Bioclimatic Suitability of Actual and Potential Cultivation Areas for Jacaranda mimosifolia in Chinese Cities

Jacaranda mimosifolia is regarded as a prized ornamental tree in the urban landscape with attractive, abundant and long-lasting violet-colored flowers and graceful tree form. It has been widely cultivated in recent years in many Chinese cities. However, the lack of scientific and practical guidance to cultivate the exotic species has brought about planting failures in some areas, incurring substantial economic losses and landscape decline. A comprehensive understanding of the current spatial pattern and climatic conditions of J. mimosifolia in China can inform species choice, planting and management. We collected data on the geographical coordinates of 257 planting cities and acquired additional information from the literature and field surveys. The limiting factors for cultivation were investigated using principal component analysis (PCA) of 19 bioclimatic parameters of the sampled sites. The potentially suitable habitats were predicted by BIOCLIM modeling using eight selected ecological-important climatic parameters. We found that the present cultivated areas were focused in the low-altitude parts of the subtropical zone, mainly covering the provinces of Yunnan, Sichuan, Guangxi, Guangdong and Fujian. The PCA results indicated that temperature was the clinching determinant of the current cultivation patterns, especially annual mean temperature, the minimum temperature of the coldest month and the mean temperature of the warmest quarter. Moisture was a necessary but not critical secondary factor. The predicting model for potential habitats was graded as “excellent” by objective validation measures. The findings can provide science-based evidence to plan the expansion of the biogeographical range of cultivation into hitherto unplanted cities and rationalize urban tree introduction and management practices.

Chromosomal-level reference genome of the neotropical tree Jacaranda mimosifolia D. Don

Jacaranda mimosifolia D. Don is a deciduous tree widely cultivated in the tropics and subtropics of the world. It is famous for its beautiful blue flowers and pinnate compound leaves. In addition, this tree has great potential in environmental monitoring, soil quality improvement, and medicinal applications. However, a genome resource for J. mimosifolia has not been reported to date. In this study, we constructed a chromosome-level genome assembly of J. mimosifolia using PacBio sequencing, Illumina sequencing, and Hi-C technology. The final genome assembly was ∼707.32 Mb in size, 688.76 Mb (97.36%) of which could be grouped into 18 pseudochromosomes, with contig and scaffold N50 values of 16.77 and 39.98 Mb, respectively. A total of 30,507 protein-coding genes were predicted, 95.17% of which could be functionally annotated. Phylogenetic analysis among 12 plant species confirmed the close genetic relationship between J. mimosifolia and Handroanthus impetiginosus. Gene family clustering revealed 481 unique, 103 significantly expanded, and 16 significantly contracted gene families in the J. mimosifolia genome. This chromosome-level genome assembly of J. mimosifolia will provide a valuable genomic resource for elucidating the genetic bases of the morphological characteristics, adaption evolution, and active compounds biosynthesis of J. mimosifolia.

Trichoderma spp. in growth promotion of Jacaranda mimosifolia D. Don

The low volume of information related to the interaction of Trichoderma fungi with seeds and seedlings represents a limitation to forest production, and it is important to carry out studies focusing on its effect on plant germinability and formation. The aim was to evaluate commercial products based on Trichoderma spp. in promoting growth of Jacaranda mimosifolia. For initial seedling growth assay, seeds were treated with Trichoderma spp. suspension and placed on germinating paper sheets. At 28 days after sowing (DAS) the following evaluations were: percentage germination (PG), root length (RL), shoot length (SL), total length (TL), fresh root mass (FRM), fresh shoot mass (FSM), fresh total mass (FTM), root dry mass (RDM), shoot dry mass (SDM) and total dry mass (BIO). To evaluate the development of Jacaranda mimosifolia plants, the experiment was conducted in a greenhouse, wherein the soil of each pot (10 L) was treated with five strains of the Trichoderma spp. (Trichoderma asperellum URM 5911; T. harzianum ESALQ 1306; T. harzianum IBLF 006 WP; T. harzianum SIMBI T5 and T. harzianum T-22 WG. Then, Jacaranda mimosifolia seeds were sown and the evaluations performed at 120 DAS. The variables were: PG at 120 DAS, shoot height (SH), stem diameter (SD), and Dickson quality index (DQI). The strains SIMBI T5, ESALQ 1306 and T-22 WG stood out in relation to RL; while ESALQ 1306 and SIMBI T5 stood out performed the RL and TL. In greenhouse, SIMBI T5 and ESALQ1306 presented higher values of ALT, CR, DC, MFT. Meanwhile, only the SIMBI T5 strain stood out for MSPA, MSR, BIO and DQI.

Reproduction, Agrotechnics and Protection of Jacaranda mimosifolia D. Don (Jacaranda Juss.) in Absheron Conditions

In research work have been extensively studied morphological aspects of seedlings on a scientific basis, propogation by seeds and cutting methods on the Absheron Peninsula species of Jacaranda mimosifolia belonging to the genus of Jacaranda Juss. of the family Bignoniaceae. The research analyzed the sowing period of seeds, soil characteristics, sowing depth, initial germination period, morphological features, agrotechnics, disease and pest control measures. Studies have shown that Jacaranda mimosifolia has the ability to adapt to open and greenhouse conditions in Absheron — In the autumn began to appear the first seedlings in the first decade of October from the seeds sown in the second decade of September in a greenhouse condition, were obtained 4.6% of seedlings at the end of the growing season. In the spring began to appear the first seedlings in the third decade of April from the seeds sown in the first decade of April, were obtained 5.2% of seedlings at the end of the growing season. In the second decade of May, 20–30 cm tall plants were transplanted to open fields. At the end of the growing season the length of the compound leaves of annual plants reached 14×15 cm. Plant height reached 1.2 m in height, 1.2–1.5 mm in diameter, stalks reached 16 cm in length, 0.2 cm in width. There are 20 leaf-stalks on 1 leaf. Keeping the temperature in the greenhouse at 22–24 °C from April to the second decade of October had a positive effect on plant productivity. As a result of the research, it was found that in Absheron conditions the plant shed their leaves in the greenhouse at a temperature below 14 °C. As a result of the research, it was found that Jacaranda mimosifolia has the ability to adapt to open and greenhouse conditions in Absheron, it is profitable to use such an ornamental plant in the construction of parks and gardens, in decoration of offices and interiors.

Jacaranda mimosifolia (jacaranda).

J. mimosifolia is a medium-large, deciduous tree, up to 20 m in height, with an attractive spreading crown. The species is native to Argentina and Brazil, but has been introduced as an ornamental to many parts of the tropics. J. mimosifolia grows best in highland areas up to 2400 m with an annual rainfall of 900-1300 mm. It grows well on well-drained sandy loam soils, although it will survive on poorer shallow soils. The species does not tolerate waterlogged or clay soils. It is a deep-rooted competitive tree, so few plants or crops can grow beneath it. J. mimosifolia is most well-known for the clusters of striking bell-shaped, blue-violet flowers that are produced during the dry season and which are characteristic of many cities in tropical and sub-tropical countries. J. mimosifolia can be established from either seed or cuttings. Fresh seed has a germination capacity of 50-92% and generally no seed pre-treatment is required. The trees need considerable care during the first two years, requiring weeding, regular watering and staking until well established. They can be fast growing on good sites achieving 3 m per year during the first two years and 1 m per year in subsequent years. Established trees respond well to light coppicing. If used as an ornamental, an open environment or large spacing is required for this light-demanding species with its wide canopy.

Induction of defense-related enzymes and enhanced disease resistance in maize against Fusarium verticillioides by seed treatment with Jacaranda mimosifolia formulations

Fusarium verticillioides is an important fungal pathogen of maize, causing stalk rot and severely affecting crop production. The aim of this study was to characterize the protective effects of formulations based on Jacaranda mimosifolia leaf extracts against F. verticillioides in maize. We compared different seed treatments comprising J. mimosifolia extracts, chemical fungicide (mefenoxam) and salicylic acid to modulate the defense system of maize host plants. Both aqueous and methanolic leaf extracts of J. mimosifolia (1.2% w/v) resulted in 96–97% inhibition of mycelial growth of F. verticillioides. While a full-dose (1.2%) extract of J. mimosifolia provided significant protective effects on maize plants compared to the inoculated control, a half-dose (0.6% w/v) application of J. mimosifolia in combination with half-strength mefenoxam was the most effective treatment in reducing stalk rot disease in pot and field experiments. The same seed treatment significantly upregulated the expression of genes in the leaves encoding chitinase, glucanase, lipid transfer protein, and pathogenesis-related proteins PR-1, PR-5 and PR-10, 72 h after inoculation. This treatment also induced the activities of peroxidase, polyphenol oxidase, protease, acid invertase, chitinase and phenylalanine ammonia lyase. We conclude that seed pre-treatment with J. mimosifolia extract with half-strength chemical mefenoxam is a promising approach for the management of stalk rot in maize.

Diversidad, Estructura y Composición de la Flora Vascular del Campus de la Universidad ISA, Santiago, República Dominicana

Se presenta la lista de especies, estructura y composición de la flora vascular del Campus de la Universidad ISA, Santiago, República Dominicana. La lista incluye el nombre científico, la familia botánica, la forma de vida, el estatus de conservación y la distribución geográfica, así como algunos de sus principales usos etnobotánicos. El Campus alberga un total de 312 especies de plantas vasculares distribuidas en 81 familias y 254 géneros. Las familias con mayor riqueza son Fabaceae (29), Poaceae (19), Asteraceae y Malvaceae (15), Arecaceae (14), Euphorbiaceae (12), Asparagaceae (10), Araceae, Bignoniaceae y Myrtaceae (9). Las formas de vida más representadas fueron la arbórea 106 (34 %) y la herbácea 95 (30 %), respectivamente. De las 312 especies, 6 son endémicas, 124 nativas y 183 introducidas, de las cuales 14 son consideradas como potencialmente invasoras. Ocho taxones se encuentran bajo alguna categoría de amenaza, de acuerdo con los criterios de la UICN y la Lista Roja de la República Dominicana. Estas especies son: Agave vivipara L., Dypsis decaryi (Jum.) Beentje & J.Dransf, Jacaranda mimosifolia D.Don., Swietenia macrophylla King, bajo la categoría de Vulnerable (VU), Coffea arabica L., Pinus occidentalis Sw. Bajo la categoría de En Peligro (EN) y Leuenbergeria quisqueyana (Alain) Lodé.