12,582~12,586 bp) single-copy region. In terms of gene order and structure, Zoysia plastomes are similar to the typical plastomes of Poaceae. The plastomes encode 110 genes, of which 76 are protein-coding genes, 30 are tRNA genes, and four are rRNA genes. Fourteen genes contain single introns and one gene has two introns. Three evolutionary hotspot spacer regions—atpB~rbcL, rps16~rps3, and rpl32~trnL-UAG—were recognized among six analyzed Zoysia species. The high divergences in the atpB~rbcL spacer and rpl16~rpl3 region are primarily due to the differences in base substitutions and indels. In contrast, the high divergence between rpl32~trnL-UAG spacers is due to a small inversion with a pair of 22 bp stem and an 11 bp loop. Simple sequence repeats (SSRs) were identified in 59 different locations in Z. japonica, 63 in Z. sinica, 62 in Z. macrostachya, and 63 in Z. tenuifolia plastomes. Phylogenetic analysis showed that the Zoysia (Zoysiinae) forms a monophyletic group, which is sister to Sporobolus (Sporobolinae), with 100% bootstrap support. Within the Zoysia clade, the relationship of (Z. sinica, Z japonica), (Z. tenuifolia, Z. matrella), (Z. macrostachya, Z. macrantha) was suggested. Full article